JP4430510B2 - Scroll type fluid machine - Google Patents

Description

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

  In general, a scroll fluid machine includes a casing, a fixed scroll provided in the casing, a drive shaft rotatably provided in the casing, and a fixed scroll provided rotatably on a tip end side of the drive shaft. And a orbiting scroll defining a plurality of compression chambers. As a conventional scroll type fluid machine, an auxiliary crank for preventing the rotation of the orbiting scroll is provided between the casing and the back of the orbiting scroll, and a fixed scroll and an orbiting scroll are provided between the auxiliary crank and the casing. There is known one provided with a spacer for adjusting a thrust gap between the two (see, for example, Patent Document 1).

  As another prior art, a configuration is also known in which a shim for adjusting a thrust gap between the fixed scroll and the orbiting scroll is provided between the casing and the fixed scroll (see, for example, Patent Document 2). In this case, the shim is provided with a plurality of cuts to prevent the shim from interfering with an assembly bolt that connects the casing and the fixed scroll using the cuts. Thereby, even if the fixed scroll, the orbiting scroll, etc. are temporarily assembled with respect to the casing, the shim can be inserted between the casing and the fixed scroll by loosening the assembly bolt.

JP-A-10-67800 JP-A-9-53574

  By the way, when assembling the scroll type fluid machine described in Patent Document 1, first, the orbiting scroll, the auxiliary crank, etc. are temporarily assembled to the casing, and the thrust gap is measured in this temporarily assembled state. Select a spacer with a thickness according to Next, the orbiting scroll, the auxiliary crank, etc. are removed from the casing and disassembled, and the selected spacer is inserted between the auxiliary crank and the casing. Lastly, the scroll type fluid machine is assembled by attaching the orbiting scroll or the like to the casing again. For this reason, it is necessary to perform the assembly work twice, and there is a problem that the assembly work is wasteful and the productivity is low.

  On the other hand, in the scroll type fluid machine described in Patent Document 2, even when a fixed scroll, orbiting scroll, etc. are temporarily assembled to the casing by using a shim provided with a plurality of cuts, The shim can be inserted in between, and the clearance in the thrust direction (axial direction) can be adjusted. Here, when assembling the fixed scroll and the orbiting scroll to the casing, in addition to adjusting the gap in the thrust direction (axial direction) of the two scrolls, it is also necessary to adjust the gap in the radial direction (radial direction). For this reason, in order to adjust the positional deviation of the two scrolls in the radial direction, for example, the orbiting scroll is swung at a low speed in a temporarily assembled state (a state in which the orbiting scroll and the fixed scroll can move relative to each other). It is conceivable to make a contact with the fixed scroll wrap. In this method, since the position of the fixed scroll in the radial direction is determined by being pushed by the lap of the orbiting scroll, positioning by such self-alignment of the fixed scroll is performed.

  When this automatic alignment method is used, in the scroll type fluid machine described in Patent Document 2, when the fixed scroll and the orbiting scroll are temporarily assembled with respect to the casing, the tooth tip of one scroll wrap is the other. It touches the tooth bottom of the end plate of the scroll. If the orbiting scroll is orbited at a low speed in this state, the fixed scroll will move unnecessarily in the radial direction due to contact resistance between the tooth tip of the wrap and the tooth bottom surface of the end plate, etc. There is a problem that can not be done.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to facilitate positioning of the fixed scroll and the orbiting scroll in the thrust direction and radial direction, and to improve assembly workability. It is an object of the present invention to provide a scroll type fluid machine that can perform the above-mentioned.

  In order to solve the above-described problems, the present invention is provided with a casing, a fixed scroll provided in the casing, a drive shaft rotatably provided in the casing, and a turnable on the tip side of the drive shaft. A scroll type comprising a orbiting scroll that defines a plurality of compression chambers with the fixed scroll, and a rotation prevention mechanism that is provided between the casing and the back of the orbiting scroll and prevents the orbiting scroll from rotating. Applies to fluid machinery.

  A feature of the configuration adopted by the invention of claim 1 is that the casing is provided with an insertion hole for inserting a spacer for narrowing the distance in the thrust direction between the fixed scroll and the orbiting scroll from the outside. .

  In the invention of claim 2, the spacer is configured to be inserted between the rotation prevention mechanism and the casing.

  According to a third aspect of the present invention, the casing is provided with a bottomed accommodation hole that accommodates the anti-rotation mechanism at a position facing the back surface of the orbiting scroll, and the insertion hole opens on a bottom surface side of the accommodation hole. It is configured to do.

  According to the first aspect of the present invention, for example, by providing the orbiting scroll so as to be axially displaceable with respect to the drive shaft, the interval of the thrust method between the fixed scroll and the orbiting scroll is large with the spacer removed. The size can be reduced with the spacer attached. For this reason, in the temporarily assembled state with the spacer removed, the lap tooth tip of one scroll does not come into contact with the bottom surface of the end plate of the other scroll, so by rotating the orbiting scroll at a low speed in the temporarily assembled state, Automatic alignment of fixed scroll can be performed. Further, since the spacer can be attached through the insertion hole, the spacer can be inserted between the rotation prevention mechanism and the casing while maintaining the state where the fixed scroll is automatically aligned. As a result, the radial positioning of the fixed scroll and the thrust scroll positioning in the thrust direction can be performed easily and with high accuracy.

  According to the second aspect of the present invention, since the spacer can be inserted from the outside toward the rotation prevention mechanism and the casing using the insertion hole, a simple structure of providing the insertion hole for inserting the spacer is provided. Thus, it is possible to reduce the distance in the thrust direction between the fixed scroll and the orbiting scroll.

  According to the invention of claim 3, the casing is provided with a bottomed receiving hole for storing the rotation prevention mechanism at a position facing the back surface of the orbiting scroll, and the insertion hole is opened to the bottom surface side of the receiving hole. Therefore, the spacer can be inserted between the bottom surface of the accommodation hole and the rotation prevention mechanism from the insertion hole in a state where the rotation prevention mechanism is attached to the accommodation hole of the casing. For this reason, since the spacer can be inserted between the anti-rotation mechanism and the bottom surface of the receiving hole without removing the fixed scroll, the position of the self-aligned fixed scroll is maintained and the thrust scroll of the orbiting scroll is thrust. Positioning can be performed.

  Hereinafter, a scroll type air compressor will be described as an example of a scroll type fluid machine according to an embodiment of the present invention, and will be described in detail with reference to FIGS.

  In the figure, reference numeral 1 denotes a bottomed cylindrical casing which is open at one end in the axial direction. The casing 1 includes an annular plate portion 1A which is located at the other axial end side and forms the bottom of the casing 1, and an annular plate portion 1A. A boss portion 1B provided on the center side and containing a main bearing 7 to be described later, a cylindrical portion 1C extending from the outer peripheral side of the annular plate portion 1A toward one end side in the axial direction, and provided at the distal end of the cylindrical portion 1C. And a flange portion 1D to which the fixed scroll 3 is attached. And the electric motor 2 is attached to the casing 1 at the other end side in the axial direction of the annular plate portion 1A.

  Reference numeral 3 denotes a fixed scroll attached to the casing 1, and the fixed scroll 3 is erected on the surface of the end plate 3 </ b> A and a disc-shaped end plate 3 </ b> A disposed so as to coincide with an axis of a drive shaft 6 described later. The spiral wrap portion 3B is formed, and a cylindrical portion 3C protruding in the axial direction toward the casing 1 from the outer edge side of the end plate 3A. And the front end surface of the cylinder part 3C of the fixed scroll 3 forms the substantially same surface as the tooth tip surface of the lap | wrap part 3B, for example, and the string-like tip seal 4 is attached to the tooth tip of the wrap part 3B. A plurality of bolt insertion holes 3 </ b> D are formed in the cylindrical portion 3 </ b> C of the fixed scroll 3 at positions facing the flange portion 1 </ b> D of the casing 1. A fixing bolt 5 is inserted into the bolt insertion hole 3D, and the fixing bolt 5 is screwed to the flange portion 1D of the casing 1. Thereby, the fixed scroll 3 is fixed to the flange portion 1 </ b> D using the fixing bolt 5.

  Note that the hole diameter of the bolt insertion hole 3 </ b> D is slightly larger than the outer diameter of the fixing bolt 5. Thereby, in a state where the fixing bolt 5 is temporarily fixed, the fixed scroll 3 can be slightly displaced with respect to the radial direction (radial direction) of the casing 1 and the orbiting scroll 11 described later. On the other hand, when the fixing bolt 5 is further tightened from the temporarily fixed state, the fixed scroll 3 is fixed so as not to be displaced in the radial direction of the casing 1 or the like.

  A drive shaft 6 is rotatably provided in the boss 1B of the casing 1 via a main bearing 7. The drive shaft 6 is screwed to the rotary shaft 2A of the electric motor 2 at the base end side, and is electrically driven. The motor 2 is rotationally driven. A step portion 6A having a large diameter is formed on the proximal end side of the drive shaft 6, and an eccentric bush 8 having a substantially cylindrical shape is attached to the distal end side of the drive shaft 6. At this time, a drive shaft hole 8A that accommodates the distal end side of the drive shaft 6 is formed on the proximal end side of the eccentric bush 8, and a circle protruding toward the drive shaft 6 side around the drive shaft hole 8A. An annular convex portion 8B is formed. On the other hand, a slewing bearing hole 8C for accommodating a later-described slewing bearing 13 is formed on the distal end side of the eccentric bushing 8, and the slewing bearing hole 8C is eccentric with a certain eccentric dimension with respect to the drive shaft hole 8A. The eccentric bush 8 is fixed to the tip of the drive shaft 6 using a retaining ring 9 and a bolt 10. As a result, the main bearing 7 is sandwiched between the convex portion 8B of the eccentric bush 8 and the stepped portion 6A of the drive shaft 6, so that the drive shaft 6 can rotate without being inclined with respect to the casing 1. ing.

  Reference numeral 11 denotes a orbiting scroll provided on the front end side of the drive shaft 6 so as to be opposed to the fixed scroll 3. The orbiting scroll 11 includes a disc-shaped end plate 11A and a front surface side of the end plate 11A. It is roughly constituted by a spiral wrap portion 11B that is erected, and a tip seal 12 is attached to the tooth tip of the wrap portion 11B in the same manner as the fixed scroll 3. Further, a cylindrical boss portion 11C is projected from the rear side of the end plate 11A so as to be located at the central portion thereof. A slewing bearing 13 is attached to the outer peripheral side of the boss portion 11 </ b> C, and the slewing bearing 13 is inserted into the slewing bearing hole 8 </ b> C of the eccentric bush 8. At this time, a slight gap is formed between the swing bearing 13 and the swing bearing hole 8C. Thereby, the orbiting scroll 11 can be displaced in the axial direction together with the orbiting bearing 13.

  When the orbiting scroll 11 is arranged at a position where the surface (tooth bottom surface) of the end plate 11A is substantially flush with the end surface of the flange portion 1D of the casing 1, the surface of the end plate 11A of the orbiting scroll 11 is the wrap portion of the fixed scroll 3. While contacting the tip seal 4 provided at the 3B tooth tip, the surface of the end plate 3A of the fixed scroll 3 contacts the tip seal 12 provided at the lap portion 11B tooth tip of the orbiting scroll 11. For this reason, by adjusting the position of the orbiting scroll 11 using a shim 26 described later so that the axial position of the end face of the end plate 11A and the end face of the flange portion 1D coincide, It is possible to adjust the thrust gap between the two.

  Further, the orbiting scroll 11 is disposed so as to overlap with the wrap portion 3B of the fixed scroll 3 by, for example, 180 degrees, and a plurality of compression chambers 14, 14... Are defined between the wrap portions 3B, 11B. Is done. During the operation of the scroll type air compressor, the orbiting scroll 11 is swung by the drive shaft 6 while sucking air from the suction port 15 provided on the outer periphery side of the fixed scroll 11 into the compression chamber 14 on the outer periphery side. During the eccentric rotation, the compressed air is sequentially compressed in each compression chamber 14, and finally compressed air is discharged from the central compression chamber 14 to the outside through the discharge port 16 provided at the center of the fixed scroll 3.

  Reference numeral 17 denotes, for example, three orbiting scroll side accommodation holes (only one is shown) provided on the back side of the end plate 11A. The orbiting scroll side accommodation hole 17 has a circular bottom with a recess recessed on the back side of the end plate 11A. Consists of holes. In addition, the three orbiting scroll side accommodation holes 17 are arranged, for example, at positions (at every 120 degrees) that are located around the boss portion 11C and are equally spaced in the circumferential direction. And in the turning scroll side accommodation hole 17, the turning scroll side coupling 22 of the rotation prevention mechanism 20 mentioned later is accommodated.

  Reference numeral 18 denotes, for example, three casing-side accommodation holes (only one is shown) provided in the annular plate portion 1A of the casing 1, and the casing-side accommodation holes 18 are located in the cylindrical portion 1C of the casing 1 and are annular plates. It is comprised by the circular bottomed hole recessed by the surface side of the part 1A. Further, the three casing-side accommodation holes 18 face the respective orbiting scroll-side accommodation holes 17 and are arranged at positions (at every 120 degrees) that are located around the boss portion 1B and are equally spaced in the circumferential direction. ing. And in the casing side accommodation hole 18, the casing side coupling 21 of the rotation prevention mechanism 20 mentioned later is accommodated.

  A substantially square guide hole 19 is provided on the radially outer side of the casing side accommodation hole 18. The guide hole 19 expands the casing side accommodation hole 18 that forms a circular hole outward in the radial direction, and opens into the casing 1 with a width that is wider than the width of a shim 26 that will be described later. The shim 26 is guided toward the bottom of the hole 18.

  Reference numeral 20 denotes three anti-rotation mechanisms provided between the casing-side accommodation hole 18 of the casing 1 and the orbiting scroll-side accommodation hole 17 of the orbiting scroll 11. The anti-rotation mechanism 20 includes couplings 21 and 22 described later. And a ball coupling composed of the ball 23 and the like.

  Reference numeral 21 denotes a casing-side coupling attached to the casing-side accommodation hole 18 of the casing 1, and the casing-side coupling 21 is formed in a substantially disc shape and is displaced in the axial direction into the casing-side accommodation hole 18 forming a circular hole. It has been fitted. In addition, an annular guide groove 21 </ b> A for guiding the ball 23 is recessed on the surface of the casing side coupling 21 that faces the orbiting scroll side coupling 22. Further, a chamfered portion 21B having a chamfered outer peripheral side is formed on the bottom side of the casing side coupling 21 facing the casing side accommodation hole 18 over substantially the entire circumference. The chamfered portion 21 </ b> B facilitates insertion of the shim 26 when a shim 26 described later is inserted between the coupling 21 and the bottom surface of the casing-side accommodation hole 18.

  The orbiting scroll side coupling 22 is attached to the orbiting scroll side accommodation hole 17 of the orbiting scroll 11, and the orbiting scroll side coupling 22 is formed in a substantially disc shape like the casing side coupling 21 and has a circular hole. Is fitted in the orbiting scroll side accommodation hole 17. An annular guide groove 22 </ b> A for guiding the ball 23 is recessed on the surface of the orbiting scroll side coupling 22 facing the casing side coupling 21.

  Reference numeral 23 denotes a ball which is sandwiched between the two couplings 21 and 22 so as to be able to roll. The ball 23 is formed of a steel material or the like and rolls along the guide grooves 21A and 22A of the couplings 21 and 22. Move. Thereby, the rotation prevention mechanism 20 supports the thrust load acting on the orbiting scroll 11 and prevents the orbiting scroll 11 from rotating.

  Reference numerals 24 and 25 denote cover members attached to the opposing surfaces of the respective couplings 21 and 22. The cover members 24 and 25 are formed in a substantially cylindrical shape and surround the ball 23 so that the couplings 21 and 22 It is fixed to the outer peripheral side. A slight gap is formed between the cover members 24 and 25 to prevent the ball 23 from separating from the guide grooves 21A and 22A. The cover members 24 and 25 prevent grease (not shown) enclosed in the guide grooves 21A and 22A from scattering and leaking between the couplings 21 and 22, and the balls 23 and the guide grooves 21A and 22A. Keeps good lubrication during.

  Reference numeral 26 denotes a shim as a spacer provided between the rotation prevention mechanism 20 and the casing 1, and the shim 26 is formed in a substantially rectangular thin plate shape on the bottom surface of the casing side accommodation hole 18 and the guide hole 19. It is arranged and is sandwiched between the casing side coupling 21 and the bottom surface of the casing side accommodation hole 18. The shim 26 has a thickness dimension T corresponding to, for example, an axial displacement dimension Δh between the surface of the end plate 11A and the end face of the flange portion 1D. For this reason, the shim 26 displaces the orbiting scroll 11 in the thrust direction (axial direction) toward the fixed scroll 3 through the anti-rotation mechanism 20, and substantially matches the axial position of the surface of the end plate 11A and the end face of the flange portion 1D. . As a result, the shim 26 adjusts the thrust gap between the fixed scroll 3 and the orbiting scroll 11 to an appropriate value by narrowing the interval in the thrust direction between the fixed scroll 3 and the orbiting scroll 11.

  Reference numeral 27 denotes a slit hole serving as an insertion hole located around the rotation prevention mechanism 20 and provided on the bottom surface side of the casing side accommodation hole 18. The slit hole 27 is disposed on the outer side in the radial direction of the casing side accommodation hole 18. In addition, it is formed by an elongated through hole extending substantially linearly along the circumferential direction of the casing 1 and opens to the bottom surface of the guide hole 19. The slit hole 27 has a length dimension larger than the width dimension of the shim 26, and allows the shim 26 to be inserted into the casing-side accommodation hole 18 in the casing 1 from the outside.

  At this time, since the slit hole 27 is opened in the guide hole 19 extending radially outward from the casing side accommodation hole 18, a larger opening area is ensured than in the case where the slit hole 27 is directly opened in the casing side accommodation hole 18. . As a result, the shim 26 can easily pass through the slit hole 27, and the shim 26 can be easily inserted and attached.

  The scroll type air compressor according to the present embodiment has the above-described configuration. When the drive shaft 6 is rotationally driven by the electric motor 2, the rotation of the drive shaft 6 is performed from the eccentric bush 8 via the swivel bearing 13. This is transmitted to the orbiting scroll 11. Thereby, the orbiting scroll 11 revolves around the drive shaft 6 in a state in which the rotation movement is prevented by the rotation prevention mechanism 20. At this time, the compression chamber 14 defined between the wrap portion 3B of the fixed scroll 3 and the wrap portion 11B of the orbiting scroll 11 is continuously reduced. As a result, the scroll type air compressor sequentially compresses the outside air sucked from the suction port 15 in each compression chamber 14, and discharges the compressed air from the discharge port 16 toward an external air tank (not shown) or the like. .

  Next, a manufacturing method of the scroll type air compressor according to the present embodiment will be described with reference to FIGS.

  First, in the thrust gap measuring step, as shown in FIG. 6, the fixed scroll 3 and the shim 26 are removed, and the orbiting scroll 11, the rotation prevention mechanism 20 and the like are attached to the casing 1. At this time, the orbiting scroll 11 is pressed toward the casing 1 so that the casing side coupling 21 of the rotation prevention mechanism 20 contacts the bottom surface of the casing side accommodation hole 18. In this state, the axial displacement dimension Δh between the surface (tooth bottom surface) of the end plate 11A and the end face of the flange portion 1D is measured as the dimension of the thrust gap.

  Next, in the fixed scroll temporary assembly step, as shown in FIG. 7, the fixed scroll 3 is attached to the casing 1 in a temporarily assembled state. At this time, the fixing bolt 5 is tightened in a somewhat loosened state so that the fixed scroll 3 is displaceable in the radial direction with respect to the casing 1 and the orbiting scroll 11.

  Next, in the radial clearance adjustment step, the temporarily assembled fixing bolt 5 is gradually tightened while the orbiting scroll 11 is orbiting at a low speed. At this time, since the tip seals 4 and 12 of the wrap portions 3B and 11B do not contact the surface of the other end plate 11A and 3A, the side surface of the wrap portion 3B of the fixed scroll 3 is pushed to the side surface of the wrap portion 11B of the orbiting scroll 11, The fixed scroll 3 moves in the radial direction, and the radial position of the fixed scroll 3 is automatically determined. As a result, the radial gap between the lap portions 3B and 11B is minimized, and the fixed scroll 3 is automatically aligned. And after completion | finish of an automatic alignment, the fixed volt | bolt 5 is tightened and the fixed scroll 3 is fixed with respect to the casing 1 in the state which cannot displace.

  Finally, in the thrust gap adjusting step, as shown in FIG. 7, a shim 26 is inserted between the casing side coupling 21 and the bottom surface of the casing side accommodation hole 18 through the slit hole 27 of the casing 1. At this time, the thickness dimension T of the shim 26 is set to a value smaller by the dimension δ than the positional deviation dimension Δh between the surface of the end plate 11A and the end face of the flange portion 1D (T = Δh−δ). Here, the dimension δ is a small value that prevents the lap portions 3B and 11B of the scrolls 3 and 11 from coming into contact with the opposite end plates 11A and 3A due to thermal expansion or the like. The orbiting scroll 11 can be displaced in the axial direction together with the orbiting bearing 13. Therefore, as shown in FIG. 2, when the shim 26 is inserted, the anti-rotation mechanism 20 is displaced in a direction away from the annular plate portion 1 </ b> A of the casing 1, so that the orbiting scroll 11 has a thickness T of the shim 26. Accordingly, it is displaced together with the rotation prevention mechanism 20 toward the fixed scroll 3 side. As a result, the surface of the end plate 11A of the orbiting scroll 11 is disposed at a position squeezed closer to the bottom (annular plate 1A) side of the casing 1 than the end face of the flange 1D of the casing 1 by the dimension δ. The tip seals 4 and 12 of the 11B tooth tip are in sliding contact with the opposite end plates 11A and 3A in a good state, and the thrust gap between the fixed scroll 3 and the orbiting scroll 11 is set to an optimum state.

  Thus, in the present embodiment, the casing 1 is provided with the slit hole 27 for inserting the shim 26, so that the fixed scroll 3 and the orbiting scroll 11 are temporarily assembled to the casing 1 in the slit hole 27. The shim 26 can be inserted between the rotation prevention mechanism 20 and the casing 1 from the outside using the. For this reason, it is not necessary to remove the fixed scroll 3, the orbiting scroll 11 and the like from the casing 1 and insert them again in order to insert the spacer as in the prior art, so that the assembly workability can be improved.

  Further, in the temporarily assembled state before the shim 26 is inserted, a gap in the thrust direction is formed between the fixed scroll 3 and the orbiting scroll 11, and the tip seals 4, 12 are on the surface (tooth bottom surface) of the other end plate 11A, 3A. ). For this reason, the fixed scroll 3 can be automatically aligned by rotating the orbiting scroll 11 at a low speed in the temporarily assembled state. At this time, in the present embodiment, the shim 26 can be inserted and attached using the slit hole 27 without removing the fixed scroll 3, so that the position of the self-aligned fixed scroll 3 is maintained and the slit is maintained. The shim 26 can be inserted between the rotation preventing mechanism 20 and the casing 1 through the hole 27 to position the orbiting scroll 11 in the thrust direction. Thereby, positioning of the fixed scroll 3 and the turning scroll 11 in the radial direction and the thrust direction can be performed easily and with high accuracy.

  Further, since the shim 26 can be inserted from the outside between the rotation prevention mechanism 20 and the casing 1 using the slit hole 27, the fixed scroll 3 can be configured with a simple configuration in which the slit hole 27 is provided in the casing 1. And the orbiting scroll 11 can be narrowed in the thrust direction.

  In particular, in the present embodiment, the casing 1 is provided with a bottomed casing side accommodation hole 18 that accommodates the rotation prevention mechanism 20 at a position facing the back surface of the orbiting scroll 11, and the slit hole 27 is formed in the casing side accommodation hole 18. Since the rotation prevention mechanism 20 is attached to the casing side accommodation hole 18, the bottom surface of the casing side accommodation hole 18 and the casing side coupling 21 of the rotation prevention mechanism 20 are connected to each other through the slit hole 27. A shim 26 can be inserted between them.

  Further, since the anti-rotation mechanism 20 is constituted by a ball coupling in which the ball 23 is sandwiched between the two couplings 21 and 22, the ball 23 is rolled along the guide grooves 21A and 22A of the couplings 21 and 22. Thus, the rotation of the orbiting scroll 11 can be prevented, and the load in the thrust direction of the orbiting scroll 11 can be received using the couplings 21 and 22 and the ball 23. Therefore, when the shim 26 is inserted between the casing side coupling 21 and the bottom surface of the casing side accommodation hole 18 through the slit hole 27, the orbiting scroll 11 is fixed to the fixed scroll together with the rotation preventing mechanism 20 that receives the thrust load. The thickness of the shim 26 is displaced toward the third side. As a result, it is possible to accurately set the thrust-direction position of the orbiting scroll 11 using the shim 26 and to optimize the thrust-direction gap easily and with high accuracy, compared with the case where only the rotation prevention is performed. it can.

  Further, since the orbiting scroll 11 is provided so as to be displaceable in the axial direction with respect to the drive shaft 6, the thrust gap between the fixed scroll 3 and the orbiting scroll 11 causes the shim 26 to move from between the rotation prevention mechanism 20 and the casing 1. The shim 26 can be made large in the removed state and can be made small in the state in which the shim 26 is attached between the rotation prevention mechanism 20 and the casing 1. For this reason, in the temporarily assembled state with the shim 26 removed, the tip seals 24 and 25 of the lap portions 3B and 11B do not come into contact with the tooth bottom surfaces of the opposite end plates 11A and 3A. The fixed scroll 3 can be self-aligned by making a swivel motion. Further, since the shim 26 can be attached through the slit hole 27, the shim 26 can be inserted between the rotation preventing mechanism 20 and the casing 1 while maintaining the state where the fixed scroll 3 is automatically aligned. As a result, the radial direction positioning of the fixed scroll 3 and the thrust direction positioning of the orbiting scroll 11 can be performed easily and with high accuracy.

  In the embodiment described above, the three rotation prevention mechanisms 20 are provided on the back surface of the end plate 11A of the orbiting scroll 11. However, four or more rotation prevention mechanisms may be provided.

  Moreover, in the said embodiment, although it was set as the structure which attaches the chip seals 4 and 12 to the tooth tip of the lap | wrap parts 3B and 11B, it is good also as a structure which omits both or one chip seal among the wrap parts 3B and 11B.

  Moreover, in the said embodiment, it was set as the structure which uses the rotation prevention mechanism 20 which consists of a ball coupling which consists of the couplings 21 and 22 and the ball | bowl 23 grade | etc.,. However, the present invention is not limited to this. For example, an auxiliary crank or the like may be used as the rotation prevention mechanism.

  Moreover, in the said embodiment, it was set as the structure which inserts the shim 26 between the rotation prevention mechanism 20 and the casing 1, However, For example, as a structure which inserts a shim (spacer) between the end plate back surface of a turning scroll and a casing. Also good. In this case, the slit hole (insertion hole) is disposed, for example, in the vicinity of the rear face of the orbiting scroll.

  Furthermore, in the above-described embodiment, the scroll type air compressor has been described as an example of the scroll type fluid machine. However, the present invention is not limited to this and can be widely applied to, for example, a vacuum pump, a refrigerant compressor, and the like. is there.

It is a longitudinal section showing a scroll type air compressor by an embodiment of the invention. FIG. 2 is an enlarged longitudinal sectional view showing an enlargement of the periphery of a rotation prevention mechanism in FIG. 1. FIG. 3 is an enlarged cross-sectional view of shims, slit holes and the like in FIG. It is a principal part expanded vertical sectional view shown in the state which removed the rotation prevention mechanism and the shim from the casing. It is the principal part enlarged plan view which looked at the slit hole etc. in FIG. 4 from the arrow V-V direction. FIG. 3 is an enlarged longitudinal sectional view of the same position as in FIG. 2 showing a casing, a turning scroll, and the like before a fixed scroll is attached. FIG. 3 is an enlarged longitudinal sectional view of the same position as FIG. 2 showing a casing, a fixed scroll, a turning scroll, and the like before attaching shims.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Electric motor 3 Fixed scroll 3A, 11A End plate 3B, 11B Lapping part 4,12 Tip seal 5 Fixing bolt 6 Drive shaft 8 Eccentric bush 11 Orbiting scroll 13 Orbiting bearing 18 Casing side accommodation hole 19 Guide hole 20 Anti-rotation mechanism 21 Casing side coupling 21A, 22A Guide groove 22 Orbiting scroll side coupling 23 Ball 26 Shim 27 Slit hole (insertion hole)

Claims (3)

A plurality of compression chambers are provided between a casing, a fixed scroll provided on the casing, a drive shaft rotatably provided on the casing, and a fixed scroll provided on the front end side of the drive shaft. In a scroll type fluid machine comprising: an orbiting scroll to be defined; and a rotation prevention mechanism provided between the casing and the back of the orbiting scroll to prevent the orbiting scroll from rotating,
The scroll fluid machine according to claim 1, wherein the casing is provided with an insertion hole through which a spacer for narrowing a distance in the thrust direction between the fixed scroll and the orbiting scroll is inserted.   The scroll fluid machine according to claim 1, wherein the spacer is configured to be inserted between the rotation prevention mechanism and the casing. The casing is provided with a bottomed accommodation hole that accommodates the rotation prevention mechanism at a position facing the back surface of the orbiting scroll,
The scroll fluid machine according to claim 2, wherein the insertion hole is configured to open to a bottom surface side of the accommodation hole.

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