Tag Archives: variable vane pump

Understanding Hydraulic Pump Types and Differences

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There are many types of machinery that are driven by or actuated by a hydraulic pump. There are a variety of different systems that are used to generate the flow and pressure required and they all have a hydraulic fluid and a system that controls the fluid and pressure with hydraulic valves. The pump needs to drive and this can be done by any force generating device such as an electric motor, an internal combustion engine, wind power or even a person operating a lever or crank.

 

How It Works

A hydraulic fluid is put under pressure by the hydraulic pump and the pressure can then be used to drive a piston or drive unit via hydraulic lines. A hydraulic valve is used to switch the force on and off to give control of the device. The control can be mechanical or electrical and may be actuated manually through a lever or a button or automatically through control system.

 

Volume and Pressure

There are many different hydraulic systems and they all used a combination of volume displacement and pressure to work. The higher the pressure the more robust a system needs to be because of the tremendous forces involved. In general higher pressure systems are more efficient and the higher the pressure the less flow is required for the same application of force. There are two general types of pumps fixed displacement types that displace the same amount of fluid every cycle and adjustable displacement types that can vary the displacement for increased or decreased pressure.

 

Pump Types

There are many different types of hydraulic pumps that have different applications. Screw type pumps are good for high volumes at relatively low pressure. They are simple and effective but not particularly efficient. A gear pump has a more balanced pressure and flow and is very simple but is not very efficient particularly as pressure increases.

 

The vane pump is widely used in system of medium pressure up to 150 bar and beyond. While the axial piston pump is used in applications that require the highest efficiency. Where high pressure above 300 bars is needed the radial piston pump combine high pressure and low flow rates needed in these applications.

 

If you need more information of hydraulic pumps, please come and visit ANSON Hydraulics Industrial Ltd. – they are the professional manufacturer of various vane pumps. You can find variable vane pump, fixed displacement vane pump, hydraulic power pack unit, and much more hydraulic pumps there. To get more details, welcome to check out their website and feel free to contact with ANSON.

 

Article Source: http://peerlessengineering.com/understanding-hydraulic-pump-types-and-differences/

Fixed vs. Variable Displacement Vane Pumps

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A hydraulic drive system uses a pressurized fluid to deliver force to distant machinery. Each system has several common components; the most universal is the hydraulic pump. The pump’s purpose is to pressurize the hydraulic fluid so that it will travel down the line and perform work on the other side. In an ‘open loop’ system, the fluid is drawn from a reserve tank, and deposited into the same tank after it has done its work. In a ‘closed loop’ system, the fluid is brought directly back to the hydraulic pump after passing through a hydraulic filter.

 

Fixed Displacement Pumps

A fixed-displacement pump has a set flow rate — every stroke of the motor moves the same amount of fluid. Fixed-displacement pumps are

 

  • Simple
  • Relatively inexpensive
  • Easier to maintain

 

The simplest type of fixed-displacement pump is the gear pump, in which the hydraulic fluid is pushed by rotating gears. In some models, the gears are sequential; in the quieter and more efficient version, the gears are interlocking. Another common variation is the screw pump, which uses the classic Archimedes screw, which looks much like a drill bit, to move the fluid. They have the advantage of providing a high rate of flow at relatively low pressures.

 

Variable Displacement Pumps

In a variable displacement vane pump, the flow rate and outlet pressure can be changed as the pump operates. This results in pumps that are

 

  • More complex
  • More expensive
  • Capable of doing a wider variety of jobs

 

The most common type of variable-displacement pump is the rotary vane pump, which is a variation of the gear pump in which the ‘gear’ is offset and the ‘cogs’ aren’t fixed, but rather extend and retract as the gear turns, allowing the pump to increase the pressure of the fluid by compacting it as it pushes the fluid through. The top-tier pumps, however, are bent-axis piston-and-cylinder pumps, much like the ones that are used in an internal combustion engine.

 

Simple, fixed-displacement pumps are perfect for single jobs that need to be repeated indefinitely over long periods of time; variable displacement vane pumps can be used to power a wider variety of tools, but require more expense and more attention.

 

As the outstanding hydraulic pump supplier, Anson always follows our policy “Technology upgrading, quality insistence, comprehensive service “. Anson committed to provide high quality vane pumps for customers, including intra vane fixed displacement vane pump, variable displacement vane pump, and power mini-pack unit and so on products.

 

If you need more information about variable vane pump and hydraulic pumps, welcome to visit Anson’s website to obtain further details.

 

 

Article Source: http://peerlessengineering.com/blog/hydraulic-pumps-fixed-vs-variable-displacement/

What Is a Variable Displacement Hydraulic Pump?

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A variable displacement hydraulic pump is a type of mechanical-electrical motor placed in a fluid channel. Built either to generate electrical power from the natural flow of fluid past it or to apply mechanical force to make stationary fluid flow in a pipe gives the variable displacement hydraulic pump a dual use — adjustable capability. Such pumps have versatile applications because they can be set to capture the maximum amount of hydraulic fluid energy as the velocity of fluid flow in a channel dynamically changes, or they can be switched to applying mechanical energy powered by electricity to increase fluid flow.

 

Hydraulic motors designed on the variable displacement hydraulic pump axial principle have three common features regardless of their size or the complexity of their controls. These include a central axis, a cylinder of pistons surrounding it, and a circular plate to which the ends of all of the pistons are attached. They are usually built on the axis piston pump or bent axis pump design, which allows the vertical angle at which the pistons are positioned to be adjusted either by angling the axle itself, or the plate that is attached to the ends of the pistons.

 

The circular array of pistons in a variable displacement hydraulic pump moves in unison, but they displace different amounts of fluid depending on their horizontal positions in the piston shafts in which they move. As the internal retainer plate, or external swash plate, rotates at an off-center vertical angle of 25° to 40° in the pipe, the pistons alternate between pushing fluid through an exhaust pipe, and pulling it into an intake pipe. These outlet and inlet pipes are known as kidney slots and the piston chambers are referred to as cylinder barrel bores.

 

Another key feature of variable displacement hydraulic pumps is what’s known as the compensator. This is a collection of controls often attached to the external housing of the pump, which adjusts the angle of the swash plate or retainer plate. If the swash plate is set to a perfect vertical angle on the pump as it rotates, the displacement will be zero and fluid flow will stop. Compensators can be simple or complex controls, but their purpose is to change the variable settings on the pump for maximum efficiency.

 

ANSON is a professional hydraulic pump supplier with rich experiences. We specialize in manufacturing intra vane pump, vane pump cartridge kits, variable displacement hydraulic pump, fixed displacement vane pump, hydraulic power pack pump and more. If you are interested in variable displacement hydraulic pump series, welcome to visit our website and feel free to contact ANSON!

 

Article Source: http://www.wisegeek.com/what-is-a-variable-displacement-pump.htm