Rotary Engine Vane Sealing Means

Abstract

A vaned rotary-type engine having vanes with a main body portion and a telescoping tip seal with separate means being provided to support the main part and support the tip seal so that neither places a radial load on the housing in which the vane rotates. The main portion has cam rollers which ride in cam tracks so that as the vane rotates the radial load is taken through the rollers. The tip seal is supported at each end by two large ball bearing units which are fixed in the housing and have carriers which abut the ends of the tip seal.

Description

BACKGROUND OF THE INVENTION

The vaned rotary engine is of the type shown in U.S. Pat. No. 3,301,233 and U.S. Pat. No. 1,986,556. However, neither of these patents provide any mechanism for performing the function of subject invention. In U.S. Pat. No. 3,132,632, sealing members are made light to provide a seal between the vanes and the housing.

SUMMARY OF THE INVENTION

A primary object of the present invention is to maintain a minimal sealing gap between the tip seal of rotary engine vanes and housing by antifriction bearings which limit in a radial direction the proximity of the vane tip seal to the housing. In accordance with the present invention, sealing between the vanes and the bearing cavity is obtained by a circumferential face seal, loaded by springs against the bearing carrier. The combination is made thermally compatible by making the components of material of like or compensating coefficients of expansion.

BRIEF DESCRIPTION OF THE DRAWING

The figure is a section taken through a vaned rotary-type engine showing the mounting of a vane having a movable vane tip seal.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The housing shown consists of an end member 10, a center section 12, and another end section 14. These sections can be fixed together by any means desired, such as by through bolts. The center section 12, which is of interest here, is formed having an inner cylindrical surface 16 and is finned at 18 to provide cooling. The vane rotor 19 mounted for rotation with respect to said housing comprises a plurality of members 20 which extend through said center section 12 and are fixed between sideplates 22 and 24, which are located on each side of the center section 12, to provide slot areas therebetween for the positioning of vanes 26 for relative sliding movement therewith.

The vane rotor 19 is mounted for rotation off center from the center of the cylindrical surface 16. Through this eccentric mounting the top surface 21 of each member 20 which forms the inner side of each chamber between the sides of vanes 26 and the cylindrical surface 16, moves from a point adjacent the surface 16 (as shown) to a point, 180.degree. away therefrom, which is a maximum distance away from the cylindrical surface 16 and back during a complete revolution.

As in the patents referred to above, air is taken in a chamber at one point, a combustible mixture is formed in one of the chambers at one point, compressed through the action of the chambers just referred to, ignited at another point, and exhausted from the chamber when the chamber approaches the point at which air is taken in.

Each vane 26 has a main body 40 which is formed as a flat plate with its sides 41 located adjacent its cooperating sideplate, 22 and 24 respectively. The bottom of each vane has a narrowed down width portion 32 which has a short shaft 34 extending outwardly on each side on which cam rollers 30 are mounted. The outer end of the vane has a slot 42 formed therein. A notch 43 is located on each side of the vane extending from the outer end down into said slot approximately halfway. A flat seal member 44 is positioned in said slot and has an extension 45 on each end which fits into a notch 43. When the bottom of the seal member 44 rests on the bottom of the slot 42, the seal member just barely projects out of the main part of the vane 40. Since the vane rotor 19 rotates both the main part of the vane 40 and the seal member 44, they are thrown radially outwardly.

To prevent the outer edge of a seal member 44 from engaging the cylindrical surface 16 as it rotates and to prevent the remainder of the vane from having contact with the seal member 44 thereby increasing the force acting through the seal member, two mechanisms are employed.

One mechanism includes cam tracks 36 positioned within said cylindrical surface 16 and between said sideplates 22 and 24 in which the cam rollers 30 are guided. The cam tracks are concentrically mounted with the cylindrical surface 16 so that as the vanes 26 sweep around the housing, the outer edge is maintained a predetermined distance from the surface while all radial forces are taken up by the cam tracks.

A second mechanism is included which takes the radial loads of the tip seal members 44 thrown outwardly by centrifugal force while maintaining the seal gap A. This mechanism includes a similar construction on each side of the center section 12. Both sides of the center section 12 adjacent the seal member 44 are cut away forming recesses 50 and 52 around the entire center section to receive an annular ball bearing member 53 and 54, respectively, along with an annular bearing carrier 56 and 58, respectively.

Each annular ball bearing member has its outer race slidably mounted in said center section with its outer surface in contact with the top annular surface 60 of the cutaway portion or recess. The inner race of the ball bearing member is positioned on the outer surface of the bearing carrier and an outwardly extending flange 62 extends around the outer periphery of the bearing carrier. A spring 66 of the Belleville washer type presses the outer race away from said center section 12 of the housing and through the balls pushes the inner race outwardly. The inner race mounted on the outer surface of the bearing carrier abutting the flange 62 pushes the annular bearing carrier outwardly so that it contacts the inside of the sideplates at B. When the spring 66, ball bearing unit 53, and bearing carrier are in position the inner diameter of the bearing carrier extends inwardly from the surface 16 for a very small distance.

It can now be seen that each seal member 44 thrown outwardly is supported at each end by the inner surfaces of the annular bearing carriers 56 and 58 and is therefore automatically spaced from the inner surface 16. An annular carbon seal 70 is positioned in each slot 72 on each side of said center section 12 and each is biased to engage the inner surface of its cooperating annular bearing carrier, 56 or 58, by a wave spring 76.

An alternate construction to attain a minimum gap at A would be to build the engine with the vane 44 engaging the adjoining housing 12 with the carriers 56 and 58, each having an inner diameter greater than the diameter of the surface 16 forming a gap 77 at each end of the vane with the carriers. This construction allows the vane 44 to rub against the inside of housing 12 during rotation. As the tip of vane 44 engaging the housing wears down, gap 77 gradually closes until the vane comes into contact at its ends with carriers 56 and 58. Bearings 53 and 54 then pick up the centrifugal load of vane 44. The gap A would then be at a satisfactory minimum condition.

Claims

We claim:

1. In combination in a rotary vane type engine, a housing having a cylindrical surface therein, a rotor mounted in said housing having sideplates and means connecting said sideplates, vanes being mounted in said rotor with each vane comprising a main inner portion and a telescoping flat tip seal, the inner portion of said vane being retained against radial movement by means located in said housing, annular stop means being mounted in a recess on each side of said housing adjacent and engaging each sideplate, said annular stop means being mounted for relative movement with said housing, the outer end of each flat tip seal of each vane engaging the inner diameter of its cooperating annular stop means thereby retaining each flat tip seal against radial movement, the portion of the outer end of each flat tip seal between said annular stops thereby being spaced a predetermined distance from the cylindrical surface of the housing.

2. A combination as set forth in claim 1 wherein the inner diameter of each annular stop is less than the inner diameter of the cylindrical surface of the housing.

3. A combination as set forth in claim 1 wherein the inner diameter of each annular stop is greater than the inner diameter of the cylindrical surface of the housing.

4. A combination as set forth in claim 1 wherein seal means are provided between the housing and the adjacent side of each annular stop means.

5. A combination as set forth in claim 4 wherein each seal means comprises an annular seal, said annular seal being positioned in an annular groove in said housing, spring means biasing said seal against its annular stop means.

6. A combination as set forth in claim 1 wherein each annular stop means includes an annular bearing means positioned in engagement with said housing, and an annular member extending inwardly to provide the portion engaging the flat tip seal.

7. A combination as set forth in claim 6 wherein each annular bearing means contains an inner and outer race, each outer race being biased outwardly from said housing to insure a positive engagement of the adjacent annular member with its cooperating sideplate.

8. A combination as set forth in claim 6 wherein flange means extends around the outer periphery of each annular member for locating its cooperating annular bearing means thereon, and means biasing each annular member towards its flange means.