JPH09228966A - Scroll type fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give a proper preload to a double-row angular bearing by forming a bearing rotationally supporting one side shaft part and the other side shaft part of an auxiliary crank as the double-row angular bearing, and providing a pre-load mechanism giving a pre-load to the bearing in a position without applying a thrust load from a turn scroll, in a scroll type fluid machine. SOLUTION: A casing side bearing 17 rotationally supporting one side shaft part 16A of an auxiliary crank 16 is formed as a back combined double-row angular bearing, a pre-load mechanism 23 giving a pre-load to an inner ring 17B2 of a back side angular bearing 17B is provided in the one side shaft part 16A. A turn side bearing 18 rotationally supporting the other side shaft part 16B is formed as a front combined double-row angular bearing, a pre-load mechanism 28 is provided in an outer ring 18B1 of a back side angular bearing 18B. The pre-load mechanisms 23, 28 are provided in a position without applying a thrust load from a turn scroll side, a proper pre-load is given to the bearings 17, 18, rolling resistance is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor, a vacuum pump and the like, and more particularly to a scroll type fluid machine provided with an auxiliary crank as a rotation preventing mechanism.

[0002]

2. Description of the Related Art Conventionally, for example, an oil-free scroll type air compressor includes a casing, a drive shaft rotatably provided at one end side of the casing, and a tip end side extending into the casing to form a crank portion. An orbiting scroll that is rotatably provided on a crank portion of the drive shaft via an orbiting bearing, and a spiral wrap portion is erected on an end plate, and is provided on the other end side of the casing facing the orbiting scroll. A fixed scroll in which a spiral wrap portion that forms a plurality of compression chambers between the end plate and the wrap portion of the orbiting scroll is erected,
In order to prevent the orbiting scroll from rotating, one side shaft portion is rotatably supported by the casing via a casing side bearing, and the other side shaft portion is rotatably supported by the orbiting scroll via an orbiting side bearing. It consists of a crank.

In the above scroll type air compressor, the eccentricity of the auxiliary crank is set to be substantially the same as the eccentricity of the drive shaft and the crank portion.

In the scroll type air compressor according to the prior art, when the drive shaft is rotationally driven by a motor or the like, the rotation of the drive shaft is transmitted from the crank portion to the orbiting scroll via the orbiting side bearing, and the orbiting scroll is Rotational movement is prevented by each auxiliary crank, and pivoting movement is performed around the axis of the drive shaft. Then, the compression chamber formed between the scrolls is continuously reduced by this orbiting motion, whereby the scroll air compressor sequentially compresses the air sucked from the suction port in each compression chamber. Compressed air is discharged from the discharge port to an external air tank or the like.

Further, an example of a scroll type air compressor according to the prior art in which an auxiliary crank is used in a rotation preventing mechanism is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-78494 (Japanese Patent Application No. 6-78494).
No. 0-217890) and Japanese Patent Application Laid-Open No. 2-279784 (Japanese Patent Application No. 1-149468), in which the bearing of an auxiliary crank of this type receives a thrust load at the time of a compression operation applied to the orbiting scroll. A double-row angular bearing is used in the. The casing side bearing is fixed to the casing via the bearing plate, and the orbiting side bearing is fixed to the orbiting scroll via the bearing plate.

[0006]

However, in the scroll type air compressor according to the prior art, the heat generated by misalignment of the bearing position of the auxiliary crank, the play of the bearing, and the temperature difference between the bearing plate on the slewing side and the bearing plate on the casing side. In order to prevent an unreasonable restraint force from being exerted on the auxiliary crank due to a difference in expansion or the like, the bearing and the bearing plate are fitted with each other in a radial direction so as to have play. Further, in order to prevent the bearing from moving easily in the radial direction, the bearing is clamped in the axial direction by a holding plate and fixed to the bearing plate.

However, the double-row angular bearing is usually used by giving a light preload, but when it is tightened in the axial direction of the bearing with a strong force as in the prior art, the rolling resistance of the bearing against steel balls becomes large. Therefore, there is a problem that the bearing is damaged early.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can continue to apply an appropriate preload to the bearing that rotatably supports the auxiliary crank, and can prevent damage to the bearing for a long period of time. An object of the present invention is to provide a scroll type fluid machine configured as described above.

[0009]

In order to solve the above-mentioned problems, the invention of claim 1 provides a casing, and a crank portion which is rotatably provided at one end side of the casing and whose tip side extends into the casing. Drive shaft, a revolving scroll having a crank portion of the drive shaft capable of revolving through a revolving bearing, and a spiral wrap portion provided upright on an end plate, and a casing other than the casing facing the revolving scroll. A fixed scroll provided on the end plate and provided with upright spiral wrap portions that form a plurality of compression chambers between the end plate and the wrap portion of the orbiting scroll, and one side shaft for preventing rotation of the orbiting scroll. Part of the auxiliary crank rotatably supported on the casing via a bearing on the casing side, and the other side shaft part is an auxiliary crank rotatably supported on the orbiting scroll via a bearing on the orbiting side. In the fluid machine, the casing-side bearing and the orbiting-side bearing of the auxiliary crank each include a double-row angular bearing, and the casing-side double-row angular bearing among the double-row angular bearings includes the wrap portion side of the orbiting scroll. Is provided as a front side, a first preload mechanism for applying a preload in the thrust direction is provided on at least one of the outer ring of the front bearing and the inner ring of the rear bearing, and / or the double row angular bearing on the orbiting scroll side is provided. Is characterized in that a second preload mechanism for applying a preload in the thrust direction is provided on at least one of the outer ring of the rear bearing and the inner ring of the front bearing.

With the above-mentioned structure, the preload in the thrust direction can be appropriately applied to the inner ring or the outer ring of the double row angular bearings on the casing side and the orbiting scroll side where the thrust load from the orbiting scroll side does not act. The preload can be maintained at an appropriate level.

According to a second aspect of the present invention, the first preload mechanism is provided between a first retainer fixed to the one side shaft portion of the casing or the auxiliary crank, and between the first retainer and the bearing. And a second retainer fixed to the other side shaft portion of the orbiting scroll or the auxiliary crank, and the second preload mechanism.
And a second pressing member arranged between the retainer and the bearing.

With the above structure, the first and second pressing members can apply an appropriate preload to the outer or inner ring of the angular bearing without being affected by the thrust load from the orbiting scroll side. Rolling resistance can be reduced.

In order to solve the above-mentioned problems, a third aspect of the present invention includes a casing, and a drive shaft rotatably provided at one end side of the casing and having a front end side extending into the casing to form a crank portion. An orbiting scroll provided on the crank portion of the drive shaft so as to be able to turn via an orbiting bearing and having a spiral wrap portion standing on the end plate, and an end plate provided on the other end side of the casing facing the orbiting scroll. A fixed scroll in which a spiral wrap portion that forms a plurality of compression chambers with the wrap portion of the orbiting scroll is erected, and a one-sided shaft portion in the casing for preventing rotation of the orbiting scroll. A scroll-type fluid machine comprising an auxiliary crank rotatably supported by a side bearing, and an auxiliary crank rotatably supported on the orbiting scroll by the orbiting scroll. At least one of a casing-side bearing and an orbiting-side bearing of the auxiliary crank is provided with a bearing housing that holds the bearing so as to be capable of minute displacement in the radial direction with respect to the orbiting scroll or the casing. The housing includes a cylindrical bearing accommodating portion for accommodating the bearing, a pair of stays that project from the bearing accommodating portion in opposite directions along the circumferential direction of the end plate and are elastically deformable, and the stays of the respective stays. It is characterized in that it is constituted by a fastening portion provided on the protruding end side and fastened to the orbiting scroll or the casing.

With the above structure, the pair of stays formed in the bearing housing has high rigidity in the circumferential direction and can be elastically deformed in the radial direction, so that misalignment of the bearings, bearing play and thermal expansion of the bearing mounting position. The radial displacement due to the difference or the like can be absorbed, and an excessive load or the like can be prevented from acting on the bearing.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, and FIGS. 1 to 10 show an embodiment according to the present invention.

First, FIGS. 1 to 3 show an air compressor as a scroll type fluid machine according to a first embodiment.

In the figure, reference numeral 1 denotes a casing of a scroll type air compressor formed in a stepped cylindrical shape.
Is a large-diameter cylindrical portion 1A, a small-diameter bearing cylindrical portion 1B formed so as to reduce the diameter of one end side of the large-diameter cylindrical portion 1A and project outward, the bearing cylindrical portion 1B and the large-diameter cylindrical portion 1B. An annular portion 1C formed between the tubular portion 1A and the tubular portion 1A, and one side shaft portion 16 of each auxiliary crank 16 described later is provided on the other surface side of the annular portion 1C.
Three bearing accommodating holes 1D (only one is shown) for accommodating A through the casing side bearing 17 are formed at predetermined intervals in the circumferential direction (for example, three), and the respective bearing accommodating holes are accommodated. An annular recess 1E having a diameter larger than the diameter of the bearing accommodating hole 1D is formed on one side of the hole 1D.

Reference numeral 2 denotes a drive shaft rotatably provided in the bearing tubular portion 1B of the casing 1 through a bearing 3, and the tip end side of the drive shaft 2 extends into the large diameter tubular portion 1A of the casing 1. The crank portion 2A is arranged such that its axis O2-O2 is eccentric with respect to the axis O1-O1 of the drive shaft 2 by an eccentric amount ε. It is connected to the orbiting scroll 4 via 8. The base end side of the drive shaft 2 projects outward from the bearing tubular portion 1B, and the projecting end serves as a drive source via a pulley or the like (both not shown).
And is driven to rotate by the electric motor.

Reference numeral 4 denotes an orbiting scroll rotatably provided on the other end side of the casing 1, and the orbiting scroll 4 is generally composed of an orbiting scroll body 5 and a support plate 6 fixed to the orbiting scroll body 5. Has been done. Here, the orbiting scroll body 5 is a disk-shaped end plate 5A on the orbiting side, and a spiral wrap erected on the end plate 5A with the center side being the winding start end and the outer peripheral side being the winding end end. And a section 5B.

The supporting plate 6 is fixed to the rear side of the end plate 5A by bolts 7, 7, ... (Only one is shown), is formed in a substantially triangular shape as shown in FIG. A boss portion 6A for holding the shaft is provided upright, and a bearing housing 27 of a swivel side bearing 18 described later is provided on the outer peripheral side.
3 holding holes 6B for accommodating are formed at predetermined intervals in the circumferential direction. The holding hole 6B has a diameter slightly larger than the holding portion 27E of the bearing housing 27,
The bearing housing 27 is loosely fitted.
The orbiting bearing 8 is a cylindrical roller bearing.

Further, between the orbiting scroll body 5 and the support plate 6, a plurality of heat radiating fins 9, 9, from the end plate 5A of the scroll body 5 toward the support plate 6, are provided.
... are formed to project.

Reference numeral 10 denotes a fixed scroll fixedly provided on one end side of the casing 1. The fixed scroll 10
Is a fixed scroll body 11 and the fixed scroll body 11
The cover 12 is fixed to the above.

Here, the fixed scroll body 11 is
The center thereof coincides with the axis O1 -O1 of the drive shaft 2, and the end plate 11A is disposed so as to face the end plate 5A of the orbiting scroll 4, and the end plate 11A is erected from the end plate 11A similarly to the wrap portion 5B of the orbiting scroll 4. Spiral wrap portion 11B
Consists of

Further, a plurality of heat radiation fins 13, 13, ... Are formed so as to project from the end plate 11A toward the cover 12 between the cover 12 and the end plate 11A. The wrap portion 11B is the wrap portion 5 of the orbiting scroll 4.
When the orbiting scroll 4 orbits, the orbiting scroll 4 orbits when the orbiting scroll 4 orbits.
A plurality of compression chambers 1 that continuously contract with the wrap portion 5B
4, 14, ... Are formed. The fixed scroll 10 is fixed to the large-diameter cylindrical portion 1A of the casing 1 by bolts 15, 15, ... (Only two are shown).

, 16 are annular portions 1 of the casing 1.
3 shows an auxiliary crank (only one is shown) as a rotation preventing mechanism which is arranged between C and the orbiting scroll 4 while being separated from each other in the circumferential direction, and each auxiliary crank 16 is as shown in FIG.
One side shaft portion 16A that is rotatably attached to the annular portion 1C side of the casing 1, and a cylindrical shape having a smaller diameter than the one side shaft portion 16A, and is rotatably attached to the support plate 6 side of the orbiting scroll 4. The other side shaft portion 16B and the one side shaft portion 1
One side positioning step portion 16C formed on the base end side of 6A,
The other side shaft portion 16B and the other side positioning step portion 16D formed on the base end side. And the auxiliary crank 1
6, the axis O3 -O3 of the one side shaft portion 16A and the axis O4 -O4 of the other side shaft portion 16B are formed with an eccentric amount substantially equal to the eccentric amount ε of the drive shaft 2.

Reference numeral 17 denotes a casing side bearing mounted in the bearing accommodating hole 1D of the casing 1, and the casing side bearing 17 is located on the front side when the wrap portion 5B side of the orbiting scroll 4 is the front side. The front side angular bearing 17A and the back side angular bearing 17B located on the back side are back-faced to each other to form a back-side combination double-row angular bearing.

Here, the front side angular bearing 17A
Is an outer ring 17A1, an inner ring 17A2, and an outer ring 17A1,
It is composed of a plurality of steel balls 17A3 serving as rolling elements arranged between the inner ring 17A2, the outer ring 17A1 is positioned in the bearing housing hole 1D by a retainer 21 described later, and the inner ring 17A2 is one side of the auxiliary crank 16. Positioning step part 16C
Is positioned on the one side shaft portion 16A.

Further, the back side angular bearing 17B
Is an outer ring 17B1, an inner ring 17B2, and an outer ring 17B1,
It is composed of a plurality of steel balls 17B3 serving as rolling elements arranged between the inner ring 17B2, the outer ring 17B1 is positioned in the bearing accommodating hole 1D by the cover 19 described later, and the inner ring 17B2 is the first preload mechanism 23. By the disc spring 26 of
The one side shaft portion 16A is positioned with a preload applied.

The outer ring 17 of the casing side bearing 17
A1 and 17B1 are positioned between the cover 19 fixed to one side of the bearing accommodating hole 1D and the retainer 21 fixed to the other side, and the inner rings 17A2 and 1A1 of the bearing 17 on the casing side are positioned.
7B2 is positioned between the disc spring 26 of the preload mechanism 23 fixed to the end face of the one-side shaft portion 16A and the one-side position determining step portion 16C with a preload in the thrust direction being applied.

18 is a support plate 6 for the orbiting scroll 4.
The orbiting side bearing 18 attached to the side is a front side angular bearing which is located on the front side when the wrap portion 5B side of the orbiting scroll 4 is the front side. 18A and the back-side angular bearing 18B located on the back side are face-to-face matched with each other to form a double-row angular bearing in a front combination.

Here, the front side angular bearing 18A
Is an outer ring 18A1, an inner ring 18A2, and an outer ring 18A1,
The outer ring 18A1 is positioned in the bearing housing 27 by the annular step portion 23F of the bearing housing 27. The outer ring 18A1 is made up of a plurality of steel balls 18A3 serving as rolling elements arranged between the inner ring 18A2. The front angular contact bearing 1
For the inner ring 18A2 of 8A, the angular bearing 18
Because of the shape of A, the outer ring 18A1 and the inner ring 18A2 are positioned by the thrust load applied to the inner ring 18A2.

Further, the back side angular bearing 18B
Is an outer ring 18B1, an inner ring 18B2, and an outer ring 18B1,
It is composed of a plurality of steel balls 18B3 serving as rolling elements arranged between the inner ring 18B2, and the outer ring 18B1 is the second
Of the bearing housing 2 by the disc spring 31 of the preload mechanism 28 of
7 is positioned with a preload applied to the inner ring 18B2
Is positioned on the shaft portion 16B on the other side by the positioning step portion 16D on the other side of the auxiliary crank 16.

The outer ring 18A1 of the orbiting bearing 18 is
18B1 is positioned between the annular step portion 27F of the bearing housing 27 and the disc spring 31 of the preload mechanism 28 in a state where a preload in the thrust direction is applied.

Further, the one side shaft portion 16A is rotatably inserted into the bearing receiving hole 1D of the casing 1 through the casing side bearing 17, and the other side shaft portion 16B is swung through the swiveling side bearing 18. It is rotatably inserted in the holding hole 6B on the scroll 4 side.

Further, each of the auxiliary cranks 16 prevents the orbiting scroll 4 from rotating when the orbiting scroll 4 is orbited by the rotational drive of the drive shaft 2 and also prevents the orbiting scroll 4 from rotating. It guides the vehicle so that it turns with a constant turning radius about the axis O1 -O1.

Reference numeral 19 denotes a cover-shaped cylindrical cover provided on one side of the bearing accommodating hole 1D, and the cover 19 is a short cylindrical portion having substantially the same diameter as the outer rings 17B1 and 18B1 of the casing-side bearing 17. 19A and the lid portion 1 of the tubular portion 19A
The flange portion 19C is formed on the outer circumference of the casing 9B and has a flange portion 19C having substantially the same diameter as the diameter of the annular recess 1E of the casing 1. The flange portion 19C is fixed to the casing 1 by screws 20 (only two of which are shown). The tip of the tubular portion 19A of the cover 19 is connected to the outer ring 1 of the rear angular contact bearing 17B.
By affixing with the screw 20 in the state of being in contact with 7B1, the casing side bearing 17 is positioned to one side in the bearing accommodating hole 1D.

Reference numeral 21 denotes a plate-shaped retainer provided on the other side of the bearing accommodating hole 1D. The retainer 21 has an insertion hole 21A formed at the center thereof through which the auxiliary crank 16 is inserted, and an outer peripheral portion thereof is provided with a screw 22 (1). Only one piece is shown in the figure) and is fixed to the casing 1. Then, the insertion hole 21 of the retainer 21
The outer ring 17A of the front side angular bearing 17A is provided on the outer periphery of A.
1 is abutted, and the bearing receiving hole 1 of the casing side bearing 17
Positioning to the other side in D. in this way,
The casing side bearing 17 is positioned in the radial direction by means of the bearing housing hole 1D, and axially positioned in the cover 19.
And the retainer 21.

Reference numeral 23 denotes a first preload mechanism provided on the side of the bearing 17 on the casing side. The preload mechanism 23 is fixed to one side shaft portion 16A of the auxiliary crank 16 through a screw 24 (only one is shown). The first retainer 25 and the retainer 2
5 and the inner ring 17B2 of the back side angular bearing 17B and a disc spring 26 serving as a first pressing member.

Here, the retainer 25 is formed in a short cylindrical shape, and the inside thereof serves as a screw insertion hole 25A, and a flange portion 25B for holding the disc spring 26 is formed on the outer peripheral side of the tip, and the screw insertion hole 25A. The screw 24 is inserted into the center of the one-sided shaft portion 16A and is fixed thereto.

The inner periphery of the disc spring 26 abuts on the flange portion 25B of the retainer 25, and the outer periphery thereof abuts on the inner ring 17B2 of the rear angular bearing 17B. As a result, the preload mechanism 23 uses the disc spring 26 disposed between the flange portion 25B of the retainer 25 fixed to the one-side shaft portion 16A by the screw 24 and the inner ring 17B2 of the casing-side bearing 17 to allow the casing-side bearing 17 to be closed. Inner ring 17
A2, 17B2 while preloading, while positioning step portion 16 on one side
Positioned between C.

27 is a support plate 6 for the orbiting scroll 4.
With respect to the bearing housing that holds the orbiting side bearing 18,
The bearing housing 27 is formed in a shallow bottomed cylindrical shape, and the bearing housing 27 is an outer ring 18A1 of the orbiting side bearing 18.
, 18B1 with short inside diameter 2
7A, an annular flange portion 27C that is located closer to the bottom portion 27B of the tubular portion 27A and that projects radially outward from the outer periphery of the tubular portion 27A, and is located at the opening side of the tubular portion 27A. And, for example, three screw holder parts 27D
The outer peripheral side of the bottom portion 27B serves as a holding portion 27E that is fitted into the holding hole 6B of the support plate 6. Further, an annular step portion 27F is formed on the bottom portion 27B side inside the tubular portion 27A, and the annular step portion 27F connects the outer ring 18B1 of the orbiting side bearing 18 inserted into the tubular portion 27A with the preload mechanism 28. Positioned in the axial direction.

Further, the holding portion 27E of the bearing housing 27 is loosely fitted into the holding hole 6B of the support plate 6 so that the orbiting side bearing 18 and the support plate 6 are fitted with each other in the radial direction to have play. Displacement errors due to misalignment of the mounting positions of the bearings 17 and 18 and difference in thermal expansion of the support plate 6 are absorbed.

Reference numeral 28 denotes a second preload mechanism provided on the side of the orbiting bearing 18, and the preload mechanism 28 has a plurality of screws 29 (only one is shown) on the side of the opening of the cylindrical portion 27A of the bearing housing 27.
The second retainer 30 is fixed to the outer ring 18B1 of the rear angular contact bearing 18B by a disc spring 31 serving as a second pressing member.

Here, the retainer 30 is formed with an insertion hole 30A through which the auxiliary crank 16 formed at the center thereof is inserted, and an inner peripheral side of the insertion hole 30A, and the fixed side has a large diameter. And an annular spring accommodating step portion 30B,
When the screw 29 is screwed into the screw holder portion 27D of the bearing housing 27, the outer peripheral portion of the retainer 30 is fixed to the opening portion of the bearing housing 27 together.

The disc spring 31 is a ring-shaped plate body having a frustoconical shape so that the inner circumference and the outer circumference have different heights, and a spring force is generated in the height direction. Further, the outer periphery of the disc spring 31 is accommodated in contact with the spring accommodating step portion 30B of the retainer 30 and the inner periphery thereof is accommodated in the rear angular contact bearing 18B.
Is in contact with the outer ring 18B1. As a result, the preload mechanism 28 includes the disc spring 3 arranged between the spring accommodating step portion 30B of the retainer 30 fixed to the bearing housing 27 by the screw 29 and the outer ring 18B1 of the rear angular bearing 18B.
1, the outer rings 18A1 and 18B of the orbiting side bearing 18
It is positioned between the annular step portions 27F while applying a preload to 1.

Further, 32 is a suction port formed on the outer peripheral side of the fixed scroll 10, 33 is a discharge port formed on the center side of the end plate 11A of the fixed scroll 10, and the suction port 32 is the outermost peripheral side. The discharge port 33 communicates with the (lowest pressure side) compression chamber 14, and the discharge port 33 communicates with the most central side (highest pressure side) compression chamber 14.

The scroll type air compressor according to the present embodiment has the above-mentioned structure, and when the drive shaft 2 is rotationally driven by the electric motor via the pulley or the like, the rotation of the drive shaft 2 becomes the crank portion 2A. Is transmitted to the orbiting scroll 4 via the orbiting bearing 8 from the orbiting scroll 4
Revolves around the axis O1 -O1 of the drive shaft 2 while preventing rotation by the auxiliary cranks 16. Then, due to this revolution movement, each lap portion 5
The compression chambers 14, 14, ... Defined between B and 11B continuously shrink, so that the scroll air compressor causes the air sucked from the suction port 32 to be compressed.
The compressed air is discharged from the discharge port 33 to an external air tank (not shown) or the like while being sequentially compressed by.

Therefore, in the present embodiment, the auxiliary crank 16
The orbiting side bearing 18 holding the other side shaft portion 16B is housed in the bearing housing 27, and the bearing housing 27 is held so as to be loosely fitted in the holding hole 6B of the support plate 6 provided in the orbiting scroll 4. Therefore, it is possible to provide a play in the radial direction between the slewing side bearing 18 and the support plate 6, thereby causing misalignment of the mounting positions of the casing side bearing 17 and the slewing side bearing 18 of the auxiliary crank 16 and the support plate 6. Even if a radial displacement error occurs due to the difference in thermal expansion, etc., the error can be absorbed.
It is possible to prevent an unreasonable restraint force from acting on the auxiliary crank 16.

The other side shaft portion 16B of the auxiliary crank 16
On the side, the orbiting side bearing 1 that rotatably supports the other side shaft portion 16B.
Since 8 is a double-row angular bearing in front combination, the thrust load transmitted from the orbiting scroll 4 side is transmitted from the bearing housing 27 to the outer ring 18A of the front angular bearing 18A.
1, through the inner ring 18A2 and the inner ring 18B2 of the rear angular contact bearing 18B to the position determining portion 16D on the other side, and then to the auxiliary crank 16.

On the other hand, in the second preload mechanism 28 on the side of the other side shaft portion 16B, the disc spring 31 provided in the opening of the bearing housing 27 causes the rear side angular bearing 18B of the double row angular bearing of the front combination. Preload can be applied to the outer ring 18B1. Moreover, the rear angular contact bearing 18
Since the thrust load applied to the orbiting side bearing 18 from the orbiting scroll 4 side is not applied to the outer ring 18B1 of B,
An appropriate preload may be applied to the orbiting bearing 18.

Further, one side shaft portion 16 of the auxiliary crank 16
In A, as described above, the thrust load applied to the auxiliary crank 16 is caused by the position determining portion 1 on one side of the auxiliary crank 16.
Inner ring 17 of front side angular bearing 17A from 6C to the other side
A2, the outer ring 17A1, and the outer ring 17B1 of the rear angular contact bearing 17B are transmitted to the screw 2 from the outer ring 17B1.
It is transmitted to the cover 19 fixed at 0.

On the other hand, the first preload mechanism 23 on the side of the one side shaft portion 16A has the disc spring 26 provided on the end surface of the one side shaft portion 16A of the auxiliary crank 16 for the rear side of the double row angular bearing of the rear combination. A preload can be applied to the inner ring 17B2 of the angular bearing 17B. Moreover, since the thrust load applied to the casing side bearing 17 from the side of the orbiting scroll 4 is not applied to the inner ring 17B2 of the rear side angular bearing 17B, it is possible to bring the casing side bearing 17 into an appropriate preload state. it can.

As described above, in this embodiment, the casing side bearing 17 of the auxiliary crank 16 and the orbiting side bearing 18 are constituted by the double row angular bearings, and the casing side bearing 17 of the rear combination has the disc spring of the preload mechanism 23. 26, a preload is applied to the inner ring 17B2 of the rear angular bearing 17B, and in the front bearing 18 of the swivel side, the disc spring 31 of the preload mechanism 28 preloads the outer ring 18B1 of the rear angular bearing 18B. The preload mechanism 2 is applied to the part where the thrust load from the scroll 4 is not applied.
3, 28 can be provided.

Further, as described above, the load in the thrust direction is released to the auxiliary crank 16 in the bearing 18 on the turning side, and the thrust load and the preload from the preload mechanism 23 in the bearing 18 are simultaneously applied in the angular bearings 18A and 18B. Since it does not act, the angular bearings 18A, 18
The rolling resistance of the bearing can be reduced by preventing an excessive preload from being applied to the steel balls 18A3, 18B3, etc., which are the B rolling elements.

On the other hand, also in the casing side bearing 17,
The thrust load can be released to the cover 19, and the bearing 1
It is possible to prevent the thrust load and the preload from the preload mechanism 28 from acting simultaneously in 7 within the angular bearings 17A and 17B, and to reduce the rolling resistance of the angular bearings 17A and 17B.

Thus, the angular bearings 17A, 17B, 1 constituting the bearing 17 on the casing side and the bearing 18 on the turning side are provided.
The rolling resistance of the steel balls 17A3, 17B3, 18A3, 18B3 of the bearings is reduced by preventing an excessive preload from being applied to the 8A, 18B, and the angular bearings 17A, 17B, 18
The service life of A and 18B can be extended, and the reliability of the scroll air compressor can be improved.

Next, FIG. 4 shows a second embodiment according to the present invention. The feature of this embodiment is that the casing side bearing for rotatably supporting one side shaft portion of the auxiliary crank is a front row combined double row angular contact. A first preload mechanism for preloading the outer ring of the front angular contact bearing of the casing side bearing is provided as the bearing.

In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 41 designates a bearing accommodating hole 1 of the casing 1.
A casing-side bearing accommodated in D is shown, and the casing-side bearing 41 is configured as a double-row angular bearing in which a front surface side angular contact bearing 41A and a rear surface side angular contact bearing 41B are combined in the rear surface.

Here, the front side angular bearing 41A
Is an outer ring 41A1, an inner ring 41A2, and an outer ring 41A1,
The inner ring 41A2 is made up of a plurality of rolling steel balls 41A3 and the outer ring 41A1 is a first
Of the preload mechanism 44 is positioned in the bearing housing hole 1D while being preloaded by the disc spring 47, and the inner ring 41A2 is positioned on the one-side shaft portion 16A by the positioning step portion 16C on one side of the auxiliary crank 16. .

The rear angular contact bearing 41B includes an outer ring 41B1 and an inner ring 41B2, and the outer ring 41B1 and the inner ring 4B.
Steel balls 41B arranged between 1B2 and serving as a plurality of rolling elements
3 and the outer ring 41B1 is a cover 48 which will be described later.
Is positioned in the bearing accommodating hole 1D by the inner ring 41B.
2 is positioned on the one side shaft portion 16A by a retainer 43 fixed by a screw 42 screwed to the one side shaft portion 16A.

Then, the outer ring 41 of the casing side bearing 41
A1 and 41B1 are the cover 48 fixed to one side of the bearing receiving hole 1D and the disc spring 4 of the preload mechanism 44 fixed to the other side.
7 and the inner ring 41A2, 41B2 of the casing side bearing 41 are positioned with a preload in the thrust direction applied.
Are positioned between the retainer 43 fixed to the end surface of the one side shaft portion 16A and the one side positioning step portion 16C.

Reference numeral 44 denotes a first preload mechanism on the casing side bearing 41 side. The preload mechanism 44 is a first retainer fixed to the other side of the bearing receiving hole 1D via a screw 45 (only one is shown). 46, the retainer 46 and the casing side bearing 4
It is composed of a disc spring 47 serving as a first pressing member arranged between the first outer ring 41B1.

Here, the retainer 46 has an insertion hole 46A through which the auxiliary crank 16 formed at the center thereof is inserted, and an inner peripheral side of the insertion hole 46A, and the fixed side has a large diameter. And an annular spring accommodating step portion 46B,
When the screw 45 is screwed to the casing 1, the outer peripheral portion of the retainer 46 is fixed to the other side of the bearing housing hole 1D together.

Further, the disc spring 47 is a ring-shaped plate body and is formed in a frustoconical shape so that the inner circumference and the outer circumference have different heights, and a spring force is generated in the height direction. Further, the outer periphery of the disc spring 47 is accommodated in contact with the spring accommodating step portion 46B of the retainer 46, and the inner periphery thereof is the front side angular bearing 41A.
Is in contact with the outer ring 41A1. As a result, the preload mechanism 44 uses the disc spring 47 disposed between the spring accommodating step portion 46B of the retainer 46 fixed to the casing 1 by the screw 45 and the outer ring 41A1 of the front side angular bearing 41A to cause the casing side bearing 41 to move. It is positioned in the bearing accommodating hole 1D while applying a preload to.

Further, reference numeral 48 denotes a cover-shaped cylindrical cover provided on one side of the bearing accommodating hole 1D, and the cover 48 is a short length having substantially the same diameter as the outer rings 41A1 and 41B1 of the casing side bearing 41. Cylindrical portion 48A and the cylindrical portion 48A
And a flange portion 48C formed on the outer periphery of the lid portion 48B of the casing 1 and having a diameter larger than the diameter of the annular recess 1E of the casing 1. The flange portion 48C is fixed to the casing 1 with screws 49 (only two are shown). There is. The tip of the cylindrical portion 48A of the cover 48 is attached to the back side angular bearing 41.
The bearing accommodating hole 1D of the casing side bearing 17 is fixed by the screw 49 while being in contact with the outer ring 41B1 of B.
Positioning to one side inside. The cover 4
The flange portion 48C of No. 8 is in contact with one side of the casing 1.

However, also in this embodiment, the thrust load applied from the orbiting scroll 4 side is the auxiliary crank 16
From the positioning step portion 16C on one side to the front angular contact bearing 4
The inner ring 41A2 of 1A, the inner ring 41B2 of the rear angular contact bearing 41B, and the outer ring 41B1 are transmitted through the outer ring 41A1.
It is transmitted from B1 to the cover 48 fixed by a screw 49. On the other hand, in the preload mechanism 44, the disc spring 47 provided in the retainer 46 fixed to the other side of the bearing housing hole 1D applies an appropriate preload to the casing side bearing 41, which is a double row angular bearing in front combination. It can be in a state.

As a result, also in this embodiment, as in the first embodiment described above, by applying a preload applied to the casing side bearing 41 separately from the thrust load, an appropriate preload is applied by the disc spring 47. It is possible to prevent unnecessary load from being applied to the steel balls 41A3 and 41B3 of the bearing 41, improve the slipperiness, and extend the life of the scroll air compressor.

Further, FIG. 5 shows a third embodiment according to the present invention. The feature of this embodiment is that the orbiting side bearing for rotatingly supporting the orbiting side shaft portion of the auxiliary crank is a double-row angular bearing having a rear surface combination. The second preload mechanism for preloading the inner ring of the angular bearing on the other side of the orbiting side bearing is provided.

In this embodiment, the same components as those in the second embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 51 denotes a slewing side bearing which is housed in a bearing housing 54, which will be described later, located in a holding hole 6B formed in the support plate 6, and the slewing side bearing 51 has a front side angular bearing 51A and a rear side angular contact. By combining the back surface with the bearing 51B, a double row angular bearing with a combination of back surfaces is formed.

Here, the front side angular bearing 51A
Is an outer ring 51A1, an inner ring 51A2, and an outer ring 51A1,
The outer ring 51A1 is positioned in the bearing housing 54 by the annular step 54F of the bearing housing 54, and the inner ring 51A2 is a preload which will be described later. Mechanism 55
It is positioned on the other side shaft portion 16B of the auxiliary crank 16 while being pre-loaded by the disc spring 58.

Further, the back side angular bearing 51B
Is an outer ring 51B1, an inner ring 51B2, and an outer ring 51B1,
It consists of a plurality of rolling steel balls 51B3 arranged between the inner ring 51B2, and the outer ring 51B1 is positioned in the bearing housing 54 by a retainer 53 fixed to the bearing housing 54 by a screw 52, and the inner ring 51B3.
2 is positioned on the other side shaft portion 16B by the other side positioning step portion 16D of the auxiliary crank 16.

Then, the outer ring 51A1 of the turning side bearing 51,
51B1 is positioned between the annular step portion 54F of the bearing housing 54 and the retainer 53, and the inner rings 51A2 and 51B2 of the orbiting side bearing 51 are arranged between the positioning step portion 16D on the other side and the disc spring 58 of the preload mechanism 55. It is positioned with a preload applied in the thrust direction.

Reference numeral 54 designates a bearing housing for holding the orbiting side bearing 51. The bearing housing 54 is constructed in the same manner as the bearing housing 27 described in the first embodiment, and the bearing housing 54 is formed in a stepped tubular shape. The bearing housing 5
Reference numeral 4 denotes a short tubular portion 54A having an inner diameter slightly larger than the outer rings 51A1 and 51B1 of the orbiting bearing 51, and a collar portion 54C formed on the outer periphery of the tubular portion 54A on the reduced diameter portion 54B side. And three screw holder portions 54D formed on the opening side of the tubular portion 54A.
The side of the reduced diameter portion 54B from the collar portion 54C of 4A serves as the holding portion 54E. An annular stepped portion 54F is formed on the reduced diameter portion 54B inside the tubular portion 54A, and the annular stepped portion 54F positions the turning side bearing 51 inserted into the tubular portion 54A to the other side. .

Reference numeral 55 denotes a second bearing provided on the side of the orbiting bearing 51.
Of the auxiliary crank 16 is shown.
A second retainer 57 fixed to the other side shaft portion 16B via a screw 56, and a plate serving as a second pressing member arranged between the retainer 57 and the inner ring 51A2 of the front side angular bearing 51A. And a spring 58.

Here, the retainer 57 is formed in a short cylindrical shape, and the inside thereof serves as a screw insertion hole 57A, and a flange portion 57B for holding the disc spring 58 is formed on the outer peripheral side of the tip, and the screw insertion hole 57A. A screw 56 is inserted into the shaft of the other side shaft portion 16B and is fixed to the center portion of the other side shaft portion 16B.

The inner periphery of the disc spring 58 has a retainer 5
7, and the outer circumference is in contact with the inner ring 51A2 of the front angular contact bearing 51. As a result, the preload mechanism 55 causes the screw 56 to move the one side shaft portion 16A.
A preload is applied to the orbiting side bearing 51 by a disc spring 58 arranged between the flange portion 57B of the retainer 57 and the inner ring 51B2 of the orbiting side bearing 51.

In this embodiment having such a configuration, the thrust load transmitted from the orbiting scroll 4 side is applied to the outer ring 51A of the front angular contact bearing 51A from the bearing housing 54.
1, through the outer ring 51B1 and the inner ring 51B2 of the rear angular contact bearing 51B to the position determining step portion 16D on the other side, and then to the auxiliary crank 16. On the other hand, in the preload mechanism 55, the disc spring 58 provided on the retainer 57 fixed to the other side shaft portion 16B by the screw 56 gives an appropriate preload to the orbiting side bearing 51, which is a double row angular bearing of the rear combination. be able to.

Thus, also in this embodiment, similarly to the above-described first embodiment, the preload applied to the orbiting side bearing 51 is appropriately applied, and an extra load is applied to the steel balls 51A3 and 51B3 of the bearing 51. Can be prevented and the slipperiness can be improved.

Further, FIG. 6 shows a fourth embodiment according to the present invention. The feature of the present embodiment is that the bearing on the side of the one side shaft portion 16A of the auxiliary crank 16 has a rear assembly similar to that of the first embodiment. Casing side bearing 17 consisting of double row angular bearings
The rear side angular bearing 1 is provided on the one side shaft portion 16A.
First preload mechanism 23 for preloading inner ring 17B2 of 7B
Has been established. Further, the bearing on the side of the other side shaft portion 16B of the auxiliary crank 16 is a slewing side bearing 51 composed of a double-row angular bearing with a rear surface combination similar to that of the third embodiment, and the other side shaft portion 16B has a front side angular bearing. Inner ring 5 of 51A
This is because a second preload mechanism 55 for preloading 1A2 is provided.

Also in this embodiment, the above-mentioned first and third
The bearings 51, 17 of the auxiliary crank 16 are the same as in the embodiment of
The thrust load applied to the auxiliary crank 16 is transmitted to the position determining portion 16D on the other side of the auxiliary crank 16 via the outer ring 51A1 of the front angular contact bearing 51A, the outer ring 51B1 of the rear angular contact bearing 51B, and the inner ring 51B2 on the orbiting side bearing 51 side. Further, on the casing side bearing 17 side, from the positioning step portion 16C on one side of the auxiliary crank 16 to the front side angular bearing 17A.
Of the inner ring 17A2, the outer ring 17A1, and the outer ring 17B1 of the rear angular contact bearing 17B.
Is transmitted to the cover 19 fixed by the screw 20.

On the other hand, the preload mechanism 55 on the orbiting side bearing 51 side is a front side angular bearing 51A to which no thrust load is applied.
The inner ring 51A2 of the bearing is preloaded, and the preload mechanism 23 of the casing side bearing 17 side can preload the inner ring 17B2 of the rear angular contact bearing 17B to which no thrust load is applied. Bearing 5
1,17 steel balls 51A3, 51B3, 17A3, 17B
It is possible to prevent an extra load from being applied to 3 and improve the slipperiness.

Next, FIG. 7 and FIG. 8 show a fifth embodiment of the present invention.
The present embodiment is characterized in that the bearing on the turning shaft side of the auxiliary crank is accommodated through the bearing housing, and the bearing housing can be finely displaced in the radial direction.

In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 61 denotes a bearing housing for holding the orbiting side bearing 18. The bearing housing 61 is formed in a shallow bottomed cylindrical shape, and the bearing housing 61 is the orbiting side bearing 1.
No. 8 outer ring 18B1 and 18A1 and a cylindrical portion 61A as a short bearing accommodating portion having an inner diameter slightly larger than the outer ring 18B1 and 18A1. Holding step 61C held by 6B
And an annular step portion 6 formed on the inner bottom of the tubular portion 61A.
1D, and a pair of stays 61E that are elastically deformable and are formed in the cylindrical portion 61A so as to project in opposite directions in the tangential direction, and a fastening portion 61F provided on the projecting end side of each stay 61E. Consists of.

Further, the tubular portion 6 is formed by the annular step portion 61D.
The orbiting bearing 18 inserted into the 1A is positioned on the other side, and the diameter of the holding step portion 61C on the small diameter side is smaller than that of the holding hole 6B of the support plate 6.

Further, the stay 61E is arranged along the circumferential direction of the end plate 5A of the orbiting scroll 4, that is, along the circumferential direction of the support plate 6, and each fastening portion 61 is provided.
A screw 62 is screwed to F and is fixed to the support plate 6.

The bearing housing 61 having such a structure
Then, although the stay 61E has high rigidity in the circumferential direction of the support plate 6, it has flexibility in the radial direction due to elastic deformation. Therefore, when a radial load is applied to the bearing housing 61. It is possible to regulate the movement in the circumferential direction and allow a minute displacement in the radial direction.

As a result, the load in the thrust direction applied to the support plate 6 from the orbiting scroll 4 can be received by the shoulder portion around the bearing housing 61. Moreover, the orbiting scroll 4 is reliably fixed in the circumferential direction, which functions to prevent rotation, and the stay 61E is curved to absorb deformation due to thermal expansion, misalignment error, and radial displacement due to bearing play. Yes, bearing on swivel side 1
Bearing loss of No. 8 and the reliability of the bearing 18 can be improved.

Further, FIGS. 9 and 10 show a sixth embodiment according to the present invention. The feature of this embodiment is that the stay of the bearing housing described in the fifth embodiment is projected from the diameter direction of the tubular portion. It has been done.

The same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 71 denotes a support plate according to the present embodiment, which is formed in a disc shape fixed to the orbiting scroll body 5 of the orbiting scroll 4 and holds the orbiting bearing 8 in the central portion. A boss portion 71A
On the outer peripheral side, a bearing housing 7 for a swivel bearing 18 to be described later is provided.
Three holding holes 71B (only one is shown) for accommodating 2 are formed at predetermined intervals in the circumferential direction.

Reference numeral 72 denotes a bearing housing for holding the auxiliary crank orbiting side bearing 18. The bearing housing 72 is formed in a shallow bottomed cylindrical shape, and the bearing housing 72 is an outer ring 18B1 of the auxiliary crank orbiting side bearing 18. A cylindrical portion 72A as a short bearing accommodating portion having an inner diameter slightly larger than 18A1, and a cylindrical portion 72A formed on the outer periphery of the cylindrical portion 72A on the side of the bottom portion 72B and held in a holding hole 71B of the support plate 71. The holding step portion 72C and the annular step portion 72D formed on the inner bottom portion of the tubular portion 72A are provided.
Has a pair of stays 72E that are formed so as to project in opposite directions in the diametrical direction and are elastically deformable in the radial direction, and a fastening portion 72F provided at the tip end side of each stay 72E.

Further, the tubular portion 7 is formed by the annular step portion 72D.
The orbiting bearing 18 inserted into the 2A is positioned on the other side, and the diameter of the holding step portion 72C on the small diameter side is smaller than that of the holding hole 71B of the support plate 71.

Further, the stay 72E is arranged along the circumferential direction of the end plate 5A of the orbiting scroll 4, that is, along the circumferential direction of the support plate 71, and each fastening portion 7 is provided.
A screw 73 is screwed to the 2F and is fixed to the support plate 71.

The bearing housing 72 thus configured
Also in the above, the shape of the stay 72E can restrict the movement in the circumferential direction, allow the movement in the radial direction, reduce the bearing loss of the orbiting side bearing 18, and improve the reliability of the bearing 18.

In each of the embodiments described above, the bearing housing that holds the minute displacement in the radial direction is used as the orbiting side bearing that rotatably supports the other side shaft portion 16B of the auxiliary crank 16. The present invention is not limited to this, and it goes without saying that it may be used for an auxiliary crank fixed side bearing that rotatably supports the fixed side shaft portion 16A.

Although the pressing member of the preload mechanism is formed by the disc spring, the present invention is not limited to this, and an elastic member such as a coil spring or rubber may be used.

[0100]

As described in detail above, according to the present invention of claim 1, the casing side bearing for rotatably supporting the fixed side shaft portion of the auxiliary crank and the orbiting side bearing for rotatably supporting the orbiting side shaft portion of the auxiliary crank. And a double-row angular bearing, respectively, and the casing-side double-row angular bearing among the angular bearings is provided with a thrust direction preload on at least one of the outer ring of the front bearing and the inner ring of the rear bearing. The first preloading mechanism is provided and / or the double row angular bearing on the orbiting scroll side is provided with a second preload in the thrust direction to at least one of the outer ring of the rear bearing and the inner ring of the front bearing. Since the preload mechanism is provided, of the double row angular bearings on the casing side and the orbiting scroll side, the inner ring that does not receive the thrust load from the orbiting scroll. Can properly apply a preload in the thrust direction to the outer ring, keep this preload at an appropriate level, reduce the loss of each angular bearing and extend its life, and eventually the reliability of the scroll fluid machine. You can improve your sex.

According to the second aspect of the present invention, the first and second pressing members can apply an appropriate preload to the outer ring or the inner ring of the angular bearing without being affected by the thrust load from the orbiting scroll side. The rolling resistance of the angular bearing can be reduced and the life of the bearing can be extended.

According to the third aspect of the invention, the stay of the bearing housing restricts the movement of the bearing in the circumferential direction and allows elastic deformation in the radial direction.
Displacement due to thermal expansion and bearing backlash can be absorbed, an excessive load or the like can be prevented from acting on the bearing, and the rolling resistance of the bearing can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a scroll type air compressor according to a first embodiment.

FIG. 2 is a cross-sectional view as seen from the direction of arrows II-II in FIG.

FIG. 3 is a vertical cross-sectional view showing an enlarged main part in FIG.

FIG. 4 is a vertical sectional view showing a second embodiment seen from the same position as in FIG.

FIG. 5 is a vertical sectional view showing a third embodiment as seen from the same position as in FIG.

FIG. 6 is a vertical cross-sectional view showing a fourth embodiment seen from the same position as in FIG.

FIG. 7 is a sectional view showing a support plate and a bearing housing according to a fifth embodiment as seen from the same position as in FIG.

FIG. 8 is a cross-sectional view as seen from the direction of arrows VIII-VIII in FIG.

FIG. 9 is a sectional view showing a support plate and a bearing housing according to a sixth embodiment, as seen from the same position as in FIG.

FIG. 10 is a cross-sectional view as seen from the direction of arrow XX in FIG.

[Explanation of symbols]

1 Casing 2 Drive shaft 2A Crank part 4 Orbiting scroll 5 Orbiting scroll body 5A, 11A End plate 5B, 11B Wrap part 6,71 Support plate 6B, 71B Holding hole 8 Orbiting bearing 10 Fixed scroll 11 Fixed scroll body 14 Compression chamber 16 Auxiliary crank 16A One side shaft part 16B Other side shaft part 16C One side positioning step part 16D Other side positioning step part 17,41 Casing side bearing 17A, 18A, 41A, 51A Front side angular bearing 17B, 18B, 41B, 51B Back side angular bearings 17A1, 17B1, 18A1, 18B1, 41A1,
41B1, 51A1, 51B1 outer ring 17A2, 17B2, 18A2, 18B2, 41A2,
41B2, 51A2, 51B2 inner ring 17A3, 17B3, 18A3, 18B3, 41A3,
41B3, 51A3, 51B3 Steel ball 18,51 Orbiting side bearing 23,28,44,55 Preload mechanism 24,29,45,56 Screw 25,30,46,57 Retainer 26,31,47,58 Disc spring (pressing member) ) 27,61,72 bearing housing 61A, 72A tubular portion (bearing accommodating portion) 61E, 72E stay 61F, 72F fastening portion

Claims (3)

[Claims] 1. A casing, a drive shaft rotatably provided at one end side of the casing, and a distal end side of which extends into the casing to form a crank portion, and the crank portion of the drive shaft is swung through a swivel bearing. A plurality of orbiting scrolls are provided between the orbiting scroll and the wrap portion of the orbiting scroll, which is provided on the end plate of the orbiting scroll so as to stand upright on the end plate of the orbiting scroll. A fixed scroll in which a spiral wrap portion forming a compression chamber is provided upright, and one side shaft portion is rotatably supported by the casing via a casing side bearing to prevent rotation of the orbiting scroll. In a scroll fluid machine, a portion of which includes an auxiliary crank rotatably supported by the orbiting scroll via an orbiting side bearing, wherein The side bearings are each composed of a double-row angular bearing, and among the double-row angular bearings, the casing-side double-row angular bearing includes an outer ring and a rear surface of the front bearing when the wrap portion side of the orbiting scroll is the front side. A first preload mechanism that applies a preload in the thrust direction is provided on at least one of the inner ring of the side bearing, and / or the double row angular bearing on the orbiting scroll side includes an outer ring of the rear side bearing and a front side bearing. A scroll fluid machine characterized in that a second preload mechanism for applying a preload in a thrust direction is provided on at least one of the inner ring. 2. The first preload mechanism is a first retainer fixed to one side shaft portion of the casing or an auxiliary crank, and a first retainer disposed between the first retainer and the bearing. 1 pressing member, and the second preload mechanism,
The second retainer fixed to the other side shaft portion of the orbiting scroll or the auxiliary crank, and a second pressing member arranged between the second retainer and the bearing. 1. The scroll type fluid machine according to 1. 3. A casing, a drive shaft rotatably provided at one end side of the casing, and a distal end side of which extends into the casing to form a crank portion, and a crank portion of the drive shaft is swung through a swivel bearing. A plurality of orbiting scrolls are provided between the orbiting scroll and the wrap portion of the orbiting scroll, which is provided on the end plate of the orbiting scroll so as to stand upright on the end plate of the orbiting scroll. A fixed scroll in which a spiral wrap portion forming a compression chamber is provided upright, and one side shaft portion is rotatably supported by the casing via a casing side bearing to prevent rotation of the orbiting scroll. In a scroll fluid machine, a portion of which includes an auxiliary crank rotatably supported by the orbiting scroll via an orbiting side bearing, wherein At least one of the side bearings is provided with a bearing housing that holds the bearing so as to be capable of minute displacement in the radial direction with respect to the orbiting scroll or the casing, and the bearing housing has a tubular shape that accommodates the bearing. Bearing housing portions, a pair of stays that are elastically deformable and project from the bearing housing portions in opposite directions along the circumferential direction of the end plate, and the orbiting scrolls provided on the projecting end sides of the stays. A scroll type fluid machine comprising a fastening portion fastened to a casing.