US3223047A

US3223047A - Power transmission

Info

Publication number: US3223047A
Application number: US312681A
Authority: US
Inventors: William W Toy
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1963-09-30
Filing date: 1963-09-30
Publication date: 1965-12-14
Anticipated expiration: 1982-12-14

Description

FIG.

II D Q 19 Dec. 14, 1965 w. w. TOY 3, 7

POWER TRANSMISSION Filed Sept. 50, 1963 s Sheets-Sheet 1 INVENTOR.

WILLIAM W. TOY

d' 6,314 KWXM A T TOR/VEYS Dec. 14, 1965 w. w. TOY 3,223,047

POWER TRANSMISSION Filed Sept. 30, 1963 3 Sheets-Sheet 2 H. E. Q

V REL Ll ZNVENTOR.

WILLIAM W. TOY

3| WlTTOR/VEYS Dec. 14, 1965 w. w. TOY

POWER TRANSMISSION 3 Sheets-Sheet 3 Filed Sept. 50, 1965 m h 6 M An V w a a a a a a m B I w B .W. C I a \w xV/ x M. m w u m m m m m ,INVENTOR.

WILLIAM W. TOY

ATTORNEYS United States Patent Oflice 3,223,047 l atented Dec. 14, 1965 3,223,047 POWER TRANSIVHSSION William W. Toy, Bloomfield Hills, Micl1., assignor to Sperry Rand Corporation, a corporation of Delaware Filed Sept. 30, 1963, Ser. No. 312,681 6 Claims. (Cl. 103162) This invention relates to power transmissions and particularly to high-speed pressure energy translating devices of the rotary type which are used as variable displacement pumps.

Such rotary fluid pressure energy translating devices comprise a rotatably mounted drive member, a plurality of cylinders, pistons reciprocable in the cylinders, and motion-converting means interconnecting the pistons and the drive member. An inlet and an outlet communicate successively with one of the end of each cylinder through a valve plate in contact with the cylinder, which valve plate has an inlet opening and an outlet opening. When such a device is operated as a pump by rotating the drive member, the motion-converting means changes the rotation of the drive member into reciprocating motion of the pistons to pump fluid from the inlet to the outlet.

In such devices, the valve plate is rotated to vary the displacement and, in turn, the output of the device by changing the relationship of the inlet and outlet openings to the top and bottom of the shapes of the pistons. A major problem in such devices is that as the valve plate is rotated from a full flow to a zero flow condition, the rotation of the parts without fluid flow causes excessive heating of the device.

It is an object of this invention to provide such a pressure energy translating device of the variable displacement type wherein optimum temperature stabilization is obtained during partial and Zero outlet flow conditions.

In the drawings:

FIG. 1 is a part sectional view of a device embodying the invention.

FIG. 2 is a sectional View taken along the line 22 of FIG. 1.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 1.

FIG. 4 is a sectional view taken along the line 44 in FIG. 1.

FIG. 5 is a sectional view taken along the line 55 in FIG. 1.

FIGS. 6, 7 and 8 are diagrammatic views showing the manner in which the invention achieves its intended purpose.

Referring to FIG. 1, the invention relates to a rotary fluid pressure energy translating device 10 which comprises a housing 11 and a rotatable cylinder block 12 having a plurality of cylinders 13 in which pistons 14 are reciprocably mounted. Connecting rods 15 are universally pivoted to pistons 14 at one end and are connected at the end thereof to drive member 16 by universal joint 17. The drive member 16 is fixed to a drive member 18. A double cardan universal joint 19 extends between the drive member and cylinder block 12 so as to maintain them in proper angular alignment.

The cylinder block 12 engages a valve plate 20 that is provided with a pair of

openings

21, 22 that are successively brought into communication with the ends of the cylinders 13. To operate such a pressure energy translating device 10 as a pump, the drive member 18 is rotated by a motor M and the

openings

21, 22 are connected, respectively, to a source of liquid and a device which is to be supplied with liquid, such as a motor. Rotation of drive member 18 causes pistons 14 to reciprocate, and fluid is drawn through inlet opening 21 and forced out of outlet opening 22. By rotating the valve plate 20 in any conventional manner, such as utilization of gear 22 and rack 23 or the like, the relative positions of the inlet opening 21 and outlet opening 22 to the bottom of the stroke of the pistons is changed so that the displacement and resultant output of the device is changed, in accordance with well-known practice.

According to the invention, a substantially radial axially extending wall or dam 25 is provided in the inlet opening 21 of valve plate 20, thereby dividing the inlet opening into a main inlet opening 21a and a secondary inlet opening 21b. In addition, valve plate 20 of the device is provided with an arcuate diversionary passage 26 in the area between the inlet and outlet. Passage 26 registers with a groove 27 in the face of valve block 24. A passage 28 extends from groove 27 to the exterior. This passage is connected by line L to a heat exchanger 29 and then to the fluid reservoir 31.

The manner in which the invention achieves the intended purpose can be best understood by referring to FIGS. 68, which are views of a cylindrical section in which the relationship of the valve plate and cylinders is shown in two dimensions.

With the unit at its full flow orientation, as shown in FIG. 6, fluid is drawn in the inlet passage throughout the main passage 21a and secondary passage 21b of the valve plate and exhausted throughout its entire outlet opening 22. Fluid is allowed to pass freely about the diversion dam 25.

With the unit at its partial flow orientation, as shown in FIG. 7, the valve plate 20 is displaced with respect to the bottom dead-center position of the pistons and valve block, permitting part of the exhaust stroke to occur in the inlet 21 of the valve plate 20. A portion of the fluid is pumped into the confined dam area or secondary inlet opening 21b, initiating a flow through the groove 27 and passage 28 to the reservoir 31.

With the unit at its nearly zero or zero flow orientation, as shown in FIG. 8, the valve plate 20 is further displaced with respect to the bottom dead-center position of the pistons and valve block, approaching a zero flow net in both inlet and

outlet openings

21, 22 of the valve plate. However, the piston orientation causes a high pressure zone within an inlet opening 21b, permitting a flow of fluid to the reservoir and replacement of this same volume with fresh fluid from the primary inlet opening 21a.

It is significant that the fluid leaving the unit A is a mixture of the inlet fluid B and the high pressure fluid C that is carried into the low pressure chamber. A means has therefore been provided to expose portions of the cooling flow (the flow entering at B and leaving at A) to the surface of the cylinder walls throughout the entire length of the cylinder above the pistons on both the high and low pressure sides. Both valve plate leakage at surfaces D and E and piston leakage enter or leave the cavities through which the cooling flow circulates. It is this complete circulation of the cooling flow through both the high and low pressure cavities, where it is also exposed to leakage, that lowers the temperature gradients within the unit.

The invention described above has the following fundamental advantages so far as providing cooling flow is concerned:

(A) A positive pressure cooling flow is provided without throttling the fluid pumped for cooling from the high pressure side of the pump.

(B) The cooling flow available increases as the unit is stroked toward cut-ofl.

(C) The volumetric capacity of the pump is unchanged when this arrangement for cooling is used.

(D) The pressure and flow characteristics of the cooling fluid as the unit is stroked back can be chosen by placement and sizing of the diversion dam 25. This design choice is independent of overallpump characteristics so far as operating pressure and flow are concerned.

(E) The expense of adding this feature to a fixed angle variable pump of the type shown is nominal. The change requires only the addition of the diversion dam and the additional passages 2628 for carrying away the cooling fluid.

I claim: 1. In a hydraulic system, the combination comprising a housing, a rotary fluid pressure energy translating device on said housing, said device being of the type having a rotatable drive member, a cylinder block rotatably mounted in said housing and having a plurality of axially positioned cylinders, pistons reciprocable in said cylinders, and motion-converting means interconnecting the reciprocating pistons to the rotatable drive member, a valve plate associated with one end of said cylinder block, said valve plate having an inlet and an outlet which alternately communicates with the cylinders in said block as said block rotates, and a dividing Wall interposed in said inlet and extending generally axially thereof to divide said inlet into a main inlet opening and a secondary inlet opening, said valve plate being rotatable to vary the displacement of said device, and a diversionary passage associated with said secondary inlet opening and adapted to register progressively therewith as the valve plate is rotated from a full-flow condition to a zero-flow condition. 2. In a hydraulic system, the combination comprising a housing, a rotary fluid pressure energy translating device on said housing, said device being of the type having a rotatable drive member, a cylinder block rotatably mounted in said housing and having a plurality of axially positioned cylinders, pistons reciprocable in said cylinders, and motion-converting means interconnecting the reciprocating pistons to the rotatable drive member, a valve plate associated with one end of said cylinder block, said valve plate having a substantially identical inlet and outlet which alternately communicates with the cylinders in said block as said block rotates. and a dividing wall interposed in said inlet and extending generally axially thereof to divide said inlet into a main inlet opening and a secondary inlet opening, said valve plate being rotatable to vary the displacement of said device, and a diversionary passage associated with said secondary inlet opening and adapted to register progressively therewith as the valve plate is rotated from a full-flow condition to a zero-flow condition.

3. In a hydraulic system, the combination comprising a housing,

a rotary fluid pressure energy translating device in said housing,

said device being of the type having a rotatable drive member,

a cylinder block rotatably mounted in said housing and having a plurality of axially positioned cylinders,

pistons reciprocable in said cylinders,

and motion converting means interconnecting the reciprocating pistons to the rotatable drive member,

a valve plate associated with one end of said cylinder block,

said valve plate having an inlet and an outlet which alternately communicates with the cylinders in said block as said block rotates,

and a dividing wall interposed in said inlet and extending generally axially thereof to divide said inlet into a main inlet opening and a secondary inlet opening,

said valve plate being rotatable to vary the displacement of said device,

and an arcuate groove in said housing of lesser radial width than said inlet and outlet adapted to overlap progressively the secondary inlet opening of the inlet as the valve plate is removed from a full open to a no-flow position,

said groove communicating with a zone of lesser pressure than the inlet pressures.

4. In a hydraulic system, the combination comprising a housing,

a rotary fluid pressure energy translating device in said housing,

said device being of the type having a rotatable drive member,

pistons reciprocable in said cylinders,

and motion-converting means interconnecting the reciprocating pistons to the rotatable drive member,

a valve plate associated with one end of said cylinder block,

said valve plate being rotatable to vary the displacement of said device,

and a diversionary passage associated with said secondary inlet opening and adapted to register progressively therewith as the valve plate is rotated from a full-flow condition to a zero-flow condition,

said diversionary passage being in communication with a fluid reservoir.

5. In a hydraulic system, the combination comprising a housing,

a rotary fluid pressure energy translating device in said housing,

said device being of the type having a rotatable drive member,

pistons reciprocable in said cylinders,

a valve plate associated with one end of said cylinder block,

and a dividing wall interposed in said inlet and extending generally axially thereof to divide said inlet into a main inlet opening and a secondary inlet OPBIlll'lg,

said valve plate being rotatable to vary the displacement of said device,

said diversionary passage communicating with a reservoir.

6. In a hydraulic system, the combination comprising a housing,

a rotary fluid pressure energy translating device in said housing,

said device being of the type having a rotatable drive member,

pistons reciprocable in said cylinders,

a valve plate associated With one end of said cylinder block,

and a dividing wall interposed in said inlet and extending generally axially thereof to divide said inlet and an arcuate groove in said housing of lesser radial Width than said inlet and outlet adapted to overlap progressively the secondary inlet opening of the inlet as the valve plate is moved from a full open to 5 no-flow position,

said groove communicating with a zone of lesser pressure than inlet pressure.

References Cited by the Examiner UNITED STATES PATENTS 2,117,512 5/1938 Scott 10341 X 2,524,235 10/1950 Schenk 103-41 X 3,108,542 10/1963 Badenoch et al. 103162 into a main inlet opening and a secondary inlet 15 opening, said valve plate being rotatable to vary the displacement of said device,

DONLEY J. STOCKING, Primary Examiner.

LAURENCE V. EFNER, Examiner.

Claims

1. IN A HYDRAULIC SYSTEM, THE COMBINATION COMPRISING A HOUSING, A ROTARY FLUID PRESSURE ENERGY TRANSLATING DEVICE ON SAID HOUSING, SAID DEVICE BEING OF THE TYPE HAVING A ROTATABLE DRIVE MEMBER, A CYLINDER BLOCK ROTATABLY MOUNTED IN SAID HOUSING AND HAVING A PLURALITY OF AXIALLY POSITIONED CYLINDERS, PISTONS RECIPROCABLE IN SAID CYLINDERS, AND MOTION-CONVERTING MEANS INTERCONNECTING THE RECIPROCATING PISTONS TO THE ROTATABLE DRIVE MEMBER, A VALVE PLATE ASSOCIATED WITH ONE END OF SAID CYLINDER BLOCK, SAID VALVE PLATE HAVING AN INLET AND AN OUTLET WHICH ALTERNATELY COMMUNICATES WITH THE CYLINDERS IN SAID BLOCK AS SAID BLOCK ROTATES, AND A DIVIDING WALL INTERPOSED IN SAID INLET AND EX-