US 4,480,972 AGranted

Gerotor motor and case drain flow arrangement therefor

AssigneeEaton Corporation

InventorSteven J. Zumbusch

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Abstract

A rotary fluid pressure device is disclosed of the type including a gerotor displacement mechanism (17), a rotary valve member (55), and a valve seating mechanism (75). The valve seating mechanism includes a balancing ring member (77) seated in an annular groove (81) defined by the valve housing (21). Leakage fluid from the gerotor displacement mechanism passes from the central case drain region (83) through the bearings (33 and 35) to an annular chamber (87). The leakage fluid is communicated from the annular chamber (87) to whichever of the ports (75 or 61) is connected to the system reservoir, through a series of fluid passages (131, 133, 135, 137, and 139). The fluid passage (139) communicates with the annular groove (81), and the leakage fluid flows past whichever of the balancing ring seals (143 or 145) is subjected to low pressure fluid, the balancing ring seal thus acting as a check valve. The invention eliminates the complicated and expensive prior art check valve assemblies (103, 105).

Claims10

Dependent claims

A rotary fluid pressure device of the type including housing means defining fluid inlet means and fluid outlet means;

fluid energy-translating displacement means associated with said housing means and defining expanding and contracting fluid volume chambers;
stationary valve means defining fluid passage means in fluid communication with said expanding and contracting volume chambers;
a rotary valve member defining valve passage means providing fluid communication between said inlet and outlet means and said fluid passage means, and having a valve surface associated with said stationary valve means;
said housing means defining annular chamber means neighboring said rotary valve member;
first and second seal means operably associated with said annular chamber means and cooperating with said housing means and said rotary valve member to define a first fluid chamber and a second fluid chamber, said first seal means substantially preventing fluid communication from said first fluid chamber to said annular chamber means, and said second seal means substantially preventing fluid communication from said second fluid chamber to said annular chamber means;
said fluid inlet means being in fluid communication with one of said first and second fluid chambers, and said fluid outlet means being in fluid communication with the other of said first and second fluid chambers;
said device including a fluid drain region adapted to receive leakage fluid from said displacement means;
characterized by;
(a) said housing means defining fluid drain passage means providing relatively unrestricted communication between said fluid drain region and said annular chamber means;
and
(b) said first and second seal means being operable to permit communication of leakage fluid from said annular chamber means to said first and second fluid chambers, respectively, when said first and second fluid chambers, respectively contain fluid at a pressure below the pressure of said fluid drain region.

8 more elements

A rotary fluid pressure device of the type including housing means defining a high pressure port and a low pressure port;

an internal gear set associated with said housing means including an internally-toothed member and an externally-toothed member eccentrically disposed within said internally-toothed member for relative orbital and rotational motion therebetween, said toothed members defining expanding and contracting fluid volume chambers during said relative motion;
stationary valve means defining fluid passage means in fluid communication with said expanding and contracting volume chambers;
a rotary valve member defining valve passage means providing fluid communication between said high pressure port and said fluid passage means, and between said fluid passage means and said low pressure port, and having a valve surface in sealing, sliding engagement with said stationary valve means, and further having an opposite surface;
a valve seating mechanism including said housing means defining an annular chamber and a generally annular balancing ring member disposed within said groove and having a transverse valve-confronting surface in engagement with said opposite surface of said rotary valve member;
said balancing ring member cooperating with said housing means and said rotary valve member to define a first fluid chamber in fluid communication with said high pressure port and a second fluid chamber in fluid communication with said low pressure port;
first and second seal means associated with said balancing ring member and being operable to substantially prevent fluid communication from said first and second fluid chambers, respectively, into said annular groove;
said device including a fluid drain region adapted to receive leakage fluid from said internal gear set;
characterized by:
(a) said housing means defining fluid drain passage means providing relatively unrestricted communication between said fluid drain region and said annular groove;
and
(b) said first seal means and said balancing ring member being operable to prevent substantially flow of fluid from said first fluid chamber to said annular groove, and said second seal means and said balancing ring member being operable to permit communication of leakage fluid from said annular groove to said second fluid chamber.

8 more elements

Dependencies are inferred from the claim text.