pressure compensated hydraulic pump manufacturer

A pressure compensator is a device built into some pumps for the purpose of automatically reducing (or stopping) pump flow if system pressure sensed on the pump outlet port, should rise above a pre-set desired maximum pressure (sometimes called the "firing" pressure). The compensator prevents the pump from being overloaded if an overload is placed on the hydraulic system.

A compensator is built into the pump at the factory and usually cannot be added in the field. Any pump built with variable displacement can be controlled with a compensator. These include several types of axial piston pumps and unbalanced (single lobe) vane pumps. Radial piston pumps can sometimes be built with variable displacement but do not lend themselves readily to this action. Most other positive displacement pumps including internal and external gear, balanced (double lobe) vane, gerotor, and screw types cannot be built with variable displacement.

Figure 1 is a schematic of a check valve axial piston pump, variable displacement, controlled with a pressure compensator. The pistons, usually 5, 7, or 9 in number, are stroking inside a piston block which is keyed to and is rotating with the shaft. The left ends of the pistons are attached through swivel joints, to piston shoes which bear against and slide around on the swash plate as the piston block rotates. The swash plate itself does not rotate; it is mounted on a pair of trunnions so it can swivel from neutral (vertical) position to a maximum tilt angle. The angle which the swash plate makes to the vertical causes the pistons to stroke, the length of stroke being proportional to the angle. Normally, at low system pressures, the swash plate remains at its maximum angle, held there by spring force, hydraulic pressure, or by the dynamics of pump construction, and pump flow remains at maximum. The compensator acts by hydraulic pressure obtained internally from the pump outlet port. When pump pressure rises high enough to over-come the adjustable spring behind the compensator piston, the "firing" pressure has been reached, and the compensator piston starts to pull the swash plate back toward neutral, reducing pump displacement and output flow. The spring in the compensator can be adjusted for the desired maximum or "firing" pressure.

Under working conditions, on a moderate system overload, the compensator piston reduces the swash plate angle just enough to prevent the system pressure from exceeding the "firing" pressure adjusted on the compensator. On severe overloads the compensator may swing the swash plate back to neutral (vertical) to reduce pump flow to zero.

Maximum Displacement Stops. Some pumps are available with internal stops to limit the tilt angle of the swash plate. These stops limit the maximum flow and limit the HP consumption of the pump. They may be fixed stops, factory installed and inaccessible from the outside, or they may be externally adjustable with a wrench.

Manual Control Lever. Some pressure compensated pumps, especially hydrostatic transmission pumps, are provided with an external control lever to enable the operator to vary the swash plate angle (and flow) from zero to maximum. On these pumps the pressure compensator is arranged to override the manual lever and to automatically reduce the swash plate angle if a system overload should occur even though the operator control lever is still shifted to maximum displacement position.

Basically the pressure compensator is designed to unload the pump when system pressure reaches the maximum design pressure. When the pump is unloaded in this way, there is little HP consumed and little heat generated even though pressure remains at the maximum level, because there is no flow from the pump.

Variable displacement pumps are usually more expensive than fixed displacement types, but are especially useful in systems where several branch circuits are to be supplied from one pump, and where full pressure may be required simultaneously in more than one branch, and where the pump must be unloaded when none of the branches is ill operation. If individual 4-way valves are used in each branch, each valve must have a closed center spool. The inlet ports on all 4-way valves must be connected in parallel across the pump line. However, if all branch circuits are operated from a bank valve of the parallel type, a pressure compensated variable displacement pump may not be necessary; a fixed displacement pump, gear, vane, or piston, may serve equally well because the bank valve will unload the pump when all valve handles are placed in neutral, but when two or more handles are simultaneously shifted, their branch circuits will automatically be placed in a parallel connection.

As in all hydraulic systems, more pump oil will flow to the branch with the lightest load. Bank valve handles can be modulated to equalize the flow to each branch. When individual 4-way valves are used in each branch, flow control valves may be installed in the branch circuits and adjusted to give the flow desired in each branch.

Figure 2 shows a multiple branch circuit in which a variable displacement pump is used to advantage. Individual 4-way valves, solenoid operated, are used for each branch, and they have closed center porting. Please refer to Design Data Sheet 54 for possible drift problems on a pressure manifold system. A pressure relief valve is usually required even with a pressure compensated pump due to the time interval required for the swash plate to reduce its tilt angle when a sudden overload occurs. The relief valve will help absorb part of the pressure spike generated during this brief interval. It should be adjusted to crack at about 500 PSI higher than the pressure adjustment of the compensator piston spring to prevent oil discharge across it during normal operation.

All hydrostatic transmission systems use a variable displacement pump with pressure compensator, and often combine the compensator with other controls such as the horsepower input limiter, load sensing, flow sensing, or constant flow control.

Hydraulic pumps are an incredibly important component within hydraulic systems. IFP Automation offers a variety of pump and hydraulic system products that deliver exceptional functionality and durability. Our partner Parker’s extensive line of hydraulic pumps deliver ideal performance in even the most demanding industrial and mobile applications. In this post, we are going to spend time discussing pressure compensated and load sensing hydraulic pumps.

Do to the surface area of the servo piston and the pressure exerted on that area, a force is generated that pushes the swash plate of the pump to a lower degree of stroke angle.

The pump tries to maintain compensator setting pressure, and will provide whatever flow (up to it’s maximum flow rate) that is necessary to reach that pressure setting.

For more information on how you can make use of hydraulic pump technology in your applications, please contact us here to receive a personalized contact by an IFP Application Engineer:

Piston pumps are typically much more complicated and are often available in wither fixed or, commonly, variable displacement configurations and with pressure compensation. These are big words that mean that piston pumps can usually adapt to the system pressure, providing maximum efficiency and flexibility. They are often used in “closed center” systems where the pump displacement varies to meet the needs of the work being done. Piston pumps use a “swashplate” to move the pistons and the angle of the swashplate & bore of the pistons determines the displacement. Pressure compensation regulates outputs in response to variations in the system. Piston pumps are typically the most efficient type of hydraulic pumps.

These pumps are designed for applications where light weight design, lower displacements, and multiple configuration capabolities are design requirements.

This Pressure Compensated Piston Pump is one of many pumps that the Hydraulic Megastore has to offer and they are all available for next day delivery.

Vickers 420 Series pumps deliver high pressure in a small package to maximize power density. They are ideal solutions for constrained space applications.

This pressure compensated load sense piston pump is just one of many pumps that the Hydraulic Megastore has to offer and they are all available for next day delivery.

The displacement of a pump is defined by the volume of fluid that the gears, vanes or pistons will pump in one rotation. If a pump has a capacity of 30 cm3, it should treat 30 ml of fluid in one rotation.

... designed for open circuits in mobile hydraulics and operate according to the swash plate principle. They are available with the option of a thru-shaft for operating additional hydraulic pumps ...

PGP 500 pumps offer superior performance, high efficiency and low noise operation at high operating pressures. They are produced in four frame sizes (PGP 502, PGP 505,PGP 511, PGP 517) with displacements ...

... Parker’s hydraulic truck pump series F1 featuring high self-priming speed and high efficiency and is one of the leading truck pumps in the market. The F1 pump provide ...

... Piston Pumps provide fixed-displacement power in a unique miniature design. Engineered for open-circuit systems, they bring flexibility to your operation. Compact ...

... machinery or in hydrostatic transmissions. Fixed displacement motors can also be used in open circuit applications, and are therefore suitable for a variety of hydraulic circuits.

... and very compact for easier and inexpensive installations. Bent Axis pumps-motors will mount directly to virtually any Bezares PTO in our extensive line.

... line of fixed displacement bent axis piston pumps were developed with spherical head pistons. This provides extremely high performance and high pressure ratings on a long life span unit. ...

... 1000bar. The HP-REMOTE pump, like all the HP Series pumps, can be installed in any hydraulic applications which requires high working pressures and moderate and controllable oil flow. ...

... HP-LEVER pump of the HP Series is a single-acting air-hydraulic pump with manual operation with an ergonomic lever. It has an oil flow rate of 2.4 to 0.1 l / min and operating pressures ...

The UPM-2V air-hydraulic pump is a double-acting pump with double 4/3 lever distributor hand valve, 4 hydraulic outputs, pressure gauge and pressure reducing valves included. ...

... bidirectional pumps require no user intervention to change the direction of rotation (simple switching of the inlet fitting). Available in displacements from 12 to 130 cc/rev, HYDRO LEDUC offers the most ...

Of the same design as the XPi pumps, the XAi fixed displacement pumps are with SAE flange and shaft and are available in displacements from 18 to 63 ...

With their unique design, PA-PAC pumps offer a robust and durable solution to the high pressure needs of truck applications. Combining the automatic dual direction of rotation, high operating pressure (up to 500 bar peak), ...

... of light weight casing piston pumps with a fixed displacement for demanding mobile hydraulics. SAP 012-108 DIN covers the displacement range 12-108 ...

The axial piston pump type V60N is designed for open circuits in mobile hydraulics and operate according to the swash plate principle. They are available with the option ...

Variable displacement axial piston pumps operate according to the bent axis principle. They adjust the geometric output volume from maximum to zero. As a result they vary the flow rate ...

The K3VG series are swash-plate type axial piston pumps which give excellent performance in high flow industrial applications in a compact and cost-effective package.

Closed circuit axial piston pumps are used as hydrostatic transmission components in self-propelled machines and for rotary drives in both fixed and mobile equipment of all kinds.

Twin flow axial piston pumps offers two different flows. In addition, we find several advantages such as lower weight or standar system solutions. BZT are available in ISO and SAE version.

Our variable volume, pressure compensated axial piston pumps continuously match output flow to the system demands. They’re designed to closely match the Eaton-Vickers PVB and PVQ and ...

The PFBA is a fixed displacement pump, axial-piston pump. It’s proven itself in a variety of operations—including die casting and injection molding machines, high-pressure ...

PMH high pressure axial piston pumps for closed loop are specifically designed to be used on heavy duty machines for traction and auxiliary functions, providing efficiency and durability.

Variable displacement pumps in closed loop; 3 basic design units and 8 max. displacement sizes of 14, 18, 21, 28, 35, 46, 56, 64 cc/rev; various control options; max. nominal pressure 300 bar, 350 bar peak; driving speed: ...

"C"" Axial Piston Pumps for high accuracy fluid metering with precision flow controls and high-pressure capability. Specifically designed for the Polyurethane Industry. Capacities from ...

Compact Design, Economical Conception. High Power Density, High Overall Efficiency, High Rotating Speeds. High Output Pressure. Simple Change of Direction of Rotation, For Industrial & Mobile Market. Splined or Keyed ...

Rotork offers a range of high quality hydraulic pumps for applications in the upstream and downstream oil and gas industries. These include an extensive range of axial piston ...

... Parker’s hydraulic truck pump series F1 featuring high self-priming speed and high efficiency and is one of the leading truck pumps in the market. The F1 pump provide ...

Parker P2/P3 High Pressure Axial Piston Pumps are variable displacement, swashplate piston pumps designed for operation in open circuit, mobile hydraulic ...

... Series pump offers variable displacement axial piston pumps for open-circuit applications. Featuring a compact footprint and continuous operating pressure ...

max flow: 21.5 GPMHyvair’s line of pressure compensated industrial piston pumps (PCP) are stocked with displacements from 0.49 cu.in/r. (8.0cc) to 4.27 cu.in/r. (70.0cc) and continuous pressure up to 3,000 PSI. All sizes in our industrial line are available with multiple control options from load sensing to dual pressure solenoid. Through drives are available on all pump sizes except the PCP33. The semi-cylindrical swash plate design allows for smooth, stable operation, increases efficiency and reduced noise by sealing pressure on its face. catalog pdf Cad File

max flow: 7.8 GPMHyvair’s line of pressure compensated industrial piston pumps (PCP) are stocked with displacements from 0.49 cu.in/r. (8.0cc) to 4.27 cu.in/r. (70.0cc) and continuous pressure up to 3,000 PSI. All sizes in our industrial line are available with multiple control options from load sensing to dual pressure solenoid. Through drives are available on all pump sizes except the PCP33. The semi-cylindrical swash plate design allows for smooth, stable operation, increases efficiency and reduced noise by sealing pressure on its face. catalog pdf Cad File

There are typically three types of hydraulic pump constructions found in mobile hydraulic applications. These include gear, piston, and vane; however, there are also clutch pumps, dump pumps, and pumps for refuse vehicles such as dry valve pumps and Muncie Power Products’ Live PakTM.

The hydraulic pump is the component of the hydraulic system that takes mechanical energy and converts it into fluid energy in the form of oil flow. This mechanical energy is taken from what is called the prime mover (a turning force) such as the power take-off or directly from the truck engine.

With each hydraulic pump, the pump will be of either a uni-rotational or bi-rotational design. As its name implies, a uni-rotational pump is designed to operate in one direction of shaft rotation. On the other hand, a bi-rotational pump has the ability to operate in either direction.

For truck-mounted hydraulic systems, the most common design in use is the gear pump. This design is characterized as having fewer moving parts, being easy to service, more tolerant of contamination than other designs and relatively inexpensive. Gear pumps are fixed displacement, also called positive displacement, pumps. This means the same volume of flow is produced with each rotation of the pump’s shaft. Gear pumps are rated in terms of the pump’s maximum pressure rating, cubic inch displacement and maximum input speed limitation.

Generally, gear pumps are used in open center hydraulic systems. Gear pumps trap oil in the areas between the teeth of the pump’s two gears and the body of the pump, transport it around the circumference of the gear cavity and then force it through the outlet port as the gears mesh. Behind the brass alloy thrust plates, or wear plates, a small amount of pressurized oil pushes the plates tightly against the gear ends to improve pump efficiency.

A cylinder block containing pistons that move in and out is housed within a piston pump. It’s the movement of these pistons that draw oil from the supply port and then force it through the outlet. The angle of the swash plate, which the slipper end of the piston rides against, determines the length of the piston’s stroke. While the swash plate remains stationary, the cylinder block, encompassing the pistons, rotates with the pump’s input shaft. The pump displacement is then determined by the total volume of the pump’s cylinders. Fixed and variable displacement designs are both available.

With a fixed displacement piston pump, the swash plate is nonadjustable. Its proportional output flow to input shaft speed is like that of a gear pump and like a gear pump, the fixed displacement piston pump is used within open center hydraulic systems.

As previously mentioned, piston pumps are also used within applications like snow and ice control where it may be desirable to vary system flow without varying engine speed. This is where the variable displacement piston pump comes into play – when the hydraulic flow requirements will vary based on operating conditions. Unlike the fixed displacement design, the swash plate is not fixed and its angle can be adjusted by a pressure signal from the directional valve via a compensator.

Flow and Pressure Compensated Combined – These systems with flow and pressure compensation combined are often called a load-sensing system, which is common for snow and ice control vehicles.

Vane pumps were, at one time, commonly used on utility vehicles such as aerial buckets and ladders. Today, the vane pump is not commonly found on these mobile (truck-mounted) hydraulic systems as gear pumps are more widely accepted and available.

Within a vane pump, as the input shaft rotates it causes oil to be picked up between the vanes of the pump which is then transported to the pump’s outlet side. This is similar to how gear pumps work, but there is one set of vanes – versus a pair of gears – on a rotating cartridge in the pump housing. As the area between the vanes decreases on the outlet side and increases on the inlet side of the pump, oil is drawn in through the supply port and expelled through the outlet as the vane cartridge rotates due to the change in area.

Input shaft rotates, causing oil to be picked up between the vanes of the pump which is then transported to pump outlet side as area between vanes decreases on outlet side and increases on inlet side to draw oil through supply port and expel though outlet as vane cartridge rotates

A clutch pump is a small displacement gear pump equipped with a belt-driven, electromagnetic clutch, much like that found on a car’s air conditioner compressor. It is engaged when the operator turns on a switch inside the truck cab. Clutch pumps are frequently used where a transmission power take-off aperture is not provided or is not easily accessible. Common applications include aerial bucket trucks, wreckers and hay spikes. As a general rule clutch pumps cannot be used where pump output flows are in excess of 15 GPM as the engine drive belt is subject to slipping under higher loads.

What separates this pump from the traditional gear pump is its built-in pressure relief assembly and an integral three-position, three-way directional control valve. The dump pump is unsuited for continuous-duty applications because of its narrow, internal paths and the subsequent likelihood of excessive heat generation.

Dump pumps are often direct mounted to the power take-off; however, it is vital that the direct-coupled pumps be rigidly supported with an installer-supplied bracket to the transmission case with the pump’s weight at 70 lbs. With a dump pump, either a two- or three-line installation must be selected (two-line and three-line refer to the number of hoses used to plumb the pump); however, a dump pump can easily be converted from a two- to three-line installation. This is accomplished by inserting an inexpensive sleeve into the pump’s inlet port and uncapping the return port.

Many dump bodies can function adequately with a two-line installation if not left operating too long in neutral. When left operating in neutral for too long however, the most common dump pump failure occurs due to high temperatures. To prevent this failure, a three-line installation can be selected – which also provides additional benefits.

Pumps for refuse equipment include both dry valve and Live Pak pumps. Both conserve fuel while in the OFF mode, but have the ability to provide full flow when work is required. While both have designs based on that of standard gear pumps, the dry valve and Like Pak pumps incorporate additional, special valving.

Primarily used on refuse equipment, dry valve pumps are large displacement, front crankshaft-driven pumps. The dry valve pump encompasses a plunger-type valve in the pump inlet port. This special plunger-type valve restricts flow in the OFF mode and allows full flow in the ON mode. As a result, the horsepower draw is lowered, which saves fuel when the hydraulic system is not in use.

In the closed position, the dry valve allows just enough oil to pass through to maintain lubrication of the pump. This oil is then returned to the reservoir through a bleed valve and small return line. A bleed valve that is fully functioning is critical to the life of this type of pump, as pump failure induced by cavitation will result if the bleed valve becomes clogged by contaminates. Muncie Power Products also offer a butterfly-style dry valve, which eliminates the bleed valve requirement and allows for improved system efficiency.

It’s important to note that with the dry valve, wear plates and shaft seals differ from standard gear pumps. Trying to fit a standard gear pump to a dry valve likely will result in premature pump failure.

Encompasses plunger-type valve in the pump inlet port restricting flow in OFF mode, but allows full flow in ON mode lowering horsepower draw to save fuel when not in use

Wear plates and shaft seals differ from standard gear pumps – trying to fit standard gear pump to dry valve likely will result in premature pump failure

Live Pak pumps are also primarily used on refuse equipment and are engine crankshaft driven; however, the inlet on a Live Pak pump is not outfitted with a shut-off valve. With a Live Pak pump, the outlet incorporates a flow limiting valve. This is called a Live Pak valve. The valve acts as an unloading valve in OFF mode and a flow limiting valve in the ON mode. As a result, the hydraulic system speed is limited to keep within safe operating parameters.

Outlet incorporates flow limiting valve called Live Pak valve – acts as an unloading valve in OFF mode and flow limiting valve in ON mode restricting hydraulic system speed to keep within safe operating parameters

According to the application such as construction machinery and various industrial vehicles and its hydraulic control system, Kawasaki offers the most suitable axial piston pump from the wide range of variations.

Kawasaki offers high efficinecy and low noise axial piston pumps suitable for variable-speed control system. The built-in large capacity suction valve enable easy configuration of the closed circuit for various systems.

Kawasaki"s bent axis type axial piston pumps have features such as high efficniency and long life. They can operate for long periods of time under severe conditions: high-pressure continuous drive, use of fire resistant fluid, etc.

Kawasaki screw pumps have been manufactured since 1936 and they are now being supplied to meet the growing demand in all industrial fields. Kawasaki screw pumps are employed for a great diversity of purposes including conveyance of heavy oils, lube oil service, pressure delivery as well as for hydraulic applications.

The Kawasaki Precision Gear Pumps are produced with the enhanced manufacturing accuracy to improve performance of the external-contact type gear pumps, which have small pulsations and good volumertic characteristics. Those pumps were originally developed for pumping and metering of polymer to the spinnerette in the production of chemical fibers, and have prevailed in many other applications.

Based in Taiwan since 1981, Camel Precision Co., Ltd. is a Hydraulic Pump supplier and manufacturer with more than 38 years of experence in the Machinery and Equipment Manufacturing Industry

In 1981 Camel Precision Co.,Ltd was founded. The management of company fully awards of high quality products requires not only sophisticate machinery, But good knowledge in technology is also important as well. Company invited senior engineers from Germany and Japan to lead the manufacturing and training of local engineers in hydraulic industry. We offer our customers industrial pumps, solenoid directional control valves, hydraulic pumps, vane pumps, external gear pump, internal gear pump, directional valve, hydraulic valves...etc.

CML, Camel Hydraulic, Camel Precision has been offering customers high-quality Hydraulic Pump production service, both with advanced technology and 38 years of experience, CML, Camel Hydraulic, Camel Precision ensures each customer"s demands are met.

CML, Camel Hydraulic, Camel Precision welcomes you to view our high quality products Vane Pump, Gear Pump, Solenoid Valve, Modular Valve, Hydraulic Pump and feel free to Contact Us.

The performance and reliability you know and expect is still available today! Formerly known as the Vickers 2000 Series, one of the most experienced and respected names in hydraulics, Servo Kinetics Inc Classic 2000 Series pumps and motors are built to original Vickers 2000 factory specifications. Servo Kinetics Inc has been the exclusive manufacturer of Servo Kinetics Inc Classic 2000 series hydraulic pumps and motors since 2006. We engineer and manufacture all Classic 2000 Series pumps and motors to aircraft/aerospace quality standards, using all original metals, in our Ann Arbor, Michigan facility. Since acquiring the Vickers 2000 product line, we’ve made major improvements in the level of support available to power plants still using these fine products.