Rotary expansible chamber devices – With mechanical sealing – Axially movable end wall or end wall portion
Patent
1987-03-20
1988-09-20
Vrablik, John J.
Rotary expansible chamber devices
With mechanical sealing
Axially movable end wall or end wall portion
418135, F04C 200, F04C 1500
Patent
active
047721901
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
A known pump of the vane type is shown in the U.S. Pat. No. 4,373,871 of Feb. 15, 1983, wherein a pressure plate faces the inlet side of the drive shaft exposed to inlet pressure. Such pressure plate is contiguous to a pump package comprising a rotor, having valves encompassed by a cam ring. The pump package is contiguous with an additional pressure plate within the pump housing which closes the pump housing and is sealed therein by abutment with a sealing ring carried annularly within the housing. The pump package is thus sandwiched between a pressure plate on the inlet side of the pump and a pressure plate at the outlet side to minimize flow losses due to unavoidable production tolerances. In order to maintain a close relationship a spring is used to startup of the pump when there is insufficient outlet pressure. The pressure plate at the outlet side of the pump package is provided with a radial sealing ring, which is held in a relatively complex sealing support assembly around a drive shaft bearing. The sealing assembly effects compensation for larger axial sealing tolerances.
BRIEF DESCRIPTION OF THE INVENTION
In the present invention, the pressure plate at the inlet side of the pump package is firmly fixed axially by being bolted to the pump housing. Such pressure plate can be manufactured with closer tolerances in order that the opposed pressure plate at the outlet side of the pump package and the housing can have at least one axially resilient sealing ring acting thereon and which sealing ring limits an area around the drive shaft exposed to outlet pressure. Such area is part of the gap or space between the housing wall and the outlet pressure plate which effects a pressure chamber. In view of the close tolerances involved, the sealing ring can achieve an additional function in dispensing with separate pressure springs acting on a pressure plate as in the prior art. There is a further advantage in that an axially effective sealing ring coacts with a resilient or elastic ring so that the sealing ring acting between the outer side of the pressure plate and a wall surface of the housing will not be forced into the gap around the drive shaft.
A detailed description now follows in conjunction with the drawing which shows a longitudinal section through a vane cell pump incorporating the invention.
Referring to the drawing, a drive shaft 3 is disposed in a pump housing 1 through a small bore 2. Drive shaft 3 is supported in an anti-friction bearing 4 in the housing, and in anti-friction bearing 6 in a pressure plate 5. Pressure plate 5 closes a large housing bore 7 and also serves as a cover for the housing. The drive shaft carries a rotor 8 splined thereto. Rotor 8 has radial slits which hold radially slidable vanes 10 within a cam ring 11. Pressure plate 12 at one side of the small bore 2 is contiguous to a pump package consisting of the rotor, vanes and cam ring. Pressure plate 5, cam ring 11 and pressure plate 12 are aligned by means of pins 9.
Pressure plate 12 has recesses with pressure flow receiving channels 13. The pressure zone of the pump is in the region of channels 13. Flow chambers, not apparent in the drawing, between vanes 10, rotor 8 and cam ring 11 communicate with a suction inlet bore 15 which will be understood to connect to a tank to provide flow to an inlet chamber 14 of partial ring shape. Pressure oil conveyed by vanes 10 to the pressure side of the pump package communicates via pressure channels 13 and a narrow pressure gap or chamber 16 to an outlet channel 17. Outlet channel 17 connects by an outlet bore (not shown) with a consumer, e.g., a hydraulic steering system. Upon start up of the pump, flow pressure responsive to the consumer demand builds up in the narrow pressure chamber 16 downstream of pressure plate 12 and such pressure flow acts against pressure plate 12 to maintain contiguity with the pump package components 8, 10 and 11, pressing the pump package against the opposite pressure plate 5 which is bolted to the housing, as shown. Thus, i
REFERENCES:
patent: 3052189 (1962-09-01), Head
patent: 3240154 (1966-03-01), Robbins
patent: 3664776 (1972-05-01), Mills et al.
patent: 4242066 (1980-12-01), Hodgson
patent: 4373871 (1983-02-01), Christ
patent: 4424014 (1984-01-01), Anderson
Keicher Eckard
Merz Johann
Vrablik John J.
Walnoha Leonard P.
Zahnradfabrik Friedrichshafen AG.
LandOfFree
Vane cell pump having resilient sealing means biasing the pressu does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vane cell pump having resilient sealing means biasing the pressu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vane cell pump having resilient sealing means biasing the pressu will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1745855