AU638225B2 - Seal structure for rotary body and vane-type rotary compressor employing the same - Google Patents

Description

I I COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Form Short Title: Int. Cl: ,Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed:.

Published: 638225 0 S

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Priority: Related Art:

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TO BE COMPLETED BY APPLICANT Name of Applicant: ATSUGI MOTOR PARTS COMPANY,

LIMITED

Address of Applicant: 1370, Onna, Atsugi-shi, Kanagawa-ken,

JAPAN

Actual Inventor: Seiji Akaike; Toshinori Aihara and Tsuneshige Kawade Address for Service: GRIFFITH HACK CO.

71 YORK STREET SYDNEY NSW 2000

AUSTRALIA

Complete Specification for the invention entitled: SEAL STRUCTURE FOR ROTARY BODY AND VANE-TYPE ROTARY COMPRESSOR EMPLOYING THE SAME The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5692A/as 1 SEAL STRUCTURE FOR ROTARY BODY AND VANE-TYPE ROTARY COMPRESSOR EMPLOYING THE SAME The present invention relates generally to a seal structure for a rotary body, such as a rotary shaft. The invention also relates to a vane-type rotary compressor having a compressor housing and a rotary shaft, between which a seal structure according to the present invention is interposed for establishing liquid-tight and gas-tight seal therebetween.

A seal used for an existing rotary body to be used in a vane-type rotary compressor includes a seal lip section and a seal ring. The latter mentioned element includes an annular washer-like backplate member an elastomeric seal ring member which is connected to the annular washer-like member by an annular band. This band is folded over an crimped to secure the two major sections, i.e. the seal lip section and the seal ring member, together.

The seal lip section is disposed on the inboard 20 side of the seal ring in such manner that a portion Sthereof seats on the inner surface of the portion of the elastomeric member which is in contact with the outer periphery of a rotary drive shaft. Upon being heated the crimped metal band and annular washer-like backplate member expand to the point where the elastomeric member, which is subject to torque due to its sliding engagement with the drive shaft, begins to rotate with respect to the two metal elements, i.e. the washer-like member and the crimped metal band. This induces friction and 30 associated wear which tends to shorten the life of the seal lip and seal ring.

S:18711N -2 According to one aspect of the present invention there is provided a seal structure for sealing between a rotary body and a stationary structure, comprising: an elastomeric seal member disposed between a rotary body and a stationary member, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said seal member having a first section to be supported on said stationary member and a second section which is arranged to sealingly contact the periphery of said rotary body; a flat metal member having a plane mating with said first section of said seal member; a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form; and means, cooperative with at least one of said flat metal member and said holder member for providing firm engagement with the first section of said seal member and causing elastic deformation of said seal member, for preventing movement of said first section of the seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member 25 and said flat metal member, which surface is perpendicular to the axis of the rotary body, for permitting an axial elastic deformation of said seAl member, in a manner so as to fit the elastically deformed portion of said seal member to said convex or concave portion and to assure said firm engagement between said holder member and said seal member.

According to a second aspect of the present invention there is provided a seal structure for a rotary body comprising: a first seal assembly comprising: a first seal member comprising an elastomeric material and disposed between a rotary body and a stationary member, said first seal member being active

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:18711N 3 while said rotary body is in rotation, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said first seal member having a first section mounted on said stationary member and a second section sealingly contacting the periphery of said rotary body, a flat metal member having a plane mating with said first section of said first seal member, a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form, and means for preventing movement of the first section of said first seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member and said flat metal member, which surface is perpendicular to the ,axis of the rotary body, for permitting an axial elastic deformation of said first seal member, in a manner so as to fit the elastically deformed portion of said first seal member to said convex or concave portion and to assure said firm engagement between said holder member and said first seal member; and Saa second seal assembly cooperative with said first seal assembly for establishing a liquid-tight and gas-tight seal between said rotary body and said stationary member, said second seal assembly comprising a oe second seal member having a third section elastically seating on said stationary member and a fourth section 9. 9.

elastically and sealingly contacting the periphery of said rotary body, said second seal member being active while said rotary body is held stationary for 9ee* establishing a liquid-tight and gas-tight seal.

9*o* :o According to a third aspect of the present invention there is provided a vane-type rotary compressor comprising: a compressor housing unit for defining an S:18711N -4internal space therein; a rotor assembly including a cam ring disposed within said internal space of said compressor housing unit and defining an oval space to house therein a rotor which carries a plurality of vanes disposed in a plurality of radially extending slits defined in said rotcr; a drive shaft rigidly connected to said rotor at one end, said drive shaft extending through a cylindrical section of said compressor housing unit and connected to a driving power source at the other end via a power train; a seal assembly disposed between said drive shaft and the inner periphery of said cylindrical section, said seal assembly comprising: an elastomeric seal member disposed between a rotary body and a stationary member for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said seal member having a first section mounted on said stationary member and a second section sealingly contacting the periphery of said rotary body; es a flat metal member having a plane mating with 'said first section of said seal member; a holder member firmly seated on said stationary %:member and holding said first section and said flat metal member in an assembled form; and means for preventing movement of the first section of said seal member relative to said holder 30 member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member and said flat metal member, which surface is perpendicular to the axis of the rotary body, for 35 permitting an axial elastic deformation of said seal member, in a manner so as to fit the elastically deformed portion of said seal member to said convex or concave portion and to assure said firm engagement between said S:18711N holder member and said seal member.

According to a fourth aspect of the present invention there is provided a vane-type rotary compressor comprising: a compressor housing unit for defining an internal space therein; a rotor assembly including a cam ring disposed within said internal space of said compressor housing unit and, defining an oval space to house therein a rotor which carries a plurality of vanes disposed in a plurality of radially extending slits defined in said rotor; a drive shaft rigidly connected to said rotor at one end, said drive shaft extending through a cylindrical section of said compressor housing unit and connected to a driving power source at the other end via a power train; a seal assembly disposed between said drive shaft and the inner periphery of said cylindrical section, said seal assembly comprising: a first seal assembly comprising a first seal S: member made of an elastomeric material and disposed between a rotary body and a stationary member, said first seal member being active while said rotary body is in 25 rotation, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight *600 seal, said first seal member having a first section mounted on said stationary member and a second section sealingly contacting the periphery of said rotary body, a 30 flat metal member having a plane mating with said first section of said first seal member, a holder member firmly

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seated on said stationary member and holding said first section and sai flat metal member in an assembled form, o and means for preventing movement of the first section of oo 35 said first seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a S:18711N 6 peripheral surface of at least one of said holder member and said flat metal member, which surface is perpendicular to the axis of the rotary body, for permitting an axial elastic deformation of said first seal member, in a manner so as to fit the elastically deformed portion of said first seal member to said convex or concave portion and to assure said firm engagement between said holder member and said first seal member; and a second seal assembly cooperative with said first seal assembly for establishing a liquid-tight and gas-tight seal between said rotary body and said stationary member, said second seal assembly comprising a second seal member having a third section elastically seating on said stationary member and a fourth section elastically and sealingly contacting the periphery of said rotary body, said second seal member being active while said rotary body is held stationary for establishing a liquid-tight and gas-tight seal.

In the preferred construction, the restricting means comprises an impression formed in the holder member, which impression is formed on a surface of the holder member mating the first section of the seal member. The holder member is formed with a plurality of the impressions circumferentially arranged with given intervals therebetween.

In an alternative construction, the restricting means comprises a cut-out in the holder member, which cut-out is formed on a surface of the holder member 30 mating the first section of the seal member. The holder member may be formed with a plurality of the cut-outs arranged with given intervals therebetween.

In another alternative construction, the restricting means comprises an impression formed in the flat metal plate, which impression is formed on a surface 1 y Vm of the metal plate mating the first section of the seal :18711N 7 member. In this case, the metal plate is formed with a plurality of the impressions circumferentially arranged at given intervals.

In yet another construction alternative, the restricting means comprises a cut-out formed in the flat metal plate, which cut-out is formed on a surface of the metal plate mating the first section of the seal member.

The metal plate is formed with a plurality of the cutouts arranged at given intervals.

In still another alternative construction, the restricting means comprises a friction means formed on a plane of one of the flat metal plate and the holder member, which plane mates with one surface of the first section of the seal member. The friction means comprises a knurled surface of the flat metal member mating with the first section of the seal member.

In the preferred construction, the first seal member is made of a synthetic resin such as a fluoroplastic and the second seal member is made of a 20 rubber such as nitrile rubber.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.

Fig. 1 is a sectional view of a vane-type rotary S 25 compressor, to which the preferred embodiment of a seal structure is employed; S: Fig. 2 is a sectional view of the preferred embodiment of a seal structure, according to the ooo: invention, which seal structure is disposed between a casing and a rotary shaft; iR Fig. 3 is an enlarged section of a seal assembly 18711N 8 forming the major part of the preferred embodiment of the seal structure according to the invention; Fig. 4 is a front elevation of a washer-like backplate; Fig. 5 is a partial enlarged section of a seal ring assembly; Fig. 6 is a section of a seal lip assembly; Fig. 7 is a front elevation of the backplate forming a first modification of the preferred embodiment of the seal structure;

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S *o o o*o* *o7o o *Bo *oo *go go o :87 1 Fig. 8 is a partial enlarged section of the seal ring assembly in the first modification of the preferred embodiment; Fig. 9 is a front elevation of the backplate forming a second modification of the preferred embodiment; embodiment; Fig. 10 is a partial enlarged section of the seal ring assembly in the second monidification of the preferred embodiment; Fig. 11 is a front elevation of the backplate

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5 0 S@ S forming a third monidification of the preferred embodiment; and Fig. 12 is a partial enlarged section of the seal ring assembly in the third modification of the preferred embodiment.

Ref-rring now to the drawings, particularly to Fig. 1, a vane-type rotary compressor has a front plate 100, a head cover"102, a housing 106 and a cam ring 108.

The front plate 100 comprises a single element which is simply formed of metal plate and is rigidly secured onto the front end of the cam ring 106 by means of fastening bolts 108. The rear end of the cam ring 106 is closed by means of a back plate 110 for defining a clearance within the cam ring for rotatably receiving therein a rotor 112 with a plurality of vanes 114. As will be appreciated, the vanes 114 are received within radially extending slits 116 formed in the rotor 112. Each vane 114 is 9 movable relative to the corresponding slit 116 so that it may protrude from the outer periphery of the rotor 112 and rotatingly and sealingly contact with the inner periphery of the cam ring.

The head cover 102 is formed with an axially extending cylindrical boss-like portion 118. The boss-like portion 118 is arranged coaxially with an outer cylinderical portion 120. The rear ends of the boss-like portion 118 and the cylinderical portion 120 are sealingly engaged with the front plate 100 for defining o therebetween an aspiration chamber 122 which is connected to an inlet port 124 for introducing therethrough a refrigerant gas. The aspiration chamber 122 is communicated with working chainbers 126 via a suction opening (not shown) which opens on the cam surface of the front plate 100. The working chamber is., th turn, communicated with a discharge chamber 128 define in the housing 104 by the cam ring 106 and the rear plate 110 Via discharge port formed through the rear platu. The discharge chamber 128 is in AaEaw". with a rjcharge port 130. The operation for condensing the refrigerant gas for condensation and thereby removing heat is performed in a per se known manner by rotation of the rotor 112.

The rotor 112 is integrally formed with a drive shaft and a support shaft 134. The drive shaft 132 extends through the boss-like portion 118 of the head 10 II

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cover 102 to project outwardly from the head cover. A bearing assembly 136 is disposed between the inner periphery of the boss-like portion 118 and the outer periphery of the drive shaft 132. Similarly, the support shaft 134 extends from the plane surface of the rotor at the side opposite to the plane surface from which the drive shaft extends. The support shaft 134 is received within a boss-like portion 138 of the rear plate. A .bearing 140 is disposed between the inner periphery of the boss-like portion 138 of the rear plate and the outer periphery of the support shaft. In the preferred embodiment, the bearings 136 and 140 comprises roller type needle bearings. An engine driven pulley 142 is associated with the drive shaft 132 via a known clutch assembly 144 which releasably engages the pulley to the drive shaft. Therefore, as clutch is engaged, the rotor 112 is driven by an automotive engine.

The preferred embodiment of a seal assembly 150 is disposed between the inner periphery of the boss-like S* 2portion 118 of the head cover 102 and the outer periphery of drive shaft. The seal assembly 150 is so designed as to establish liquid tight and gas-tight seal therebetween.

Figs. 2 and 3 show the detailed construction of the preferred embodiment of the seal structure according to the invention. The preferred embodiment of the seal structure generally comprises a seal ring assembly 152 11 and a seal lip assembly 154 similarly to that in the prior art set forth above. The seal ring assembly comprises an elastometric seal ring 156 and a washer-line backplate 158. The seal ring 156 and the backplate 158 are retained in assembled form by means of an annular ring shaped holder member 160. The holder member 160 comprises a circumferentially extending major section 162 and radially extending edge sections 164 and 166 radially and inwardly extending from the axial edges of the major 1 section. With the major section 162 and the edge sections 164 and 166, the holder member 162 is formed into a cross-sectionally channel shaped configuration

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defining a space for receiving the outer ends of the seal ring 156 and the backplate 158. The holder member 160 is rigidly secured onto the inner periphery of the boss-like go* portion 120.

*eso The seal ring 156 has a seal m section 168 sealingly contacting the outer periphery of the drive shaft 132. The seal ring 156 is cooperative with a seal lip 168 which has coaxially arranged cylinderical section's 170 and 172 and a radially extending section 176 connecting the inner and outer cylinderical sections 170 and 172. An annular projection 178 projecting from the inner periphery of the inner cylinderical section 170.

On the other hand, the outer periphery of the outer cylindrical section 172 elastically and sealingly contact with ~'he inner periphery of the boss-like portion 120 of 12 -13the head cover 104. A core 180 is inserted in the seal lip 168. The core 180 is of cross-sectionally L-shaped configuration and extends over the outer cylindrical section 172 and the radially extending section 174.

In the practical operation, the seal ring 156 is active for establishing the liquid tight and gas-tight seal while the drive shaft rotates, and the seal lip 170 is active for establishing seal while the drive shaft does not rotate.

Figs. 4 and 5 show the further detail of the seal ring assembly. In this preferred embodiment, the seal ring 156 is made of a fluoroplastic, such as Teflon (trademark). In this embodiment, the holder member 160 is so constructed that it can maintain firm engagement with the assembly of the seal ring 156 and the back plate 158 in order to prevent the seal ring 156 from rotatating with the drive shaft 132, which enables the working life of the compressor to be prolonged. This construction is designed to overcome the problem discussed in the introductory section of the disclosure, wherein the metal and elastomeric components of the seal upon becomming heated expand at different rates and become loose to the point where relative movement (slippage) occurs.

In this construction, the seal ring 156 is formed into a configuiation essentially L-shaped in cross-section. As set forth, the seal ring 156 has the seal tongue section 168 integrally formed with a radially extending section 169 which has a surface mating with the back plate 158. The holder member 160 clamps the radially extending section 169 of the seal ring 156 and the back plate 158. In order to firmly hold the outer circumferential portion of the seal ring 156 and the back plate 158, the holder member 160 is formed with a plurality of cut-outs 160a, as shown in Fig. 4. The cut-outs 160a essentially kfmi-circular and are arranged around the circumference of the holder at given intervals.

These cut-outs 160a are used as shown in Fig. 5 to defined S :voids into which the circumferential edge portion of the elastomeric seal ring 156 can bulge during the clamping action. The portions of the seal ring 156 which bulge into the cut-outs 160a defined a kind of locking block arrangement which prevents relative rotation therebetween.

Thus, even though an expansion differential tends to occur o. between the metal and elastomeric components of the seal, since one of the metal components is locked together with the elastomeric seal ring 156 the tendancy of the members to rotate independently is prevented.

2 The above described construction is used in combination with a seal lip assembly 154 which is shown in Fig. 6. The seal lip 168 is made of a nitrile rubber.

The core 180 associated with the seal lip 168 comprises a shaped metal insert. A garter spring 182 surrounds the lip section and biases the same inwardly into contact with the drive shaft shaft 132. The shaped metal insert 180 is 14 covered with elastomeric material in such manner to define a shoulder section 184 which is arranged to cooperate with, the construction shown in Figs. 4 and 5. This shoulder section 184 is designed to cooperated with the holder member 160 so that the two sections seat snugly together and cooperate to prevent any relative rotation between components of the seal arrangement.

Figs. 7 and 8 show a second seal construction which enables the working life of the compressor to be prolonged. In this arrangement the annular back plate 158 is formed with a plurality of indents or cut-outs 158a about the periphery thereof. When assembled, as shown in Fig. 8, the seal ring 156 and the back plate 158 are sock clamped together in s*VIe a manner that the seal ring 156 is squeezed into the cut-outs 158a formed about the periphery of the back plate 158 and thus provides an interlocking act"ion which even in the event of notable expansion still tends to hold the two members together and

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prevent relative rotation therebetween. Due to the clamping the holer member 160 is deformed in a manner S. causing it to partially extend into the cut-outs (see the S"lower right hand corner of Fig. 8) thus establishing an interlock between the two metal members 158 and 160) of the instant section of the seal. This ensures that relative rotation between these elements is also prevented.

Figs. 9 and 10 show a second seal construction 15 *6 C)

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60 900 0: 0S 0 00 00e0 which prolongs the life of the seal and therefore the service life of the device in which it is disposed. In this embodiment the back plate 158 is knurled (KN) and thus provided with a surface which is sufficiently rough to provide a vast number of small indentations into which the elastomeric member 156 can be squeezed to interlock the two members.

Figs. 11 and 12 show another seal construction which can be used to prolong the life of the assembled article. In this arrangement the back plate 158 is formed with a plurality of openings 158b. In this embodiment the openings 158b are circular and formed by drilling for example. It is of course possible to punch the holes out and thus formi'burrs on one side. When the seal ring 156 and the back plate 158 are clamped together a portion of the elastomeric seal ring 156 is squeezed into the holes in manner similar to the above embodiments. In the event that the holes are formed by punching, the burrs can be pressed advantageously into the elastomeric member to provide additional interlocking.

Although each of the above disclosed arrangements have been described individually and shown in various modifications of vane compressor it will be clearly understood that all of the features can be and are intended to be used in combination with one or any number of the others in order to derive the maximum benefit. The disclosure in isolation is deemed to be advantageous to 0 *000: 00 00 S

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0 00 *0 16 clarify the indvidual merit or each arrangement and not detract from the advantages of the others and to further clarify that use of any one or any combination of the features or their equivalents falls within the scope of S the present invention which is limited only by the claims set forth hereinbelow.

Furthermore, though the preferred embodiment of the seal structures according to the present invention has been disclosed in terms of a type applied in a vane-type rotary compressor, the same seal structures may be 10 *applicable in various devices which have a rotary body rotatable about a stationary member.

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Claims (26)

1. A seal structure for sealing between a rotary body and a stationary structure, comprising: an elastomeric seal member disposed between a rotary body and a stationary member, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said seal member having a first section to be supported on said stationary member and a second section which is arranged to sealingly contact the periphery of said rotary body; a flat metal member having a plane mating with said first section of said seal member; a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form; and means, cooperative with at least one of said flat metal member and said holder member for providing firm engagement with the first section of said seal member and causing elastic deformation of said seal member, for preventing movement of said first section of the seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member 25 and said flat metal member, which surface is perpendicular to the axis of the rotary body, for permitting an axial elastic deformation of said seal member, in a manner so as to fit the elastically deformed portion of said seal member to said convex or concave portion and to assure said firm engagement between said holder member and said seal member.

2. A seal structure as set forth in claim 1, wherein said preventing means comprises at least one recess formed in said holder member, which recess is formed on a surface of said holder member mating said first section of said seal member.

3. A seal structure as set forth in claim 2, wherein said holder member is formed with a plurality of V V *c V V V V S S NPA4 0 ,:18711 N 19 recesses circumferentially arranged at given intervals.

4. A seal structure as set forth in claim 1, wherein said preventing means comprises at least one cut-out formed in said holder member, which cut-out is formed on a surface of said holder member mating said first section of said seal member. A seal structure as set forth in claim 4, wherein said holder member is formed with a plurality of cut-outs arranged at given intervals.

6. A seal structure as set forth in claim 1, wherein said preventing means comprises at least one recesss formed in said flat metal member, which recess is formed on a surface of said metal member mating said first section of said seal member.

7. A seal structure as set forth in claim 6, wherein said metal member is formed with a plurality of recesses circumferentially arranged at given intervals.

8. A seal structure as set forth in claim 1, wherein said preventing means comprises at least one cut-out formed in said flat metal member, which cut-out is formed on a surface of said metal member mating said first section of said seal meber.

9. A seal structure as set forth in claim 8, *wherein said metal member is formed with a plurality of cut-outs arranged at given intervals.

10. A seal structure as set forth in claim 1, wherein said preventing means comprising an uneven to portion formed on a plane of either one of said flat metal member and said holder member, which plane mates 30 with one surface of said first section of said seal S" "member. m b11. A seal structure as set forth in claim wherein said uneven portion comprises a knurled surface of said flat metal member mating with said first section S 35 of said seal member.

12. A seal structure for a rotary body comprising: a first seal assembly comprising: a first seal member comprising an elastomeric 20 material and disposed between a rotary body and a stationary member, said first seal member being active while said rotary body is in rotation, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said first seal member having a first section mounted on said stationary member and a second section sealingly contacting the periphery of said rotary body, a flat metal member having a plane mating with said first section of said first seal member, a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form, and means for preventing movement of the first section of said first seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member and said flat metal -member, which surface is perpendicular to the axis of the rotary body, for permitting an axial elastic deformation of said first seal member, in a manner so as to fit the elastically deformed portion of said first seal member to said convex or concave portion and to assure said firm engagement :between said holder member and said first seal member; and a second seal assembly cooperative with said firot seal assembly for establishing a liquid-tight and gas- tight seal between said rotary body and said stationary member, said second seal assembly comprising a second 30 seal member having a third section elastically seating on S said stationary member and a fourth section elastically and sealingly contacting the periphery of said rotary 9**9 body, said second seal member being active while said rotary body is held stationary for establishing a liquid- tight and gas-tight seal.

13. A seal structure as set forth in claim 12, wherein said first seal member is made of a synthetic resin and said second seal member is made of a rubber. 21

14. A seal structure as set forth in claim 13, wherein said first seal member is made of a fluoroplastic. A seal structure as set forth in any one of claims 12 to 14, wherein said second seal member is made of nitrile rubber.

16. A seal structure as set forth in any one of claims 12 to 15, wherein said preventing means is incorporated with one of said flat metal member and said holder member and defines a space for accommodating bulging of said first seal member due to elastic deformation thereof.

17. A seal structure as set forth in any one of claims 12 to 16, wherein said preventing means comprises at least one recess formed in said holder member, which recess is formed on a surface of said holder member mating said first section of said first seal member.

18. A seal structure as set forth in claim 17, wherein said holder member is formed with a plurality of recesses circumferentially arranged at given intervals.

19. A seal structure as set forth in any one of claims 12 to 16, wherein said preventing means comprises at least one cut-out formed in said holder member, which cut-out is formed on a surface of said holder member 25 mating with said first section of said first seal member. «*e

20. A seal structure as set forth in claim 19, wherein said holder member is formed with a plurality of said cut-outs arranged at given intervals.

21. A seal structure as set forth in any one of 30 claims 12 to 16, wherein said preventing means comprises at least one recess formed in said holder member, which recess is formed on a surface of said holder member mating with said first section of said first seal member. :e :S 22. A seal structure as set forth in claim 21,

35. wherein said metal member is formed with a plurality of recesses circumferentially arranged at given intervals. 23. A seal structure as set forth in any one of claims 12 to 16, wherein said preventing means comprises 22 at least one cut-out formed in said flat metal member, which cut-out is formed on a surface of said metal member mating said first section of said first seal member. 24. A seal structure as set forth in claim 23, wherein said metal member is formed with a plurality of said cut-outs arranged at given intervals. A seal structure as set forth in any one of claims 12 to 16, wherein said preventing means comprises an uneven portion formed on a plane of either one of said flat metal member and said holder member, which piane mates with one surface of said first section of said first seal member. 26. A seal structure as set forth in claim wherein said uneven portion comprises a knurled surface of said flat metal member mating with said first section of said first seal member. 27. A vane-~type rotary compressor comprising: a compressor housing unit for defining an internal space therein; a rotor assembly including a cam ring disposed within said internal space of said compressor housing unit and defining an oval space to house therein a rotor which carries a plurality of vanes disposed in a plurality of radially extending slits defined in said 25 rotor; a drive shaft rigidly connected to said rotor at one end, said drive shaft extending through a cylindrical section of said compressor housing unit and connected to a driving power source at the other end via a power S 30 train; Sa seal assembly disposed between said drive shaft and the inner periphery of said cylindrical section, said S: seal assembly comprising: an elastomeric seal member disposed between a rotary 35 body and a stationary member for sealing contact with the periphery of said rotary body for establishing a liquid- tight and gas-tight seal, said seal member having a first section mounted on said stationary member and a second 23 section sealingly contacting the periphery of said rotary body; a flat metal member having a plane mating with said first section of said seal member; a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form; and means for prevent: ing movement of the first section of said seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member and said flat -metal member, which surface is perpendicular to the axis of the rotary boody, for permitting an axial elastic deformation of said seal member, in a manner so as to fit the elastically deformed portion of said seal member to said convex or concave portion and to assure said firm engagement between said holder member and said seal member. 28. A vane-type rotary compressor comprising: a compressor housing unit for defining an internal space therein; a rotor assembly including a cam ring disposed "within said internal space of said compressor housing 25 unit and defining an oval space to house therein a rotor which carries a plurality of 'vanes disposed in a plurality of radially extending slits defined in said rotor; a drive shaft rigidly connected to said rotor at one end, said drive shaft extending through a cylindrical section of said compressor housing unit and connected to a driving power source at the other end via a power S: train; a seal assembly disposed between said drive shaft :o 35 and the inner periphery of said cylindrical section, said seal assembly comprising: a first seal assembly comprising a first seal member w\ made of an elastomeric material and disposed between a :18711N 24 rotary body and a stationary member, said first seal member being active while said rotary body is in rotation, for sealing contact with the periphery of said rotary body for establishing a liquid-tight and gas-tight seal, said first seal member having a first section mounted on said stationary member and a second section sealingly contacting the periphery of said rotary body, a flat metal member having a plane mating with said first section of said first seal member, a holder member firmly seated on said stationary member and holding said first section and said flat metal member in an assembled form, and means for preventing movement of the first section of said first seal member relative to said holder member in a circumferential direction, said preventing means including a convex or concave portion formed in a peripheral surface of at least one of said holder member and said flat metal member, which surface is perpendicular to the axis of the rotary body, for permitting an axial elastic deformation of said first seal member, in a manner so as to fit the elastically deformed portion of said first seal member to said convex or concave portion and to assure said firm engagement between said holder member and said first seal member; and 25 a second seal assembly cooperative with said first L.e 6 seal assembly for establishing a liquid-tight and gas- tight seal between said rotary body and said stationary member, said second seal assembly comprising a second seal member having a third section elastically seating on 30 said, stationary member and a fourth section elastically 5* and sealingly contacting the periphery of said rotary sell: body, said second seal member being active while said rotary body is held stationary for establishing a liquid- .i tight and gas-tight seal. o 35 29. A vane-type rotary compressor as set forth in claim 28, wherein said first seal member is made of a synthetic resin and said second seal member is made of a ubber. S: 11N 25 A vane-type rotary compressor as set forth in claim 29, wherein said first seal member is made of fluoroplastics. 31. A vane-type rotary compressor as set forth in any one of claims 28 to 30, wherein said second seal member is made of nitrile rubber. 32. A vane-type rotary compressor as set forth in any one of claims 28 to 31, wherein said preventing means is incorporated with one of said flat metal member and said holder member and defines a space for accommodating bulging of said first seal member due to elastic deformation thereof. 33. A vane-type rotary compressor as set forth in any one of claims 28 to 32, wherein said preventing means comprises at least one recess formed in said holder member, which recess is formed on a surface of said holder member mating said first section of said first seal member. 34. A vane-type rotary compressor as set forth in claim 33, wherein said holder member is formed. with a plurality of saJ4 recesses circumferentially arranged at given intervals. 35. A vane-type rotary compressor as set forth in any one of claims 28 to 32, wherein said preventing means comprises at least one cut-out formed in said holder member, which cut-out is formed on a surface of said go holder member mating said first section of said first seal member.

36. A vane-type rotary compressor as set forth in 30 claim 35, wherein said holder member is formed with a plurality of said cut-outs arranged at given intervals.

37. A vane-type rotary compressor as set forth in o any one of claims 28 to 32, wherein said preventing means ;comprises at least one recess formed in said flat metal 35 member, which recess is formed on a surface of said metal member mating said first section of said first seal member.

38. A vane-type rotary compressor as set forth in N 11N 26 claim 37, wherein said metal member is formed with a plurality of said recesses circumferentially arranged at given intervals.

39. A vane-type rotary compressor as set forth in any onf. of claims 28 to 32, wherein said preventing means comprises at least one cut-out formed in said flat metal member, which cut-out is formed on a surface of said metal member mating said first section of said first seal member.

40. A vane-type rotary compressor as set forth in claim 39, wherein said metal member is formed with a plurality of said cut-outs arranged with given intervals.

41. A vane-type rotary compressor as set forth in any one of claims 28 to 32, wherein said preventing means comprising an uneven portion formed on a plane of either one of said flat metal member and said holder, which plane mates with one surface of said first section of said.first seal member.

42. A vane-type rotary compressor as set forth in claim 41, wherein said uneven portion comprises a knurled surface of said flat metal member mating with said first section of said -irst seal member. "43. A seal structure for a rotary body substantially as hereinbefore described with reference to the 25 accompanying drawings. Dated this ist day of April 1993 ATSUGI MOTOR PARTS, COMPANY, LIMITED By their Patent Attorneys GRIFFITH HACK CO o eo S:18711N