US2813488A

US2813488A - Pumping unit having flow directing means

Info

Publication number: US2813488A
Application number: US383318A
Authority: US
Inventors: Theodore J Deska
Original assignee: Eaton Manufacturing Co
Current assignee: Eaton Corp
Priority date: 1953-09-30
Filing date: 1953-09-30
Publication date: 1957-11-19
Anticipated expiration: 1974-11-19

Description

Nov. 19, 1957 T. J. DESKA 2,813,488

PUMPING UNIT HAVING FLOW DIRECTING MEANS Filed Sept. 50, 1953 2 Sheets-Sheet 1 25 56. 4 INVENTOR.

F'J MEODORE figs ATTOENE 5 Nov. 19, 1957 T. J. DESKA 2,813,433

PUMPING UNIT HAVING FLOW DIRECTING MEANS Filed Sept. so, 1953 2 Sheets-Sheet z INVENTOR. lira-came J. 065/(4 FIG-8 BY Arrow/vs s PUMPING UNIT HAVING FLOW DIRECTING MEANS Theodore J. Deska, Detroit, Mich., assignor to Eaton Manufacturing Company, Cleveland, Qiiio, a corporation of Ohio Application September 30, 1953, Serial No. 383,318

Claims. (Cl. 10342) This invention relates to rotary pumps and pumping units of the positive displacement type adapted to be driven by a vehicle engine for supplying actuating fluid under pressure to a hydraulic power steering motor or other auxiliary device to be actuated.

This application is related, as to subject matter and ownership, to earlier application Serial No. 261,654, filed December 14, 1951, now Patent 2,724,335, granted November 22, 1955.

A rotary pump being driven and used in this manner is subject to operation at widely varying speeds. The out put capacity of the pump must be suflicient to meet the requirements of the auxiliary device during low speed operation of the vehicle, and accordingly, the pressure and volume values of the pump delivery during high speed operation of the vehicle are usually considerably in excess of the requirements or" the auxiliary device.

The auxiliary device is usually contained in a closedloop external circuit through which fluid is forced by the pump and the excess fluid is by-passed from the discharge side of the pump to the intake side thereof. The present invention is particularly concerned with the by-passing of this excess fluid and, as one of its objects, aims to provide a rotary pump having novel flow directing means by which the by-passed fluid is returned to the intake side of the pump with minimum turbulence and noise.

Another object is to provide a rotary pump having novel flow directing means by which the by-passed fluid is returned to the intake side in a manner such that the velocity and direction of the stream of by-passed fluid will assist the flow of intake fluid toward the intake port of the pump and such that the energy of the high Velocity fluid will be utilized in increasing the pressure head of the fluid in the intake at points downstream from the junction point of the stream of by-passed fluid with the stream of intake fluid.

Still another object is to provide a rotary pump having novel flow directing means for the purpose mentioned above and which comprises deflector means located in the intake passage and substantially opposite a junction port connecting the by-pass passage with the intake passage.

A further object is to provide a rotary pump with a flow directing means of the kind above indicated and comprising an insert sleeve extending along the intake passage and having a fluted portion defining such deflector means.

The invention can be further briefly summarized as consisting in certain novel combinations and arrangements of parts hereinafter described and more particularly set out in the claims hereof.

In the accompanying sheets of drawings, forming a part of this specification:

Fig. l is mainly an end elevation of a pumping unit embodying this invention, but with portions of the unit broken away;

Fig. 2 is a partial vertical axial section taken through 2,813,438 Patented Nov. 19, 1957 bypass valve means;

Fig. 5 is a partial transverse vertical section taken on section line 55 of Fig. 2 and showing the rotor chamber and the gear type rotors therein;

Fig. 6 is an elevational view showing the flow directing insert in a detached relation;

Fig. 7 is an end view of the insert; and

Fig. 8 is a sectional view taken through the insert longitudinally thereof on section line 88 of Fig. 7.

The rotary pump 10 which will be presently described in detail is shown in the drawings as forming a part of a pumping unit 11 which supplies hydraulic fluid under pressure to a closed-loop external fluid circuit 12. The external fluid circuit 12 includes an auxiliary or accessory device which is operated by the hydraulic pressure being supplied by the pump 10 and may be a hydraulic power steering device 13 which is here shown only diagrammatically. The external fluid circuit also includes delivery and return conduit members or fittings 14 and 15 by which the rotary pump 10 is operably connected with such circuit.

The pumping unit 11 also includes a reservoir member 16 which is mounted on and supported directly by the rotary pump 10 and defines a reservoir chamber 17 adapted to contain a quantity of the hydraulic fluid. A fitting 18 extending into the reservoir 16 has an axial passage 19 through which fluid being returned from the external circuit 12 is directed into the reservoir chamber 17. The fitting 18 also forms a support for a substantially cylindrical strainer 20 which is disposed around this fitting and through which the returned fluid must pass in flowing into the reservoir chamber.

The rotary pump 10 is provided with a pump housing 22 which is formed by a pair of connected

housing sections

22 and 22 The housing section 22* comprises a body member having a rotor chamber 23 therein. This hous ing section 22 is also provided with a pair of arcuately extending intake and

discharge ports

24 and 25 which communicate with the rotor chamber 23 at one end thereof. The discharge port 25 is in the form of an arcuate pocket which can be conveniently referred to as a blind pocket inasmuch as this pocket does not have any intake or discharge passage connected therewith but communicates only with the pumping chambers 35. The housing section 22 forms a cover for the rotor chamber 23 and contains a pair of arcuately extending intake and

discharge ports

26 and 27 which communicate with the rotor chamber 23 at the opposite end thereof.

As shown in the drawings, the rotary pump 10 also includes a shaft 28 having its outer end rotatably sup ported in the housing section 22 by a bushing 29 mounted in the latter. The inner end of the shaft 28 is rotatably supported by a bushing 30 mounted in the housing section 22 As shown in Fig. 2, the inner end of the shaft projects beyond the bushing 30 and also extends through an annular packing 31 which is mounted in the housing section 22 adjacent the bushing. The inner end of the shaft 28 is adapted for connection with an available rotating part from which the rotary pump is to be driven. The housing section 22 is provided with a flange 32 adapted for connection with an available support on which the rotary pump 10 is to be mounted.

The pump 1b also includes rotor means operable in the rotor chamber 23 for producing a pumping action and which rotor means comprises a pair of outer and

inner rotor members

33 and 34. These rotor members port 27 through a connecting passage 42.

chamber 39 defines a dash pot cylinder 44.

have toothed portions in cooperating meshing engagement for defining variable pumping chambers 35 therebetween and whch pumping chambers come into communication with the intake and discharge ports in succession. The outer rotor member 33 is rotatably supported by a cylindrical liner or bushing 36 mounted in the rotor chamber 23. The inner rotor member 34 is mounted on the shaft 23 and is connected therewith by the key 37.

The housing section 22* is provided with an intake passage 38 extending in depending relation from the reservoir chamber 17 and which connects the reservoir chamber with the intake port 24. The housing section 22 is also provided with a return fluid passage 15 which connects the return conduit 15 of the external fluid circuit with the passage 19 leading into the reservoir chamber 17. The housing section 22 contains a valve chamber 39 which extends in spanning relation to the intake and

discharge ports

26 and 27 of this housing member and which contains a suitable bypass valve means, such as the valve assembly 46 here shown and which will be further described presently.

As shown in Fig. 4, the valve chamber 39 is provided at an intermediate point thereof with an internal annular valve seat 41. inwardly of the valve seat 41 this valve chamber is in communication with the discharge A portion 39 of this valve chamber which is located outwardly of the valve seat 41, is in communication with a bypass passage 43 through which by-passed fluid is returned to the intake side of the pump in a manner to be explained hereinafter. The extreme inner end portion of the valve The extreme outer end portion of the valve chamber 39 defines a spring chamber and delivery passage 45 through which the pumped fluid being supplied to the external fluid circuit 12 is delivered. The outer end of the valve chamber is closed by the fitting or conduit member 14 which has a passage 14 therein connecting the delivery passage 45 with the external fluid circuit.

The valve assembly 40 is operable in the valve chamber 39 as a by-pass valve means which controls the flow of by-passed fluid from the valve chamber through the passage 43. This valve assembly comprises a volume control valve member 46 and a pressure relief valve member 47. The volume control valve member 46 is a hollow valve member having an axial passage 48 therein and also having radial ports 49 through which the axial passage is connected with the discharge port 27. At an intermediate point thereof, the valve member 46 is provided with a valve plunger portion which cooperates with the valve seat 41. At its inner end, the valve member 46 is provided with a dash pot plunger 51 which is operable in the dash pot cylinder 44. A compression spring 52, located in the delivery passage 45 and disposed between the fitting 14 and the outer end of the valve member 46, acts on this valve member tending to shift the same in a direction to cause closing movement of the valve plunger portion 50 in relation to the valve seat 41.

At a point adjacent its outer end, the axial passage 48 of the volume control valve member 46 is provided with an internal annular valve seat 53. The volume control valve member 46 is also provided with radial by-pass ports 54 adjacent this internal valve seat 53 and which are continuously in communication with the valve chamber portion 39 The pressure relief valve member 47 is slidable in the outer end portion of the axial passage 48 of the valve member 46 and includes a valve plunger portion 55 which cooperates with the internal annular valve seat 53,. A compression spring 56 located in the axial passage 48 of the valve member 46 acts on the pressure relief valve member 47 and urges the same in an outward direction to a position engaging the valve seat 53 for closing the by-pass ports 54.

A spring ring 57 mounted in the valve member 46 retains the pressure relief valve member 47 in the axial passage 48 and forms a stop against which the pressure relief valve member is adapted to be held by the compression spring 56. The pressure relief valve member 47 has an axial passage 58 therein which includes a flow control orifice 59. The axial passage 58 and the flow control orifice 59 connect the delivery passage with the discharge port 27 through the axial passage 43 and the radial openings 49 of the valve member 46.

The valve assembly 46) is more fully disclosed and claimed in copending patent application Serial No. 261,655, filed December 14, 1951, now Patent 2,752,853, granted July 3, 1956. For the purposes of the present invention, it is sufficient to explain that the valve assembly 40 is responsive to the pressure of the spring 52 and the fluid pressure differential across the orifice 59. When the pump 10 is being driven at a relatively high rate of speed, the resultant effect of these pressures causes the valve assembly 40 to be shifted toward the left in opposition to the spring 52 to thereby move the edge of the valve plunger portion 50 past the shoulder 41* of the internal valve seat 41 to thereby cause opening of the volume control valve member 46 for by-passing pumped fluid from the discharge port 27 to the by-pass passage 43 for return to the intake side of the pump, The amount of fluid which is thus by-passed for return to the intake side of the pump is dependent upon the extent of this opening movement of the valve member 46 and will be such that the rate at which pumped fluid will be supplied to the external fluid circuit 12 through the delivery passage 45 will be automatically maintained at a desired substantially constant value.

The pressure relief valve member 47 is responsive to the pressure of the spring 56 and to the fluid pressures acting on opposite ends of this valve member. When the pump 10 is being operated at the relatively high speed mentioned above, the resultant effect of these forces causes the pressure relief valve member 47 to be shifted towards the right in opposition to the spring 56 to cause an opening movement of the valve plunger portion relative to the bypass ports 54 for by-passing pumped fluid from the delivery passage 45 to the by-pass passage 43 for return to the intake side of the pump. The amount of fluid thus by-passed through the bypass ports 54 will depend upon the extent of this opening movement of the pressure relief valve member 47 and will be such that the pressure of the fluid being supplied to the external fluid circuit 12 will be automatically maintained at a desired substantially constant pressure value.

In accordance with the present invention, the pumped fluid which is by-passed through the passage 43 by the functioning of the valve members 46 and 47 is returned to the intake side of the pump in a novel manner which will now be described and by which turbulence in the intake fluid and noise resulting therefrom will be pre vented or kept at a minimum, and also by which the velocity of the by-passed fluid can be used to assist the flow of intake fluid to the intake port 24. The by-pass passage 43 accordingly extends between and connects the valve chamber 39 and the intake passage 38.

In utilizing the by-passed fluid for the purposes just mentioned above, the present invention provides a flow directing means in the pump housing 22 by which the bypassed fluid is directed along the intake passage 38 in a donwstream direction, that is, toward the rotor chamber 23. This flow directing means is preferably in the form of an insert 61 located in the housing section 22 and extending axially in the intake passage 38. The insert 61 is here shown as being an open-ended sheet metal sleeve having a relatively tight engagement in the intake passage 38 and whose upper end 61 communicates with the reservoir chamber 17. The lower end 61 extendstransversely of a junction port 62 located in the side wall of the intake passage 38 and through which port the bypass passage 43 communicates with the intake passage.

The lower end 61 of the insert extends at least partway across the junction port 62 and cooperates with the side Wall of the intake passage 38 in defining an annular space or pocket 63 whose lower end is in communication with the intake passage and faces in the downstream direction of the latter, that is, opens toward the rotor chamber 23. The portion of the insert 61 which is located opposite the junction port 62 forms a deflecting means for the bypassed fluid entering the intake passage 38 through the junction port, such that this by-passed fluid will be deflected or directed toward the rotor chamber 23.

The by-passed fluid enters the intake passage 38 through the junction port 62 as a velocity stream and when this velocity stream has been deflected in the downstream direction by the insert 61, the energy of this by-passed fluid will be utilized in accelerating the flow of intake fluid toward the rotor chamber 23 through the passage 61 of the insert and through the intake passage 38. The walls of the intake passage 38 are continuous throughout the portion of this passage extending from the junction port 62 to the rotor chamber 23, such that the intake fluid will be confined therein and the energy of the by-passed fluid will be utilized in creating a pressure head in this portion of the by-pass passage tending to accelerate the filling of the pumping chambers 35 with a solid body of intake fluid.

When the by-passed fluid enters the intake passage 38 through the port 62, it is desirable that the mingling or confluence of the stream of by-passed fluid with the stream of intake fluid, take place with minimum disturbance or noise-producing turbulence. To assist in achieving this desired result, the portion of the wall of the insert 61 located opposite the junction port 62, is shaped to constitute a deflector 64 for facilitating a smooth mingling of the by-passed fluid with the intake fluid.

The deflector 64 is here shown as being an inwardly olfset transversely concave fluted portion or external indentation of the wall of the insert 61. The transversely concave deflector portion 64, being located directly opposite the port 62, will be eflective on the stream of by-passed fluid to direct the same out of the pocket 63 and into the intake passage 38 in the above-mentioned downstream direction. The fluted portion forming the deflecting means 64 can be shaped or drawn in the side wall of the insert 61 by any suitable forming operation and dies.

From the foregoing detailed description and the accompanying drawings, it will now be readily understood that this invention provides novel flow directing means in a positive displacement rotary pump, and in a pumping unit embodying such a rotary pump, by which fluid being bypassed from the discharge side of the pump to the intake side can be mingled smoothly and with minimum turbulence and noise with the stream of intake fluid. Likewise, it will be seen that this novel flow directing means also provides for utilizing the by-passed fluid as a velocity stream for assisting the flow of intake fluid to the intake port for maintaining the latter substantially filled at all times and preventing the formation of a vacuum or void condition therein, and for utilizing the energy of the high velocity by-passed fluid for increasing the pressure head of the intake fluid at points downstream from the junction point of the by-pass passage with the intake passage. Additionally, it will be understood that this flow directing means is employed in the form of an open-ended insert sleeve mounted in the pump housing so as to extend along the intake passage for a portion of the length thereof and with the lower end portion of the insert cooperating with the by-pass passage as a deflecting means effective on the stream of by-passed fluid.

Although the flow directing means of this invention and the rotary pump and pumping unit embodying the same have been illustrated and described herein to a somewhat detailed extent, it will be understood, of course, that the invention is not to be regarded as being limited correspondingly in scope but includes all changes and modifications coming within the terms of the claims hereof.

Having thus described my invention, I claim;

1. In a rotary pump, a housing having therein a rotor chamber and intake and discharge passages communicating with said rotor chamber, rotor means operable in said rotor chamber for producing a pumping action, said housing also having a valve chamber communicating with the discharge passage and a by-pass passage connecting said valve chamber with the intake passage through a junction port, valve means in said valve chamber and operable to by-pass pumped fluid through said by-pass passage, said intake passage having a substantiallycontinuous side wall between the junction of said by-pass passage therewith and said rotor chamber for confining the fluid being supplied to said rotor chamber, and flow directing means comprising an insert sleeve extending along said intake passage and having one end thereof extending transversely of said junction port, a portion of the wall of said sleeve adjacent said one end being oflset radially inwardly of the sleeve and forming a deflecting portion located substantially opposite said junction port.

2. In a rotary pump, a housing having therein a rotor chamber and intake and discharge passages communicating with said rotor chamber, rotor means operable in said rotor chamber for producing a pumping action, said housing also having a valve chamber communicating with the discharge passage and a by-pass passage connecting said valve chamber with the intake passage through a junction port, valve means in said valve chamber and operable to by-pass pumped fluid through said by-pass passage, said intake passage having a substantially continuous side wall between the junction of said by-pass passage therewith and said rotor chamber for confining the fluid being supplied to said rotor chamber, and flow directing means comprising an insert sleeve extending along said intake passage and having a fluted portion disposed substantially opposite said junction port.

3. In a pumping unit of the character described, a housing having therein a rotor chamber and intake and discharge ports communicating with said rotor chamber, means defining a reservoir chamber supported directly by said housing at an elevation above said rotor chamber, rotor means operable in said rotor chamber for producing a pumping action, said housing also having in take passage means therein connecting said reservoir chamber with said intake port for supplying fluid to the latter, said intake passage means having a substantially continuous and imperforate side wall for confining in said intake passage means the fluid being supplied therethrough to said intake port, means for by-passing pumped fluid from said discharge port to said intake passage means including a by-pass passage communicating with said intake passage means through a junction port in the side wall of the latter, and flow directing means comprising an open-ended insert sleeve having its upstream end relatively tightly engaged in said intake passage means and its downstream end extending at least part-way across said junction port and defining with said side wall an intervening pocket with which said junction port communicates and whose open end faces in the downstream direction of said intake passage means, the downstream end of said insert sleeve having a deflecting flute formed in the wall thereof and located substantially opposite said junction port.

4. In a pump and reservoir combination, a housing structure containing a reservoir chamber and a rotor chamber provided with intake and discharge ports, said reservoir chamber being at an elevation above said rotor chamber, rotor means operable in said rotor chamber for the delivery of pumped fluid through the discharge port, said housing structure also having a permanently open intake passage connecting said reservoir chamber with the intake port and a passage for pumped fluid communicating with said intake passage through a permanently open junction port located in the side Wall of the latter, and flow directing means comprising an insert sleeve located in and extending axially along said intake passage, said sleeve having an open upstream end tightly engaged in said intake passage and an axially open down stream end extending at least part-way across said junction port, said downstream end having an external indentation in the side wall thereof, said indentation being located substantially opposite to said junction port and defining with the side Wall of said intake passage an intervening pocket with which said junction port communicates and which pocket has an open end communicating directly with said intake passage and facing in the downstream direction thereof.

5. A pump and reservoir combination as defined in claim 4 in which the upstream end of said insert is axially open and has a substantially uniform-size cylindrical shape above said indentation.

References Cited in the file of this patent UNITED STATES PATENTS Mack July 13, Dunham Sept. 7, Staley Sept. 24, Davis Aug. 5, Moody July 31, Ruth July 9, Caserta Dec. 28, Jacobsen Apr. 12, Eames Nov. 22, Hunter Feb. 7, Drude June 5,

FOREIGN PATENTS Great Britain June 13, Germany Aug. 17,