putzmeister hydraulic pump free sample

As a general rule, only mineral hydraulic fluids of type HLP may be used for concrete pumps and industrial technologies. These hydraulic fluids must also meet the minimum requirements of DIN 51524-2.

Only fluids that meet the minimum requirements of DIN 51524-2 and these Putzmeister specifications for the viscosity grade ISO VG 46 and are confirmed in writing by the manufacturer may be used.

As a general rule, only bio-degradable hydraulic fluids of category 4 (HEES – synthetic ester) of DIN ISO 15380 and viscosity grade ISO VG 46 may be used for concrete pumps and industrial technologies. These hydraulic fluids must also meet the minimum requirements of this standard.

Only fluids that meet the minimum requirements of DIN ISO 15380 and these Putzmeister specifications for the viscosity grade ISO VG 46 and are confirmed in writing by the manufacturer may be used.

Today concrete pumps are predominantly operated by hydraulic systems. Putzmeister places its trust in the benefits of free-flow hydraulics because the most important performance factors are the concrete pressure, low-loss oil delivery and costs.

When large quantities of concrete are pumped, large quantities of oil also flow inside the hydraulic system. More power is transferred inside a closed free-flow hydraulic circuit because the oil is conveyed from the pump to the drive cylinders without loss. The adapted hydraulic System ensures extremely powerful interaction between components. Compared to the open circuit, this ingenious drive technology requires significantly less oil and does not generate as much heat. The system is also economical to operate because it achieves a high degree of energy efficiency and is easy to service.

Putzmeister develops, produces, sells and serves its customers worldwide with technically high-quality and service-oriented machines in the following areas: truck-mounted concrete pumps, stationary concrete pumps, stationary placing booms and accessories, concrete mixing, industrial technology, pipe delivery of industrial solids, concrete placement and removal of excavated material in tunnels and underground, mortar machines, plastering machines, screed conveying, injection and special applications.

Boom and base structure – Putzmeister added value

The use of long-reach boom pumps Tough construction site practice makes

machine. Putzmeister concrete pumps reserves on the truck for accessories and

Putzmeister large boom pumps from the consistently high quality.

a variable-position telescopic support. efficient pumping of concrete has been

horizontal reach of the boom, as the telescopic support from Putzmeister. To ensure that these

This means the pumps are suitable both long-term, components and new devel-

truck-mounted concrete pumps grip, no additional switchovers of at a glance: Better work with

boom control. Aided by a computer, the The pumping process is optimised by high output If EBC operation is preselected, damping

controlled. Moreover, the concrete place- intelligent working range restriction. The safe working is moved. During pumping operations

ment performance of the concrete pump boom and end hose are very smooth, ■ Simple boom control unburdens (without movement of the boom), damp- With EBC

can be increased. allowing the concrete pump operator to the operator ing must be activated on the left-hand

The concrete pump operator is unbur- ely. vibration damping EBC then balances out vibrations in the Without EBC: With EBC, the vibrations are damped to

surroundings and the movement of the liding with itself in critical positions with Touch Control rate. The still end hose can be moved moved and slewed and pump pulsations cause EBC reduces the vertical movement of the

EPS – Ergonic Pump System – ensuring ® Further information about Ergonic® systems can

operation of the concrete pump and the ency of concrete (PUMI®). This means operational safety

ductivity and performance with minimum through” the transfer tube, even if it is of ■ Less noise emission and low fuel The pump operator can display important

EPS (Ergonic® Pump System) has Pump data, such as delivery pressure, ■ Vibrations in the machine and The individual parameters for the machi-

considerable advantages over convent- delivery rate of the hydraulic pump, boom are reduced ne can be set here.

concrete pump fully electronically and signals, is actively and perfectly co- concrete pump The doubly-protected electronic and

ensures that the pumping process runs ordinated. This is not really possible with ■ Fewer hydraulic components hydraulic control system means that the

perfectly. conventional hydraulic control systems. ■ Doubly protected control machine can continue to be operated in

In purely hydraulic control systems, The pump operator receives up-to-date

hydraulic components are required, i.e. ■ The strength of the radio signal and

The S transfer tube elephant – extremely Free-flow hydraulics –

wear-proof and ideal for difficult concrete mixes a decisive benefit to pumping

Stationary concrete pumps with the The S-valve is the first choice for concrete The S-tube is suitable for the most dif- When large quantities of concrete are The SN control system ensures a con- Pbar Pressure peak without SN

S-transfer tube are continually setting pressures above 85 bars. This is especi- ficult concretes, such as stiff hydrocon- pumped, large quantities of oil flow in trolled movement of the material which

new world records in vertical and hori- ally useful for long pumping distances crete or mixes of crushed quartz, granite the hydraulic system. is typical of Putzmeister concrete

zontal delivery. For example, in 2008 at over stationary pipelines. or basalt. The range of consistencies This is where Putzmeister concrete pumps. It avoids wear-inducing pressu-

the Burj Khalifa/UAE concrete was pump- extends to K1 (1” slump) and screen sizes pumps with their free-flow hydraulics re peaks and increases the service life of

ed vertically over 606 metres! Even in The Putzmeister S-valve is especially up to around 63 mm. come into their own. drive, delivery line and fastenings.

system is used. Of course it is also avail- oil flow inside the hydraulic pump. tively metered by a continuous regula - Delivery gap

able with truck-mounted concrete pumps. ■ The lack of directional valves pre- tion system even when only minimal old long 58

■ Putzmeister concrete pumps are 59

The easy to dismantle collar allows for easy 5 Change-over / shut-off valve Concrete pump hydraulic cylinder

make every job a complete success Further information can be obtained from your retailer or from www.putzmeister.de

i-DAISY makes the operator aware of the covered thanks to DAISY. Scheduling diagram of a concrete pump service

A hydraulically lowered container makes work on the construction site easier. The delivery hoses and Well equipped for all jobs: in spacious add-on con- next TÜV (MOT equivalent) due date or provider

Supervision and parameterization of status data Tested Putzmeister quality parts Manufacturer’s inspection for occupational safety High-quality wear parts: Putzmeister quality Most advanced training modules Individual training on site and in the

Booms (Specifications in m) Pumps Large-volume pumps improve

NEW: 36-4 35.6 31.4 23.9 8.5 4/Z-folding ...14 H 140/88* 70/112* 2100 230 27/17* by the pumping unit.

If you are supplying pump supplies, you can find the most favorable prices at Alibaba.com. Whether you will be working with piston type or diaphragm type systems, reciprocating or centrifugal, Alibaba.com has everything you need. You can also shop for different sizes hydraulic pump putzmeister wholesale for your metering applications. If you operate a construction site, then you could need to find some concrete pump solutions that you can find at affordable rates at Alibaba.com. Visit the platform and browse through the collection of submersible and inline pump system, among other replaceable models.

A hydraulic pump putzmeister comes in different makes and sizes, and you buy the tool depending on the application. The pump used by a filling station is not the one you use to fill up your tanks. There are high flow rate low pressure systems used to transfer fluids axially. On the other hand, you can go with radial ones dealing with a low flow rate and high-pressure fluid. The mixed flow pump variety combines radial and axial transfer mechanisms and works with medium flow and pressure fluids. Depending on what it will be pumping, you can then choose the hydraulic pump putzmeister of choice from the collection at Alibaba.com.

Alibaba.com has been an excellent wholesale supplier of hydraulic pump putzmeister for years. The supply consists of a vast number of brands to choose from, comes in different sizes, operations, and power sources. You can get a pump for residential and large commercial applications from the collection. Whether you want a water pump for your home, or run a repair and maintenance business, and need a supply of hyd pump putzzmeister, you can find the product you want from the vast collection at Alibaba.com.ther it is for refrigeration, air conditioning, transfer, or a simple car wash business, anything you want, Alibcom. it has easy to get the pump you need, all of which. can your a business needs in with a range of products from high-performance machines, such as a pump for men and women.

These are just a few of the tips I suggest to owners of concrete pumps, especially first time pump owners. My first priority is always SAFETY, and that should be yours also.

This is a very key part of your pump. You spend several hundreds of dollars or even hundreds of thousands of dollars on a pump, and you still see operators filling the reservoirs with dirty, nasty old buckets. These are what they call contaminants- solid particles, air, water or any other matter that impairs hydraulic fluid function. Particle contamination accelerates wear of the hydraulic components in the system. Particles larger than the components internal clearances cause damage through friction. However, the particles that are the most damaging are those that are smaller than the internal clearances. Particles that are smaller than 5 microns produce little slits on the clearances causing tremendous wear, destroying the pumps, and other components I see this all of the time. Hydraulic oil is the “life blood” of the concrete pump and needs to be as clean as possible. I have had several hydraulic pumps from customers that I have seen torn down and they have debris in them from sand to paint to wood pieces. You wouldn’t use that dirty bucket to put oil in your own car so why would you do it on the thing that makes you your “ bread and butter”? The idea of filter carting the oil is great but this is not the answer for all pumps. For example, in a Putzmeister pump, the filters are BEFORE the hydraulic pumps so filter carting would work, but it is not cleaning your hydraulic filters, so you still need to change filters at regular intervals. Another contaminant is moisture. Moisture in the hydraulic oil tank is a killer of Hydraulic pumps. When the water particles are compressed, the water boils and turns to steam causing tiny explosions that ‘pit’ out the metal and bronze parts of the pump piston group or gears causing eventual failure.

Aeration is another killer. In aeration, air bubbles get into the fluid usually because of bad supply hoses, loose fittings, and/or hose clamps. These air bubbles are compressed causing erosion of the pump components in somewhat the same fashion as moisture.

Cavitation occurs when the hydraulic pump is starved for fluid. When this happens, air enters the pump causing the same damage as aeration. Cavitations can be distinguished by a constant sound where aeration is a more intermittent sound.

2. Hydraulic lines When to change the hydraulic hoses? This is the question that has haunted us forever in this industry. First, let’s look at the hose. It is made up of three parts: an inner layer that carries the fluid, the outer reinforcement layer (steel or fabric), and the outer protective layer. All of these have to be in good working order to allow your machine to run safely. When you take away any one of these things, you are asking for trouble. Hoses are one of the things that, if you keep on top of them, can help you prevent your machine from breaking down. The signs of a bad hose are bubbling of the outer layer, abrasion of the outer layer, cracking or dry rotting of the outer layer, steel or fabric poking out of the outer layer and when you get to the fitting, leaking around the crimp and weeping around the fitting flange. Leaking and weeping of the fitting flange is something you really need to be careful of. Don’t try to tighten a hydraulic line when the line is under a load or pressurized. The possibility of a cracked fitting or a bad crimp when you try to tighten could result in the hose exploding. This is were you hear about guys getting hands cut off, guys being blinded or oil blown up under the skin resulting in amputation of the hand. You really need to be careful and think before you do. Always wear protective clothing, gloves, and safety glasses when doing these things. This also goes for steel lines because the oil you see leaking is most likely a cracked flare on the line or a loose fitting. Again, THINK FIRST. Shut off the machine and then tighten it the line. Stand back after tightening when you pressurize the system. I prefer not to tighten anything during a pour if possible. I like to tell my guys to put a bucket under it to catch fluid and call me with the size of the hose if they don’t have it on the truck. When they do have it, see if they can change it between redimix trucks or if it is a really bad leak, shut the truck down and change immediately. The possibility of doing damage to hydraulic components due to lack of oil outweighs shutting the truck down and changing it. Sometimes you might just have a drip and you think that you can just tighten it, but tightening it may crack it more and make things worse. This becomes a judgment call. Always go on the side of SAFETY.

This is an area that can drive you completely nuts. There are some electrical problems that can happen in the field and then, when you get back to the shop, don’t show up. I have seen it more times than you can believe. The way to try to avoid this is to keep all electrical panels, inside and out, as clean as possible and make sure all the seals are in good working condition. You should only replace fuses with the specified voltage and relays with specified amperage. Changing fuses to higher amperage and relays to lower amperage could create more problems than you started with. I have seen entire electrical components burnt to a crisp by using a 30-amp fuse in a terminal that was supposed to have a 3.5 amp. This is a very expensive repair! Pumps now days have very low amperage systems and the days of a test light are just about gone. Your average test light takes 1 amp to light when brand new. Over time, the wire gets damaged inside the insulation, the clips connection to the wires break and separate, and the amount of amps to light the light go up. It can get as bad as 10 amps to light. You can even pop a fuse on a lower amp fuse just by trying to troubleshoot a problem. The use of an ammeter is your best bet.

Anyway, back to keeping you from these problems! Try not to keep things in the control panel like water nozzles, screwdrivers, and spare relays especially metal covered ones. Any of these can actually touch circuits in the panel and create a problem. Also cables, wire looms, and junctions outside of the panels can get damaged. The tendency to load up the pump cell by the water box area with spare elbows, clamps, wrecking bars and lumber is trouble waiting to happen. These can all damage electrical components and break wires. If you have ever pinched a wire and tried to find it in some of the manufacturers’ wiring looms, you understand where I am coming from. The other thing to look out for is corrosion. Loose plugs, loose junction boxes, and loose terminal connections can all lead to a problem.

These are all things to look out for. I’m not saying you need to check these daily but the vibrations from the pump do things you would not believe. Follow-up on the electrical system, keep areas clean and clear, look over connections to make sure they’re tight and check for potential pinch points for looms, cables and wires.

For those of you using some form of acid to clean your machine, DON’T! The use of a little more elbow grease can save you a lot of future problems in all facets of your concrete pump, especially in the maintenance area. Acid destroys some seals on electrical wiring looms and the insulation on cables, and junction boxes. Acid also creates corrosion on plug terminals and electric valves. If acid gets on any chrome (as in HYDRAULIC CYLINDER), it will pit and eat away the chrome causing premature cylinder damage. And hose of you with chrome material cylinders- need I say more?

The most important thing you can do to keep your machine running is to abide by all of the safety rules that are out there. When you bought your pump you were given an owners manual from the concrete pump manufacturer that probably includes a Safety manual, parts manual, operations manual and a trouble-shooting guide. These manuals are very valuable tools and yet are rarely used. Read your manuals from front to back and use them regularly. They will help you with repairs and better prepare you if you have to call for tech service. You don’t know how many times someone calls me for info on a repair that is in their manual or asks me a trouble shooting question and tells me, “I’m having trouble with this valve thingy”. Remember the frustration you feel with the break down is only compounded by you not knowing what you are trying to convey to the mechanic on the other end of the phone. To save everyone’s time, make sure you read the manuals!

Accumulators-make sure they are drained before you set foot in a hopper. Most of the newer ones have automatic drains when you turn the truck off, but earlier models, only had a manual drain. On these machines, the valve can still switch even with the engine off. To make life simpler, the rule at our company is “ALL GAGES AT ZERO BEFORE YOU STEP IN THE HOPPER”. Make sure you pay attention to this, especially if you purchase a used pump.

Routine maintenance is a very critical part of keeping a concrete pump running. If you don’t take the time to do routine maintenance, you will create very large, and expensive problems. Look around for bad gaskets on the boom, leaky hydraulic fittings, grout in your water box, blown fuses, and non-working electrical components. These lead to break down and/or your pump not working safely. The last thing is GREASE. Let me say that again. GREASE! Be it a mechanical or hydraulic pump, these machines need grease. Saying, “Oh, I’ll grease it next time I pump” could be your downfall. I am a big proponent of the auto greasers but you still need to keep them full. If you don’t have the auto greasers, I suggest you look at investing in one. The cost of the unit is most of the time what it costs to tear down the bearings and replace wear sleeves, lip seal. If you need to start replacing the guide band and s-tubes or rock valve shafts, you have now surpassed the cost of the auto greaser ten-fold!

The old saying, “why do it right the first time when you can do it right thefor twice the money the second time”, is not one you want to practice with a concrete pump. Not taking care of the problem the right way the first time usually costs you a lot more money when you finally get around to fixing it right the second time! Like I said in the electric section, I once worked on a pump where the customer used a piece of nine-wire as a fuse. This worked for a short time but then one day the circuit shorted out and the PC board that this nine wire was in completely “fried”. What started off as a bad wire to a proximity switch ended up a new PC board, proximity cable, and 2 new proximity switches plus a sizeable labor bill. So do it right the first time because in the long run, you don’t save any money if you don’t.

I am going to putz this week for a training school I was going to bring back a gallon to try. Seems like spray cans would be to expensive,how much is a can also to do think you can get as good of coverage compared to a regular pump can? Thanks Terry from WI.

I got some of this product to try and must say I am not pleased with it. Yes it does work, though it turns everything white by leaving a film on it. It is also way too expensive and I would much rather use hydraulic oil than this to keep costs down.

The link through the Putz website lists it for $53.00 a gallon, considerably more than hydraulic oil, but perhaps discounts are available? Where I"m from (NJ) I, in six years of pumping have never been confronted about using hydraulic oil in my hopper, or on the outside of it, though whenever I"ve been on streets or "high profile" type jobs i"ve been respectful and not oiled the exterior. What types of rules and regulations are there throughout other parts of the country and even in NJ that I am not aware of regarding oiling the hopper?

The invention relates to a hydraulic system, preferably for activating and actuating a mobile thick matter pump, having a primary circuit which activates a first hydraulic consumer and has a first hydraulic drive assembly which comprises at least one motor-driven hydraulic pump, having a secondary circuit which activates a second hydraulic consumer and has a second hydraulic drive assembly which comprises at least one further motor-driven hydraulic pump, the hydraulic consumers which are arranged in the primary circuit and in the secondary circuit being loaded in a first operating state via their hydraulic drive assemblies independently of one another with hydraulic oil from a tank.

Hydraulic systems of this type are used, for example, for activating and actuating mobile thick matter pumps which have a hydraulic drive mechanism for the thick matter pump, which drive mechanism is arranged in the primary circuit, and a hydraulic drive and control mechanism for a distributor boom which is configured, for example, as a folding boom, which drive and control mechanism is arranged in the secondary circuit. In the operating state of a thick matter pump of this type which is preferably configured as a concrete pump, although the drive mechanism of the thick matter pump and that of the distributor boom are actuated simultaneously but independently of one another via their respective hydraulic pumps, the oil supply in the hydraulic circuits being limited in the process by way of the oil quantity which is delivered by the associated hydraulic pumps, there are also operating states, in which only one of the hydraulic circuits is activated. This is the case, for example, before and after pumping operation during unfolding and folding of the distributor boom between a folded-in transport position and a folded-out operating position. In modern concrete pumps, this unfolding and folding operation runs in a program-controlled manner. Since this operation at the same time means a waiting time for the pump driver, there is a requirement for a rapid embodiment which leaves much to be desired with the pump outputs which are usually available in the boom hydraulic circuit, although they are sufficient for normal operation.

Proceeding herefrom, the invention is based on the object of improving the known hydraulic system of the type specified at the outset, in such a way that an increased operating speed is made possible for specific tasks within the hydraulic system in the case of a given pump output in the different hydraulic circuits.

The object according to the invention is achieved primarily by virtue of the fact that, in a second operating state, when the first consumer is at a standstill, at least part of the hydraulic oil from the primary circuit is fed into the secondary circuit in order to activate the second consumer. By way of this measure, more oil is made available for the operation of the second consumer without an increase in the rotational speed of the motor-driven hydraulic pumps, and therefore a higher output, in particular a higher operating speed, is achieved.

In the case of the application which is preferably taken into consideration of a thick matter pump, the first consumer which is arranged in the primary circuit is expediently configured as a hydraulic drive mechanism of the thick matter pump, whereas the second consumer which is arranged in the secondary circuit is configured as a drive and control mechanism of a distributor boom which consists of a plurality of boom arms. In this case, the measure according to the invention can be used, for example, for the automatic folding and unfolding of the distributor boom, by oil from the main circuit of the thick matter pump being fed to the boom circuit, for example via a suitable valve controller.

According to one preferred embodiment of the invention, the hydraulic drive mechanism of the thick matter pump has two hydraulic drive cylinders which are connected via in each case one piston rod to a delivery cylinder and are connected at their one end via in each case one main line to the at least one hydraulic pump which is arranged in the primary circuit and are connected at their other end via an oil oscillation line to one another, the primary circuit and the secondary circuit being connected to one another via a connecting line, in which a first control valve which selectively releases or shuts off the oil flow is arranged. In order to ensure the build-up of pressure which is required for feeding into the secondary line, at least one second control valve which selectively shuts off or releases the oil flow to the tank is expediently arranged within the primary circuit. One further design variant provides that at least one third control valve which selectively shuts off or releases the oil flow to, from or between the hydraulic cylinders is arranged within the primary circuit.

A further advantageous refinement of the invention provides that at least one reversible and adjustable main pump and a feed pump which opens on the pressure side into the primary circuit and on the suction side into the tank are arranged in the closed primary circuit. In this case, one first design variant provides that the connecting line which contains the control valve is branched off from one of the main lines of the primary circuit. In order that the pressure which is necessary for the boom control can be built up by the main pump, the main pump is activated in this case in such a way that the pressure side of the main pump is at the relevant main line. Accordingly, in this case, the piston of the drive cylinder which is connected to the relevant main line has to be moved into its end position which is adjacent to the oil oscillation line. In a further design variant, the connecting line which contains the control valve is connected via in each case one non-return valve to one of the main lines of the primary circuit. As a result, the main pump can selectively be activated in such a way that the pressure side lies either at the one main line or at the other main line.

Furthermore, a control valve which releases or shuts off the throughflow can be arranged in the oil oscillation line between the hydraulic cylinders. A further advantageous or alternative refinement in this regard can consist in that stroke compensation loops which are fitted with infeed and outfeed valves are arranged in the region of the end positions of the drive cylinders, and in that a control valve which is configured as a shut-off valve or a directional valve which can be connected selectively to the secondary circuit is arranged in at least one of the stroke compensation loops.

FIGS. 1 to 6 show hydraulic circuit arrangements of hydraulic systems having a closed primary circuit for actuating a two-cylinder thick matter pump and a secondary circuit for the control of a distributor boom, and

FIGS. 7 and 8 show hydraulic circuit arrangements of hydraulic systems having an open primary circuit for activating and actuating a two-cylinder thick matter pump and having a secondary circuit for the control of a distributor boom.

The hydraulic circuits which are shown in the drawing are intended for thick matter pumps which have two delivery cylinders (not shown), the end-side openings of which open into a material supply container and can be connected alternately during the pressure stroke via a transfer tube to a delivery line. The delivery cylinders are driven in opposite stroke movements via hydraulic drive cylinders 7, 8 which are arranged in a first primary circuit I. For this purpose, the drive pistons of the drive cylinders 7, 8 are connected via a common piston rod to the delivery pistons in the delivery cylinders. The drive cylinders 7, 8 form a first consumer in the primary circuit I which, moreover, has a hydraulic drive assembly which comprises at least one motor-driven hydraulic pump 1, 2. Furthermore, a secondary circuit II is provided in all exemplary embodiments, which secondary circuit II has a second hydraulic drive assembly which comprises a further motor-driven hydraulic pump 22. The hydraulic consumers which are arranged in the primary circuit I and in the secondary circuit II can be loaded in a first operating state via their hydraulic drive assemblies independently from one another with hydraulic oil from a common tank 60. In this way, although the primary circuit I with the drive cylinders 7, 8 and the secondary circuit II with the boom controller 24 can be driven at the same time, they can be driven separately from one another via their respective hydraulic pumps 1, 2, 22.

One special feature of the invention consists in that, in a second operating state when the consumer which comprises the hydraulic cylinders 7, 8 is at a standstill, at least part of the hydraulic oil from the primary circuit I can be fed into the secondary circuit II in order to activate the distributor boom. This measure achieves a situation where the unfolding and folding of the distributor boom which is configured as a folding boom can be carried out more rapidly when the thick matter pump is at a standstill by way of the feed of compressed oil from the primary circuit I. In order to achieve this, the primary circuit I and the secondary circuit II are connected to one another in all exemplary embodiments via a connecting line 29, in which a first control valve 28 (FIG. 1 to 4, 6 to 8) or 35 (FIG. 5) which selectively releases or shuts off the oil flow is arranged. In order to generate the pressure which is required for feeding in in the primary circuit I, various design variants are proposed which will be explained in greater detail in the following text.

The exemplary embodiments according to FIGS. 1 to 6 relate to hydraulic systems, the primary circuit I of which is configured as a closed hydraulic circuit. There, the drive cylinders 7 and 8 which form the consumer are driven by the main lines 17, 18 via a reversible and adjustable main pump 1 in opposite stroke movements. This means that the piston 70 in the drive cylinder 7 extends when the piston 80 in the drive cylinder 8 is pushed back via the oil which flows in the oil oscillation line 19. When both pistons 70, 80 in the drive cylinders 7, 8 have reached their end position, the main pump 1 reverses its delivery direction, with the result that the pistons move in the respectively other direction. From the closed primary circuit I consisting of main pump 1, main lines 17, 18, drive cylinders 7, 8 and oil oscillation line 19, a corresponding oil quantity is always fed out via the scavenging shuttle valve 5 and the pressure limiting valve 6 into the tank 60 which is under atmospheric pressure. Here, the oil quantity to be fed out can be set via the pressure limiting valve 6. The scavenging shuttle valve 5 has two control lines 25, 26 which are connected to the main lines 17 and 18 and push the valve slide of the scavenging shuttle valve 5 to and fro, depending on which side the high pressure prevails. Via the outfeed lines 20 and 21, oil is then fed out via the main line 17 or 18 from the low pressure side to the tank 60. In addition, a feed pump 2 which is connected on the suction side to the tank 60 is provided, via which feed pump 2 an oil quantity which corresponds to the oil quantity which is fed out at the scavenging shuttle valve 5 is fed in again on the low pressure side of the main pump 1 via the non-return valves 3 and 4 which are connected to the main. lines 17 and 18. A possible excess quantity flows via the pressure limiting valve 43 into the tank 60.

If the main pump 1 is at zero delivery, a pressure equilibrium prevails in the lines 17 and 18, with the result that the valve slide of the scavenging shuttle valve 5 remains in the center position and no oil is fed out. In this state, the complete oil quantity of the feed pump 2 flows via the pressure limiting valve 43 into the tank 60.

On account of leaks which occur in the drive cylinders 7 and 8, oil has to be fed in or fed out in certain operating states, in order that the relevant pistons 70, 80 can in each case reach their end positions. If, for example, the piston 80 in the cylinder 8 does not reach its bottom-side end position, whereas the piston 70 in the cylinder 7 has reached its rod-side end position, oil can be fed to the cylinder 8 via the throttle 16, the non-return valve 13 and the oil oscillation line 19, with the result that the piston 80 in the cylinder 8 also reaches its bottom-side end position. If, in contrast, the piston 70 in the cylinder 7 has not yet reached its rod-side end position, whereas the piston 80 in the cylinder 8 is already situated in its bottom-side end position, oil is fed out via the non-return valve 11, with the result that the piston 70 in the cylinder 7 can move into its rod-side end position. Here, the piston end position valve 10 which is configured as a ball cock has to be open. On the side of the cylinder 8, the non-return valve 12 corresponds to the bottom-side non-return valve 11, whereas the piston end position valve 9 there corresponds to the piston end position valve 10. Secondly, the non-return valve 14 on the cylinder 8 corresponds to the rod-side non-return valve 13 on the cylinder 7, whereas the rod-side throttle 16 there corresponds to the throttle 15. The secondary circuit II which is configured as a boom circuit contains a hydraulic pump 22 which can optionally be configured as a fixed displacement pump or as a variable displacement pump. The hydraulic pump 22 is connected on the suction side to the tank 60 and on the pressure side via the pressure line 23 to the consumer which is configured as a boom controller 24.

In the exemplary embodiments according to FIGS. 1 to 4 and 6 to 8, a control valve 28 which is configured as a 2/2-way valve is provided in the connecting line 29 between the primary circuit I and the secondary circuit II. In the rest position, the directional valve 28 shuts off the connection between the primary circuit I and the pressure line 23 in a manner which is free from leakage oil, whereas the connection is opened in the switched position. In order that the pressure which is necessary for the boom controller 24 can be built up by the main pump 1, the main pump 1 is activated in such a way that the pressure side is at the main line 17 in the case of FIG. 1. The piston 70 of the drive cylinder 7 therefore has to be moved there into its rod-side end position. Since, during the feeding to the secondary circuit II (boom circuit), the primary circuit I is opened and the oil which is fed into the secondary circuit II no longer flows back to the main pump 1, only as much oil can be fed in as is replenished by the feed pump 2. The maximum possible quantity can be limited via the electrically proportional (EP) quantity adjusting means 27 of the main pump 1.

In the exemplary embodiment according to FIG. 2, two additional non-return valves 30 and 31 are provided, via which a connection can be produced from the main line 17 or 18 to the directional valve 28. As a result, the main pump 1 can selectively be activated in such a way that the pressure side lies either at the main line 17 or at the main line 18. If the pressure side is at the main line 18, the piston in the drive cylinder 8 has to be moved into its rod-side end position.

In the exemplary embodiment according to FIG. 3, an additional control valve 32 which is configured as a shut-off valve is provided, which control valve 32 guides the oil which is fed out via the scavenging shuttle valve 5 and the pressure limiting valve 6 to the tank 60 in the non-activated state. In order to feed into the secondary circuit II (boom circuit), the control valve 32 is activated. As a result, the connection to the tank 60 is shut off, with the result that no more oil can be fed out to the tank 60. The complete oil quantity of the feed pump 2 is therefore available via the main pump 1 for feeding into the secondary circuit II.

In the case of the exemplary embodiment according to FIG. 4, an additional shut-off valve 34 is provided between the throttle 16 and the non-return valve 13 of the stroke compensation loop. If the piston 70 in the drive cylinder 7 is situated in its rod-side end position and if pressure is built up on account of the feeding into the secondary circuit II (boom circuit), oil flows from the main line 17 via the throttle 16, the connecting line 19 and the non-return valves 13, 11 to the low pressure side 18. This oil is therefore not available for feeding into the boom circuit. The valve 34 is open in the non-activated state. If the valve 34 is activated, no more oil can flow out and the complete oil quantity of the feed pump 2 is available for feeding into the secondary circuit.

In the exemplary embodiment according to FIG. 5, a control valve 35 which is configured as a directional valve is provided as an alternative in the stroke compensation loop of the cylinder 7 instead of the control valve 28. In the non-activated state, oil can flow via the throttle 16 and the non-return valve 13. If the directional valve 35 is activated and the piston 70 in the drive cylinder 7 is situated in its rod-side end position, a connection of the main line 17 is produced via the drive cylinder 7 and the line 29 to the pressure line 23 of the secondary circuit II (boom circuit). At the same time, the outfeed to the low pressure side via the throttle 16 and the non-return valve 13 is shut off. No more oil can therefore flow out, with the result that the complete oil quantity of the feed pump 2 is available for feeding in.

In the case of the exemplary embodiment according to FIG. 6, an additional shut-off valve 33 is provided in the oil oscillation line 19. In the non-activated state, the shut-off valve 33 connects the drive cylinders 7 and 8, with the result that they can carry out the above-described delivery cycle. If the shut-off valve 33 is activated, the connection through the oil oscillation line 19 is shut off, with the result that the pistons 70, 80 can no longer move in the drive cylinders 7, 8. The oil compensation on account of the leakage in the drive cylinders 7, 8 also can no longer take place. As a result, pressure can be built up in the drive cylinders 7, 8 and in the main lines 17, 18 by way of the main pump 1 in any desired position of the pistons 70, 80. The pressure limiting valve 52 which is connected via the non-return valves 53 and 54 to the pressure chambers between the drive cylinders 7, 8 and the shut-off valve 33 prevents impermissibly high pressures in the case of a closed shut-off valve 33, which impermissibly high pressures might occur on account of the pressure intensification in the drive cylinders 7, 8.

In each case one open primary circuit I is provided for driving the concrete pump in the exemplary embodiments according to FIGS. 7 and 8. In the case of FIG. 7, the main pump 44 sucks the oil via the suction line 48 directly from the tank 60. A reversing valve 36 is situated between the main line 47 and the work lines 17′ and 18′, which reversing valve 36 selectively connects the main line 47 to the work line 17′ or 18′ and the non-connected line 18′ or 17′ to the tank 60. The pistons 70, 80 in the drive cylinders 7 and 8 then move in opposite stroke movements as described above. In order to reverse the direction of movement, the reversing valve 36 is activated in the opposite direction. The main pump 44 has an electrically proportional (EP) adjusting device 45. If, in the case of FIG. 7, hydraulic oil is to be fed into the secondary circuit II (boom circuit), the valve 36 is not activated. The connection of the main line 47 to the work lines 17′, 18′ is therefore shut off. If the directional valve 28 is then activated, oil can be fed via the main line 47 and the line 29 from the primary circuit I to the secondary circuit II. Here, the complete delivery volume of the main pump 44 can theoretically be fed into the secondary circuit II. In practice, the oil quantity which is fed in is set via the electrically proportional quantity adjusting means 45.

In the exemplary embodiment according to FIG. 8, as an alternative both the boom pump 22 is LS (load sensing) regulated by way of regulator 37 and the main pump 44 by way of regulator 46. Here, a directional valve 38 is provided, via which the load pressure of the drive cylinders 7, 8 which is signaled via the line 41 or the load pressure of the boom controller which is signaled via the line 42 is fed selectively to the load sensing regulator (LS) 46 of the main pump 44. In the case of LS-regulated hydraulic pumps, the high pressure of the hydraulic pump is compared with the load pressure and the difference of the two pressures is kept constant via an adjusting member. The adjusting member ensures that the oil quantity is independent of the load pressure. The load pressure of the drive cylinders 7, 8 is tapped off selectively by the work line 17′ or 18′ via the shuttle valve 37. If the directional valve 38 is not activated, the load pressure of the drive cylinders 7 and 8 passes to the regulator 46 of the main pump 44. Said regulator 46 regulates the pressure difference at the adjustment throttle 50, by way of which the speed of the pistons 70, 80 in the drive cylinders 7 and 8 can be set in a manner which is independent of the load pressure. If hydraulic oil from the primary circuit I is to be fed into the secondary circuit II, the load pressure of the boom controller is signaled to the regulator 46 of the main pump 44 by way of activation of the valve 38 via the line 42. Said regulator 46 regulates the pressure difference at the adjustment throttle 51 in a manner which is independent of the load pressure, by way of which adjustment throttle 51 the quantity of hydraulic oil which is fed in can be set.

In the above text, the invention has been described in detail for the application case of a mobile two-cylinder thick matter pump. It is possible in principle to also transfer the principle on which the invention is based to other hydraulic systems having at least two hydraulic circuits, as occur, for example, in excavators or other work machines.

In summary, the following is to be noted: the invention relates to a hydraulic system, preferably for activating and actuating a mobile thick matter pump. The hydraulic system comprises a primary circuit I which activates a first hydraulic consumer and has a hydraulic drive assembly which comprises at least one motor-driven hydraulic pump 1, 2, 44. Furthermore, a secondary circuit II is provided which activates a second hydraulic consumer and has a second hydraulic drive assembly which comprises at least one further motor-driven hydraulic pump 22. The hydraulic consumers 7, 8; 24 which are arranged in the primary circuit I and in the secondary circuit II can be loaded in a first operating state via their hydraulic drive assemblies independently of one another with hydraulic oil from a common tank 60. One special feature of the invention consists in that, in a second operating state when the first consumer 7, 8 is at a standstill, at least part of the hydraulic oil from the primary circuit I is fed into the secondary circuit II in order to activate the second consumer 24. The first consumer 7, 8 which is arranged in the primary circuit I is advantageously configured as a hydraulic drive mechanism of the thick matter pump, whereas the second consumer 24 which is arranged in the secondary circuit II is configured as a drive and control mechanism of a distributor boom which consists of a plurality of boom arms.

Truck-mounted concrete pumps have a very wide range of concrete-related uses, for example, the construction of bridges or high-rise buildings. They consist of a truck, a supporting device, a piston pump and a boom with 4 to 6 arm hinges. The hydraulic pump is powered by the truck‘s diesel engine. Thus, no external power supply is required to operate it. The machine is operated remotely, allowing the operator to move the flexible boom arm as well as control the concrete flow rate. The concrete required is fed through a truck mixer to the feed pump‘s intake chamber.

The M70-5 used in Fukushima is mounted on a semitrailer, which is driven by a 500 hp tractor unit. In order to distribute the pump‘s 80-tonne weight evenly, the vehicle has 10 axles with a total length of 2.14 m. Putzmeister‘s M70-5 is the world‘s largest truck-mounted concrete pump. As if that wasn‘t enough, with the M42-5, Putzmeister is bringing another innovative product to the market that is setting the standard once again. The new design, from boom to chassis, has allowed the all-important overall road traffic weight to be reduced to below 32 tonnes. This means that there‘s still room for things like disposable load, equipment, water and fuel. In addition, the clever relocation of the feed pipe in the boom area and the improved rigidity of the steel construction keep the distribution boom steady. Thus, even when the boom is fully extended, concrete can be poured with precision. The running costs of the M42-5 have been considerably reduced as specially designed parts were used and less fuel is required. The volume of hydraulic oil required alone has been halved to just 300 litres!

From September 2012, the M42-5 will be used at construction sites, including for building stadia, in the hot climes of Qatar. In preparation, extensive field tests are already under way, proving its suitability for extreme conditions. Field-test machines are fitted with an array of various online sensors that monitor the hydraulic system as well as having many other functions. Regular inspections provide information, above all, on the mechanical condition of the machines. This, together with feedback from the machine operators, is fed into the ongoing optimisation phase in order to ensure that a comprehensively tried-and-tested, and reliable product is on offer as soon as production begins.

Putzmeister stands for maximum quality, which unites the company and its customers. The condition of the hydraulic oil is particularly important for problem-free operation. Putzmeister has been taking advantage of OELCHECK lubricant analyses since 1994. Hydraulic oil is tested for:On-the-job maintenance for the machinesConcrete pumps can be used from as little as a few hours a month to as much as 2,000 hours a year. Reliable operational data is often not available. Therefore, Putzmeister recommends a hydraulic oil analysis after every 500 operating hours. The findings are crucial for ensuring improved oil servicing or determining if an oil change is necessary. Regular oil analyses come as standard for machines with a maintenance contract. In such cases, oil specimens are sent by the Putzmeister branch or the assembler on site. Putzmeister also recommends immediate extensive laboratory testing if the hydraulic system stops functioning properly or the oil looks strange.

For clean oil testing of the oil used in production, oil analyses are carried out as part of the process audit. Product stability and cleanliness of the hydraulic oils are also checked. Thanks to the checks carried out during the production process, the oil quality specified upon delivery of the machine can be guaranteed.

In the OELCHECK laboratory the main characteristics of the hydraulic oil, such as viscosity, additivation and wear protection, are carefully tested in each case. The cleanliness of the hydraulic oil also plays an extremely important role. It is essential for a trouble and wear-free operation of the installations. In general, approximately 80% of hydraulic system failures are caused by impurities in the hydraulic oil. Therefore, by counting the particles, OELCHECK carefully examines hydraulic oil cleanliness (also see „Determining cleanliness categories“, ÖlChecker Winter 2004, pg. 10 et seq.).

Putzmeister sees the hydraulic oil used in a pump as an important structural component, which is a decisive factor for performance and functional safety. Therefore, it‘s not just oil manufacturers‘ product specifications that are compared. Only hydraulic oils that have been proven to meet the company‘s high quality requirements are approved for use in Putzmeister machines. As a general rule, HLP hydraulic oils, whose performance often far exceeds the minimum requirements of DIN 51524-T2, are used Putzmeister will decide which viscosity category to apply for each case (HLP 22, 32, 46 or 68) on the basis of the respective climatic conditions and other operational conditions. The oil levels in the machines vary from < 100 litres to > 1,000 litres. In the new M42-5, the newly developed hydraulic system meant that the oil volume could be reduced to approx. 300 litres. Putzmeister was able to take this even further. Thanks to the considerably lower oil levels, operating costs fall and, after an oil change, less waste oil is released into the environment. However, since the volume of hydraulic oil is considerably lower, the demands made on it are that much greater. However, if only Putzmeister-approved oils are used and regular OELCHECK lubricant analyses are carried out, these oils will rise to any challenge.