US2485491A - Reciprocating vane pump - Google Patents

Description

Patented Oct. 18, 1949 RECIPROCATIN G VANE PUMP Ray G. Holt, Euclid, Ohio, assignor, by mesne assignments,

to Borg-Warner Corporation,

Chicago, Ill., a corporation of Illinois Application August 30, 1943, Serial No. 500,519 Z Claims. (Cl. 10S-136) This invention relates to pumps of the radially reciprocable vane type and has as the general object thereof the provision of an improved arrangement of vanes, supporting rotor, eccentrically embracing sleeve and center pin for controlling the radially inner terminal of the vanes and maintaining the outer terminal portion thereof in contact with the surrounding sleeve.

I am aware that springs have been proposed for urging the vanes radially outwardly into engagement with the embracing sleeve or housing but I am not aware of any previous construction incorporating the improved feature of my arrangement.

It is a particular object of my invention to provide in combination a new center pin construction having an improved mode of operation and coaction with the vanes controlled thereby.

Other and more particular objects, advantages and uses of my invention will become apparent from a reading of the following specification taken in connection .with the accompanying drawings forming a part thereof and wherein:

Fig. 1 is a broken-away cross sectional view taken substantially on line I-I f Fig. 2 and showing one preferred embodiment;

Fig. 2 is a broken-away axial sectional view taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a broken-away cross sectional view showing a second alternative arrangement;

Fig. 4 is a broken-away axial sectional view of the arrangement shown in-Fig. 3; and

Fig. 5 is a broken-away, sectional view showing a third alternative arrangement.

Referring now in greater detail to theiigures of the drawing, one preferred embodiment is illustrated in Figs. l and 2 and includes essentially a housing indicated generally at I0 formed with a cylindrical bore I2 and ports I4 and I6 either of which ports may become selectively the inlet or the outlet port depending upon the direction of operation of the iiuid displacement device as well as whether the same is being operated as a pump or as a motor. Bore I2 preferably has insertedl therein a liner or sleeve I8, formed of a suitable wear-resistant metal such as bronze or steel. This liner I8 is formed with ports 20 and 22 for cooperation respectively with ports I4 and I6 in the housing I0. Received within sleeve I8 is the center portion of a rotor 24 eccentrically positioned with reference to the sleeve and having journals 26 and 28 received in reduced bores 32 and 34 on either side of main bore I2 for rotation therein about a fixed axis.

Rotor 24 is formed with a plurality of radially 2 extending slots 36 in which lare mounted for radial reciprocation a corresponding plurality of vanes 38 the outer terminal portions of which engage the inner periphery of the sleeve I8 while the radial inner terminals thereof are adapted g to be engaged and controlled by a specially constructed roller-like center pin 40.

It is to the special construction of this center pin 40 and the novel mode of coacton thereof in combination that my invention is especially directed. l

In this preferred embodiment roller-like center pin 40 is in the form of a coiled strip of spring steel with the ends thereof spaced apart to provide a small free joint opening and give the desired value of radially outward pressure against the inner end of blades 38. One end of this coiled strip is dened by a pair of inwardly converging portions 42 and 44 while the opposed end is defined by a complementary pair of outwardly diverging portions 46 and 48 thus forming a free joint wherein the terminal portions of the spring strip always present a bearing surface for the inner ends of the vanes in effecting the transition of the vanes across the free joint opening from one end of the spring roller to the other;

Spring roller-like center pin 40 engages each of the vanes 38 throughout the axial extent thereof applying radially outward pressure thereto for maintaining the requisite sealing engagement of the outer ends of the vanes with the surrounding sleeve I8. This is effective to take up for the wear occurring between the elements aswell as rendering practicable a more liberal tolerance upon initial installation.` The center pin 40 is also preferably made with sufficient strength to normally prevent any inward radial compression thereof by the action of the vanes in the rotation of the vanes in contact with the bore. Coupling connection 50 may be employed for transmitting torque to the rotor 24 in the event that the assembly is to be operated as a pump or alternatively for the purpose of transmitting power from the assembly in the event the same is to be operated as a fluid motor.

Turning now to Figs. 3 and 4 there is illustrated still another form of roller-like resilient center pin construction indicated generally at 140. In this modification the center pin |40 is made of rubber or rubber-'like material such as a synthetic composition. In other respects this center pin is similar in function and mode of operation to that above described.

Referring to Fig. 5, this modification differs from the above forms in the use of a helical a 'substantially continuous flat peripheral sur-v face i eiective to engage the inner terminal portions of thevanes or blades 38 substantiallyl throughout the axial extent thereof.

` While I have disclosed only those ports of a -iluid displacement device essential to cooperation in the present combination, it is to be understood that in an actual installation all ofthe conventional elements necessary will be provided. It will also be noted that while I disclose and describe the provision of a wear-resistant liner I8 lt is contemplated thatthe outer ends of vanes Il may operate in direct contact with a bore formed in the housing where no such liner is to be provided, and where the word bore" is employed in the claims both arrangements are contemplated.

From the above it will appear that I have provided a resilient preloaded center pin or roller arrangement in combination with an eccentric A rotor type of fiuid displacement device, which center pin or roller while not subject to appreciable radially inward compression, nevertheless `functions to maintain the vanes in sealed engagement with the surrounding cylindrical housing bore. This has :the ladvantage among other things of making it unnecessary to observe the close tolerances in manufacture that are normally required in the absence of this resilient center pin construction. It will be noted that the present resilient center pin construction is quite distinguishable from the previously known resilient means employed in pumps oi the opposed rotary vane type having irregular or camshaped bores. In these -former arrangements the cams formed in the bore are effective during certain portions of the arcuate movement to move opposed vanes or blades radially in the direction of one another and hence employ, 4for example, coil compression springs for subsequently urging the vanes radially apart. The present invention is clearly distinguishable in that the substantially circular cross section of the cylindrical bore employed results in appreciably no relative radial movement of opposed vanes lwith respect :to one another. Ihe herein disclosed resilient roller arrangement has the marked advantage that a predetermined or substantially select loading of the resilient rotor may be employed and :there is no requirement that an excess loading be provided for during rotation as is the case with irregular lbore contour type of uid displacement devices.

Therefore, I am aware of no previous application or appreciation of the use of an elongated, resilient. roller-like center pin in combination with an eccentric rotor reciprocable vane type of iluid displacement device and incorporating the advantages herein disclosed.

While I have disclosed my invention in conexample rather than limitation and that my in- A ventionshould `be deiined vby the appended twins'.-v

I claim: l. In a rotary uid displacement device including means deiining a cylindrical bore having iluld inlet and outlet portscommunicating therewith.-

- a rotor positioned eccentrically within said bore for rotationvtherein, radially reciprocable elongated vanes carried by said rotor and means defining an elongated roller-like resilient center pin engaging the radial inner terminals or said vanes 'and maintaining the radial outer terminals thereof in sealing engagement with said cylindrical bore, said means comprising a hellcally coiled spring, said coiled spring having a ground peripheral surface eilective to increase the area ot contact between successive turns 'and the radial inner terminals of .the respective vanes.

2. In a rotary iluid displacement device including a housing formed with a. cylindrical .bore and having fluid inlet and outlet ports communicating with said bore, a rotor positioned eccentrlcally within said Ibore for rotation therein, radially reciprocable elongated vanes carried yby said rotor and means denning an elongated roller-like resilient center pin contacting the inner-radial extremities of said vanes and overlapping said vanes axially at 'both axial. extremities of said vanes and functioning to maintain the outer radial terminals of said vanes in sealing engagement with said cylindrical bore, said resilient center pin consisting of 'a helically coiled spring, the peripheral surfaces of each turn being generated by a straight chordal line having an axial dimension less than .the diameter of said coil spring whereby to provide a greater area of contact between said coil and said vanes than would -be provided by a spring of circular cross-section fbut less area of contact than would be provided by a solid center -1,111- y RAY G. HOLT.

REFERENCES CITED The following references are of record in the le of this patent:

UNIIED STATES PA'I'ENIS Number Name Date 456,351 Adams July 21, 1891 949,219 Clement et al Feb. 15, 1910 1,265,070 Feyzes May 7, 1918 1,980,404 Harman et al. Nov. 13, 1934 2,036,711 Martin Apr. 7, 1936 2,326,803 Samiran Aug. 17, 1943 FOREIGN PATENTS Number Country Date 186,489 Germany June 28, 1907

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