Sauer-Danfoss adds two pumps to series 45 line - mobile hydraulics

Diesel Progress North American Edition, March, 2004

Sauer-Danfoss has completed its series 45 range of axial piston open circuit hydraulic pumps with the addition of two new frame sizes. The series 45 is a family of variable displacement, axial piston pumps for open circuit applications. Overall, the pumps are used in a variety of material handling, agricultural, forestry and construction equipment.

The new models are the frame E pumps, 100 cc to 147 cc, which are now the largest models in the series 45 family, Also new are the frame J pumps, 45 cc to 75 cc, which fill in the middle portion of the product line.

Specifically, both the E and J frame pumps are targeted at mobile off-highway applications including cranes, telehandlers, forklift trucks, wheel and backhoe loaders, as well as forestry and agricultural machinery.

One of the keys to the new pumps is the shrinking amount of space on many types of off-highway equipment. Stuart Archer, product portfolio manager, said the compact size of E and J pumps, and throughout the series 45, leaves more space for other components on the equipment. Further, the servo pistons are located close to the pump controls to speed up response time.

Archer said the new pumps have low noise levels, which becomes increasingly more important every year as OEMs strive to meet vehicle noise regulatory requirements and reduce operator fatigue. Further, the single-piece housing assembly is designed to minimize potential leak points at installation and in operation, Archer said.

The J frame pump features include displacements from 25 cc to 147 cc, speeds up to 3600 rpm, pressures up to 4495 psi continuous, and 400 5800 psi peak. There are a variety of control system options including load-sensing and pressure-compensated available and through-drive capability for multicircuit systems.

The series 45 frame E pumps have a dual servo piston design with a cradle type swashplate set in polymer-coated journal bearings. The bias piston increases swashplate angle. The displacemcnt piston decreases swashplate angle.

At equal pressure, the larger diameter displacement piston overpowers the bias piston. Nine reciprocating pistons displace fluid from the pump inlet to the pump outlet as the cylinder block rotates on the pump input shaft. The block spring holds the piston slippers to the swashplate via the slipper retainer. The cylinder block rides on a bimetal valve plate optimized for high volumetric efficiency arid low noise. Tapered roller bearings support the input shaft and a viton lipseal protects against shaft leaks.

An adjustable one spool or two spool control senses system pressure and load pressure. The control ports system pressure to the displacement piston to control pump output flow.

Both pump families are currently in production, with both being built at Sauer-Danfoss' Ames, Iowa, operations. The K and L pumps in the 45 series are built at Sauer-Danfoss' facility in Slovakia, while the J, H, G and E frames sizes are built in Ames.

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