About This Product; Performance Description; Unit Description; Layout Of The Axial Piston Unit - Bosch REXROTH A4 Series Instruction Manual

5 About this product

5.1 Performance description

The HS5E control system is used for electrohydraulic control of the swivel angle,
pressure, and torque limitation of an axial piston unit. It is designed for stationary
applications.
Refer to the data sheet and the order confirmation for the technical data, operating
conditions and operating limits of the HS5E control system.

5.2 Unit description

The HS5E control system is based on an axial piston variable pump in swashplate
design for hydrostatic drives in open circuit. The flow is proportional to the drive
speed and the displacement. The flow can be infinitely varied by adjusting the
swashplate angle.
Open circuit With an open circuit, the hydraulic fluid flows from the reservoir to the variable
pump and is transported from there to the consumer via a directional valve. From the
consumer, the hydraulic fluid flows back to the reservoir via the directional valve.

5.2.1 Layout of the axial piston unit

Fig. 2: Cutaway diagram of A4VSO....HS5E
1 HS5E control system
2 Stroking piston
3 Swashplate
4 Swivel angle sensor

5.2.2 Functional description

An electrically actuated proportional valve (1) controls the swivel angle and pressure
of the A4V... variable pump and limits its torque. By means of the pump's stroking
piston (2), this valve determines the position of the swashplate (3).
With a non-rotating pump and depressurized actuating system, the system uses
spring centering to retain the swashplate in swivel angle position "zero" or at swivel
angle value "zero" (when properly calibrated, "retention" is by spring force only).
The control electronics consists of one swivel angle controller, one pressure
controller, and one valve controller as well as one torque limiter. A swivel angle
4
2
3
RE 92076-01-B/10.2017, A4... with HS5E pilot control valve/Series 3x, Bosch Rexroth AG
About this product
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