Brueninghaus Hydromatik Rexroth A4VSG pump
Hydraulic variable pump A4VSG71, A4VSG125, A4VSG180, A4VSG250, A4VSG355, A4VSG500, A4VSG750, A4VSG1000
Series 10, 11 and 30
Size 71 to 1000
Nominal pressure 5100 psi (350 bar). Peak pressure 5800 psi (400 bar)
The A4VSG or AA4VSO axial piston variable pump in swash plate design is designed for hydrostatic drives in closed circuits.
Flow is proportional to drive speed and displacement. By adjusting the swash plate angle it is possible to steplessly vary the output flow.
– Swash plate design
– Infinitely variable displacement
– Reversible flow
– Numerous control options
– Low noise level
– Long service life
– Drive shaft capable of absorbing axial and radial loads
– Low power / weight ratio
– Modular design
– Short control times
– Tandem pumps possible, full thru drive
– Swivel angle indicator standard
– Installation position optional
– Operation on HF-fluids under reduced operational data possible
Table of values (theoretical values, without efficiency and tolerances; values rounded)
|Nominal pressure||p N||bar||350||350||350||350|
|Flow||at n max||q V max||l/min||227||325||432||550|
|Power||Δ p = 350 bar||P max||kW||132||190||252||321|
|Torque||Δ p = 350 bar||Tmax||Nm||395||696||1002||1391|
|Nominal pressure||p N||bar||350||350||350||350|
|Flow||at n max||q V max||l/min||710||900||1200||1600|
|Power||Δ p = 350 bar||P max||kW||414||525||700||933|
|Torque||Δ p = 350 bar||Tmax||Nm||1976||2783||4174||5565|
DR Pressure control: The DR pressure control serves to maintain a constant pressure in a hydraulic system within the control range of the pump. The pressure can be steplessly set on the control valve (setting range 20 to 350 bar).
Optional: with remote-controllable pressure control (DRG)
FR Flow control
Maintaining a constant flow in a hydraulic system.
Optional: With remote-controllable pressure control (FRG), no connection from XF to the tank (FR1, FRG1)
DFR Pressure and flow control
This controller keeps the flow of the pump constant even under changing operating conditions. A mechanically adjustable pressure controller overrides the flow control.
Optional: No connection from XF to the tank (DFR1)
LR2 Power control with hyperbolic characteristic
The hyperbolic power control keeps the specified drive power constant at the same drive speed.
Optional: with pressure control (LR2D), remote-controllable pressure control (LR2G); with flow control (LR2F, LR2S); with hydraulic stroke limiter (LR2H); with mechanical stroke limiter (LR2M); with hydraulic two-point control (LR2Z); with electric relief valve as start assistance (LR2Y).
LR3 Power control with remote-controllable power characteristic
This hyperbolic power control keeps the specified drive power constant, whereby the power characteristic can be controlled remotely.
Optional: with pressure control (LR3D), remote-controllable pressure control (LR3G); with flow control (LR23, LR3S); with hydraulic stroke limiter (LR3H); with mechanical stroke limiter (LR3M); with hydraulic two-point control (LR3Z); with electric relief valve as start assistance (LR3Y).
LR2N and LR3N Hydraulic control, pilot pressure related
With overriding power control. The displacement is increased in proportion to the pilot pressure in PSt .
The additional hyperbolic power control overrides the pilot pressure signal and keeps the specified drive power constant.
remote controllable power characteristic (LR3N); with pressure control (LR.DN), remote controllable pressure control (LR.GN); with electric pilot pressure specification (LR.NT).
MA Manual control
The displacement is steplessly adjustable via a hand wheel.
EM Electric motorized control
The displacement is steplessly controlled via an electric variable motor. With a programmed sequence control, various intermediate displacements can be selected by means of built-on limit switches or a potentiometer for swivel-angle feedback.
HD Hydraulic control, pilot pressure related
Stepless adjustment of the pump displacement according to the pilot pressure. The control is proportional to the specified pilot pressure set point.
Control characteristics (HD1, HD2, HD3); with pressure control (HD.B), remote controllable pressure control (HD.GB); with power control (HD1P); with electric pilot pressure specification (HD1T)
HM1/2 Hydraulic control, volume related
The pump displacement is steplessly adjustable depending on the flow of pilot fluid in ports X1 and X2.
Application: 2-point switching. Base device for servo or proportional controls
HS, HS4 Control system with servo or proportional valve
The displacement is steplessly controlled via a servo or proportional valve and electric swivel-angle feedback. Electrically or electronically controllable.
Optional: with servo valve (HS); with proportional valve (HS4); with short-circuit valve (HSK, HS4K, HS4KP); without valves (HSE, HS4E); suitable for tank installation (HS4M). The HS4P control system is equipped with mounted pressure transducer, which means that it can be used for electric pressure and power control.
Control system EO1/2
The displacement is steplessly controlled via a servo or proportional valve and electric swivel-angle feedback. Electrically controllable.
With short-circuit valve (EO1K, EO2K); without valves (EO1E, EO2E)
DS1 Speed control, secondary control
The DS1 speed control controls the secondary unit in such a way that the necessary torque is available for the required speed. When connected to a constant pressure system, this torque is proportional to the displacement and thus also proportional to the swivel angle.
DFE1 Electro-hydraulic control system
The power, pressure and swivel angle control of the A4VSO…DFE1 variable pump is performed by means of an electrically controllable proportional valve. The flow at the proportional valve determines the position of the swash plate – and thus the pump flow – via the stroke piston and the displacement pick-up. When the electric engine is switched off and the actuator system is depressurized, the pump swivels to maximum displacement by means of spring force (Vg max).
Optional installation position. The pump housing must be filled with fluid during commissioning and stay full when operating. In order to obtain the lowest noise level, all connections (suction, pressure, case drain ports) must be linked by flexible couplings to tank. Avoid placing a check valve in the case drain line. This may be permissible in individual cases, but only after consultation with us.
The A4VSG pumps in the standard design, should be used with good quality, petroleum oil based, anti-wear hydraulic fluids. More detailed information regarding the selection of hydraulic fluids and their application limits can be found in our Data Sheets RA 90 220
(Petroleum Oil), RA 90 221 (Biodegradable Fluids) and RA 90 223 (Type HF–Fire Resistant/Synthetic Fluids).
When operating with environmentally compatible fluids (Biodegradable) or Fire Resistant (Type HF synthetic fluids) possible reduction of the operating specifications may be required. Please consult with us and your fluid supplier.
For a reliable continuous operation bearing flushing is required with the following operating conditions:
– Applications with special fluids (non mineral) due to limited lubricity and narrow temperature range
– Operation with mineral oils, however with marginal conditions for temperature and viscosity
– With vertical mounting (shaft up). In order to ensure lubrication of front bearing and shaft seal, we recommend bearing flushing.
The bearing flushing port “U” is located in the mounting flange area of the pump. The flushing oil flows through the pump’s front bearing and leaves via the case drain.
Operating Viscosity Range
In order to obtain optimum efficiency and service life, we recommend that the operating viscosity (at normal operating temperature) be selected from within the range.
The service life of the shaft seal is influenced by the pump speed and the case drain pressure. It is recommended that the average, continuous case drain pressure of 2 bar absolute at operating temperature not be exceeded (maximum permissible case drain pressure 4 bar absolute at reduced speed, Momentary (t < 0.1 s) pressure spikes of up to 10 bar absolute are permitted. The service life of the shaft seal decreases with an increase in the frequency of pressure spikes.
The case pressure must be equal to or greater than the external pressure on the shaft seal.
Notes on Hydraulic Fluid Selection
In order to select the correct fluid, it is necessary to know the operating temperature in the tank (open circuits) in relation to the ambient temperature. The hydraulic fluid should be selected so that, within the operating temperature range, the fluid viscosity is within the optimum range (νopt; shaded area). We recommend that the higher viscosity grade is selected in each case.
Example: At an ambient temperature of X°, the operating temperature in the reservoir is 140 °F (60 °C). In the optimum operating viscosity range (νopt; shaded area), this corresponds to viscosity grades VG 46 or VG 68, VG 68 should be selected. Important: The leakage fluid (case drain fluid) temperature is influenced by pressure and speed and is typically higher than the tank temperature. However, maximum temperature at any point in the system must be less than 195°F (90°C).
|Details model of Rexroth A4VSG pump|