JP2007303414A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine capable of applying the axial preload to a rotation preventing coupling for a movable scroll without disposing a shim between a rear casing and a front casing. <P>SOLUTION: A compressor as the scroll fluid machine is provided with an EM coupling 54 containing movable and fixed plates 56, 58 and a ball 62 as the rotation preventing coupling, and a compression coil spring 66 to press the fixed plate 58 between the fixed plate 58 and the front casing 12 toward the movable plate 56. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine suitable as a compressor of a refrigeration circuit used for air conditioning of a vehicle.

A scroll compressor as a fluid machine of this type includes a rear and front cane sig, a scroll unit including a movable and fixed scroll is accommodated in the rear cane sig, and a drive shaft for the scroll unit is disposed in the front casing. (Patent Document 1).
The scroll compressor described above executes a series of processes from suction of refrigerant to compression discharge by the movable scroll turning with respect to the fixed scroll as the drive shaft rotates. During the turning of the movable scroll, the movable scroll is in a state in which the rotation is prevented by the rotation prevention coupling, and the rotation prevention coupling is disposed between the end surface of the front casing and the movable scroll.

The above-described rotation prevention coupling not only prevents the rotation of the movable scroll but also receives a thrust force from the movable scroll, so the axial preload of the rotation prevention coupling affects the initial rotational torque characteristics of the scroll compressor. Effect.
On the other hand, the axial preload of the rotation prevention coupling varies greatly due to variations in processing accuracy and assembly accuracy of the components of the scroll compressor. For this reason, in the compressor of Patent Document 1, when the front casing is fastened to the rear casing, a shim is interposed between the casings, and the above-described variation is absorbed by the thickness of the shim. A desired axial preload is applied.
Japanese Utility Model Publication No. 3-78990

However, the adjustment of the axial preload by the shim described above takes a lot of time and effort to assemble the compressor, greatly reducing its productivity, and it is necessary to prepare shims of various thicknesses. As a result, Shim stocks are increasing the cost of scroll compressors.
The present invention has been made on the basis of the above-mentioned circumstances, and the object of the present invention is excellent in assembling workability and large in cost reduction in setting the axial preload of the rotation prevention coupling. It is to provide a scroll type fluid machine that contributes.

In order to achieve the above object, a scroll type fluid machine of the present invention is provided between an end surface of a front casing and a rotation prevention coupling, and when the front casing is fastened to a rear casing, the rotation prevention cup An elastic member that presses the ring toward the movable scroll is provided.
According to the scroll type fluid machine of claim 1, at the same time as the front casing is fastened to the rear casing, the elastic member presses the rotation preventing coupling against the movable scroll, and the rotation preventing coupling receives the preload in the axial direction thereof. Give.

  Specifically, the rotation prevention coupling is formed on each of the movable plate and the fixed plate, and the ring-shaped movable plate and the fixed plate, which are supported on the end surfaces of the movable scroll and the front cane sig, respectively, and face each other with a space therebetween. And the elastic member is disposed between the end surface of the front casing and the fixed plate, and the elastic member is disposed between the end surface of the front casing and the fixed plate. (Claim 2).

According to a second aspect of the present invention, the rotation-preventing coupling prevents the movable scroll from rotating while the movable scroll is turning, and the ball held between the annular race grooves of the movable and fixed plates rolls along the annular race groove.
In this case, the end surface of the front casing has a recess at a portion corresponding to the annular race groove of the fixed plate, and the fixed plate is pressed by the end surface of the front casing and the elastic member at the outer peripheral edge and the inner peripheral edge. (Claim 3). According to this configuration, the parallelism of the fixed plate with respect to the movable plate is maintained regardless of the annular race groove, and the slicing force from the movable scroll does not hit the annular race groove of the fixed plate.

Further, the elastic member comprises a compression coil spring that presses the inner peripheral edge of the fixed plate (Claim 4), and this compression coil spring prevents rotation of the axial preload proportional to the tightening force of the front cannig against the rear casing. Grant to the coupling.
In this case, when the front cannig is fastened to the rear casing, it is preferable that a gap is secured between the casings (Claim 5), and the presence of this gap makes it possible to prevent the rotation prevention coupling in the axial direction. The load can be adjusted by the fastening force of the front casing.

  Since the scroll type fluid machine according to claims 1 to 4 includes an elastic member that presses the rotation prevention coupling against the movable scroll, the rotation prevention is achieved without interposing a shim between the rear casing and the front casing. A desired initial rotational torque characteristic can be obtained by applying a preload in the axial direction to the coupling. Further, since no shim is required for assembling the scroll type fluid machine, the assembling work is facilitated and the cost can be reduced.

  In the scroll type fluid machine according to the fifth aspect, since the axial preload to be applied to the rotation prevention coupling can be adjusted by the tightening force of the front casing, the processing accuracy and assembly accuracy of the component parts in the scroll type fluid machine can be adjusted. Can be absorbed by adjusting the preload, and the initial rotational torque characteristics of the scroll type fluid machine can be obtained easily and stably.

FIG. 1 shows a scroll compressor as a scroll type fluid machine. This scroll compressor is incorporated in a refrigeration circuit for air-conditioning a vehicle, and is used for compression of refrigerant circulating in the refrigeration circuit.
The scroll compressor includes a rear casing 10 and a front casing 12, and a scroll unit 14 is accommodated in the rear casing 10. The scroll unit 14 includes a fixed scroll 16 fixed to the rear casing 10 and a movable scroll 18 assembled so as to mesh with the fixed scroll 16. A series of processes from suction of refrigerant through compression to discharge is continuously performed.

  More specifically, a discharge chamber 20 is formed in the rear casing 10 between its end wall and the fixed scroll 16 of the scroll unit 14, and the discharge chamber 20 is formed in the discharge hole 22 of the scroll unit 14 (fixed scroll 16). While being connectable via the discharge valve 24, it is connected to the refrigerant circulation path of the refrigeration circuit via a discharge port (not shown) formed in the rear casing 10.

The rear cannig sig 10 is also provided with a refrigerant suction port (not shown). This suction port introduces the refrigerant into the rear casing 10 from the refrigerant circulation path, and the introduced refrigerant is sucked into the scroll unit 14. Is done.
On the other hand, a drive shaft 26 is disposed in the front casing 12, and the drive shaft 26 has a large diameter end portion 28 and a small diameter shaft portion 30. The large diameter end portion 28 is rotatably supported by the front casing 12 via a needle bearing 32, and the small diameter shaft portion 30 is rotatably supported by the front casing 12 via a ball bearing 34. Further, a lip seal 36 is disposed between the small diameter shaft portion 30 and the front casing 12, and the lip seal 36 partitions the inside of the front casing 12 in an airtight manner.

  A small-diameter shaft portion 30 of the drive shaft 26 protrudes from the front casing 12, and the protruding end is connected to a drive pulley 38 incorporating an electromagnetic clutch. The drive pulley 38 is rotatably supported by the front casing 12 via a bearing 40. ing. The drive pulley 38 is connected to an output pulley on the engine side of the vehicle via a belt, and is rotated by receiving power from the engine. Therefore, during driving of the engine, if the electromagnetic clutch in the drive pulley 38 is on, the drive shaft 26 is rotated together with the drive pulley 38.

On the other hand, a crank pin 42 protrudes from the large-diameter end portion 28 of the drive shaft 26 toward the movable scroll 18, and the crank pin 42 supports a boss 47 of the movable scroll 18 via an eccentric bush 44 and a needle bearing 46. ing. Accordingly, when the drive shaft 26 is rotated, the movable scroll 18 performs a turning motion via the crank pin 42 and the eccentric bush 44.
In FIG. 1, reference numeral 48 indicates a counterweight for the movable scroll 18, and this counterweight 48 is attached to the eccentric bush 44.

Further, the front casing 12 has an annular end surface 50 that has entered the rear casing 10, and a rotation prevention coupling 54 is disposed between the end surface 50 and the end wall 52 of the movable scroll 18.
In this embodiment, the rotation prevention coupling 54 is constituted by a so-called EM coupling, and the EM coupling 54 has a movable plate 56 and a fixed plate 58 having a ring shape. These movable and fixed plates 56 and 58 surround the boss 47 of the movable scroll 18 and are arranged in a face-to-face relationship with each other. As is clear from FIG. 2, the movable plate 56 is supported by the end wall 52 of the movable scroll 18. On the other hand, the fixed plate 58 is supported by the end face 50 of the front casing 12.

Each of the movable and fixed plates 56 and 58 has a plurality of annular race grooves 60 by pressing, and each annular race groove 60 has a circular arc shape in cross section and is arranged at equal intervals in the circumferential direction of the plate. ing. More specifically, the annular race groove 60 has a size corresponding to the turning radius of the movable scroll 18, and its central portion has a convex hemispherical shape.
Steel balls 62 are sandwiched between the annular race grooves 60 of the movable and fixed plates 56 and 58, respectively, and these balls 62 are relatively moved along the corresponding annular race grooves 60 as the movable scroll 18 turns. As a result, the movable scroll 18 is prevented from rotating.

  As is apparent from FIG. 2, an annular recess 64 is formed on the end surface 50 of the front casing 12, leaving the outer peripheral edge, and the recess 64 is a fixing plate 58 corresponding to the annular race groove 60. Interference between the rear portion of the front casing 12 and the front casing 12 is avoided. Therefore, the end surface 50 of the front casing 12 supports the outer peripheral edge portion of the fixed plate 58 at the outer peripheral edge portion.

  On the other hand, the inner peripheral edge of the fixed plate 58 protrudes radially inward from the inner peripheral edge of the end surface 50, and a compression coil spring 66 as an elastic member is bridged between the inner peripheral edge of the fixed plate 58 and the front casing 12. Has been passed. The compression coil spring 66 is disposed so as to surround the boss 47 of the movable scroll 18, presses the inner peripheral edge of the fixed plate 58 toward the movable scroll 18, and applies an axial preload to the EM coupling 54. Yes.

  The pressing force of the compression coil spring 66, that is, the axial preload of the EM coupling 54 is adjusted when the front casing 12 is fastened to the rear casing 10. More specifically, as shown in FIG. 1, the front casing 12 is fastened by screwing a plurality of fastening bolts 69 into the rear casing 10. At this time, a gap 71 is provided between the rear casing 10 and the front casing 12. And the presence of the gap 71 increases the screwing amount (screwing torque) of the fastening bolt 69, so that the contraction amount of the compression coil spring 66, that is, the pressing biasing force increases, and the EM coupling 54 axial direction is increased. The preload can be adjusted. As a result, variations in processing accuracy and assembly accuracy of the components in the scroll compressor can be absorbed by the compression coil spring 66, and a desired initial rotational torque characteristic can be given to the scroll compressor. Can be improved.

  As described above, since the recess 64 described above is formed in the end surface 50 of the front casing 12, the fixing plate 58 is formed on the end surface 50 of the front casing 12 and the compression coil spring 66 at the outer peripheral edge and inner peripheral edge thereof. The back portions of the fixing plate 58 that are respectively supported and corresponding to the annular race grooves 60 do not interfere with the end surface 50. Therefore, the parallelism of the fixed plate 58 with respect to the movable plate 56 is reliably maintained, and the thrust force from the movable scroll 18 does not hit the annular race groove 60 of the fixed plate 58. As a result, smooth rolling of the ball 62 is ensured and wear of the EM coupling 54 can be reduced.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, instead of the compression coil spring 66, the elastic member may be an elastic ring 68 such as rubber that can be elastically deformed as shown in FIG. In this case, the elastic ring 68 presses the outer peripheral edge portion of the fixed plate 58, and the inner peripheral edge portion of the fixed plate 58 is supported by the end surface 50 of the front casing 12.

  Further, as the rotation prevention coupling, a ball coupling 70 as shown in FIG. 4 may be used instead of the EM coupling 54 described above. The ball coupling 70 has movable and fixed races 72 and 74 supported on the end wall 52 of the movable scroll 18 and the end surface 50 of the front casing 12, respectively. The races 72 and 74 have a ring shape in which both surfaces are flat. Eggplant. The movable and fixed races 72 and 74 sandwich a plurality of balls 80 via movable and fixed rings 76 and 78, and the movable and fixed rings 76 and 78 have radial slots 80 that guide each ball 80 in the radial direction. Are formed respectively.

Even in the ball coupling 70 described above, the axial preload can be adjusted by pressing the inner peripheral end of the fixed race 74 with the compression coil spring 66.
Finally, it goes without saying that the scroll type fluid machine of the present invention can be used not only as a compressor for a refrigeration circuit incorporated in a vehicle air conditioner but also as a compressor or an expander in various fields.

It is sectional drawing which showed the scroll compressor of one Example. It is the figure which expanded and showed the EM coupling periphery of FIG. It is the figure which showed the elastic member of the modification. It is the figure which showed the ball coupling of the modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rear casing 12 Front casing 14 Scroll unit 16 Fixed scroll 18 Movable scroll 26 Drive shaft 50 End surface 54 EM coupling (rotation prevention coupling)
56 movable plate 58 fixed plate 60 annular race groove 62 ball 64 recess 66 compression coil spring (elastic member)
68 Elastic ring (elastic member)
69 Fastening bolt 70 Ball coupling (rotation prevention coupling)
71 gap

Claims (5)

A scroll unit disposed in the rear casing and composed of a movable and fixed scroll;
A front casing that is fastened to the rear casing housing via fastening bolts, and in which the drive shaft of the movable scroll is disposed;
A rotation-inhibiting coupling provided between an end surface of the front casing and the movable scroll to prevent rotation of the movable scroll;
An elastic member provided between an end surface of the front casing and the rotation prevention coupling, and an elastic member that presses the rotation prevention coupling toward the movable scroll when the front casing is fastened to the rear casing. A scroll type fluid machine comprising: The rotation prevention coupling is
A ring-shaped movable plate and a fixed plate, which are respectively supported by end surfaces of the movable scroll and the front cane sig, and face each other with a space therebetween;
An annular race groove formed in each of the movable plate and the fixed plate and having a circular arc cross section;
A ball sandwiched between the annular race grooves of the movable and fixed plate,
The scroll type fluid machine according to claim 1, wherein the elastic member is disposed between an end surface of the front casing and the fixed plate. The end surface of the front casing has a recess in a portion corresponding to the annular race groove of the fixed plate,
The scroll type fluid machine according to claim 2, wherein an outer peripheral edge and an inner peripheral edge of the fixed plate are pressed by an end surface of the front casing and the elastic member.   The scroll type fluid machine according to claim 3, wherein the elastic member is a compression coil spring that presses the inner peripheral edge of the fixed plate.   The scroll type fluid machine according to any one of claims 1 to 4, wherein the front cane sig is fastened to the rear casing with a gap.

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