US2868136A - Pump - Google Patents

Description

Jan. 13, 1959 E. K. BENEDEK PUMP F'il ed May 13, 1954 w m L new 5 (e12 K. fie/zeoek, deceased Mel L. ezzedek, (2092? '12::

M! i Z [7775 United States PUMP Application May 13, 1954, Serial No. 429,632

1 Claim. (Cl. 103-161) The present invention relates to pump construction and, more particularly, relates to radial piston type pumps constructed to provide a substantially constant outlet pressure and capable of simple modification to vary its capacity.

,The basic principle of operation of the radial type pump has, of course, long been understood in the art. I am of course aware of prior art pump structures wherein a drive member is rotatably mounted on a fixed pintle and carries a plurality of radially extending bores in which reciprocatable pistons are mounted. I am also, of course, aware of the fact that numerous means and methods of reciprocating the pistons have been provided in the prior art, among which is the expedient of positively actuating the pistons by means of a circular cam mounted eccentrically of the axis of rotation of the drive member. The present invention is an improvement over these prior art devices and provides a great simplification and hence reduction in expense over those pumps heretofore known.

In the pump construction of the present invention, a single conventional ball or roller bearing having an inner and outer race separated by rolling balls or rollers, is provided for actuating the reciprocating pistons, and the pistons themselves are constructed of conventional hardened roller bearings slidable axially along their length as a result of forces applied against the ends thereof by the inner race of the above mentioned bearing. By utilizing those conventional parts in a novel manner and in combination with other simplified structural components, applicant has been able to provide an unusually efi'icient pump capable of manufacture at a minimum of cost.

It is therefor an object of the present invention to provide a novel and improved radial piston type pump.

Another object of the present invention is to provide a novel piston type pump wherein the pistons comprise free floating cylindrical members.

Still a further object of the present invention is to provide a novel fuel pump or the like having radially movable reciprocal pump pistons and wherein reciprocation of the pistons is accomplished by the positioning thereof within the inner race on an anti-friction roller bearing mounted eccentrically of the pump drive.

A feature of the present invention is the provision of a pump capable of manufacture from cylindrical parts almost exclusively.

Another feature of the present invention is a novel piston actuating and carrying block mounted for rotation on a fixed pintle and positioned within the inner race of an anti-friction bearing for the reciprocation of the pistons without positive driving connection therewith.

Still another object of the present invention is to provide a simplified radial-type fluid pump for operation at a substantially constant maximum output pressure.

Still other features and objects of the present invention will at once become apparent to those skilled in the art from a consideration of the attached drawings wherein:

Figure 1 is a side elevational view in cross-section ilatent O" 2,868,136 Patented Jan. 13, 1959 ice ' 2 lustrating the assembly of a pump constructed according to the present invention.

Figure 2 is a cross-sectional view taken along the line II-ll of Figure l and illustrating applicants novel piston and piston actuation mechanism, and

Figure 3 is a cross-sectional view taken along the line III-llI of Figure 1 illustrating applicants simplified outlet pressure control.

As shown on the drawings:

As may be seen from consideration of Figures 1 through 3, the pump of the present invention comprises a housing 10 having a pintle support aperture 11 at one end thereof and having a flange 12 at the opposite end for the attachment of a closure end plate 13. The end plate 13 carries a cylindrical bearing 14for supporting a rotatable drive shaft 15.

A conventional non-rotatable cantilever type pintle 16 is rigidly secured within the aperture 11, preferably by means of a shrink or press fit. As may be seen from Figures 2 and 3, the pintle is provided with a pair of longitudinally extending bores 17 and 18 for conducting fluid from the pump inlet 19 to the outlet 20 via the suction and pressure pumping chambers 21 and 22 respectively.

The pumping mechanism of the pump comprises a rotatable cylinder block 23 having a bore 24 therein for rotatable cooperation with the pintle 16. The block 23 is preferably machined from a cylindrical bar for purposes of cost minimization and is provided with a generally polygonal aperture 25 at the right hand end thereof for cooperation with a similar polygonal shaped end 26 on the drive shaft 15.

The cylinder block 23 is provided with a plurality of radially extending cylinder bores 27 in which reciprocable pistons 28 are slidablyrnount'ed. In the inexpensive pump unit contemplated, it is preferred that the pistons 28 comprise hardened needle or roller bearings of a selected conventional size but it will, of course, be understood that other materials may be satisfactorily used.

Sliding movement of the pistons 21 is limited by an abutment shoulder 27a in the bottom of each cylinder 27. This abutment prevents the pistons 28 from dropping into the slotted chambers 21 and 22 when the pump is not in operation.

The pistons 28 are forced radially inwardly toward the pintle '16 by means of the eccentric action of the internal bearing race 29a of the ball bearings 29. The external race 2% is fixably secured in the housing 10 by means of an annular spacer ring 30 and an abutment shoulder 31. The circular bore in which the outer race 2% sits is, of course, eccentric to the axis of rotation ,of the cylinder block 23 and, depending upon the eccentricity the length of the effective piston stroke varies. It will be understood that while for sake of simplicity the pump of the present invention is illustrated with a fixed eccentricity, nevertheless, adjustment may be accomplished if so desired by mounting the outer race 29b in a block slidable transversely of the pintle 16.

In operation, the cylinder block 23 is rotated by the shaft 15 relative to the pintle 16. This rotation will cause a centrifugal force to be applied against the pistons 28 urging them radially outwardly against the internal ring 29a of the bearing 29. The outward force will cause the pistons to move outwardly where possible drawing fluid from the inlet 19 and causing a frictional drive between the outer ends of the pistons 28 in the internal bearing race 29a. This frictional contact will cause the bearing race 29a to rotate with the cylinder block 23 since the friction between the bearing races 29a and 29b is very small. As a result of the eccentricity of the ball bearing 29, on one side of the pintle 16 the pistonswill be permitted to move outwardly and on the oppositeside thereof, the bearing 29a will force the pistons inwardly to pump fiuid from the outlet 20.

Lubrication of the entire device is achieved through the slight leakage permitted around :the external wall of the pistons 28. This leakage oil fully .lubricates all of the relatively few moving parts and is prevented fromcg'ress of the shaft 15 by means of the seal v32. Since the pintle 16 is preferably pressed into .the housing bore 11, there is substantially ,no leakageat .the bore .11. However, in order to render leakage absolutely impossible, a safety O-ring 33 is preferably provided.

While it has been found that the pump operates extremely satisfactorily as above described, it is also within the scope of the present invention to providecompression springs for urging the pistons 28 radially outwardly. Such springs maybe positioned between the piston stop abutment 27a and-the-pistons 28 to provide a substantially positive suction stroke in .pump applications in which the cylinder block 23 is intended to rotate at a relatively low angular velocity.

From the above description -it will be apparent that applicant :has provided a novel and extremely simple radial piston-type pump. Through the construction herein shown conventional bearings may be utilized for the pump piston actuation, as well as for the pump pistons themselves. Further, assembly of the device is exceedingly simple since no mechanical connections are necessary between the various rotating parts. This absence of connections also eliminates any noise which often has become excessive in prior art pumps and which is, of course undesirable. This-is particularly true when pumps of the type herein disclosed are to be utilized as fuel pumps for .oil furnaces, vehicles and other similar types of apparatus which must necessarily run in the ,hearing presence of people.

An extremely simple and yet highly effective pressure limiter is provided in the pump of the present invention as maybe seen in Figure 3. There, the pintle 16 is. provided with a slight transverse channel '34 leading to a radially directed port 35. A check valve in'the form of a ball bearing 26 is resiliently urged against the outer end :of the port 35 by means of a spring 37. Upon the attainment of the desired pump operating pressure, the check valve ball 36 will unseat permitting fluid to flow from the passageway 18 to the passageway 17 through the relief port 38. In this manner, a very simple pressure relief valve is provided, capable of manufacture from a single radial bore, thereby eliminating the necessity for a plurality of closure plugs and other similar devices ordinarily utilized in connection with pump valve structures.

It will be apparent, therefor, that I have provided a novel and highly eflicient pump having an absolute minimum of moving parts and utilizing a maximum of standard parts readily available at mass produced or volume prices. As will be apparent, the pump of the present invention may be manufactured with an absolute minimum of tools and, in situations where the bearings are readily available, rotary machining equipment such as lathes are practically the only tools necessary for construction of this device.

It will be understood that variations and modifications maybe made to the above identified structure without departing from the scope of the novel concepts of the present invention and it is not, therefore, intended that the application be limited except as necessitated by the scope .of the appended claim.

What is claimed is:

A radial piston pump comprising a fixed pintle having inlet and outlet ports therein, a cylinder block rotatably mounted on said pintle, a plurality of radially extending bores in said block for sequential cooperation with said inlet and outlet ports, a .cylindrical piston freely slidable in each of said bores, a roller bearing positioned around saidcylinder block with the inner race thereof in abutting relation with the outer ends of said pistons, a fixed housing supporting said pintle and roller bearing in eccentric relation to each other, a radial passage extending through said housing to a point adjacent said pintle and having a diameter overlapping extensions of said inlet-and outlet ports, and separate apertures connecting said passage with the respective inlet and outlet, said aperture connecting said outlet to said passage being substantially concentric of the axis of said passage and said aperture connecting said inlet to said passage being eccentric of the axis of said passage and a spring pressed check valve in said passage and normally closing the aperture leading to the outlet to provide a high pressure bypass from said outlet to said inlet said passage providing the guide for said valve with the spring of said spring pressed valve being positioned concentric of the axis of said passage and the check valve having its outer surface guided by the walls of the passage for concentrically contacting and closing the aperture connecting the passage and the outlet.

References Cited in the file of this patent UNITED STATES PATENTS 1,112,158 Pedersen Sept. 29, 1914 2,130,299 Ernst Sept. 13, 1938 2,292,181 Tucker Aug. 4, 1942 2,293,693 Wylie Aug. 18, 1942 2,646,755 Joy July 28, 1953 2,743,582 Wiedmann May 1, 1956 FOREIGN PATENTS 594,852 Great Britain Nov. 20, 1947

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