External gear pumps, series AP - BUCHER Hydraulics - #3

bucher

HYDRAULICS

Gear pumps are widely used in modern hydraulic systems due to their high performance, long service life and low pur­chase and maintenance costs.

Product development has made it possible to achieve high operating pressures, excellent volumetric and mechanical efficiency, and lower noise levels, in operation, by means of:

- meticulous CAD design of the gear teeth and balanc­ing areas

- an exacting choice of high-performance materials Product description

- carefully controlled heat treatments

- increasingly tight coupling tolerances, and a high standard of surface finish.

Bucher Hydraulics S.p.A. has achieved these results by constantly improving its design, control, and manufacturing techniques in line with the latest technological develop­ments, while simultaneously introducing a Quality Control System which ensures that every single product offers the same high standards.

1. 2. 3. 4. 5.

Drive gear Driven gear Balancing Pump body Front cover

6. 7. 8. 9.

Rear cover Mounting tie rod Balancing seal Oil seal

10. Shaft seal

Referring to the pump shown in the figure, the drive gear (1) drives round the driven gear (2), transferring the oil from the suction port to the pressure port as it turns round.

The gears are made from high strength steel alloy.

The bushings (3) serve a dual purpose:

- to act as a bearing for the gears

- to balance axial and radial thrust in proportion to the change in operating pressure.

The gears-bushings assembly is fitted inside the pump body (4), in which generally the suction and pressure ports are formed.

The pump body is made of high strength extruded alumi­nium alloy.

The front cover (5), which also acts as a mounting flange, and the rear cover (6) are connected to one another by mounting tie rods (7).

The pump assembly is completed by a series of seals:

- Balancing seals (8) can be fitted in recesses in the bushings as shown in the figure, or in the covers. Their purpose is to delimit the longitudinal balancing area separating the suction and pressure zones.

- Oil seals (9) prevent oil from leaking out.

- An oil retaining ring with the dual purpose of preven­ting oil leaks from the drive gear shaft and preventing dust or other pollutants from entering the pump itself. Unless otherwise specified, the seals are in nitrilic compound offering high mechanical strength and heat resistance.

- Viton seals are available on request.

(see 2.2 Recommended fluids/Allowed temperatures).

The Bucher Hydraulics S.p.A. product range includes sin­gle pumps of groups 05-100-200-300 (corresponding to the common group denominations: 05-1-2-3) and several com­binations of double pumps, triple pumps, and so on, that can be assembled together according to versions of displace­ment, flanging, and auxiliary valves indicated in this catalo­gue.

Bucher Hydraulics S.p.A. will examine any request for spe­cial versions, features, and customisations not shown in this catalogue.

To make such a request, please contact our Sales Depart­ment.

200-P-991218-E-02/09.07 AP