JP2001074043A - Eccentric thrust bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric thrust bearing with excellent operating smoothness and capable of coping with increase of bearing load capacity. SOLUTION: This eccentric thrust bearing 10 has a ball unit 13 constituted by holding a large number of ball 15 groups on fan type windows 16, 17 of a holder 14 in a state of arranged continuously and adjacent to each other in the peripheral direction, and it is formed like a total ball bearing. Consequently, the number of the balls 15 can be maximized, and the bearing load capacity can be largely increased compared with a conventional eccentric thrust bearing of a ball using type. Movement of a revolving scroll member becomes smooth while eccentric revolving motion of the member is supported by rolling motion with the ball 15 groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric thrust bearing for supporting an eccentric orbiting motion in, for example, a scroll compressor.

[0002]

2. Description of the Related Art In a conventional scroll compressor, an orbiting scroll member that eccentrically orbits with respect to a frame is supported via an eccentric thrust bearing.

An eccentric thrust bearing of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 11-93950 and Japanese Patent Application Laid-Open No. 10-184676.
As shown in the official gazette, one rolling element is placed in a circular raceway groove provided at several places on the inner surface of a pair of two races.
It is configured so that it can be rotated one by one.

In the former publication, a ball is used as a rolling element, and in the latter publication, a so-called double conical roller such as an abacus ball is used as a rolling element.

[0005]

The conventional eccentric thrust bearing using the above-mentioned ball has excellent operation smoothness, but has a limit in increasing the bearing load capacity due to the limited number of balls used. is there. On the other hand, in the conventional eccentric thrust bearing using the above-mentioned double tapered rollers, although the bearing load capacity can be increased, since there are many sliding portions between the double tapered rollers and the circular raceway grooves, the operation of the orbiting scroll member is smooth. It is pointed out that the property decreases.

In view of such circumstances, an object of the present invention is to provide an eccentric thrust bearing having a structure which is excellent in operation smoothness and can cope with an increase in bearing load capacity.

[0007]

A first eccentric thrust bearing according to the present invention is interposed between a movable member which eccentrically turns and a fixed member which is arranged to face the movable member in the axial direction. An annular retainer having a fan-shaped window penetrating in the axial direction except at least two places around the circumference, the retainer being provided with an eccentrically rotatable ball unit interposed between the two members; A plurality of balls rotatably housed and held adjacent to each other in a circumferential direction in each fan-shaped window of the container, and at least two connecting portions of the retainer and portions of the fixing member corresponding to the connecting portions. In contrast, a support shaft and a circular concave portion that is loosely fitted to the support shaft are separately provided.

[0008] In this configuration, since the configuration is like a full ball bearing, the number of balls used can be increased as much as possible, and the bearing load capacity can be reduced as compared with the conventional eccentric thrust bearing using a ball. It can be increased significantly. Further, since the ball and the double tapered rollers are not slidably in contact with the inner peripheral wall of the circular raceway groove and guided as in the conventional example, the ball group is rolled with respect to the movable member and the fixed member. In addition to being able to reduce the rotational resistance of the movable member, the operation smoothness and wear resistance are improved even in a severe environment such as poor lubrication conditions. Further, since the eccentric rolling range of the ball unit is regulated by the circular concave portion and the support shaft provided for the retainer and the fixing member of the ball unit, the ball unit does not protrude from between the two members. Be bound.

A second eccentric thrust bearing according to the present invention is interposed between a movable member which eccentrically turns and a fixed member which is arranged to face the movable member in the axial direction, and is fixed to the movable member. Having a movable race, a fixed race fixed to a fixed member, and a ball unit interposed eccentrically rotatable between the two races, the ball unit,
An annular retainer having a sectoral window penetrating in the axial direction except at least two places around the circumference, and a number of balls rotatably housed and held in each sectoral window of the retainer so as to be adjacent to the circumferential direction. And a support shaft and a circular recess loosely fitted to the support shaft are provided for at least two connecting portions of the retainer and a portion of the fixing member corresponding to the connecting portion.

In this configuration, it is essential to provide a race, and the basic operation is the same as that of the first eccentric thrust bearing.

In a third eccentric thrust bearing according to the present invention, in the above first or second configuration, at least two connecting portions of the retainer are installed at positions opposed to each other by approximately 180 degrees.

In this configuration, since the connecting portions of the retainer are arranged in a well-balanced manner in the first or second configuration, the movement of the ball unit in all directions in the radial direction of the fixed member and the fixed side race is performed. Can be made substantially even.

In a fourth eccentric thrust bearing according to the present invention, in any one of the first to third configurations, the same circular concave portion is provided in the movable member or the movable race in correspondence with the circular concave portion. The support shaft is also loosely fitted in a circular recess provided in the movable member or the movable race.

In this configuration, since the movement of the movable member or the movable race in all directions in the radial direction of the fixed member or the fixed race is restricted, the trajectory of the eccentric turning motion of the movable member or the movable race is controlled. Becomes stable.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

FIGS. 1 to 6 show a first embodiment of the present invention. FIG. 1 is a sectional view of a scroll compressor, and FIG.
Is an exploded perspective view of the eccentric thrust bearing, FIG. 3 is a plan view showing an internal configuration of the eccentric thrust bearing, FIG. 4 is a sectional view taken along line (4)-(4) of FIG. 3, and FIG. FIG. 4 is a diagram showing a state in which the movable race is eccentric, and FIG. 6 is a schematic diagram used to explain the operation of the eccentric thrust bearing.

The illustrated scroll compressor 1 has a generally well-known configuration, for example, a rotary shaft 2 such as a motor shaft is driven to rotate, and an orbiting scroll connected to an eccentric shaft portion 2a at its shaft end. By making the member 3 eccentrically swivel,
The volume of the compression chamber between the orbiting scroll member 3 and the fixed scroll member 4 is changed to compress the fluid in the compression chamber.

Note that the rotating shaft 2 is
Are supported via two rolling bearings 6, 7, and
The eccentric shaft portion 2 a of the rotary shaft 2 is fitted and mounted on the cylindrical boss portion 3 a of the orbiting scroll member 3 via a rolling bearing 8. Further, an eccentric thrust bearing 10 for supporting the eccentric orbiting movement of the orbiting scroll member 3 is provided between the orbiting scroll member 3 and the frame 5.

This embodiment has a feature in the configuration of the eccentric thrust bearing 10 described above, and will be described in detail below.

The eccentric thrust bearing 10 has a ball unit 13 non-separably interposed between two upper and lower races 11 and 12.

The upper race 11 is fixedly attached to the lower surface of the orbiting scroll member 3, and the lower race 12 is fixed to the upper surface of the frame 5. Due to such a relationship, the upper race 1
Reference numeral 1 denotes an eccentric orbiting motion integrally with the orbiting scroll member 3, so that it is hereinafter referred to as a movable race, and the lower race 12 is fixed to the frame 5 and is immobile. In addition, both races 11 and 1
Although not shown, the two can be fixed to the orbiting scroll member 3 and the frame 5 by, for example, arranging uneven portions on both and fitting them together.

The ball unit 13 includes the ring-shaped cage 1
4 is a configuration in which a large number of balls 15 groups are held. The retainer 14 is provided with fan-shaped windows 16 and 17 that penetrate in the axial direction except for two places 180 degrees opposite each other on the circumference.
The balls 15 are rotatably housed and held in the fan-shaped windows 16 and 17 of the cage 14 so as to be adjacent to each other in the circumferential direction.

Incidentally, grooves 18 and 19 are provided on the outer periphery of the inner-diameter annular portion and the inner periphery of the outer-diameter annular portion constituting the fan-shaped windows 16 and 17 of the retainer 14, respectively. , 19
Each ball 15 is caught in the fan-shaped windows 16 and 17 by the axial engagement of each ball 15 with the annular projections on both sides of the ball.
5 is held in a non-separable state so that it can rotate and revolve. The balls 15 are forcibly fitted to the fan-shaped windows 16 and 17 of the retainer 14 in a snap-fit form from the axial direction.

Further, as shown in FIG. 4, the axial dimension of the retainer 14 is set slightly smaller than the diameter dimension of the ball 15, so that only the ball 15 group is formed on the two races 11 and 12. And the cage 14 is not in contact with the two races 11 and 12.

Further, at least two
A circular through hole 25 as a circular concave portion is formed in each of the connecting portions 20, 20.
At the portions corresponding to 0 and 20, round bar-shaped pins 26 as support shafts that are loosely fitted in the circular through holes 25 are provided, respectively. The eccentric rolling range of the ball unit 13 is regulated by the circular through-hole 25 and the round bar-shaped pin 26, whereby the ball unit 13 is moved from between the movable race 11 and the fixed race 12. It is restrained not to protrude. That is, when the above-mentioned ball unit 13 performs eccentric rolling motion, the inner peripheral wall surface of the circular through hole 25 of the retainer 14 is slidably guided on the outer peripheral surface of the round bar pin 26 of the fixed race 12. Thus, the eccentric rolling range of the ball unit 13 is restricted.

The races 11 and 12 described above are:
It is formed of a metal material such as JIS standard SUJ2 or SAE standard 5120 that has been subjected to quenching / tempering treatment (sulfur quenching) or carburizing hardening treatment as required, or ceramics. The retainer 14 of the ball unit 13 is formed of various synthetic resin materials, and the ball 15 of the ball unit 13 is formed of a general metal material such as bearing steel or ceramics. In addition, as the ceramic material, for example, mainly silicon nitride, and as a sintering aid, yttria and alumina, and other materials using aluminum nitride, titanium oxide, and spinel as appropriate, alumina, silicon carbide, zirconia,
Aluminum nitride and the like can be mentioned. Specifically, 1.5-5.5% by weight of yttria, 1-2% by weight of aluminum nitride,
2 to 4.5% by weight of alumina, 0.5 to 0.5% of titanium oxide
It is preferable to use a ceramic containing 1.0% by weight and the remainder being silicon nitride.

By the way, the above-described eccentric thrust bearing 10
Then, the orbiting scroll member 3 and the movable race 11
As shown in FIGS. 6A to 6D, when the center point O is eccentrically swiveled to O1, O2, O3, and O4 with time, the ball unit 13 is moved in accordance with the movement.
Will roll within a range regulated by the circular through-hole 25 and the round bar-shaped pin 26. in this way,
The eccentric orbiting motion of the orbiting scroll member 3 has a large number of balls 1
Since the eccentric rotation is guided by the rolling operation by the fifth group, the eccentric turning movement becomes smooth.

As described above, in the eccentric thrust bearing 10 according to the present embodiment, a large number of balls 15
The fan 15 is held in such a state that it is arranged continuously adjacent to the fan-shaped windows 16 and 17 in the circumferential direction.
The ball 15 is used as much as possible.
The bearing load capacity can be increased in accordance with the number of used bearings, and the bearing load capacity can be greatly increased as compared with the conventional eccentric thrust bearing using a ball.

Also, instead of guiding the balls and the double tapered rollers by sliding them against the inner peripheral wall of the circular raceway groove as in the conventional example, the ball 15 group is rolled with respect to the races 11 and 12. Therefore, the rotational resistance of the orbiting scroll member 3 can be reduced, and the operation smoothness and wear resistance can be improved even in a severe environment such as poor lubrication conditions.

Further, when the amount of eccentric orbital movement of the orbiting scroll member 3 temporarily changes, the eccentric rolling range of the ball unit 13 is restricted, so that the ball unit 13 cannot follow and eccentrically move. 1
The fifth group rotates and can guide the eccentric orbiting operation of the orbiting scroll member 3 and the movable race 11 by rolling, and can prevent the sliding phenomenon like the conventional eccentric thrust bearing using the double conical rollers, and can operate smoothly. Sex will be maintained.

When one of the races 11 and 12 and the ball unit 13 is worn or damaged with the passage of time, only the corresponding one can be replaced independently, so that the entire bearing can be replaced. This is advantageous in that the running cost can be reduced as compared with the case of performing the operation. In addition, since a large number of balls 15 of the ball unit 13 are accommodated and held in the fan-shaped windows 16 and 17 of the retainer 14 in a non-separable manner, handling during the transporting process, the assembling process, or the replacement is facilitated.

FIGS. 7 and 8 show a second embodiment of the present invention. FIG. 7 is an exploded perspective view of the eccentric thrust bearing, and FIG. 8 is a plan view showing an internal configuration of the eccentric thrust bearing of FIG.

The second embodiment is characterized in that the ball unit 13 of the first embodiment is provided with four sets of a circular through-hole 25 and a round bar-shaped pin 26 for regulating the eccentric rolling range. .

That is, the retainer 1 of the ball unit 13
4, connecting portions 20 are provided at four positions at every 90 degrees on the circumference of the four connecting portions 2.
0 is provided with one circular through hole 25.
Further, a round bar-shaped pin 26 is provided at a position corresponding to the four circular through holes 25 in the fixed side race 12. The retainer 14 has four fan-shaped windows 16a, 16
b, 17a and 17b are provided.

In this case, since the number of connecting portions 20 of the retainer 14 is increased to four, the strength of the retainer 14 is improved, and the eccentric rolling range of the ball unit 13 can be more reliably regulated. Become like

FIGS. 9 to 12 show a third embodiment of the present invention. FIG. 9 is an exploded perspective view of the eccentric thrust bearing,
10 is a plan view showing the internal configuration of the eccentric thrust bearing of FIG. 9, FIG. 11 is a sectional view taken along line (11)-(11) of FIG. 10, and FIG. It is a figure which shows the state which carried out the eccentricity.

The third embodiment is characterized in that, based on the configuration of the second embodiment, the eccentric turning range of the movable race 11 is also restricted.

That is, the circular through-holes 2 of the cage 14 are provided at four positions on the movable side race 11 at every 90 degrees on the circumference.
5, one circular through hole 27 having the same size and shape is provided. A small-diameter shaft portion 26a protrudes from the free end side of each round bar-shaped pin 26 provided on the fixed-side race 12, and this small-diameter shaft portion 26a is provided with respect to the circular through hole 27 of the movable-side race 11. It is loosely fitted.

In such a configuration, the movable race 11
However, the eccentric turning motion based on the center of the fixed race 12 is performed, and the trajectory of the eccentric turning motion of the movable race 11 can be stably maintained.

It should be noted that the present invention is not limited to only the above embodiment, and various applications and modifications are conceivable. (1) In each of the above embodiments, if a solid lubricant is coated on at least one of the inner surfaces of the races 11 and 12 and / or the ball 15 or a special surface treatment is applied, a severe environment such as poor lubrication conditions is obtained. It can exhibit excellent operation smoothness and abrasion resistance even when used in the above.

Examples of the above-mentioned solid lubricant include soft metals such as gold, silver and copper; fluororesins such as PTFE (polytetrafluoroethylene);
(Diamond-like carbon).

The above-mentioned special surface treatment includes, for example, a manganese phosphate treatment. In this manganese phosphate treatment, after washing the surface of the object to be treated, alkali degreasing treatment, and washing with ion-exchanged water, pre-treating with a surface conditioner and applying an aqueous solution of a manganese phosphate compound to the surface of the object to be treated. The used film forming process is performed. As a result, on the surface of the object to be treated, surface corrosion due to the manganese phosphate compound and precipitation of crystals of the manganese phosphate on the surface occur, and on the surface of the object to be treated,
Due to the surface corrosion action, minute and shallow irregularities (initial irregularities) are formed, and a film made of manganese phosphate is formed on the entire surface. Although relatively large unevenness is unevenly unevenly distributed on the surface of the processing object before the formation of this coating, the unevenness is reduced to small unevenness evenly by the corrosion action. You. Further, the coating is also formed by waving according to the surface irregularities of the processing object. Since the coating having such irregularities has the required lubricating properties, the initial conformability can be ensured, and a lubricating component such as oil is held in the valleys of the irregularities in the wavy coating. Therefore, long-term smooth operation is ensured. (2) In the above embodiments, the inner peripheral wall surface of the circular through hole 25 of the retainer 14, the outer peripheral surface of the round bar-shaped pin 26, the inner peripheral wall surface of the circular through hole 27 of the movable race 11, and the like are described. By coating with a solid lubricant as exemplified in (1), excellent operation smoothness and wear resistance can be exhibited even when used in a severe environment such as poor lubrication conditions.

[0043]

According to the eccentric thrust bearing of the present invention, the number of balls used is increased as much as possible by adopting a form like a so-called full ball bearing. As a result, the bearing load capacity can be greatly increased.

In addition, instead of guiding the ball or the double tapered roller in sliding contact with the inner peripheral wall of the circular raceway groove as in the conventional example, the ball group is rolled with respect to the movable member or the fixed member. As a result, the rotational resistance of the movable member can be reduced, and the operation smoothness and abrasion resistance can be improved even in use in a severe environment such as poor lubrication conditions.

Further, since the eccentric rolling range of the ball unit is regulated by the circular recess and the support shaft provided for the retainer and the fixing member of the ball unit, the amount of eccentric turning movement of the movable member is temporarily reduced. Even if it changes, the rolling operation of the ball group can be maintained after the ball unit is restrained so as not to protrude from between the two members. Therefore, the operation smoothness can be maintained, for example, the sliding phenomenon like the conventional eccentric thrust bearing using the double tapered rollers can be prevented.

Further, when any one of the races and the ball unit constituting the eccentric thrust bearing undergoes abrasion or damage with the passage of time, only the corresponding one can be replaced independently. This is advantageous in that the running cost can be reduced as compared with the case of replacing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a scroll compressor using an eccentric thrust bearing according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of an eccentric thrust bearing.

FIG. 3 is a plan view showing the internal configuration of the eccentric thrust bearing.

4 is a sectional view taken along line (4)-(4) of FIG.

FIG. 5 is a view showing a state where the movable race is eccentric in FIG. 4;

FIG. 6 is a schematic view used to explain the operation of the eccentric thrust bearing.

FIG. 7 is an exploded perspective view of an eccentric thrust bearing according to a second embodiment of the present invention.

FIG. 8 is a plan view showing the internal configuration of the eccentric thrust bearing of FIG. 7;

FIG. 9 is an exploded perspective view of an eccentric thrust bearing according to a third embodiment of the present invention.

FIG. 10 is a plan view showing the internal configuration of the eccentric thrust bearing of FIG. 9;

FIG. 11 is a sectional view taken along line (11)-(11) of FIG.

FIG. 12 is a view showing a state in which the movable race is eccentric in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Rotating shaft 3 Orbiting scroll member 4 Fixed scroll member 5 Frame 10 Eccentric thrust bearing 11 Movable race 12 Fixed race 13 Ball unit 14 Cage 15 Ball 16 and 17 Fan-shaped window of cage 20 Connection of cage Part 25 Circular through hole of connecting part

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 3H039 AA03 AA12 BB05 CC02 CC23 CC35 3J012 AB20 BB02 EB20 FB10 HB04 3J101 AA02 AA34 AA42 AA53 AA62 BA10 BA35 BA50 BA70 DA03 EA01 EA31 EA41 EA42 EA44 EA53 EA78 FA29

Claims (4)

[Claims] An eccentric thrust bearing interposed between a movable member eccentrically rotating and a fixed member disposed to face the movable member in the axial direction, the eccentric thrust bearing being interposed between the two members so as to be eccentrically rotatable. An annular retainer having a fan-shaped window penetrating in the axial direction except at least two places around the circumference, and a ball unit is provided in each of the fan-shaped windows of the retainer. A plurality of balls that are stored and held adjacently so as to be able to roll, and at least two connecting portions of the retainer and a portion of the fixing member corresponding to the connecting portion,
An eccentric thrust bearing, wherein a support shaft and a circular concave portion loosely fitted to the support shaft are separately provided. 2. An eccentric thrust bearing interposed between a movable member eccentrically rotating and a fixed member disposed to face the movable member in the axial direction, the movable side fixed to the movable member. It has a race, a fixed side race fixed to a fixed member, and a ball unit interposed eccentrically rotatable between the two races, wherein the ball unit penetrates in the axial direction except at least two places around the circumference. An annular retainer having a fan-shaped window, and a plurality of balls rotatably housed and held adjacent to each other in the circumferential direction in each of the fan-shaped windows of the retainer; For the connecting portion and the portion corresponding to the connecting portion in the fixing member,
An eccentric thrust bearing, wherein a support shaft and a circular concave portion loosely fitted to the support shaft are separately provided. 3. The eccentric thrust bearing according to claim 1, wherein at least two connecting portions of said retainer are installed at positions substantially facing each other by 180 degrees. 4. The eccentric thrust bearing according to claim 1, wherein the movable member or the movable race is provided with the same circular concave portion corresponding to the circular concave portion. An eccentric thrust bearing, wherein the thrust bearing is loosely fitted in a circular recess provided in a movable member or a movable race.