US3035526A

US3035526A - Variable volume pump

Info

Publication number: US3035526A
Application number: US685133A
Authority: US
Inventors: Weberg Carroll
Original assignee: HAZEL B PHILLIPS; JOHN H RUTLEDGE
Current assignee: HAZEL B PHILLIPS; JOHN H RUTLEDGE
Priority date: 1957-09-20
Filing date: 1957-09-20
Publication date: 1962-05-22
Anticipated expiration: 1979-05-22

Description

y 1962 o. G. PHILLIPS 3,035,526

VARIABLE VOLUME PUMP Filed Sept. 20, 1957 4 Sheets-Sheet 1 /4//orm 4 Sheets-Sheet 2 O. G. PHILLIPS VARIABLE VOLUME PUMP May 22, 1962 Filed Sept. 20, 1957 1962 o. G. PHILLIPS 3,035,526

VARIABLE VOLUME PUMP Filed Sept. 20, 1957 4 Sheets-Sheet 3 x a A ////A INVENTOR.

BY CARROLL WEBEEG,

E EC 70/?- Al /owe y 1962 o. G. PHILLIPS 3,035,526

I VARIABLE VOLUME PUMP Filed Sept. 20, 1957 4 Sheets-$heet 4 INVEN TOR. 0/1/ 6. PH/LL/RS, 5y CAR/POLL WEBERG} Y XECIJTOR.

ilnited States Patent fire 3,035,526 Patented May 22, 1962 Calif.

Filed Sept. 20, 1957, Ser. No. 685,133 3 Claims. (Cl. 103-161) The invention relates to variable volume pumps in general and relates in particular to a variable volume pump which is of special utility in hydraulic transmissions of the type having a variable volume pump which drives a hydraulically actuated motor.

it is an object of the invention to provide a variable volume pump which is of simple construction, yet positive in its operation from zero to maximum fluid delivery, and operates smoothly due to the absence of fluid hammer which results from uneven distribution of liquid in the pump chambers and from existence of unfilled spaces in the pumping cylinders due to improper feeding of the hydraulic liquid thereto.

It is an object of the invention to provide a hydraulic pump having a plurality of cylinders arranged in a circle around an axis, these cylinders having therein pistons which are connected to a spider adapted to be shifted from a position on the axis of rotation of the cylinders, to an offset position whereby relative reciprocation of the pistons in the cylinders occurs as the cylinders are rotated around said axis, there being also centrifugal means for pumping the hydraulic liquid positively into the cylinders as the pistons pass through their intake strokes in the cylinders.

it is a further object of the invention to provide a 'variable volume pump of the character described in the preceding paragraph wherein the cylinders are contm'ned in cylindrical bodies arranged with their axes parallel to the axis around which the cylinders revolve, these cylindrical bodies being adapted to oscillate on their own axes as the pumping action takes place.

A further object of the invention is to provide a variable volume purrrp of the character described in the foregoing wherein the oscillation of the cylindrical bodies effects opening and closing of inlet valves associated with the cylinders.

A further object of the invention is to provide a variable volume pump having a rotatable body containing a plurality of circularly arranged cylinders and also containing a cylindrical pump which rotates with and acts during the rotation of the rotatable body to deliver the hydraulic fluid under pressure to the cylinders.

It is a further object of the invention to provide a variable volume pumping device having simple control means for shifting the crank element of the pumping device between centralized and eccentric positions, enabling the volumetric delivery of the pump to be readily regulated between zero and maximum values. When this variable volume pump is connected to a positive displacement motor in a hydraulic transmission, the transmission will be in idling condition when the crank element is in its centralized position, for the reason that at such time the pump will deliver no hydraulic fluid and therefore the motor will not be driven. As the crank element of the pump is gradually shifted from centralized to full eccentric position, the pumping of hydraulic fluid to the motor will be started and proportionately increased, giving a gradual change in speed of the output shaft of the motor, Without slippage of fluid and with minimum power loss in the transmission.

It is an object of the invention to provide an automatic control for the variable volume pump which responds to pressure variations in the inlet and outlet passages associated with the pump cylinders, it being contemplated also that the automatic control may be supplanted by a manually operated control.

A further object of the invention is to provide in this variable volume pump a simple and effective means for driving the cylinder-carrying rotor and also the crank spider at the same speed of rotation around their respectrve axes.

Further objects and values of the invention may be brought out in the following part of the specification wherein some small details have been explained for the purpose of competence of disclosure, without intending, however, to limit the scope of the invention which is set forth in the appended claims.

Referring to the accompanying drawings which are for illustrative purposes only:

FIG. 1 is a sectional view of a preferred embodiment of the invention;

FIG. 2 is a cross-sectional View On a reduced scale taken substantially as indicated by the line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken as indicated by the line 3-3 of FIG. 1;

PEG. 4 is a cross-sectional view taken as indicated by the line 44 of FIG. 1

FIG. 5 is a fragmentary sectional view taken as indicated by the line 5-5 of FIG. 2.

As shown in FIGS. 1 and 2, the variable volume pump includes a shell 16 having a hub 11, a radial wall 12 which extends from the inner end of the hub 11, and the cylindrical wall 1-3 which cooperates with the radial wall 12 an a radial end wall 14 to define a cylindrical chamber 15. As shown in FIG. 1, a chambered cover 16 is arranged over the outer space of the end wall 14, and bolts 17 are employed to clamp the flanges of the

members

14 and 16 against the flange 18 of the shell 10. The hub 11 contains a bearing 19 which supports therein a drive shaft 20 having on its inner end a chambered head 21 which is positioned within the inner end of the hub portion 11.

The end wall 14 has therein an annular channel 22 facing the chamber 15, concentric to the shaft 20 and having an inner cylindrical wall 23 which supports the inner race of a ball bearing 24. The chamber 15 is essentially filled by a rotor 25 which is of cylindrical form and is adapted to be driven by the shaft 20 so that it will rotate within the chamber 15. The rotor 25 has a front face 26 which confronts the radial wall 12 of the shell 10, a cylindrical face 27 which confronts the cylindrical wall 13 of the shell -10 and a rear face 28 which confronts the end wall 14. The rotor 25 has a forwardly extending hub 29 which fits upon the head 21 of the shaft 20 and is adapted to be driven through a key 39. The end of the rotor 25 opposite from the hub 29 is supported by the ball bearing 24. For this purpose a flanged ring 31, secured to the rightward face of the rotor 25 by machine screws 32 is provided, this ring 31 having a cylindrical wall 33 which engages the outer race of the bearing 24. a

The rotor 25 has therein a plurality of cylindrical openings 34 which are arranged in a circle concentric to the axis of rotation of the rotor 25 and on individual axes which are parallel to the axis of rotation of the rotor 25. These openings 34 extend into the rotor 25 from the inner (rightward) face thereof and support therein cylindrical bodies or parts 35 which are assembled in the openings 34 prior to the securing of the ring 31 on the rotor 25. Centrally within the rotor 25 there is a crank chamber 36 having radially extending portions 37 which communicate with the cylindrical openings 34 to permit connection of crank and piston parts which will be later described. Also, the rotor has in its periphery openings 38 which connect the outer face of the rotor 25 with the outer portions of the cylindrical openings 34. Each of the bodies has therein a diametral cylinder 39 extending from one face to the other thereof and has in the inner end a piston guide sleeve 40. The sleeves 40 are shown as extending about half way through the respective diametral cylinders 39. In each cylinder there is a piston 41. Wrist pins 42 at the inner ends of the pistons 41, connect them to a spider 43 which is rotatable upon a crank pin or member 44 adapted to be shifted from a centralized position on the axis of rotation of the rotor 25 to an eccentric position. The crank pin 44 has a portion 45 which projects through the opening 46 in the central portion of the end wall 14 and is secured to a lever 47 which is supported on a-pin 48 arranged on an axis parallel to the axis of rotation of the rotor 25. This lever 47 swings in a plane perpendicular to the axis of the rotor 25 and is positioned adjacent the outer face of the end wall 14 and within the chamber of the cover 16. The lever 47 is adapted to be swung between two extreme positions. The first of these positions is one wherein the crank pin 44 is on dead center. That is to say, it is positioned on the axis of rotation of the rotor 25. The second extreme position of the lever 47 is that wherein the crank pin 44 is offset to maximum extent from the axis of the rotor 25, as shown in FIG. 1.

The shaft 20, through the key 30 and the rotor hub 29 is adapted to drive the rotor 25. A flexible connection 50 is arranged to connect the head 21 of the shaft 20 with a tubular extension 51 forming a part of the spider 43, for driving the spider 43 in timed relation to the rotation of the rotor 25. The flexible connection 50 is shown as a short shaft 52 having its leftward end lying within the head 21 of the shaft 20 and being connected to the head 21 by radially projecting rollers 54 engaging longitudinal channels 53 in the head 21. The opposite (rightward) end of the shaft 52 has thereon diametrally opposed rollers 54 which engage longitudinal channels 55 in the inner face of the tubular extension 51 of the spider 43. The spider 43 therefore, has the same angular speed of rotation as the rotor 25. A spring-pressed member 50' urges the shaft 52 rightwardly into engagement with a centralizing socket bearing member 51 carried by the crank pin 44. When the crank pin 44 is centralized on the axis AA of the rotor 25, the wrist pins 42 are disposed in a circle concentric to the rotor axis AA and there will be no reciprocating movement of the pistons 41 in the cylinders 39 upon rotation of the rotor 25 and the spider 43 at this time, but when the crank pin 44 is shifted into offset position, each piston 41 will move through one cycle of reciprocation during each rotation of the rotor 25, and the amount of reciprocatory movement of the pistons in the cylinders, and likewise the volumetric displacement of the pump, will be proportionate to the amount of displacement of the crank pin 44 from dead center.

For example, the crank pin 44 is, in F165. 1 and 2,

shown offset upwardly to maximum extent from the rotor axis AA. The uppermost piston 41, designated specifically by the'numeral 41a, is in fully advanced (raised) position in its cylinder 39, and the diametrally opposed piston 41, designated specifically by the numeral 41d, is in fully retracted position. The piston 41a is ready to start its intake stroke and the piston 41d is at the end of its intake stroke and ready to start its discharge stroke. Itwill be perceived that the wrist pins 42, specifically identified as 42a and 42d, which connect the pistons 41a and 41d to the spider 43 are in alignment, or on the center line c-c which passes through the center of the crank pin 44 and the rotor axis AA, but that the wrist pin 42,. specifically indicated by the numeral 42b, which connects the piston 41b to the spider 43 is offset upwardly from a diametral line bb which passes through the rotor axis AA and through the centers 0 of the 4 cylindrical bodies 35 which contain the pistons 41b and 41s. The wrist pin specifically indicated by the numeral 4212, being displaced upwardly from the center line bb swings the inner end of the piston 4112 laterally so that the piston 41b is in a tangential or angular position relative to the center line 11-]; instead of radial to the center of the rotor 25, and the cylindrical body 35 which contains the piston 41b is rocked in counterclockwise direction around its center 0, and at the same time the piston 41d is retracted inwardly. The piston 410 is further retracted and the cylindrical body 35 which contains it is likewise rocked, but to a lesser extent, in counterclockwise direction around its axis, but the piston 41d is aligned with the center line c-c. As rotation of the rotor 25 carries a piston, such as the piston 4 1a, from the position in which it is shown in the upper part of FIG. 2 through the positions of the pistons 41b and-41c to the position of the piston 41d, the piston 41a will be gradually retracted and rocked in counterclockwise direction until the position indicated by the piston 410 is reached, and as the piston then moves from the position of the piston 410 to the position of the piston 41d it will be retracted to' its fullest extent and brought again into alignment with the center line cc. As further rotation of the rotor 25 can'ies the piston from the position of the piston41d through the positions of the pistons 41c and 41 back to the original position of the piston 41a, it will be rocked in clockwise direction relative to the line bb and will be gradually advanced outwardly so as to discharge fluid from the cylinder in which it is movable. The rocking of a piston as it revolves with the rotor around the axis AA effects a rocking of the cylindrical body 35 in which it is supported. The cylindrical wall 13 of the shell 10 has therein an outlet or discharge passage 58 which extends along the inner face of the cylindrical wall '13 from a point 59, FIG. 2, to a point 60. When a discharge opening 38 moves in counterclockwise direction from the position indicated at 38d in FIG. 2 it will be in open communication with the discharge passage 58 and will remain in communication with the discharge passage 53 as it moves through the positions 38s and 38] to the starting position of the outlet opening 38 shown in the upper part of FIG. 2. Therefore, as the pistons 41 are moved outwardly in their respective cylinders, the contents of the cylinders will be displaced positively into the discharge passage 58 and then through the discharge opening 61 of the shell 10.

It is a purpose of the rocking of the cylindrical bodies 35 to open inlet valve means connectedto the cylinders 39, for admission of fluid, during the times the cylinders 39 move in counterclockwise direction from the starting position indicated by the. piston 41a to the end of the intake cycle corresponding to the position of the piston 41d, and to close the intake valve means as the cylinders are revolved through the discharge portion of their movement, namely, from the position indicated by the piston 41d and in counterclockwise direction to the position indicated by the piston 41a. The intake valves for the cylinders 39 are identical, therefore, the detailed description of one of them will constitute a disclosure of all. From FIGS. 1 and 5 it will be perceived that each cylindrical body 35 has a portion 63 extending leftwardly from the cylinder bore 39. In this extension 63 there is a port 64 having an inlet mouth 65 and having a laterally elongated outlet opening 66 communicating with the inner end of the associated cylinder 39 adjacent the end of a piston guide sleeve 40. The port 64 is referred to as the rocking port for the reason that it rocks with the cylindrical body 35 in which it is situated, through the various angular positions in which it is shown in FIGS. 2 and 3, so that its inlet port 64 will be rocked into and out of communication with a non-rocking port 67 disposed at the outer end of a supercharger passage 68 Which is formed in the leftward portion of the rotor 25.

The number of supercharger vanes or passages 68 corresponds to the number of cylinders in the rotor. In the present instance there are six of the supercharger passages and they each are arranged so that their inner ends communicate with an annular fluid inlet chamber or fluid space 69 formed between the hub 29 of the rotor 25 and the hollow hub portion 1 1 of the shell 10, there being a fluid inlet 70 in the shell leading into chamber 69. In the radial wall 12 of the shell 10 there is an annular groove 71 which communicates with the outer ends of all of the outwardly extending supercharger passages 65 which are formed in the rotor so as to provide a centrifugal pump for carrying the hydraulic fluid under pressure to the cylinders to produce the effect of forcing the hydraulic fluid into the cylinders as the pistons which operate therein are retracted. The pump, therefore, during the fluid intake strokes of the pistons, operates without suction in the ordinary sense, but instead the hydraulic fluid under pressure from the supercharger or centrifugal pumping means of the device enters the cylinders under pressure and instead of being pulled in by the action of the pistons 41, the fluid applies pressure to the pistons assisting in moving them inwardly during their intake strokes. It will be perceived that each piston operates in a guide sleeve 40 of smaller internal diameter than the cylinder 39, the result being that there is an annular space 73 around the exterior of each extended piston 41, the inner of which annular space 73 communicates with a fluid inlet port 64. Therefore, when a piston 41 is extended as shown at the top of FIG. 2, the hydraulic fluid entering under pressure through the port 64 may flow outwardly in the annular space 73 to the other end of the cylinder 39 and will progressively fill the cylinder 39 from the outer end thereof inwardly as the piston is retracted through the positions indicated by the pistons 41b, 41c and 41d of FIG. 2.

Manually operable and also automatic means are provided for swinging the lever 47 between centralized and offset positions. As shown in FIGS. 1 and 4, the lever 47 has a radial slide or movable wall 74, defined by parallel flanges 75 and being adapted to receive a square slide block or cross-head 76 having therein a circular cavity 77 which receives an eccentric 78 which is fixed on the inner end of a shaft 79 which projects out through the end wall of the cover 16 and is arranged to receive on this outer end lever means whereby it may be rotated, thereby swinging the eccentric 78 around the center of the shaft 79 and displacing the block 76 laterally so that the lateral movement will be transmitted to the lever 47, causing it to swing around the axis of the supporting pin 48.

For the automatic shifting of the crank pin 44 from centralized toward eccentric or offset position a fluid expansible device 80 is provided which consists of a cylinder 81 supported in the cover 16 at a side of the lever 47, this cylinder '81 having therein a piston 82, the exposed end of which is arranged to engage the lever 47. The fluid space 83 of the cylinder 81 is connected with a source of variable fluid pressure which will act upon the piston 82 so as to cause it to force the lever 47 and the crank pin 44 supported thereby in a direction away from the centralized position in which the parts are shown in FIG. 4 toward the eccentric position thereof shown in FIG. 1. The fluid space 83 of the cylinder 81 is connected by a duct 84 with the channel 71 which communicates with the outer ends of the passages 68 of the supercharger means so that the pressure variations in the channel 71 will act against the piston 82 to eifect a shifting of the crank pin 44. For example, assuming that the engine which drives the shaft 20 is operating at idling speed and the crank pin 21 is in centralized position, increase in the engines speed to about 1,000 r.p.m. will create sufiieient pressure in the channel 71 and in the cylinder space 83 to start shifting the crank pin rightwardly from the centralized position in which it is shown in FIG. 4, and the extent to which the crank pin 44 is shifted into ofiset position will thereafter depend upon speed of rotation of the rotor 25 and the reactive pressure built up in the arcuate discharge passage 58 of the shell 10 and in the discharge opening 61.

In opposing relation to the fluid expansible device there is a fluid expansible device 86 comprising a cylinder 87 which is supported in the wall of the cover 16 and has therein a piston 88 urged into engagement with the lever 47 by a spring 89. The spring 81 provides a resilient, adjustable means for urging the crank pin 44 into neutral or centralized position. The outer end 90 of the spring 89 engages a head 91 which is carried on the inner end of an adjusting screw 92 threaded through the cylinder head 93. The fluid space 94 of the cylinder 87 is connected through a duct member 95 with the discharge opening 61 of the shell 10 in order that fluid pressure derived from the outlet of the pumping device will act in a direction to shift the crank pin 44 back toward centralized position as the reactive fluid pressure in the discharge opening 61 of the pump increases. In a preferred use of the variable volume positive displacement pump shown herein, the discharge opening 61 is connected to a fluid operated motor which is connected to the vehicle wheels in order to drive the same. The fluid pressure in the discharge opening 61 is, therefore, representative of the fluid pressure required to drive the fluid motor. During the starting and acceleration of the vehicle, the reaction of the fluid motor against the fluid pressure delivered thereto from the discharge opening 61 will eifect a proportionate increase in the fluid pressure in the discharge opening 61 and in the cylinder 87, FIG. 4. This will result in a retraction of the crank pin 44 toward centralized position and a reduction in the reciprocatory movement of the pistons 41. The reduction in the efiective crank arm connected to the pistons 41 will enable the pistons to displace the hydraulic fluid under high pressure but at reduced volume for each rotation of the rotor 25 which may then operate at higher speed.

From the foregoing explanation it will be perceived that as counterclockwise rotation of the rotor 25 carries a piston from the position of the piston 41a through the positions of the pistons 41b and 410, the cylindrical body 35 which contains the piston will be rocked in counterclockwise direction, but will be returned to a position wherein the cylinder 39 thereof will be again radial when the piston reaches the position of the piston 41d. Likewise, it will appear from a further inspection of FIG. 2 that as a piston moves in counterclockwise direction from the position of the piston 41d through the positions of the pistons 41c and 41 the cyiindrical body 35 containing the piston will be rocked in clockwise direction around the axis, 0, thereof, but as the piston moves from the position of the piston 41 to the position of the piston 41a, the cylindrical body 35 which contains the piston will be rocked back into original position wherein the piston is extended radially. Also, as a piston moves from the retracted position of the piston 41d into the positions of the pistons 41a and 41; it will be gradually moved outwardly through a discharge stroke and will reach its fully extended position when it arrives at the position of the piston 41a.

What is claimed is:

1. In a rotary pump: a rotor supported for rotation about a rotor axis and having a plurality of cylindrical openings around and spaced from said axis, said cylindrical openings having axes which are nonradial with respect to the rotor axis; cylindrical bodies rotatably disposed in said cylindrical openings; cylinders in said cylindrical bodies in crossing relation to the body axes; pistons in said cylinders, the inner ends of said pistons being faced toward said rotor axis; a crank member; a spider rotatable on said crank member, said spider being connected to the inner ends of said pistons; flexible means connecting the rotor and spider together for rotating said spider on said crank member in timed relation to the rotation of said rotor; means for moving said orank member between a position close to the rotor axis and a position displaced to a side of said rotor axis, said bodies rocking on said respective body axes as said bodies are revolved around said rotor aX-is while said crank member is in a position displaced to aside of said rotor axis; and a shell in which said rotor is operably disposed, said shell having outlet means communicating with the outer ends of said cylinders; fluid inlet passageway means in said rotor including a non-rocking port communicating with each cylindrical opening; inlet valve means, includinga rocking port in each of said cylindrical bodies movable into and out of register with the respective non-rocking ports upon the rocking of said bodies, said inlet valve means thus being opened and closed as said rocking ports move into and out of register with the respective non-rocking ports upon the rocking of said bodies as they revolve around said rotor axes, the rocking ports of said inlet valve means having fluid connections with respective cylinders, the outlets of said connections being positioned intermediate the ends of the respective cylinders, there being spaces arranged along the inner faces of said cylinders from the connection outlet toward the outer ends of said cylinders so that the fluid flows outwardly under centrifugal force from said connection outlets to fill the cylinders as said pistons move through their intake strokes.

2. A rotary pump as defined in claim 1 wherein said means for rotating said spider rotates the spider at the same angular speed as the angular speed of rotation of said rotor.

3. A rotary pump as defined in claim 1 wherein said outlet means of said shell comprises a wall forming a semicircular channel placed so as to be in communication with the outlet ends of said cylinders during the time the inlet valve means are closed.

References Cited in the file of this patent UNITED STATES PATENTS 1,778,238 Wilsey Oct. 14, 1930 2,115,121 Phillips Apr. 26, 1938 2,245,570 Centervall June 17, 1941 2,336,996 McDonough Dec. 14, 1943 2,393,128 Temple Jan. 15,1946 2,573,472 Martin Oct. 30, 1951 2,797,643 Sherman July 2, 1957