US3009422A

US3009422A - Pump

Info

Publication number: US3009422A
Application number: US655092A
Authority: US
Inventors: Jr William E Davis; Paul D Crothers
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1957-04-25
Filing date: 1957-04-25
Publication date: 1961-11-21
Anticipated expiration: 1978-11-21

Description

Nov. 21, 1961 w. E. DAVIS, JR, ET AL 3,009,422

PUMP

Filed April 25, 1957 4 Sheets-Sheet 1 S I. I! I ll L II i J1| H 1 if -f ID n &

w/zz/wv f. $25 372 A TTOF/Vf) 4 Sheets-Sheet 2 PUMP W. E. DAVIS, JR., ET AL Nov. 21, 1961 Filed April 25, 1957 Nov. 21, 19 1 w. E. DAVIS, JR, ETAL 3,009,422

PUMP

Filed April 25, 1957 4 Sheets-Sheet 3 w/zu/w z Ygwm/e 5401 46769771695 Nov. 21, 1961 w. E. DAVIS, JR., ET AL 3,009,422

PUMP

Filed April 25, 1957 4 Sheets-Sheet 4 I 1 I II TIE-5 gwfaaw United States Patent 3,009,422 PUMP William E. Davis, Jr., Eau Gallic, Fla., and Paul D. *Crothers, Hamilton, Ohio, assignors to The Bendix Corporation, a corporation of Delaware Filed Apr. 25, 1957, Ser. No. 655,092 2 Claims. (Cl. 103-162) The present invention relates to fluid pumps and more particularly to variable volume fluid pumps of the wobble or swash plate type.

It is an object of the present invention to provide for a fluid pump a relatively light weight and compact wobble plate and control therefor constructed to facilitate, manufacture and being reliable in operation.

Other objects and advantages of the invention will become readily apparent from the following detailed description taken in connection with the appended drawings in Which:

FIGURE 1 is a plan view of a pump embodying the present invention;

FIGURE 2 is a sectional View taken along line 2-2 of FIGURE 1;

FIGURE 3 is an exploded view of a wobble plate and its bearing supports;

FIGURE 4 is an end view of the pump shown in FIG- URE 1 viewed from the right of the figure;

FIGURE 5 is a sectional view taken along lines 5-5 of FIGURE 4; and

FIGURE 6 is a sectional view taken along lines 6-6 of FIGURE 1.

Referring now to the drawings numeral 10 designates a housing having a bolted-on end portion 12 provided With a fluid inlet 14 and a fluid outlet 16. A rotor 18 is mounted in the housing and is provided with a tubular extension 19 having an operative connection with a drive shaft v20 which is adapted to be driven by suitable means not shown. The rotor 18 is provided with a plurality of angular-1y disposed cylinders 22 in which are reciprocably mounted plungers 24. The plungers 24 are rounded at one end to receive shoes 26 which bear against the arcuate front face 28 of Wobble plate 30. A pair of convex bearing members or

trunnions

32 and 34 are formed on the wobble plate 30 and extend rearwardly therefrom in planes substantially parallel to a plane through the axis of rotation of rotor 18.

Trunnions

32 and 34 are diametrically opposed on opposite sides of the drive shaft 20 on a transverse axis through the wobble plate 30 and are received in pillow blocks or concave bearing

members

36 and 38 respectively which are respectively mounted in

cavities

40 and 42 formed in the housing 10. Each

pillow block

36 and 38 is formed with two bearing surfaces at right angles to each other, as best shown in FIGURE 3.

Wobble plate 30 is urged toward its maximum pumping stroke position by a piston or movable wall 44; and is urged toward its minimum or no stroke position by a piston or movable wall 46 disposed on the opposite side of the trunnion axis from the piston 44.

Piston 44 is reciprocably mounted in a plug 48 which forms one wall of a chamber 50. A conduit 52 connects chamber 50 with the outlet 16 whereby piston 44 is rendered responsive to pump outlet or discharge pressure. A spring or resilient member 54 reacts between the plug 48 and a retainer 56 on the piston 44 to urge the piston into engagement with the wobble plate so as to position the plate 30 in pumping position when the pump is started and before the outlet pressure has built up sufliciently to move piston 44.

Piston 46 is reciprocably mounted in a sealing member 58 located in a chamber '60; and is responsive to the pressure in chamber 60. Chamber 60 is alternately connected 3,009,422 Patented Nov. 21, 1961 to inlet 14 and outlet 16 through conduit 62 and a valve device 64. The area of piston 46 subjected to fluid pressure in chamber 60 is larger than the area of piston 44 subjected to fluid pressure in chamber 50. The areas of pistons 44 and 46 are proportioned so that when both chambers 50 and 60 are connected to the outlets 16, piston 46 will be moved against wobble plate 30 with a force greater than the combined fluid pressure and spring forces acting on piston 44. Thus when chambers 50- and 60 are both connected to the outlet 16 the wobble plate will be moved toward minimum or no stroke position. When chamber 60 is connected to the inlet 14 the combined fluid pressure and spring forces acting on piston 44 are suflicient to move the wobble plate 30' toward maximum pumping stroke position. An adjustable abutment 66 in chamber 60 is disposed to engage piston 46 at a predetermined rotation of wobble plate 30 to determine the maximum pumping stroke of the plungers 24.

Valve device 64 includes a cylinder 68 formed in the end wall 12 of the pump housing, a valve block 70 is positioned in cylinder 68 and is formed in longitudinal bore 72 intersected by a pair of transverse bores 74 and 76. Block 70 is adjustably positioned in cylinder 68 by means of adjustment nut 78 to place the bores 74 and 76 in respective registration with conduits '62 and 80. Conduit 80 is connected to outlet 16. Rotor 18 is formed.

with a cavity or cylinder 82 to accommodate a cup-shaped member 84 which is bolted to housing 12 in alignment with cylinder 68. A spring 86 is mounted in member 84 between perforated spring retainers 88 and 90. Retainer 88'abuts an end of member 84 and is aligned with a port 92 formed in said member to permit passage of fluid from cavity 82 into the member 84. Retainer abuts an end of a valve 94 which is reciprocably mounted in longitudinal bores 72 of valve block 70. A passage 96 conmeets the end of valve 94 with an annular groove 98 formed thereon. A second groove 100 is formed in valve 9'4 between lands 102 and 104 and is located to register with bore 74 when valve '94 is in neutral position. Spring 86 is arranged to urge valve 94 to the right as viewed in FIGURE 2 to bring groove 98 in communication with bore 74 whereby chamber 60 is brought into communication with inlet 14 through passage 96, port '92, cavity 82, passage 106, pump chamber 108 and conduits 110 and 112. In some installations pump chamber 108 is supplied With leakage fluid and need not be connected directly to the inlet in which case chamber 60 is brought into communication with fluid at pump chamber pressure. When the outlet pressure acting on valve 94 has reached a predetermined value, the force of spring 86 will be overcome and the valve will be moved to the left as viewed in FIGURE 2 to connect chamber 60 through conduit 62 and bore 74 with the outlet 16 via bores 72 and 76 and conduit 80. An auxiliary cam plate 114 having a central depending flange 1 16 disposed within the central opening of wobble plate 30 is provided with a plurality of openings 118 each of which is adapted to receive a plunger shoe 26. Cam plate 114 is urged into engagement with wobble plate 30 by means of a spring 120 acting through a thrust member .122 which is slidably. mounted on rotor extension 19. Cam plate 114 is provided to insure retraction of plungers 24, which due to their angular disposition within the rotor are normally urged towards the retracted position by centrifugal force.

Although a particular embodiment of my invention has been described, it will be understood by those skilled in the art that the objects of the invention may be attained by the use of constructions difierent in certain respects from that disclosed without departing from the underlying principles of the invention.

We claim:

1. A pump comprising a housing having first and second end walls, an inlet and an outlet in said housing, a rotor in said housing, a plurality of angularly disposed cylinders formed in said rotor, a plunger in each of said cylinders, 21 one piece wobble plate in said housing having a front face formed to engage said plungers, a pair of diametrically opposed convex trunnion members formed on the rear side of said wobble plate and extending rearwardly therefrom substantially parallel to the axis of rotation of said rotor, a pair of concave bearing members formed in said first end wall to respectively receive said trunnion members, means defining a pair of diametrically opposed chambers in said first end wall, said chambers being spaced equidistantly between said bearing members, a pair of pistons respectively mounted in said chambers and formed to directly engage said one piece wobble plate substantially opposite the circumference defining the points of engagement of said plungers with said wobble plate, means defining a cavity in said rotor symmetrically disposed about the axis of rotation of said rotor, a cylinder formed in said second end wall adapted to register with said cavity, a valve housing mounted in said cylinder and adapted to project into said cavity, a conduit connecting said valve housing to one of said chambers, a valve in said valve housing adapted to alternatively connect said conduit to said inlet and outlet, and a passage adapted to connect the other of said chambers with said outlet.

2. A pump comprising a housing having an end wall, an inlet and an outlet in said housing, a rotor in said housing, a plurality of angularly disposed cylinders formed in said rotor, a plunger in each of said cylinders, a one piece wobble plate in said housing having a front face formed to engage said plungers, a pair of diametrically opposed convex trunnion members formed on the rear side of said wobble plate and extending rearwardly therefrom substantially parallel to the axis of rotation of said rotor, a pair of pillow blocks mounted in said end wall of said housing to receive said trunnions, at least one of said pillow blocks having two trunnion engaged bearing surfaces at substantially a right angle, means defining a pair of diametrically opposed chambers in said end wall, said chambers being spaced equidistantly between said pillow blocks, a pair of pistons respectively mounted in said chambers and formed to directly engage said one piece wobble plate substantially opposite the circumference defining the points of engagement of said plungers with said wobble plate, conduit means for alternatively connecting one of said chambers to said inlet and outlet and spring means in the other of said chambers urging the piston mounted therein into engagement with said wobble plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,453,538 Rauch Nov. 9, 1948 2,455,062 Ifield Nov. 30, 1948 2,484,337 Ferris Oct. 11, 1949 2,502,546 Adams Apr. 4, 1950 2,513,758 Talbot July 4, 1950 2,543,624 Gabriel Feb. 27, 1951 2,554,047 Moon May 22, 1951 2,601,830 Berlyn et a1 July 1, 1952 2,604,048 Wahlmark July 22, 1952 2,661,701 Ferris Dec. 8, 1953 2,749,844 Weisenbach et a1 June 12, 1956 2,826,922 Wiggermann Mar. 18, 1958 2,845,876 Keel Aug. 5, 1958 FOREIGN PATENTS 580,177 Great Britain Aug. 29, 1946