US3759638A

US3759638A - Sealing devices for rotary piston machines

Info

Publication number: US3759638A
Application number: US00212176A
Authority: US
Inventors: M Brille
Original assignee: Renault SA
Current assignee: Renault SA
Priority date: 1971-01-05
Filing date: 1971-12-27
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18
Also published as: GB1380050A; FR2120480A5; DE2200248A1; DE2200248B2

Abstract

A sealing device for rotary piston machines of the type having radial segments fitted into cavities in the stator, characterized in that this device is comprised of a detachable assembly formed by a segment holder support, a lateral shim, a radial segment and their resilient bearing means, said assembly being fitted into a corresponding cylindrically-walled cavity provided in the stator and a lateral cheek, said assembly coming into resilient bearing contact against a lateral sealing shim situated in the opposite cheek, an exterior thrust washer ensuring that this assembly is maintained in resilient juxtaposition with the radial segment and of the lateral sealing shims.

Description

United States Patent 1191 Brille 1451 Sept. 18,1973

[54/] fif gg gm FOR ROTARY N FOREIGN PATENTS OR APPLICATIONS 997,814 7/1965 Great Britain l23/8.0l [75] Inventor: Maurice G. Brille, Billancourt,

France a Primary ExaminerCarlton R. Croyle [73] Assignee: Regle Nationale Des Usines Renault, Assistant vExfmmend:hard Gluck Binancourt prance Attorney-Richard K. Stevens et a1.

[22] Filedz. Dec. 27, 1971 [57] ABSTRACT [21] Appl' 212,176 A sealing devicefor rotary piston machines of the type having radial segments fitted into cavities in the stator, [30] Foreign Application Priorit 1) characterized in that this device is comprised of a de- Jan 5 1971 France 7100086 tachable assembly formed by a segment holder support, 7

a lateral/shim, a radial segment and their resilient bear- [521 LS. Cl. I I i ll'lg means, said assembly being fitted into a corre- [511 Inc. 01...... i 01; 19/02 F64c 15/00 slmding cylindricauy'waued cavity Pmimd [58] Field oi p 1 67 128 stator and a lateral cheek, said assembly coming into t 6 21 resilient bearing contact against a lateral sealing shim i situated in the opposite cheek, an exterior thrust [56] Reerences Cited washer ensuring that this assembly is maintained in resilient juxtaposition with the radial segment and of the UNITED STATES PATENTS I V lateral sealing shims. 3,326,455 6/1967 Kell 123/801 x 3,369,739 2/1968 Abermeth 418/129 x 10 Claims, 4 Drawmg Figures 27 Z0 18 1 6 1 5 a 1 g 25 v 6 J 9 17 n W//////// 23 11- 4 24 8 T m 3 4 g 20 I g l SEALING DEVICES FOR ROTARY PISTON MACHINES This invention relates to a sealing device for rotary piston machines, whose rotor or rotary piston comprises a peripheral profile with epicyclic lobes rotating in a stator of conjugate profile comprising an additional lobe.

In these appliances radial sealing segments are usually arranged to join up with the stator lobes, each lobe thus forming a combustion or compression chamber according to whether it is a case of an engine or a compressor.

These segments are generally completed by radial sealing segments. Lateral sealing shims ensure continuity of sealing between radial segments and lateral segments. All these sealing elements have the advantage of being mounted in the stator and of being fixed.

The object of the present invention is to derive the utmost benefit from this advantage with an arrangement which enables quick and easy changing of each segment, this changing being able to take place, if necessary, without stopping the machine, the latter continuing to rotate with the two lobes adjacent to the segment to be changed being put out of operation.

Another objectof the invention is to be able to adjust, during operation, the directional setting of the radial segment.

In fact it is advantageous to be able to carry out, during operation, an adjustment of the inclination of the radial segments as a function of various parameters, such as rate of flow, amount of leakage, power'or effis ciency, the adjustment of this setting angle being likewise very important for preventing identations on the rotor surface.

For this purpose the device forming the subject matter of this invention is characterised by a cylindrical support angularly adjustable about its axis and comprising at one end a seating collar for accornodating a lateral sealing shim, whose outer face constitutes a closure bearing face,-and whose opposite face is extended over the full width of the rotor by a cylindrical shaped element truncated longitudinally substantially along a sector of its section and of the same outer diameter as the collar, a slot situated in the axial plane of said shaped element receiving a sealing segment whose contact profile, which is substantially cylindrical, has as pivot axis the same axis as the cylindrical outer bearing surface of the segment support formed by said collar and said shaped element.

The assembly formed by the segment support, the lateral shim, the radial segment, their resilient bearing means and the means for the angular setting of the seg ment is fitted into a corresponding cylindrically-walled cavity provided in the stator and a lateral-cheek, said assembly coming into resilient bearing contact against a lateral sealing shim situated in the opposite cheek. An exterior thrust washer supporting the control means for the angular adjustment of the segment-holder assembly ensures that this assembly is maintained in resilient juxtaposition with the segment and with the lateral sealing shims. g

Another object of the invention is to allow the dismantling of a defective assembly and the putting into position of a new assembly without the machine having to be stopped. For this purpose the cylindrical portion in the stator and the lateral cheek comprises a longitudinal dovetailed slot with which an equivalent slot in the oscillating support registers in the mean position.

After dismounting the closure washer from the assembly the latter is simply withdrawn, nothing opposing its long'tudinal sliding. The angular adjustment members ensure a convenient @ip on the assembly so as to effect this removal. On reassembly a guide fillet with a double dovetail is inserted into the corresponding slot of the cheek and of the stator and a new assembly, guided by its own slot into the lower dovetail of said fillet, is sunk into the seating.

For the purpose of preventing premature contact between segments, guides and rotor, thus risking damage to their surfaces, the radial segment is kept sunk in at maximum clearance of the space swept by the surface of the rotor in its seating by means of beads of lowrnelting point material, such as wax, which are removed without residues and sunk into drilled holes having their axis on the lateral surface of contact of the segment with the corresponding surface of their seating in the support.

After the complete insertion of the assembly the guide fillet is withdrawn and the closure washer replaced. The gradual rise in temperature of the assembly due to contact of hot components of the machine causes melting of the wax plugs and the gradual release of theresilient means due to longitudinal shearing of the wax plugs in a pasty state and the putting into operational contact of segment with the surface of the rotor.

Such a device while remaining relatively simple in production allows great possibilities in adjustment and renders the replacement of worn components as a routine operation, even in extreme cases of changing without' stopping the machine. These extreme cases can arise in marine machines or in any industrial installation which must ensure continuous service without failure. I

The simple shapes of the shims, guides and segments allow them to be produced economically from fritted porous self-lubricating materials.

One embodiment of the device according to the invention appears in greaterdetail in the following description and drawings, in which:

FIG. 1 is a view in axial section along the line II (FIG. 3) of a segment holder assembly in accordance with the invention mounted on the machine.

FIG. 2 is an end view of the same assembly showing the control members for adjusting the angular setting of the segment holder.

FIG. 3 is a section along the line III-III (FIG. 1) of a segment holder assembly in operation,

FIG. 4 is a section similar to FIG. 3 of a segment holder in the course of being mounted on a machine in operation.

Referring to thedrawings, in FIG. 1 the segment holder support 1 is mounted in the seating of a stator 2 in which a rotor 3 rotates. On this support there'is mounted a radial sealing segment 4 bearing in an axial slot against pressure springs 5 (these springs could if necessary be of the same type as those used in french Patent No. 1,431,008 in the Applicants name) and there is also mounted a lateral sealing shim 6 with its pressure springs 7 and its screwed-in support cover 8.

A screwed-in plate 9 fitted into the end of the support 1 ensures that the segment 4 is held in position during the mounting operations.

For this mounting operation there is likewise provided a dovetailed double guide slot 16 in which a guide bead 17 engages (FIG. 4).

The means for adjusting the inclination setting of the segment holder assembly 1 comprise a connecting sembly, after adjustment of the inclination of the segment holder assembly, on a bearing and locking washer 18.

The control of the adjustment of this inclination is ensured by a screw 25 operated by a knurled knob 28 and mounted freely rotatably in a boss 29, likewise mounted freely rotatably in the bearing washer 18 in accordance with the same arrangement as the boss 14 in the component 10.

This arrangement offers the advantage of an adjusting and locking device which forms a self-contained unit not requiring any special machining to the main components such as the cheek l9 and the stator, except for the threaded holes for fastening the screws 20. It likewise remains simple in production and with minimal space requirements.

The segment holder assembly is kept in its seating by the bearing washer 18 fixed on to one check 19 of the machine by screws 20. On the opposite cheek 21 there is fastened by means of further screws 20 a cover 22 containing a lateral sealing shim 23 and its thrust springs 24.

In operation the scaling is ensured by the sealing

shims

6 and 23 and the radial segment, the sealing pressure being ensured by the

springs

5, 7 and 24.

The changing of worn parts is effected in respect of the lateral shim 23 by dismounting the cover 22. In respect of the other parts, i.e. the shim 6 and the segment 4 mounted in the support 1 in a self-contained assembly, a standard exchange of these assemblies is made for assemblies with new wear-prone parts kept in store.

For this purpose the knurled knob 28 is detached from the threaded rod 25 and this latter is disengaged from the boss 29. This allows the dismounting of the component 10 after the nut 12 and the screw 15 have been removed. The removal of the washer 18 then allows the segment holder assembly to be withdrawn, which can be gripped by the rod 12.

In order to reassemble a new segment holder assembly the fillet 17 is inserted into the corresponding slot 16 in the stator cavity. The segment 4 is previously kept sunk into its seating by means of plugs or beads 26 (FIG. 4) made of heat-destructible material such as wax which does not leave any deleterious residues, so as to remain temporarily clear of the line 27 bounding the space swept by the rotor 3. The body 1 is then fitted by its corresponding slot 16 into the guide fillet l7 and sunk into the stator cavity. The fillet 17 left projecting beyond the cheek 19 is then withdrawn and the closure washer 18 is replaced with the control means for adjusting the inclination. As soon as the assembly undergoes a rise in temperature, thus melting the plug 26, the segment 4 comes into contact with the rotor surface and a new setting adjustment can be undertaken.

A replacement of the complete assembly can likewise be efiected very quickly after stoppage, by dismounting the screws 20, removing the complete assembly and putting into place a new assembly likewise comprising the washer 18 and the adjustment members. In this case the preceding procedure is no longer necessary but involves a stoppage of the machine for a very short time. While the segment holder assembly 1 pivots during the adjustments for setting the inclination, the

shims

6 and 23, which are of the same diameter as the outer diameter of the segment holder and fit into the same bore of the

cheeks

19 and 21, remain fixed because they are held in rotation by the ends of the lateral segments 30 (FIGS. 3 and 4) which are fitted into the shims. The

shims

6 and 23 comprise a concentric circular channel 31 which enables them to interlock against the portion 32 of the body 1 which forms the connection between the end seating collar and the truncated cylindrical zone forming the radial segment holder.

What is claimed is z 1. Sealing device for rotary piston machines of the type having radial segments adjusted in a support within the stator, comprising as a detachable unit a segment holder support, a lateral shim and a radial segment, said segment holder support fitting in a cylindrically walled cavity open along axial direction of the rotary piston machine and having an axial slot in which the radial segment is disposed, a part of said holder support extending outside of te stator to form a sealing collar for a screwed-in cover, said lateral shim having approximately the same diameter as said collar and the cylindrically walled cavity for said holder support, and being disposed between said screwed-in cover and the part of the segment holder fitted in the stator, and first resilient spring means between said segment holder and said radial segment, and second resilient spring means between said cover and the lateral shim to press the radial segment and the lateral shim against the piston, in sealing connection.

2. A device as claimed in claim 1 in which temporary guide means are provided to ensure the insertion of the support into its cavity.

3. A device as claimed in claim 2, in which the cylindrical portion in the stator comprises a longitudinal dovetailed slot, with which an equivalent slot in the segment holder support registers in the mean position, a fillet whose section is adapted to the profile of the two united slots ensuring the guiding of said support during its insertion into the cavity.

4. A device as claimed in claim 1, with means to hold said radial segment in its seating during its mounting on the machine in operation comprising a shearing bead or plug made of heat-destructible material.

5. A device as claimed in claim 4, in which said shearing bead or plug is made of wax and is inserted in drilled holes having their axis on the lateral surface of contact of the segment with the corresponding surface of its seating in the support, its length being proportional to the force of resistance to sheering to be provided.

6. A device as claimed in claim 1, in which the segment holder assembly comprises means for adjusting the angular setting of the segment holder assembly having the radial segment therein and means for locking the inclination of the segment holder assembly.

7. A device as claimed in claim 6, in which the adjusting means of the angular setting are detachably 9. A device as claimed in claim 1, in which the lateral sealing shim is of approximately the same diameter as the segment holder and contains a concentric circular channel for interlocking with a portion of said segment holder assembly.

10. A device as claimed in claim 6, in which the inclination locking means are mounted on the intermediate connecting component and the bearing washer.

, l l l

Claims

1. Sealing device for rotary piston machines of the type having radial segments adjusted in a support within the stator, comprising as a detachable unit a segment holder support, a lateral shim and a radial segment, said segment holder support fitting in a cylindrically walled cavity open along axial direction of the rotary piston machine and having an axial slot in which the radial segment is disposed, a part of said holder support extending outside of te stator to form a sealing collar for a screwed-in cover, said lateral shim having approximately the same diameter as said collar and the cylindrically walled cavity for said holder support, and being disposed between said screwed-in cover and the part of the segment holder fitted in the stator, and first resilient spring means between said segment holder and said radial segment, and second resilient spring means between said cover and the lateral shim to press the radial segment and the lateral shim against the piston, in sealing connection.

7. A device as claimed in claim 6, in which the adjusting means of the angular setting are detachably mounted on an outer bearing washer positioned over said screwed-in cover.

8. A device as claimed in claim 7, in which the control of the angular setting adjustment is effected by means of a screw held in translation by a swivelling boss firmly attached to the outer bearing washer, said screw driving rotarily the segment holder assembly by means of an additional swivelling boss attached to an intermediate connecting component which is in engagement with the segment holder assembly.

9. A device as claimed in claim 1, in which the lateral sealing shim is of approximately the same diameter as the segment holder and contains a concentric circular channel for interlocking with a portion of said segment holder assembly.