Rexroth A10VG pump

Hydraulic axial piston pump A10VG18, A10VG28, A10VG45, A10VG63

Description

Closed circuit

Control devices: HD, HD3, HW, DG, DA1, DA2, EP3, EP4, EZ1, EZ2, etc.

Nominal pressure 4350 psi (300 bar); Peak pressure 5100 psi (350 bar)

Control device: MD, HD, HW, DG, DA, EP, EZ, etc.

The A10VG variable axial piston pump of swash plate design for hydrostatic closed circuit transmission

– Flow is proportional to drive speed and displacement and is infinitely variable

– Output flow increases with the swivel angle of the swash plate from 0 to its maximum value

– Flow direction changes smoothly when the swash plate is moved through the neutral position

– A wide range of highly adaptable control devices is available for different control and regulating functions

– The pump is equipped with two pressure-relief valves on the high pressure ports to protect the hydrostatic transmission (pump and motor) from overload

– The high-pressure relief valves also function as boost valves

– The integrated boost pump acts as a feed and control oil pump

– The maximum boost pressure is limited by a built-in boost pressure relief valve

Product Introduction:

Model: A10VG

Closed circuit

Control devices: HD, HD3, HW, DG, DA1, DA2, EP3, EP4, EZ1, EZ2, etc.

Nominal pressure 4350 psi (300 bar); Peak pressure 5100 psi (350 bar)

Control device: MD, HD, HW, DG, DA, EP, EZ, etc.

Technical Data

Table of values (theoretical values, without efficiency and tolerances; values rounded)

1) Restricted maximum speed: – at half corner power (e.g. at Vg max and pN /2)

2) Intermittent maximum speed: – at high idle speed

– at over speed: Δp = 70…150 bar and Vg max

– at reversing peaks: Δp < 300 bar and t < 0.1 s.

3) Without boost pump

4) – The area of validity is situated between the minimum required and maximum permissible speed. It applies for external stimuli (e.g. engine 2-8 times rotary frequency, cardan shaft twice the rotary frequency).

– The limit value applies for a single pump only.

– The load capacity of the connection parts has to be considered.

5) 14kg: MD control, 18kg: HD control

Hydraulic fluid

Before starting project planning, please refer to our data sheets RE 90220 (mineral oil), RE 90221 (environmentally acceptable hydraulic fluids) and RE 90223 (HF hydraulic fluids) for detailed information regarding the choice of hydraulic fluid and application conditions. The variable pump A10VG is unsuitable for operation with HFA, HFB and HFC. If HFD or environmentally acceptable hydraulic fluids are being used, the limitations regarding technical data and seals mentioned in RE 90221 and RE 90223 must be observed.

Details regarding the choice of hydraulic fluid

The correct choice of hydraulic fluid requires knowledge of the operating temperature in relation to the ambient temperature: in a closed circuit the circuit temperature. The hydraulic fluid should be chosen so that the operating viscosity in the operating temperature range is within the optimum range (νopt) – the shaded area of the selection diagram. We recommended that the higher viscosity class be selected in each case. Example: At an ambient temperature of X °C an operating temperature of 60 °C is set. In the optimum operating viscosity range (νopt; shaded area) this corresponds to the viscosity classes VG 46 or VG 68; to be selected: VG 68.

Please note: The case drain temperature, which is affected by pressure and speed, is always higher than the circuit temperature.

At no point in the system may the temperature be higher than 115 °C.

Shaft seal ring

The service life of the shaft seal ring is affected by the speed of the pump and the case drain pressure. It is recommended that the average, continuous case drain pressure at operating temperature 3 bar absolute not be exceeded (max. permissible case drain pressure 6 bar absolute at reduced speed, see diagram). Short term (t < 0.1 s) pressure spikes of up to 10 bar absolute are permitted. The service life of the shaft seal ring 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 ring.

Control unit, DG – Hydraulic Control, Direct Operated

With the Direct Operated Hydraulic Control (DG), pump displacement is controlled by a hydraulic control pressure applied

directly to the stroke cylinder through either the X1 or X2 port. In this way, the swash plate and thus the displacement is switchable from Vg = 0 to Vg max. Each direction of through put flow is assigned to a port.

MD – Mechanical Pivot Control (Size 18 only)

The swash plate is adjusted directly and thus the displacement of the pump is continuously varied depending on the position of the pivot. A swivel direction of the pivot is assigned to each flow direction.

HD – Hydraulic Control, Pilot-Pressure Related

Depending on the pressure difference of the pilot pressure pSt in the two control lines (ports Y1 and Y2), the stroke cylinder of the pump is supplied with control pressure via the HD control unit. Thus the swash plate – and therefore, the displacement – to be infinitely adjustable. A different through put flow direction is associated with each control line. If the pump is also equipped with a DA control valve, automotive operation is possible for travel drives.

HW – Hydraulic Control, Mechanical Servo

Depending on the actuation direction a or b of the control lever, the stroke cylinder of the pump is supplied with control

pressure via the HW control unit. Thus, the swash plate – and, therefore, the displacement – to be infinitely adjustable. A different through put flow direction is associated with each direction of control lever actuation.

DA – Hydraulic Control, Speed Related

The DA control is an engine speed-dependent, or automotive, type control system. The built-in DA regulating cartridge generates

a pilot pressure that is proportional to pump (engine) drive speed. This pilot pressure is directed to the positioning cylinder of the pump by a solenoid actuated 4/3 way directional valve. Pump displacement is infinitely variable in each direction of flow, and is influenced by both pump drive speed and discharge pressure. Flow direction (i.e. machine forward or reverse) is controlled by energizing solenoid a or b. Increasing pump drive speed generates a higher pilot pressure from the DA cartridge, with a subsequent increase in pump flow and/or pressure. Dependent on the selected pump operating characteristics, increasing system pressure (i.e. machine load) causes the pump to swivel back towards a smaller displacement. Engine overload (anti-stall) protection is achieved by the combination of this pressure-related pump de-stroking, and the reduction of pilot pressure as the engine speed drops. Any additional power requirement, such as implement hydraulics, may result in further engine pull down. This causes a further reduction in pilot pressure and therefore pump displacement. Automatic power division and full utilization of available power is thus achieved for both the vehicle transmission and the implement hydraulics, with priority given to the implement hydraulics. To provide controllable reduced vehicle speed operation when high engine speeds are required for fast implement hydraulics, various inching options are available. The DA regulating cartridge can also be used in pumps with conventional control devices, such as EP, HW or HD, to provide an engine anti-stall function, or as a combination of automotive and displacement control functions.

EP – Electric Control, With Proportional Solenoid

Depending on the preselected current I at the two proportional solenoids (a and b), the stroke cylinder of the pump is supplied with control pressure via the EP control unit. Thus the swash plate and therefore the displacement to be infinitely adjustable. One direction of through put flow is assigned to each proportional solenoid.

EZ – Electric Two-Position Control, With Switching Solenoid

By energizing or de-energizing a control current to either switching solenoid a or b, the stroke cylinders of the pump are supplied with control pressure by the EZ control unit. In this way, the swash plate and thus the displacement is switchable without intermediate settings from Vg = 0 to Vg max. Each direction of through put flow is assigned to a switching solenoid.