JP2013160063A - Scroll-type fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a smooth compression operation even in the state in which a lateral load acts on a drive shaft, in a scroll-type fluid machine.SOLUTION: A scroll-type fluid machine includes: a housing 1; a fixed scroll 7 which is configured by vertically installing a fixed lap 71 formed in the housing 1; a bearing case 5 which is fixed to the back side of the housing 1; a drive shaft 6 which is rotatably and pivotally supported in the bearing case 5 and has an eccentric shaft part 61 in the front part thereof; a driven pulley 12 which is secured to a back end protruding from the back part of the bearing case 5 and over which a transmission belt 17 is looped; and an orbiting scroll 8 which is pivotally supported by the eccentric shaft part 61, and has an orbiting lap 81 meshing with the fixed lap 71 on a surface facing the fixed scroll 7; wherein a leg part 54 fixed to a pedestal 20 is formed fixedly on or integrally with the lower part of the bearing case 5.

Description

  The present invention relates to a scroll fluid machine suitable for use in an air compressor, a vacuum pump, or the like.

  A scroll fluid machine includes a housing, a bearing case fixed to the housing, a fixed scroll provided in the housing, a drive shaft rotatably supported in the bearing case and rotatable by an electric motor, and the drive shaft A revolving scroll that is pivotally supported by an eccentric shaft provided in the shaft and capable of revolving by rotation of the drive shaft, and a revolving motion of the revolving scroll by rotation of the drive shaft causes a fixed wrap of the fixed scroll and a revolving scroll of the revolving scroll to It is known that a crescent-shaped compression chamber is formed between the swirl wrap and the fixed wrap, and suction, compression, and discharge are performed while changing the volume of the compression chamber.

  Then, in order to drive the drive shaft, the driven pulley is fastened to the end of the drive shaft, and the electric belt that is wound around the driven pulley provided in the motor is wound around the driven pulley, thereby rotating the motor. A configuration for transmitting to the drive shaft via a transmission belt is employed (see, for example, Patent Document 1).

JP 2005-282495 A

  However, in the prior art described in Patent Document 1, the scroll fluid machine is fixed to the fixed body by providing the housing with a leg and fixing the leg to a fixed body such as a base. Therefore, when a load in the direction perpendicular to the shaft (hereinafter referred to as “lateral load”) acts on the end of the drive shaft via the driven pulley when the tension of the transmission belt acts on the end of the drive shaft, As a result, a fixed bending moment acts on the entire housing including the legs, causing a shift in the meshing position of the fixed wrap and the orbiting wrap. A phenomenon in which abnormal noise is generated due to contact with a force larger than necessary (hereinafter referred to as “galling phenomenon”) occurs, and not only a smooth compression operation cannot be obtained, but also both laps are damaged. , There are possibly bringing the scroll fluid machine overall failure.

  In view of the above problems, an object of the present invention is to provide a scroll fluid machine that enables a smooth compression operation even when a lateral load is applied to a drive shaft.

  In order to solve the above problems, a first invention is a housing, a fixed scroll formed by standing a fixed lap formed in the housing, a bearing case fixed to the rear side of the housing, and the bearing A drive shaft pivotally supported by the case and having an eccentric shaft portion at a front portion; a pulley fixed to a rear end portion projecting from a rear portion of the bearing case; and a transmission belt wound around the drive shaft; and the drive shaft A rotating wrap that is pivotally supported by the eccentric shaft portion and that meshes with the fixed wrap on a surface facing the fixed scroll, and revolves by rotation of the drive shaft, and the fixed wrap and the orbiting lap mesh with each other. And a revolving scroll that forms a compression chamber between the revolving wrap and the fixed wrap, and is fixed to a fixed body at a lower portion of the bearing case. Parts wherein the fixed or that are integrally formed.

  According to a second aspect of the invention, there is provided a housing, a fixed scroll formed by standing a fixed lap formed in the housing, a bearing case fixed to the housing, and pivotally supported by the bearing case. A drive shaft having an eccentric shaft portion, and a revolving wrap which is pivotally supported by the eccentric shaft portion of the drive shaft and meshes with the fixed wrap on a surface facing the fixed scroll, and is revolved by the rotation of the drive shaft. A leg that moves and engages the fixed wrap and the orbiting wrap to form a compression chamber between the orbiting wrap and the fixed wrap, and is fixed to the bearing case on the fixed body. The part is fixed or integrally formed.

  According to a third invention, in the first or second invention, the housing does not have a leg portion fixed to the fixed body.

  According to the present invention, the leg portion is fixed or integrally formed with the bearing case for rotatably supporting the drive shaft, so that even if a lateral load is applied to the drive shaft, It is possible to always obtain a smooth compression operation by minimizing the displacement of the mutual meshing positions.

It is a front view of the scroll type fluid machine in the present invention. It is an external appearance perspective view of a scroll type fluid machine similarly. It is the III-III line longitudinal cross-sectional view in FIG. It is sectional drawing of the principal part of another Example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the front side of FIG. 1 and the left side of FIG. 3 are the “front side” of the scroll fluid machine, the back side of FIG. 1 and the right side of FIG. Is defined.

  The scroll fluid machine includes a rear housing 2 formed of, for example, an aluminum alloy, and a front lid body 3 formed of, for example, an aluminum alloy that is fixed to the front side of the housing 2 with a plurality of bolts. The housing 1 includes a bearing case 5 that is fixed to the rear surface of the housing 3 by a plurality of bolts 4 and is formed of, for example, a casting having a higher strength than the housing 1.

  A fixed scroll 7 having a spiral fixed wrap 71 standing rearward is provided on the inner surface facing the rear of the lid 3, and a number of cooling fins 74 are also provided on the front surface.

  In the housing 1, that is, in a space formed between the housing 2 and the lid 3, a turning scroll 8 in which a spiral turning wrap 81 is erected on the front surface facing the fixed scroll 7 is provided. The orbiting scroll 8 is pivotally supported by an eccentric shaft portion 61 formed at the front end portion of the driving shaft 6 in the front-rear direction that is rotatably supported in the bearing case 5.

  The drive shaft 6 is rotatably supported by front and rear ball bearings 10 and 11 provided in the bearing case 5 in the front-rear direction so as to be spaced apart from each other by a predetermined amount, and the front end portion includes the above-described eccentric shaft portion 61 or Balance weight portions 62 are integrally formed on the outer periphery of the front portion. A driven pulley 12 is fastened by a bolt 13 to the rear end portion of the drive shaft 6 protruding from the rear end of the bearing case 5. The driven pulley 12 has an upper end of an endless transmission belt 17 in which a lower portion is wound around a main driving pulley (not shown) fixed to an output shaft of an electric motor (not shown) installed below the scroll fluid machine. Is multiplied. Thereby, the rotation of the electric motor is transmitted to the drive shaft 6 through the main pulley, the transmission belt 19 and the driven pulley 12.

  A large number of cooling fins 82 are provided on the rear surface of the orbiting scroll 8, and the disc-shaped orbiting plate 14 is fixed with a plurality of bolts 15. Between the revolving plate 14 and the rear side surface of the housing 2, a plurality of rotation preventing mechanisms 9 for revolving while preventing the revolving motion of the revolving scroll 8 are provided in the circumferential direction of the revolving plate 14, that is, the revolving scroll 8. It is provided at equal intervals along.

  The driven pulley 12 rotates integrally with the drive shaft 6, and a centrifugal fan 18 for cooling the fixed scroll 7, the orbiting scroll 8, and the like is fixed to the driven pulley 12. A fan cover 19 that covers the centrifugal fan 18 is fixed to the rear surface of the bearing case 5. 2 shows a form in which the transmission belt 17, the centrifugal fan 18, and the fan cover 19 are removed for convenience of explanation.

  When the drive shaft 6 pivotally supported by the bearing case 5 is rotated by the electric motor, the orbiting scroll 8 performs a revolving motion, and accordingly, the crescent-shaped compression chamber 16 partitioned by the fixed wrap 71 and the orbiting wrap 81 is provided. The volume gradually decreases from the outer peripheral side toward the inner peripheral side, and the suction, compression, and discharge are repeated. Thereby, the external gas sucked into the compression chamber 16 from the suction port 72 provided in the upper front portion of the lid 3 is gradually compressed toward the inner peripheral side, and the discharge port provided in the center of the lid 3 73 is finally discharged to the outside as compressed gas.

  The bearing case 5 includes a cylindrical portion 51 facing in the front-rear direction, a flange portion 52 provided on the outer periphery of the front portion of the cylindrical portion 51 and fixed to the rear surface of the housing 3 by bolts 4, and extends downward from the flange portion 52. A plurality of leg portions 54 integrally formed at the lower portion of the extending portion 53 and a corner portion between the outer peripheral surface of the cylindrical portion 51 and the rear surface of the flange portion 52, and increase the rigidity of the entire bearing case 5. The rib 55 is integrally formed. The left and right leg portions 54 are fixed to the pedestal 20 that is a fixed body by a plurality of bolts 21, thereby fixing the scroll fluid machine to the pedestal 20.

  In the present embodiment, as shown in FIG. 3, the left and right leg portions 54 are integrally formed at the lower portion of the bearing case 5, but the present invention is not limited to this embodiment. As in another embodiment shown in FIG. 4, the bearing case 5 and the leg portion 540 are configured separately from each other, and the lower portion 50 of the bearing case 5 is fitted into the recesses 541 provided in the left and right leg portions 540. Thus, the leg portion 540 may be fixed to the bearing case 5. In this case, the leg portion 540 is detachably fixed to the lower portion 50 of the bearing case 5 with a bolt (not shown), so that the leg portion 540 is attached to the other leg portion in accordance with the environment in which the scroll fluid machine is used. It is possible to exchange it.

  According to the present embodiment, as described above, the leg portion 54 (or 540) is provided on the bearing case 5 that rotatably supports the drive shaft 6, and the leg portion 54 (or 540) is fixed to the pedestal 20. Even if the tension of the electric belt 17 acts as a lateral load on the rear end portion of the drive shaft 6, the drive shaft 6 is supported by the bearing case 5 that is superior in strength to the housing 1. Even if a lateral load acts on the rear end of the drive shaft 6 via the driven pulley 12 due to the tension of the transmission belt 17, the lateral load action line A and the fulcrum (the legs 54 (or 540) are attached to the base 20. The moment arm r between the fixed points B) can be shortened as compared with the configuration in which the leg portion is provided on the housing at a position far away from the action line A as in the prior art. Thereby, the fixed bending moment acting on the bearing case 5 including the leg portion 54 (or 540) can be remarkably reduced as compared with the prior art, and the tilt of the bearing case 5 is suppressed and the drive shaft 6 is moved in the axial direction. Tilt can be significantly reduced compared to the prior art.

  Further, since the lateral load acting on the rear end portion of the drive shaft 6 is directly transmitted to the leg portion 53 of the bearing case 5, the fixed bending moment is not transmitted to the housing 1 that is not fixed to the pedestal 20. It can be. Therefore, even if the lateral load acting on the drive shaft 6 is excessive and the drive shaft 6 is slightly tilted with respect to the axial direction together with the bearing case 5, the housing 1 is slightly tilted together with the bearing case 5. Therefore, as compared with the configuration in which the housing 1 is directly fixed to the pedestal 20 as in the prior art, a shift in the meshing positional relationship between the fixed lap 71 and the turning lap 81 is unlikely to occur. As a result, even when a lateral load is applied to the rear end portion of the drive shaft 6, the displacement of the meshing position between the fixed lap 71 and the turning lap 81 is minimized, and the galling phenomenon is prevented. A smooth compression operation can always be obtained.

As mentioned above, although each embodiment of this invention was described, it is possible to give a various deformation | transformation and change to each embodiment within the range which does not deviate from the summary of this invention.
(I) The bearing case 5 and a part or the whole of the housing 2 are integrally formed.
(Ii) Instead of the structure shown in FIG. 4 for fixing the leg 540 to the bearing case 5, a recess (not shown) is provided in the lower part of the bearing case 5, and the leg 540 is fitted into the recess from below and fixed. Shall.

DESCRIPTION OF SYMBOLS 1 Housing 2 Case 3 Cover body 5 Bearing case 6 Drive shaft 7 Fixed scroll 8 Orbiting scroll 9 Anti-rotation mechanism 10, 11 Ball bearing 12 Driven pulley 14 Orbiting plate 15 Bolt 16 Compression chamber 17 Power transmission belt 20 Base 51 Cylindrical part 52 Flange Part 53 extension part 54, 540 leg part 541 recess 55 rib 56 lower part 61 eccentric shaft part 71 fixed wrap 72 suction port 73 discharge port 81 turning lap

Claims (3)

A housing;
A fixed scroll formed by standing a fixed wrap formed in the housing;
A bearing case fixed to the rear side of the housing;
A drive shaft pivotally supported by the bearing case and having an eccentric shaft portion at a front portion;
A pulley fixed to a rear end protruding from the rear portion of the bearing case, and a transmission belt is wound around;
A pivot wrap pivotally supported by the eccentric shaft portion of the drive shaft and meshing with the fixed wrap on a surface facing the fixed scroll, and revolves by the rotation of the drive shaft, and the fixed wrap and the pivot wrap And a revolving scroll that forms a compression chamber between the revolving wrap and the fixed wrap by meshing with each other,
A scroll type fluid machine, wherein a leg portion fixed to a fixed body is fixed or integrally formed at a lower portion of the bearing case. A housing;
A fixed scroll formed by standing a fixed wrap formed in the housing;
A bearing case fixed to the housing;
A drive shaft pivotally supported by the bearing case and having an eccentric shaft portion;
A pivot wrap pivotally supported by the eccentric shaft portion of the drive shaft and meshing with the fixed wrap on a surface facing the fixed scroll, and revolves by the rotation of the drive shaft, and the fixed wrap and the pivot wrap And a revolving scroll that forms a compression chamber between the revolving wrap and the fixed wrap by meshing with each other,
A scroll type fluid machine, wherein a leg portion fixed to a fixed body is fixed to or integrally formed with the bearing case.   The scroll fluid machine according to claim 1 or 2, wherein the housing does not have a leg portion fixed to the fixed body.

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