US2129886A - Pump - Google Patents

Description

A. J. sYRoV-Y Sept. 13. 1938.

PUMP

Filed July 5, 1935 2 shuts-sheet 1 In @A .m Q d I w Sept. 13, 1938.

A. J. SYROVY PUMP Filed July 5, 1935 2 Sheets-Sheet 2 I\NVENTOR. flzzyzzsiz'zz J7 Syra r BY ATTO 151 5 Patented Sept. 13, 1938 UNlTED STATES PUMP Augustin .l. Syrovy', Detroit, Mich, 'assignor to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application July 5, 1935, Serial No. 29,788

1 Claim.

This invention relates to pumps and refers more particularly to improvements in pumps adapted to produce and maintain pressure on a fluid, such as oil, suitable for use in systems of a motor vehicle transmission control although my improvements are adaptable to a wide variety of applications. Asillustrative of one system of transmission control to which my pump is adaptable, reference is made to the co-pending applilil cations Serial No. 724,434 filed May 7, 1934 and Serial No. 752,948 filed November 14, 1934.

One object of my invention is to provide an improved pump which will efiiciently and quickly m provide a relatively high pressure of the oil, such pressure is attained.

Further objects of my invention are to provide a pump having improved characteristics of fiuid seal; a pump capable of long and continuous service such as is required in motor vehicle usage, without undue heat generation, noise, wear or failure through other causes.

Another object of my invention is to provide an improved pump having relatively rotating parts for self adjustment whereby wear is minimized, fluid seal is promoted, and manufacture and assembly of the pump parts is facilitated.

A further object of my invention is to provide an improved control of the pressure of the fluid developed by the pump; minimize noise incident to operation of the pump and particularly during the porting events in the cycle of pumping operation; and to provide a compact and novel arrangement of pressure accumulator and control of pressure delivery.

In carrying out the objects of my invention, I preferably employ a pump of the wabble plate type adapted to vary its inclination or level-off in response to fluid pressure delivery to automatically maintain a predetermined delivery pressure; also to minimize movement of the pump parts after the iluid has reached its predetermined desired pressure. As a feature of my invention the pump is arranged for maximum delivery to quickly build up its desired pressure, the fluid displacement by the pump then Ming quickly reduced. instead of being gradually reduced as 5D the pressure builds up to the desired maximum.

Further objects and advantages of my invenreside in the novel combination and arrange-- ment of. parts more particularly hereinafter described and claimed, reference being had to the 55 accompanying drawings illustrating several empressure being maintained preferably without requiring operation of the pump after the required (Cl. Nit-4W2) bodiments of certain features of my invention and in which:

Fig. 1 is a sectional plan view of my pump assembly taken along line |-l of Fig. 2.

Fig. 2 is a side elevational view of the pump assembly, with certain parts in cross section.

Fig. 3 is a sectional view along line33 of Fig. 1.

Fig. 4 is aside elevational view of the right hand end of the pump viewed in Fig. 1.

Fig. 5 is a detail sectional view along line 5-5 of Fig. 1.

Fig. 6 is a detail sectional view along line '6--6 of Fig. 5.

Fig. 7 is a fragmentary View of a-pump rotor and port seating element of modified form but adapted for use in the Fig. 1 assembly.

Fig. 8 is a detail sectional view along line 8-8 of Fig. '7.

Referring to the drawings the pump assembly comprises a casing structure A adapted for attachment at openings in to a suitable support such as the transmission structure of a motor vehicle (not shown). The casing receives the pump drive shaft I l journalled at one end in a bearing l2 carried by the casing and supported at the other end in a cylindrical ported base portion l3 of the casing in a manner more particularlyhereinafter set forth.

The shaft H has a drive gear I l suitably fixed thereto and adapted to receive power from a suit: able source such as a drive shaft of the transmission (not shown); Base 13 has inlet and outlet passages l5 and i6 respectively for the fluid, such as oil, admitted to the pump and delivered therefrom under pressure. The inlet i5 is exposed to a suitable reservoir of oil which has a level above this passage or in suitable communication with a reservoir of oil as may be desired.

Tightly pressed into the cylindrical opening ll of base 93 is a cylindrical port seat body or ring it formed of bronze or other suitable material journalling the adjacent end of shaft 5 I, this body having inlet and outlet passages l9 and 20 communicating radially at one end with passages l5 and it respectively. The other ends of the passages l and 20 form circumferentially spaced arcuate inlet and outlet ports 2i and 22 having their adjacent ends terminating in relatively narrow pairs of grooves 23, 24 and 23 24 The grooves. of each pair taper toward each other (see Fig. 6) and are brought closely together preferably sumciently so that they are momentarily brought into communication with each other by the inlet and outlet ports of the pumping cylinders as will presently be apparent.

Surrounding shaft II for rotation therewith is the pump rotor B preferably of steel or other suitable material. This body is keyed or otherwise fixed at 25 to shaft II and preferably has a. clearance with the shaft sufl'lcientto permit the body to slightly shift its position so that the surface at the cylinder head end 26, which is rotatably slidably engaged with the adjacent ported surface of body l8, may accommodate itself to the latter surface. More specifically, in the form illustrated, the body B has a generally cylindrical opening 21 accommodating the shaft II, this opening tapering from the keyed end of body B, which fits the shaft, to the opposite end. The body B may thus rock 'about its inner end at key 25 for relatively free movement at the surface of ports 2i, 22 whereby the bodies l8 and B are relatively self-adjustable to provide and maintain a good fit preventing leakage, wear, and binding of the parts. Furthermore, when the pump is run-in, a self-lapping action takes place at the rubbing surfaces between bodies i8 and B. The body B has a plurality of circumferentially spaced cylinders 28 opening inwardly toward a wabble or swash plate C, the cylinder head portion 26 having ports 29 for each cylinder. These ports, as body B rotates, successively register with ports 2| and 22 so that they are alternately intake and discharge ports.

Each cylinder 28 slidably receives a piston 30 urged inwardly by a spring 3| into contact with plate C, the inner rounded end 32 of each piston slidably engaging the outer ring 33 of the plate C. This ring is supported by bearing 34 carried by a swinging arm 35 pivotally supported at 36 from casing A. At the other side of shaft II the arm 35 is pivotally connected at 31 to an outwardly extending link 38 pivoted at 39 to a lever 40. The lever is pivotally supported at 4! to a projection 42 of the outer'closed end of the accumulator cylinder D.

Slidable in cylinder D is a piston 43 urged inwardly by a heavy spring 44, the piston having an outwardly extending rod 45 adapted to engage lever 40 to swing the latter to the dotted position in Fig. l for levelling-off the plate C and minimizing or eliminating reciprocation of pistons 30. Piston 43 moves against spring 44 in response to a predetermined desired pressure of'the fluid delivered by the pump, the delivery passage 20 being in communication through passage 48 with, the accumulator cylinder D at the discharge 41. The oil under pressure is led to a suitable point of usage from cylinder D through the casing passage 48. A cover plate 49 is -secured by fasteners II to the inner end of the casing A and closes oi! the inner end of cylinder D and the chamber of auxiliary pump E where such pump is employed. 7

The pump E comprises a driving gear II and driven gear 52 together with oil inlet and outlets 53, respectively, and is-adapted to supply oil under a relatively low pressure to lubricate parts of the engine or transmission (not shown).

As the shaft l I drives rotor B, with plate C positioned asin Fig. 1 for maximum piston stroke.

approximately half of pistons 20 are moving inwardly drawing in oil thro'ugh port 2| and ports 29 associated therewith, while the remaining pis tons are discharging oil under pressure through their associated ports 28 andoutlet port 22 for passage to cylinder D at 41. As eachv port 20 moves across the face of body ll between ports 22 and 2i thereof to cut-oflpressure deliveryand piston moves to the outward limit of its travel is not abruptly cut-off but such action takes place very gradually as the port 28 progressively moves to include groove 24. Since groove 24' narrows toward groove 22, the cut-off is further accentuated in a gradual manner, the port 28 momentarily registering with groove 23'- just prior to passage beyo'nd groove 24'. In this manner I have found that a very quiet and efllcient pumping action is obtained, free from hydraulic "hammer and other noises incident to pumping. In passing from intake to pressure delivery between parts 2 i and 22, I preferably provide similar grooves 22, 24 for a similar action with each cylinder port 29 as will be readily understood.

When the pump is initially operated, the pressure of the oil delivered at 41 to cylinder D rapidly builds up to the desired amount, say 500 pounds per square inch for example, and as this pressure is nearly reached (determined by the value of spring 44) the piston 43 moves outwardly increasing the capacity of cylinder D and moving rod 45 into contact with lever 40. Continued movement swings lever 40 and thereby swings plate C about its pivot 36 into a position approximately transverse to the axis of shaft l I. This levelling-oi! of plate C progressively lessens the stroke of pistons 20 until they finally are substantially motionless so far as reciprocation is concerned, assuming of course that oil under pressure is not being relieved from the delivery system. Any minor leakages which may be present in the delivery system will require only a small movement of the pistons to maintain the maximum desired oil pressure in the cylinder D.

By normally spacing rod 45 from lever 40, there is provided a lost motion connection between the wabble plate structure and the control therefor and the plate C does not start to level-off as soon as piston 43 begins to move accompanied by further compression of spring 44 so that the maximum stroke of the pistons 22 is realized longer than otherwise. In this manner the maximum.

pump pressure is rapidly attained. The plate C is, of course, free to assume any position intermediate its inclined position of Fig. 1 and its fully levelled-oi! position under control of rod 45 according to the demand placed on the delivery system. It will therefore be understood that while the wabble plate C is normally swingable about its pivotal mounting in response to actuation of the control therefor, including the rod 45, this plate is free from such movement and is not actuated when the control member is operated in opposite directions respectively by the fluid pressure within the cylinder D and the spring 44 in taking up and establishingthe lost motion connection between the plate 40 and the control therefor.

It should be noted that, in levelling-off, the plate 0 moves the pistons 2| outwardly to the outer limit of their travel. This is desirable in minimizing air trapping between cylinder head 20 and'the outer ends of cylinders 28.

The accumulator cylinder D stores oil under 1 pressure so that when oil is delivered under preslater spring 44 also asthe load medium control-' 76 aiaaeso ling the regulation of the stroke oi pistons 3| and consequently controlling regulation of the pump delivery.

Referring now to the modified form of my m vention shown in Fig. 7, I have illustrated only a portion of the pump assembly of Fig. 1, iii/being understood that my Fig. 7- structure may be readily used with the Fig. 1 assembly as will be readily understood. Similar parts are designated. by similar reference characters.

' In Fig. 7 the body 8' does not have a clearance with shaft H, the relative self-adjusting movement between the face of cylinder head 26' having ports 20' and the face of the non-rotating member 55 having inlet and outlet ports 2i,'22 resulting in a self-lapping and sealing action as aforesaid. Thus, the casing part if tightly receives the cylindrical body I! formed with intake and delivery passages 19' and 20 but the adjustable member 55 is now interposed between bodies I. and B.

The member 55 is formed with a spherical convex outer face 56 fltting a like concave spherical face of body I! so that relative adjustment may readily take place between the relatively rotating faces of body B and member I5. In order to permit the desired small amount of relative movement between body it and member 55 and at the same time to prevent member 65 from rotating with body B, a pin 51 is passed through body II and enters member I! (circumferentially spaced from passages l9 and 20') in an opening 58 thereof having a clearance with pin 51.

Ina fluid pump, a supporting structure, a drive ,,shaft Journaled in said supporting structure, a

direction of said shaft, a wabble plate control piston in said cylinder, means for conducting fluid under pressure from said fluid conducting means to said cylinder for operating said control piston, a spring, acting to oppose movement, of said control piston by said fluid pressure, a rod secured at one end thereof to said piston and extending through said spring, a lever supported for pivotal movement and lying beyond but in the path of movement of the other end of said rod and constituting a lost motion connection between said control piston and said wabble plate, and a link connecting said lever and wabble plate for swinging said wabble plate in response ,to

movement by said control piston, said lost mo-" tion connection accommodating substantial fluid pressure movement ofsaid piston prior to swinging movementof said wabble plate in responseto fluid pressure in said cylinder.

, a AUGUSTIN J. SYROVY.

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