US3858486A

US3858486A - Rotor means and fluid containing chambers in fluid handling devices with working chambers of radialward variable volume

Info

Publication number: US3858486A
Application number: US164059A
Authority: US
Inventors: Karl Eickmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-06-04
Filing date: 1971-07-15
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07

Abstract

The rotor of a fluid handling machine has axially extending passages therethrough communicating with working chambers for radial pistons and connecting inlet and outlet control ports in a housing surface on one side of the rotor, with correspondingly shaped and arranged balancing chambers in an opposite housing surface on the other side of the rotor so that the different pressures exerted by the inlet and outlet control ports on one side of the rotor, are balanced and the rotor floats between the two housing surfaces.

Description

United States Patent 11 1 Eickmann 1 Jan. 7, 1 975 [76] Inventor: Karl Eickmann, 2420 lsshiki,

Hayama-machi, Kanagawa-ken, Japan [22} Filed: July 15, 1971 1211 Appl. N0.2 164,059

Related US. Application Data 63] Continuation of Ser. No. 830,319, June 4, 1969,

abandoned.

[52] 'U.S. Cl. 91/487 [51] Int. Cl. F01b 13/06 Field of Search 91/485, 497,487

[56] References Cited UNITED STATES PATENTS 2,381,741 8/1945 Grosser 91/497 2,712,794 7/1955 I-Iumphreys 91/492 2,895,426 7/1959 Orshansky 91/492 2,972,962 2/1961 Douglas 91/488 3,068,805 12/1962 Byers 9 1/484 FOREIGN PATENTS OR APPLICATIONS 105,638 4/1917 Great Britain 91/491 Primary Examiner-William L. Freeh Attorney, Agent, or Firm-Michael S. Striker [5 7] ABSTRACT The rotor of a fluid handling machine has axially extending passages therethrough communicating with working chambers for radial pistons and connecting inlet and outlet control ports in a housing surface on one side of the rotor, with correspondingly shaped and arranged balancing chambers in an opposite housing surface on the other side of the rotor so that the different pressures exerted by the inlet and outlet control ports on one side of the rotor, are balanced and the rotor floats between the two housing surfaces.

4 Claims, N0 Drawings ROTOR MEANS AND FLUID CONTAINING CHAMBERS IN FLUID HANDLING DEVICES WITH WORKING CHAMBERS OF RADIALWARD VARIABLE VOLUME The present application is a continuation application of my copending application Ser No. 830,3l9 filed June 4, 1969, and now abandoned.

BACKGROUND OF THE INVENTION In pumps, compressors, hydraulic motors and engines, and other fluid handling devices, the rotor is mounted between two housing surfaces, one of which has control ports including an inlet port and an outlet port. Since the control ports exert pressure on the rotor, the same is slightly axially displaced and abuts an opposite housing surface with great pressure so that the same may be damaged, and a welding of the rotor to the housing surface could occur.

CROSS-REFERENCE TO OTHER APPLICATIONS The present invention is related to the subject matter described in my British Pat. application No. 24,344 and in my US. Pat. application Ser. No. 461,483. These applications disclose axially extending passages through the rotor ending in balancing ports, which are difficult and expensive to manufacture.

SUMMARY OF THE INVENTION It is the object of the invention to completely balance a rotor between two housing surfaces, one of which is provided with inlet and outlet ports which cause one sided pressure on the rotor.

With these objects in view, the present invention provides balancing chambers in a housing surface directly opposite and axially registering with the-control ports, and provides the rotor with passages therethrough whose open ends communicate with the control ports and the balancing chambers, respectively, and whose central portions communicate with the expanding and contracting working chambers of the rotor. Since the same pressure prevails on opposite sides of the rotor, the same floats between two liquid films which forms in the clearances between the rotor surfaces and the housing surfaces.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal sectional viewillustrating an embodiment of the invention;

FIG. 2 is a cross-sectional view taken on line II-II in FIG. 1;

FIG. 3 is a longitudinal sectional view taken on line III-III in FIG. 1; 7

FIG. 4 is a cross-sectional view taken on line IV-IV in FIG. 3; and

FIG. 5 is a fragmentary cross-sectional view taken online V-V in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT All Figures show the same embodiment of the invention in different sectional views.

A housing means 1 includes two cover members 2 and 3 with bearings 16 supporting a shaft 17 for rotation about a main axis. A rotor 27 is integral with shaft 17, or connected with the same by non-circular connecting means 19. Rotor 27 rotates about the main axis at the same angular speed as shaft 17.

Working chambers 8 are provided in rotor 27 angularly spaced from each other and a piston 9 is mounted in each working chamber for radial movement. The housing means has also an actuating ring 22 supported in bearings 23 and having an endless inner cam surface eccentric t0 the axis of shaft 17. Each piston 9 carries at its outer end thereof a slide shoe 21 which is in sliding contact with the eccentric cam surface of actuator ring 22 during rotation of rotor 27. A joint including a part-cylindrical projection 25 and a part-cylindrical recess 26 embracing projection 25 connects each piston 9 with the respective slide shoe 21. Recess 26 of joint 25, 26 extends over an angle greater than 180. During rotation of rotor 27 with shaft 17, the eccentric cam surface acts on the slide shoes 21 to radially move the pistons 9 so that the working chambers 8 expand and contract.

Rotor 27 has on opposite sides annular lateral rotor surfaces 6 and 7 which are located in parallel planes perpendicular to the axis of rotor 27 and shaft 17. The rotor surfaces 6 and 7 slide on matching housing surfaces 4 and 5 respectively provided on the cover members 2 and 3. The housing surfaces 4 and 5 are spaced in axial direction a slightly greater distance than the rotor surfaces 6 and 7, so that a small clearance exists between each rotor surface and the corresponding housing surface. The clearances are very small so that a very small leakage flow occurs, while at the same time the friction in the fluid film between adjacent rotor and housing surfaces is small enough so that a good efficiency and sealing capacity is maintained.

In accordance with the invention, the rotor 27 is provided with axially extending passages which communicate at the center portions thereof with the inner ends of the working chambers 8, as best seen in FIG. 3. Each passage has two axially aligned portions 10, I1 respectively extending between the inner end of the working chamber 8 and openings on the opposite rotor surfaces 6 and 7.

The radial distance of passages 10, 11 from the axis of shaft 17 is selected so that the ends 10 of the passages communicate with control ports 12a, 13a in the respective housing surface 5, the control ports being located at the ends of inlet and outlet passages 12 and 13. In this manner, each working chamber 8 is successively connected with the inlet and outlet means l2, 13 during expansion and contraction of the working chambets 8.

The ends 11 of the axial passages open into balancing chambers 14 and 15 provided in the housing surface 4, and having ashape best seen in FIG. 4. The control ports 12a and 13a have exactly the same shape as the balancing chambers 14 and 15, and the same crosssectional area. Port communicates through the respective passages 10, 11 with pressure fluid containing balancing chamber 14, and port communicates through other passages l0, 11 with the fluid containing balancing chamber 15. The same pressure acts in port 13a and chamber 15, and another pressure acts at the same force in port 12a and in the balancing chamber 14. If high pressure prevails in one of the control ports 12a, 13a and in the respective associated balancing chamber 14, 15, the fluid enters into the clearance'at both ends of rotor 27 between the rotor surfaces 6, 7 and the housing surfaces 4, of the cover members, so that in these regions corresponding pressure prevails. A fluid film is created in each gap between the housing surfaces and the rotor surfaces, and flows outward in radial direction from the control ports 12a, 13a and balancing chambers l4, 15, one fluid film being formed between surfaces 7 and 5 and the other between surfaces 6 and 4. Both fluid films have the same pressure, and the clearances between the rotor surfaces and housing surfaces are equal. Consequently, rotor 27 floats between fluid films in the clearances adjacent the rotor end surfaces 6, 7, and between films of fluid which exert opposite equal forces on the rotor. The free floating of the rotor assures that the clearances on both rotor surfaces 6 and 7 remain of the same thickness, and that the rotor 27 floats substantially exactly in the middle between the housing surfaces 4 and 5 of the cover members 2 and 3, regardless of how low or high the pressure in the fluid handling device is. Although the surfaces 6, 7 and 4, 5 are very smooth, they have small valleys and hills, even if machined to a very highdegree. Therefore, it may happen that rotor 27 momentarily does not float exactly in the middle, or

that the fluid films at the ends of the rotor are not at exactly equal pressures.

In accordance with the invention, axial bores are provided through rotor 27 in angularly displaced positions so that a communication between both clearances at both ends of the rotor is assured. In this manner, during a revolution of the rotor, all parts of the fluid films at the ends of the rotor 27, on rotor surfaces 6, 7, temporarily communicate with each other. Higher pressure in one of the clearances would cause flow of fluid from the respective fluid film to the lower pressure area at the other side of the rotor. In this manner, an additional pressure equalization between the fluid films at the rotor ends is assured, and the floating of the rotor 27 in a middle position between the housing faces 4 and 5 is improved.

The ends of bores 20, and the surrounding areas on the rotor surfaces 6 and 7 may also serve to cause bydrodynamic traction to draw fluid into the proximities of bores 20 and thereby into the respective clearances.

The provision of the fluid containing balancing chambers 14 and 15m the cover member 2 remote from the cover member 3 which has the control ports 12a, 13a already assures floating of the rotor between equal fluid films, but the bores 20 assist additionally to assure the equal spacing of the floating rotor from the housingsurfaces 4, 5.

The construction of the invention permits it to make the passages l0, ll of equal cross-sectional area throughout the entire length, so that they can be easily machined, for example, pressed, broached, or drilled.

The fluid-containing balancing chambers 14 and 15 are not necessarily deep, and consequently can be inexpensively machined.

By eliminating one sided pressure of the rotor on the housing, the efficiency and reliability of the apparatus is improved.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of pumps and hydraulic motors differing from the types described above.

While the invention has been illustrated and described as embodied in a fluid handling device with axially balanced rotor, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitutes essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. Fluid handling device with radially balanced rotor, comprising a housing including a hollow central part having first and second radially extending end faces, said housing further including first and second end members rigidly connected with said central part, abutting against the respective end faces and having bearings defining a main axis, said end members having confronting first and second radial planar housing surfaces spaced a fixed predetermined axial distance from each other, said first end member having inlet and outlet conduit means respectively opening into partcircular inlet and outlet control ports provided in said first housing surface and each extending along an arc of at least said ports being circumferentially spaced'from each other about said main axis and having different fluid pressures; an actuator ring mounted in said central housing part and having an annular inner cam surface eccentric to said main axis; and a rotor mounted in said bearing means for rotation about said main axis and having at the ends thereof first and second radial planar rotor surfaces, said first and second rotor surfaces being spaced from one another by an axial distance which is slightly less than said predetermined distance and respectively forming first and secondclearances with said first and second housing surfaces, said rotor having angularly spaced working chambers and including displacement means in said chambers, said displacement means having outer ends slidingly engaging said cam surface during rotation of said rotor and said rotor also having a plurality of passages angularly spaced by the same angle as said work'- ing chambers and each communicating with one of said working chambers, each passage having a constant cross section along the full length thereof and respectively having first and second open ends in said first and second rotor surfaces, said first open ends being spaced from said main axis by the same radial distance as said control ports in said first housing surface and communicating with said control ports during rotation of said rotor, said second end member having in said second housing surface part-circular balancing chambers having the same shape and radial distance from said main axis as said control ports in said first housing surface so that pairs which are each composed of a control port and a balancing chamber are successively connected to each other by said passages during rotation of said rotor whereby the same pressure prevails in each bal ancing chamber as in the control port with which the respective balancing chamber communicates through said passages so that the fluid films in said first and sec ond clearances exert equal pressures on corresponding areas of said first and second rotor surfaces and said rotor is caused to float between said first and second housing surfaces, said rotor further having a plurality of bores extending axially therethrough and having open ends in said first and second rotor surfaces, the open ends of said bores being radially spaced from said control ports and from said balancing chambers and said bores being angularly spaced from said passages in the circumferential direction of said rotor and connecting said first clearance with said second clearance.

2. Fluid handling device as claimed in claim 1 wherein each displacement means includes a piston displacement member guided in the respective working chamber for radial movement and a slide shoe member in sliding engagement with said eccentric cam surface, said piston member having a part-cylindrical projection at the outer end thereof having an axis parallel'to said main axis, and said shoe member having a partcylindrical recess in the inner end thereof receiving said projection for providing a joint connecting said slide shoe member with said piston member for angular movement, and for axial movement during floating displacement of said rotor between said first and second housing surfaces, said part-cylindrical recess embracing said protection over an angle greater than 180.

3. A device as claimed in claim 6 wherein said passages are parallel with said axis and communicate at the central portions thereof with the inner ends of said working chambers, respectively, said inner ends being spaced equal radial distances from said axis.

4. A device as claimed in claim 1 wherein said housing surfaces and said rotor surfaces are annular and have the same radial width.

Claims

1. Fluid handling device with radially balanced rotor, comprising a housing including a hollow central part having first and second radially extending end faces, said housing further including first and second end members rigidly connected with said central part, abutting against the respective end faces and having bearings defining a main axis, said end members having confronting first and second radial planar housing surfaces spaced a fixed predetermined axial distance from each other, said first end member having inlet and outlet conduit means respectively opening into part-circular inlet and outlet control ports provided in said first housing surface and each extending along an arc of at least 120*, said ports being circumferentially spaced from each other about said main axis and having different fluid pressures; an actuator ring mounted in said central housing part and having an annular inner cam surface eccentric to said main axis; and a rotor mounted in said bearing means for rotation about said main axis and having at the ends thereof first and second radial planar rotor surfaces, said first and second rotor surfaces being spaced from one another by an axial distance which is slightly less than said predetermined distance and respectively forming first and second clearances with said first and second housing surfaces, said rotor having angularly spaced working chambers and including displacement means in said chambers, said displacement means having outer ends slidingly engaging said cam surface during rotation of said rotor and said rotor also having a plurality of passages angularly spaced by the same angle as said working chambers and each communicating with one of said working chambers, each passage having a constant cross section along the full length thereof and respectively having first and second open ends in said first and second rotor surfaces, said first open ends being spaced from said main axis by the same radial distance as said control ports in said first housing surface and communicating with said control ports during rotation of said rotor, said second end member having in said second housing surface part-circular balancing chambers having the same shape and radial distance from said main axis as said control ports in said first housing surface so that pairs which are each composed of a control port and a balancing chamber are successively connected to each other by said passages during rotation of said rotor whereby the same pressure prevails in each balancing chamber as in the control port with which the respective balancing chamber communicates through said passages so that the fluid films in said first and second clearances exert equal pressures on corresponding areas of said first and second rotor surfaces and said rotor is caused to float between said first and second housing surfaces, said rotor further having a plurality of bores extending axially therethrough and having open ends in said first and second rotor surfaces, the open ends of said bores being radially spaced from said control ports and from said balancing chambers and said bores being angularly spaced from said passages in the circumferential direction of said rotor and connecting said first clearance with said second clearance.

2. Fluid handling device as claimed in claim 1 wherein each displacement means includes a piston displacement member guided in the respective working chamber for radial movement and a slide shoe member in sliding engagement with said eccentric cam surface, said piston member having a part-cylindrical projection at the outer end thereof having an axis parallel to said main axis, and said shoe member having a part-cylindrical recess in the inner end thereof receiving said projection for providing a joint connecting said slide shoe member with saId piston member for angular movement, and for axial movement during floating displacement of said rotor between said first and second housing surfaces, said part-cylindrical recess embracing said protection over an angle greater than 180*.