variable displacement hydraulic pump animation manufacturer

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.

In axial piston variable pumps, the flow is proportional to the drive speed and the displacement. The flow can be steplessly changed by adjusting the swivel angle. Axial piston variable ...

... 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 of a thru-shaft for operating additional ...

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 ...

... piston pump type V30D is designed for open circuits in industrial hydraulics and operate according to the swash plate principle. They are available with the option of a thru-shaft for operating additional ...

... 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.

Axial piston twin flow pump. With a very high performance in all job conditions. Due to its twin flow configuration this pump allows a great variety of solutions in different job applications.

Air hydraulic pump, double pneumatic motor, double effect, foot operated with lock-up function, lever distributor valve (4/3), 10L tank, oil flow 8.5 / 0.26 l / min

... customer system options for mechanical, hydraulic and electric input solutions are available. Further special regulating features like torque control and pressure cut-off are also available. The reliable ...

... needs of truck hydraulics, the TXV variable displacement pumps with LS (Load Sensing) control allow flow regulation to suit the application requirements. The pump ...

... rev. displacements, these pumps are designed to operate in both directions of rotation (clockwise or counter-clockwise). Only one reference regardless of direction of rotation. The TXV indexable pumps ...

... PVG is a variable-displacement axial-piston pump designed to take on your most demanding applications. It offers high-pressure, superior performance in a compact design ...

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. ...

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 ...

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 ...

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 ...

In an axial-piston pump, the pistons and cylinder rotate around the center, longitudinal axis. The pistons and shoes move in and out of the cylinder because they are sliding upon a stationary, variable angle, swashblock.

Piston design - Solid, hollow, or with piston rings. The design and weight of the pistons will have a major effect on pump efficiency. The Parker F11 design with its lightweight head and retained balls can reach significantly higher speeds than swashplate pumps with their longer, heavier pistons.

Some pumps and motors can run over-centre, which means they can provide flow or rotate their drive shaft in both directions. These are commonly used in closed circuit, mobile vehicle drives systems.

Bent axis designs tend to have much heavier duty shaft bearings than swashplate pumps. This is because they are more commonly used as motor drive units and have to take the wheel loads against their shaft. Swashplate pumps, on the other hand, tend to be driven through flexible couplings that will remove any side loads, so the internal bearing is sized just to take the internal loads from the dynamic and pressure loading forces.

Noise level can be an issue with piston pumps. The noise is generated by the discontinuities in the flow e.g. as the pistons move forward and backward they create a pulsating flow that passes into the complete hydraulic system and vibrates or radiates from other components further down the circuit. This flow discontinuity is further complicated by the supply port which connects and disconnects each piston as it rotates. The timing of the opening and closing can create other, higher frequency flow discontinuities. Often different timing plates are available for different operating conditions e.g. fixed speed or variable speed applications.

Case leakage line pressures are critical for controlling the pressure balance of the slipper against the suction pressure. Care should be taken with some pump controllers as the valves exhaust into the pump casing and can create dangerous pressure spikes. Make sure case drain lines are sufficiently sized. One possible solution may be to use a more compliant, clear plastic hose for the case leakage line which will have the effect of damping out these peaks before damage the slippers. Case leakage line temperatures are also a good way of monitoring the health of the pump as discussed in the vane pump section.

If you are in doubt about the most appropriate pump to use in your application then always talk to manufacture or distributor who should be able to offer the most appropriate pump range and advise the expected service life.

Designed to be cost effective, stable and low-maintenance, the PVWJ is a variable displacement axial piston pump with a medium control response. Like all Oilgear pumps, it thrives on low viscosity fluids and comes in a variety of frame sizes and available displacement rates.

PVWJ pumps were design and manufactured in such a way that we can offer customers greater flexibility to selectively match pressure and capacity for their specific application.

We offer 3 frame sizes and a total of 10 displacement rates, coupled with a variety of optional controls. The PVWJ family of pumps provides easy field interchangeability.

All Oilgear pumps are designed to thrive on low-viscosity fluids such as high water content and fire resistant fluids, like Skydrol™, Stack Magic™, Erifon™ and 98/2.

As with all Oilgear pumps, all contact surfaces such as the cylinder surface running on the valve plate and the pistons running on the swashblock surface are all hardened for incredible durability.

The PVWJ range provides a broad range of controls and porting options to take on your most demanding applications. For low to medium horsepower equipment, the PVWJ pumps are uniquely designed for enhanced stability and less maintenance. Further to that, they’re also a much quieter option for your operations (achieved with the use of static seals (O-rings) to reduce control noise.

Quiet in operation, super high efficiency, compact design, competitive pricing and impressive lead time are the key attributes of the Oilgear PVWJ open loop piston pump. Available in 10 displacement sizes, the PVWJ pumps offer a large selection of readily interchangeable controls. With improved response controls and reduced noise levels, its rugged cylinder design enhances performance.

The patented, pressure lubricated swashblock design offers high performance for high-cycling operations. It also contributes to the pump’s ability to run on low-viscosity fluids, including high water content, fire-resistant and other special fluids.

Zeus Hydratech fully supports the Oilgear PVWJpump product line and is the only valid source for OEM parts in the South of the UK. All Oilgear repairs are machined and tested per our original factory specifications.

With a lower operating pressure and smaller variable displacement, Eaton PVQ Series piston pumps are a versatile option for machine tools, small presses and shears, conveyor lines and more. Eaton Vickers PVQ piston pumps are in-line, variable displacement units. Their displacements range from 10 cc to 45 cc (0.6 to 2.75 cu in) at operating pressures up to 210 bar (3,045 psi) to effectively handle lower pressure applications, like as PVQ10, PVQ13, PVQ20, PVQ25, PVQ32, PVQ40, PVQ45. Displacement is varied by means of pressure and/or flow compensator controls. An impressive assortment of control options offers maximum operating flexibility.

Vickers PVQ series is capable of operating with many types of hydraulic fluid. Water-content and phosphate ester fluids can be accommodated, in addition to the typical petroleum based and synthetic fluids.

Many Eaton Vickers PVQ pumps are available in a thru-drive configuration to accommodate a multitude of application and installation requirements. Thru-drive models can be coupled to various types and sizes of fixed and variable displacement pumps, resulting in a compact and versatile package. Such a package offers lower installed cost by reducing the installation size and by requiring only one mounting pad on the prime mover.

Quiet Vickers PVQ have excellent operating characteristics, and the pumps’ many control and mounting options allow choosing the optimum model for any application. Additionally, Vickers PVQs possess the same durability and long life characteristics expected of the best industrial products in today’s marketplace.

HEASH TECH, who is know the hydraulic components of Eaton Vickers, provide Vickers PVM pumps to end-users in competitive prices, such as PVQ10, PVQ13, PVQ20, PVQ25, PVQ32, PVQ40, PVQ45. For other Eaton Vickers pumps like PVH, PVM, VMQ, PVSX, welcome inquiry us! We will respond soon for your demand of Vickers pumps, motors, valves.

Another option is to utilize a load sense compensator. With a load sense compensator, this compensator will include a lighter spring setting to control the swash plate. Upstream pressure is ported into a load sense port on the pump, as the pressure requirement increases, the pressure acts against the load sense piston. Once the pressure requirement is higher than the offset, the pump swash plate angle changes and the pump begins to increase flow, by increasing the swash plate angle, until we have enough pressure to balance the piston. Once balanced, the flow remains steady until the load changes.

The offset pressure is normally 200-300 PSI. With a load sense compensator, the pump produces what the load requires plus the spring offset, normally 200-300 PSI.

With a standard pressure compensator, you would have to set the pump at 2600 PSI to accomplish the work. When the work only requires 1500 PSI, the pump will be trying to produce 2600 PSI. Fifty percent of the time, your system will be operating at 1100 PSI of inefficiency, which means heat. With a load sense compensator, when the load requires 1500 PSI, the pump will actually produce about 17-1800 PSI. Yes, this is 300 PSI inefficient, but that is much better than 1100 PSI inefficient.

With a varying load, the load sense is a much better system. For additional control, you can utilize an electronic proportional flow control or throttle. You can use an electrical signal to vary the hydraulic signal which is received by the pump’s load sense line. This would give you full electronic control of the amount of flow the pump produces.

There are additional control options which allow you to remotely control the pressure compensator. With this remote compensator control, you can set 2 or more different system pressures. With the ability of a variable piston pump to build 5,000 or more PSI; the additional setting can be used when operating components with a much lower pressure requirement.

The next control is a torque limiting or HP limiting control. By adding an additional spring and piston, you can set a pump to always maximize its allowable input torque, therefore, maximizing output flow and pressure at a defined setting.

Our pump has an output of 15 CIR, a maximum flow of about 113 gallons at 1750 RPM. Our prime mover is an electric motor, 75HP with a 1.15 service factor. I want to keep my cylinder moving as fast as possible, but I also want to ensure that I never exceed a power demand 82 HP.

At 82 HP, the pump can produce 1254 PSI at full output, 113 GPM. As the load requires more pressure, the pump will begin to reduce flow and increase pressure. At 90 GPM flow, the system will produce about 1560 PSI; at 60 GPM we can get almost 2350 PSI. At 4500 PSI, the pump flow will be reduced to about 31 GPM. The advantage of this pump is that the internal controls of the pump are adjusting to maximize flow and pressure at all times without exceeding the available HP.

If I wanted to use a pump which could produce 113 gallons of flow at 4500 PSI, I would need 296 HP. If I choose a 75 HP motor with a pressure compensated variable piston pump, the motor would stall before the pressure compensator could kick in and reduce the pump flow. Depending on the load, a load sense pump could also stall the 75 HP motor if the load pressure is high enough to use up the HP before the pressure compensator kicks in. With a torque limiting (HP) control, we utilize the full limits of the prime mover and maximize power usage.

A hydraulic pump is literally the heartbeat of your hydraulic system. If you’re new to hydraulics, you’d be surprised at how many ways you can push fluid under pressure. The rotating and/or reciprocating of gears, vanes or pistons offer a designer constrained by any performance or budget envelope the options to best suit any application, especially since each of the primary pump construction styles offers unique options within each series.

Piston pump technology exclusively employs axially or radially reciprocating pistons relative to the input shaft. Fixed and variable displacement pumps are offered in all three primary construction variations — axial swashplate, bent-axis and radial. For both axial and bent-axis piston pumps, you will notice their pistons reciprocate in parallel as the rotating group orbits the shaft. Radial piston pumps look more like old wartime engines from aircraft, with their pistons reciprocating perpendicular to the input shaft. Although the most complicated design, piston pumps enjoy power and efficiency not possible in gear or vane pumps.

Axial-piston stylesThe fixed-displacement piston pump offers designers a relatively inexpensive entry point to the piston pump. They provide reliable, high-pressure fixed flow for open-circuit hydraulic systems with no fancy controls. However, the control options available to piston pumps offer many clever tactics to control your hydraulic system, from pressure compensation to electrohydraulic proportional control with onboard pressure transducers.

A pressure compensator is a relief valve for the control piston of the variable-displacement pump. The compensator is a very low flow component that essentially controls the swashplate angle to modify displacement in such a way as to maintain a set pressure. Any downstream flow demand lowers pressure drop at the pump, causing the pump to increase flow to maintain pressure. So long as downstream flow demand does not exceed the pump’s maximum flow rate, the pump can compensate and remain at full pressure. However, any flow exceeding its maximum rating will be subject to the downstream actuators’ load pressure.

Manufacturers offer various forms of displacement and pressure control. For example, load sensing control allows the pump to read downstream load pressure signals to reduce flow during off-demand periods and at reduced pressure equal to a few hundred psi higher than the highest load. A step further, you’ll find horsepower limiting (sometimes called torque or power limiting), which provides the machine maximum flow and pressure so long as the total demand is less than the prime mover’s capacity. Should a machine, such as an excavator, demand higher flow and pressure than the engine can supply, such as when multiple high-pressure actuators are simultaneously activated, the pump will automatically restrict flow to reduce the total power required.

Regardless of compensator type, each variation achieves its result by varying only the swashplate angle. For axial piston pumps, the swashplate pivots to increase or decrease displacement as required by the compensator as directed by the control piston. As a result, the control piston moves in the same axial plane as the rotating shaft, serving up a compact and powerful package.

Bent-axis piston technologyAlthough axial piston pumps are easily the most popular, other piston pump designs are offered with variable displacement. You may be aware of the bent-axis piston motor (Figure 1), which is famous for its high power and high-speed reputation. Its shaft and bearing assembly rotate at a taper relative to an axial piston motor. Despite their high-pressure design, the bent-axis configuration offers 25% higher rotational speed than straight-axis motors, and their bearing design is better suited to pulley or gear-driven applications. The force vector from a gear or pulley must oppose the bent direction of the motor (Figure 2), much like your arm pulling against a surgical band from underfoot to do bicep curls.

The tapered, oversized roller bearings inside a bent-axis piston motor provide superior side load protection to resist the steeply angled rotating group side load. For example, a swashplate on an axial piston motor may allow a maximum of 15-22° angle, while the bent axis piston motor operates at 40° or more. This extreme angle allows the motor to achieve high displacement in a small package, resulting in a high radial load on the input shaft. Resisting these side loads requires the heavy-duty tapered bearings like those you see in Figure 3 and explains the necessity to pull from the opposing direction as the motor angle.

The same benefits of the bent-axis piston motor apply to its pump kin. Superior power density, high-speed operation and high resistance to radial load make these the top choice for mobile hydraulic designs driven directly by diesel or gas engines. In addition, their inherently robust design makes them the top choice for gear or pulley-driven pump applications (as long as the installation recommendations are adhered to). Although the tapered roller bearings provide high side-load resistance, because the bearings are loaded to remove excessive clearances, excessive wear may occur. As a result, you’re more likely to replace the bearings on a bent-axis piston pump than in other designs.

You may be surprised to know that variable-displacement bent-axis piston motors are offered by manufacturers. Unfortunately, their appearance doesn’t seem to offer any place to mount any useful swashplate angling device. Their construction varies significantly from a swashplate variable-displacement pump, where instead of varying swashplate angle, the entire lens plate slides up and down inside the port plate.

A stroke piston opposed by a bias spring and control piston works much the same as in an axial piston pump. The compensator receives a pilot signal from the pressure port to balance the pressure drop at the pump’s outlet, varying the angle of the rotating group as required to maintain pressure.

The leading manufacturers of piston pumps offer most, if not all, control options for their bent-axis piston pumps. Basic pressure compensation with no other function often goes by pressure cut-off in product literature (or pressure override). The basic pressure cut-off control simply observes outlet pressure and adjusts the swashplate angle to alter flow rate, thereby maintaining a set pressure drop. So long as system demand is less than maximum flow, the outlet pressure remains at compensator set pressure. However, should demand rise above maximum pump flow, your circuit is at the mercy of the path of least resistance.

To be honest, selecting a pressure-compensated bent-axis piston pump for anything other than high-speed belt or pulley driven applications is an expensive bit of overkill. The control devices of variable-displacement bent-axis piston pumps are often quite advanced; you can expect various advanced controls such as horsepower limiting, hydraulic proportional control or even electro proportional control. I’m aware of one particular manufacturer that offers no less than seven kinds of horsepower-limiting controllers for one pump!

Proportional pump control uses proportional pressure-reducing valves in place of standard pressure compensators. For example, imagine a bent-axis piston pump where the spring offset stroke piston fights against spring pressure by infinitely varying the pressure inside the control side of the piston. Precise pressure observed by downstream transducers offers a closed-circuit feedback loop for the machine controller to adjust the proportional valve setting to match the desired outlet pressure. Some pumps may even take it a step further to include a linear transducer to provide precise displacement feedback, guaranteeing your circuit precise output flow and pressure despite fluctuations from the load, temperature, or viscosity.

With so many pump options on the market, do we really need so many advanced options for a single pump style? My vote is yes because the bent-axis piston pump offers unique advantages over other designs. The variety of control options available ensures that your system, no matter how complex, has the pump design you need.