US 5,156,531 AGranted

Radial piston pump

AssigneeZahnradfabrik Friedrichshafen AG

InventorsPeter Schmid, Gunter Pannek, Klaus Weckbrodt, Michael Reichenmiller

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Abstract

This invention relates to a radial piston pump in whose suction bore (22) a load regulator (24) is inserted. The pump is to be regulated so that a constant stream and, as required, a variable large regulating stream will be available. For this purpose, a spool valve (26) that can be activated electromagnetically is inserted in a bore (23) that intersects the suction bore (22) and that spool valve can establish a connection to a suction duct (28) that is connected to a cam chamber (14) to make the regulating stream available by means of a collar (33). From suction bore (22) there furthermore branches off a shutter bore (34) that is likewise connected to the cam chamber (14) via a ring groove (35) and additional bores (36) in the pump housing (3). Shutter bore (34) limits the constant stream. The regulating stream is supplied to a consumer with fluctuating power consumption, for example, a hydrofan, that is powered with an rpm proportional to the cooling water temperature. The constant stream is used to supply, for example, a level regulation and lubricating stream. The load regulator (24) as well as the oil guides (bores, ducts, ring grooves) are machined into a cover (2).

Claims11

Dependent claims

In a radial piston pump including a housing (3), a drive shaft (4) arranged in the housing, a cam (5 mounted on the shaft for driving at least one piston (6) to draw an oil flow into a cam chamber (14) via a suction intake bore (22), the piston having inlet portion (13) which communicate with the cam chamber, and an output load regulator (24) arranged in the intake bore, the regulator including an adjustable valve (26) for altering the flowthrough cross-section to the piston in order to provide a regulating oil pressure stream in accordance with the power consumption of a consumer connected to the pump,

the improvement which comprises
(a) said piston (6) comprising a hollow piston containing a plurality of radial inlet ports (13) above and below a centerline (M) of the housing cover when the pump is in an installed position;
(b) means arranged within said suction bore for dividing the oil flow into the regulating oil pressure stream and a constant stream, said adjustable valve being arranged in a bore (23) which intersects the suction intake bore (22), said adjustable valve bore communicating with a suction duct (28) arranged parallel to the suction intake bore and connected with the cam chamber, said suction duct (28) being connected with the suction bore (22) via the adjustable valve and with the cam chamber (14) via an annular channel (30) and openings (32) in the housing cover (2) that are distributed uniformly over the circumference above and below the centerline (M), said openings which are below the centerline being smaller than said openings that are arranged above the centerline;
and
(c) a solenoid (27) connected with said housing for actuating the adjustable valve to control the regulating oil pressure stream through said suction duct, said channel, said openings, and into said piston via said inlet ports.

2 more elements

Dependencies are inferred from the claim text.