Axial Piston Sauer PV Pump
Hydraulic Sauer-Sundstrand axial piston pump PV20, PV21, PV22, PV23, PV24, PV25, PV26, PV27

Closed circuit
Series 20
Size: PV20, PV21, PV22, PV23, PV24, PV25, PV26, PV27
Nominal pressure 210 bars, Maximum pressure 350 bars.

The Sauer PV axial piston variable displacement pumps, Series 20, are of swash plate construction with variable flow capability suitable for hydrostatic transmissions with closed circuit. The flow rate is proportional to the pumps driven speed displacement, which, in turn, is determined by the swash plate angle. The latter is infinitely adjustable between zero and maximum displacement. Flow direction is reserved by titling the swash plate to the opposite side of the neutral or zero displacement position. These units and parts are fit, form and function replacements for Sauer-Sundstrand series 20 components.

– Suitable for a variety of applications
– Multiple displacements and options available
– 8 different frame sizes
– Engineered to provide a long service life and reliability
– Fixed displacement motor can be operated in either direction of rotation
– Multiple drive shaft options and control options
– Heavy duty bearings and shafts
– Replacement parts also available
– Direct replacements for Sauer-Sundstrand 
   
Features of Sauer PV pump
The full-length shaft with a high efficient tapered roller bearing arrangement offers a high loading capacity for external radial forces. Additional pumps can be built on. The hydro-mechanical servo displacement control maintains the selected swash plate position and hence pump displacement. Upon release of the control handle, the swash plate automatically returns to the null position and the flow become zero. High case pressures can be archived without leakage even at the lowest temperature by using suitable shaft seals. The servo valve arrangement offers the facility to incorporate function regulators and remote control system. Axial piston units are designed for easy servicing, complete dismantling and reassembly can be carried out standard hand tools, and all components or sub-assemblies are replaceable.
Servo Displacement Control (Linear response)
Regular by control handle on the servo valve, the swash plate can be infinitely varied in both directions with the help of the servo system.
The pump displacement resulting from any control handle position can be established using figures
The angle of the control handle for stroke initiation and for the final position of the stroke can vary from unit to unit within the range of the tolerance band.  
Reversing time
Time for the directional change of the flow from Qmax across 0 to Qmax depending on the size of the control orifice fitted in the supply port to the servo valve.The values given assume movement of the control handle directly from one end position to other.

Technical Data of Sauer PV Pump 
Table of values (theoretical values, without efficiency and tolerances; values rounded)   

Size	Dimension	Sauer-Sundstrand PV pump
		PV20	PV21	PV22	PV23	PV24	PV25	PV26	PV27
Max. displacement	cm3	33,3	51,6	69,8	89,0	118,7	165,8	227,3	333,7
Max. flow	dm3 min-1	119,5	159,9	196,1	230,5	278,9	348,1	429,59	557,2
		4	6	4	1	4	8		8
Charge pump	cm3	12,3	12,3	18,03	18,03	18,8	32,8	32,8	65,5
Maximum pressure	MPa	35
Nominal pressure	MPa	21
Max. pressure of control	MPa	3,5
Charge pressure	MPa	0,8 – 2,0
Max. pressure in case	MPa	0,25 continuous 0,5 intermittent
Max. speed	min-1	3590	3100	2810	2590	2350	2100	1890	1670
Min. speed	min-1	500
Nominal speed	min-1	1500
Kinematic viscosity range of working fluid - starting - operating - optimum	Mm 2s-1	1000 12 – 600 25 - 35
Kind of working fluid		mineral oil
Operating temperature	oC	- 40 to + 50
Max. temperature of working fluid in tank	oC	80
Purity of working fluid	µm	10
Direction of shaft rotation		clockwise or counter clockwise
Max. swash plate angle	o	± 18
Dry weight	kg	45	55	63	78	124	164	212	270