US3486454A

US3486454A - Piston pump with remote control of displacement

Info

Publication number: US3486454A
Application number: US721705A
Authority: US
Inventors: John Tuzson
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp; Hughes Tool Co
Priority date: 1968-04-16
Filing date: 1968-04-16
Publication date: 1969-12-30
Anticipated expiration: 1986-12-30
Also published as: GB1259623A; DE1918406A1; DE1918406B2; FR2006264A1; JPS4942083B1

Description

Dec. 30, 1969 J. TUZSON 3,486,454

PISTON PUMP WITH REMOTE CONTROL OF DISPLACEMENT Filed April 16, 1968 61 2 Sheets-Sheet 1 1 ezz/0r rfofizz 7295012 I Dec. 30, 1969 J. TUZSON 3,486,454

PISTON PUMP WITH REMOTE CONTROL OF DISPLACEMENT Filed April 16, 1968 J 2 Sheets-Sheet 2 tfofizz ij 02L f2: 1

outer periphery, whereby,

United States Patent US. Cl. 103-38 Claims ABSTRACT OF THE DISCLOSURE A hydraulic apparatus comprises a piston pump provided with upper and lower swashplate parts. The upper swashplate part is connected to a drive shaft in a manner such as to be capable of rocking in all directions. An electric motor serves to drive the shaft which has a ratchet mounted thereover and is fixed to the lower swashplate part which carries a one way clutch on its when the electric motor is reversed, an escapement serves to rotate the upper swashplate part which changes its angle with respect to the shaft thereby varying the displacement of the hydraulic apparatus.

BACKGROUND OF THE INVENTION Field of the invention This invention resides in the field of positive displacement pumps, and more particularly to a pump of this type in which means are provided for varying the angle of the swashplate for varying the displacement.

Description of the prior art The most pertinent art appears to be Patent No. 3,139,037 by T. Budzich, which comprises a positive displacement pump having a cam plate resting against a thrust bearing and may be rotated by a lever thereby varying the displacement. A modified form of this invention shows two cam plates in cooperative relationship, each provided with a handle for rotatable movement for varying the displacement. In the present invention there is an important distinction and improvement thereover in that by reversing the motor a lower swashplate part, operably associated with an upper swashplate part, is rotated which thereby varies the displacement. Because of this important distinction, it is apparent that the displacement of the pump can be varied from a remote position which may be desirable under certain conditions such as its application in a hydraulically powered deep oil well pump.

SUMMARY OF THE INVENTION The preferred embodiment of this invention comprises a cylinder block provided with cylindrical bores and having operable therein axially disposed pistons which are operably associated with a two part swashplate, one part, the upper swashplate part, is connected to a shaft in a manner such as to be capable of rocking in all directions and carries slippers engaging spherical heads of the pistons. The other swashplate part, or lower swashplate part, has a ratchet fixed thereto and carries a one way clutch on its outer periphery whereby when the electric motor is reversed an escapement serves to rotate the lower swashplate part which changes its angle with respect to the shaft, thereby varying the displacement of the pump.

This invention consists of the novel constructions, arrangements and devices to be hereinafter more fully described and claimed for carrying out the novel features Patented Dec. 30, 1969 "ice of the invention as will be apparent from the following description of a preferred form of this invention, illustrated with reference to the accompanying drawings, wherein:

FIGURE 1 is a vertical cross sectional view through an axial piston pump according to this invention and showing a dual swashplate comprising top and bottom cam plate parts;

FIGURE 2 is a fragmentary view, of an oil well as an illustration in which the pump (block diagram) may be used, identified by the line 1-1, FIGURE 1, also shown is an electric motor and switch;

FIGURE 3 is a cross section view in toto, taken through the pump on line 33, FIGURE 1; and

FIGURE 4 is a cross section view taken on line 4-4, FIGURE 1.

Referring to the drawings the piston pump is indicated by the numeral 10 having a housing comprising four

sections

11, 12, 13 and 14.

The housing section 13 is in the form of a cylinder block that has cylinder bores 15 with pistons 16 operable therein, provided with bores 17 and ports 18 in fluid communication within the housing section 11. Check valves 19 are carried in the bores 17 comprising balls 20 acting on the ports 18. Springs 21 are biased between the balls 20 and stops 22. The pistons 16 are provided with spherical heads 23 engaging slippers 24. Return springs 25 are seated in annular grooves 26 disposed around the cylinder bores 15 and are biased against annular rings 27 carried by the pistons 16 thereby urging the slippers 24 against a face 28 of an upper swashplate part 29, which is in face to face engagement with a lower swashplate part 30.

The upper swashplate part 29 has a bore 31 centrally therethrough provided with four grooves 32 therethrough in matching engagement with four arcuate faced splines 33 which are homogeneous with a hub 34 which is keyed to a drive shaft 35. This arrangement permits rocking of the upper swashplate part 29 with respect to the drive shaft 35, although locked to the drive shaft 35.

Two of the arcuate faced splines 33 are provided with tolerances regarding width with respect to their matching grooves 32 and the other two arcuate faced splines 33 are provided with tolerances at their outer periphery with regard to their respective matching grooves '32; These tolerances are for the purpose of preventing locking of the lower swashplate part 29 when rocking occurs in a certain given direction, such as between the arcuate faced splines 33.

The shaft 35 is supported at one end by a self-centering bearing 36 in the housing section 13 and in addition is supported by a bearing 37 mounted in the outer face 38 of the housing section 11. The lower swashplate part 30 is in engagement with the upper swashplate part 29 and is supported by a thrust bearing 39 which is supported in the housing section 11.

A wrap-around one way spring clutch 40 mounted around the outer periphery of the lower swashplate part 30 is connected to the housing section 11 by means of an anchor 41.

A compound ratchet 4'2 is keyed to the drive shaft 35 comprising a first ratchet part 43 and a second ratchet part 44 having teeth inclined in opposite directions. First and

second pawls

45 and 46 are pivotally mounted on the outer face of the lower swashplate 30 and are operably engageable with the teeth of the first and

second ratchet parts

43 and 44 respectively. A ratchet pawl spring 47 suitably mounted is biased against the first pawl 45 thereby urging it into engagement with the teeth of the first ratchet part 43. The compound ratchet 42 and its associated components may be termed an escapement.

Referring back to the cylinder bores check valves 48 are provided for cylinder ports 49, one each, communicable with, one each, of the cylinder bores 15 and also, one each is communicable with, one each, of pas sages 50 in communication with a discharge port 51 in the housing section 14. An intake port 52 is disposed in the housing section 12.

Referring now to FIGURE 2 which shows the piston pump 10 in block form, disposed in an oil well 53 shown fragmentary which is driven by a reversible electric motor 54 having electrical lines 55 connected to an 011 and on switch 56 having electrical lines 57 connected to a source of power not shown.

A discharge conduit 58 provided with a pressure gauge 59 is connected to the discharge port 51.

OPERATION When the pump is operating, the first pawl 45 is in engagement with the first ratchet part 43 and the wraparound spring clutch 40 is disengaged from the outer periphery of the lower swashplate part 29, thereby causing both upper and

lower swashplate parts

30 and 29 to rotate with the drive shaft which thus provides fluid displacement of the pump in volume predicated on the relative position of the upper swashplate part 30 to the lower swashplate part 29.

If the upper swashplate part 30 is in a position for maximum displacement and it is desired to reduce the displacement, the oil and on switch 56 is operated to reverse the reversible electric motor 54 which causes the first pawl 45 to disengage from the first ratchet 43 and simultaneously causes the second pawl 46 to engage the second ratchet part 44 thus permitting stepwise rotation of upper swashplate part 30 with respect to lower swashplate part 29, which is immobilized by the engagement of the one way wrap-around spring clutch 40. Relative rotation of upper 30 and lower 29 swashplate parts reduces the angle of inclination of the swashplate assembly and reduces the displacement of the piston 16. The extent to which the escapement is rotated determines the displacement of the pump. When the rotation of the compound ratchet 42 reaches the point where minimum displacement of the pump and if continued maximum dispacement is achieved, further movement of the compound ratchet 42 increases the displacement of the pump and if continued maximum displacement is reached, after which displacement falls 01f again.

As mentioned heretofore one of the important features of this invention is the ability of the operator to control the displacement of the pump remotely therefrom such as its use in oil wells.

As is apparent, the second ratchet part 44 moves one tooth at a time on reversing the motor by means of the off and on switch 56. The motor may be reversed and stopped and repeated until the desired displacement is acquired.

I claim:

1. A piston pump comprising in combination:

(A) a housing,

(a) a cylinder block as part of said housing provided with cylinder bores therein,

(b) pistons reciprocally operable in said cylinder bores,

(c) intakes and discharge ports in said housing,

(B) a drive shaft extending into said housing and supported therein,

(C) swashplate means comprising upper and lower parts, said upper swashplate part being connected to said drive shaft in a manner such as to be capable of rocking in all directions and said lower swashplate part being operably engaged with said pistons,

(a) a thrust bearing mounted in said housing against which the said lower swashplate part rests,

an escapement means connected to said drive shaft and operably connected with said lower swashplate part, and

a wrap-around one way spring clutch anchored at one end to the said housing and engageable with the outer periphery of said lower swashplate.

2. A piston pump according to claim 1 wherein slipper means is operably mounted between said pistons and the inner face of the said upper swashplate part.

3. A piston pump according to claim 1 wherein the said pistons with bores therein are provided with check valves engaging ports at their upper ends, and wherein the lower ends of the said cylindrical bores are provided with ports which are engaged by check valves.

4. A piston pump according to claim 1 wherein the said housing comprises four sections.

5. A piston pump according to claim 1 wherein the said drive shaft is driven by an electric motor connected to a power source.

References Cited UNITED STATES PATENTS 1,908,612 5/1933 Johnson 103-162 2,900,839 8/1959 Mackintosh 103-38 X 2,919,591 l/1960 Watson l0338 X 3,010,339 11/1961 Brock 10338 X 3,139,037 6/1964 Budzich 103173 FOREIGN PATENTS 675,754 7/ 1952 Great Britain.

WILLIAM L. FREEH, Primary Examiner US. Cl. X.R.