JP2005201339A - Thrust receiving mechanism and sealed type compressor provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust receiving mechanism for a sealed type compressor capable of preventing the wear of a race by suppressing the occurrence of the forcible slide of a cylindrical roller. <P>SOLUTION: The thrust receiving mechanism 21 is composed of the cylindrical rollers (rolling bodies) 18m, 18s, retainers 17m, 17s for retaining the rolling bodies, and the plate-like races 19m, 19s, and 16 which are brought into rolling contact with the rolling bodies. The shape of long holes 20m, 20s of the retainer for retaining the rolling body is formed into a non-rectangular shape, for example, such as a nearly H-type shape, a nearly I-type shape, a nearly hand drum shape, and a shape or the like of adding a protrusion A to a rectangular shape. By this, the inclination angle of the rolling body can be enlarged. A contact point Q of the rolling body and the retainer can be brought closer to a fulcrum R of the rolling body. Consequently, the force to skew the rolling body can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thrust receiving mechanism that rotatably supports a swirling member while receiving a force in a thrust direction orthogonal to the swirling direction, and a compression for a supercritical refrigeration cycle in which a discharge pressure exceeds a critical pressure of a refrigerant. It is effective when applied to a machine.

  Conventionally, as disclosed in Patent Document 1, for example, a thrust cylindrical roller bearing is known as a thrust receiving mechanism that supports a turning scroll that turns while receiving a force in a thrust direction orthogonal to the turning direction. .

JP 2002-213440 A

  In such a thrust cylindrical roller bearing 21, as shown in FIG. 2, substantially cylindrical first and second rollers (cylindrical rollers) 18m and 18s are arranged on the front and back of the center race 16 so as to be substantially orthogonal to each other. For this purpose, first and second cages 17m and 17s provided with rectangular holes 20m and 20s each having a substantially rectangular shape, which are orthogonal to each other, are attached and fixed to the orbiting scroll and the middle housing, respectively. In the left-right direction, the second roller 18s is configured to roll between the race 16 and the respective race plates 19m and 19s in the up-down direction in the figure.

  Generally speaking, the relationship between the cage and the cylindrical roller is described. Normally, the cylindrical roller always has an irregular slip due to uneven load, lubrication, race flatness, roller cylindricality, etc. The roller needs some kind of restraint to maintain its movement posture. In the thrust cylindrical roller bearing described above, the elongated hole of the cage that holds the cylindrical roller constantly regulates the motion posture of the cylindrical roller. However, when the restraint is severe, the contact load between the cylindrical roller which is constantly tilting and the elongated hole of the cage becomes large. As a result, the cylindrical roller is forced to slide due to an external force from the cage.

  By the way, the thrust cylindrical roller bearing (Oldham bearing) of the scroll compressor has peculiarities other than the contact described above, and the movement of the cylindrical roller and the cage in one direction is caused in the thrust direction by the swivel unit. The cylindrical roller receives the force and reciprocates, and the cage also reciprocates along with the movement. Therefore, when the cylindrical roller starts to move or when the speed of the cylindrical roller is higher than the speed of the cage, the cylindrical roller pushes the cage, while when the cylindrical roller stops or the speed of the cylindrical roller is higher than the cage speed. Is smaller, the cage collides with the cylindrical roller. By the way, as shown in FIGS. 5 (b) and 5 (c), the cylindrical roller that reciprocates is inclined all the time, and the shape of the long hole that holds the cylindrical roller is rectangular. The portion in contact with is the end of the rolling surface of the cylindrical roller. As a result, an external force from the cage is applied to this end, and a forced slip occurs with the end of the rolling part as the operating point and the inner side of the end of the cylindrical roller as a fulcrum. There was a problem of causing it.

  The present invention has been made in view of the above problems, and its purpose is to influence the external force at the time of contact between the cylindrical roller and the cage while providing a constraint for maintaining the posture of the cylindrical roller in a state without inclination. It is an object of the present invention to provide a thrust receiving mechanism and a hermetic compressor including the thrust receiving mechanism capable of preventing the occurrence of race wear by suppressing the occurrence of forced slip (skew) of a cylindrical roller.

The present invention provides, as means for solving the above problems, a thrust receiving mechanism according to each of the claims and a hermetic compressor including the thrust receiving mechanism.
The thrust receiving mechanism according to claim 1 is composed of a rolling element, a cage that holds the rolling element, and a plate-like race that is in rolling contact with the rolling element, and an elongated hole that holds the rolling element of the cage. This is a non-rectangular shape, which reduces the force (moment force) that skews the rolling elements (cylindrical first and second rollers), suppresses forced skew, and wears the race. Can be reduced.

  The thrust receiving mechanism according to claims 2, 3, and 4 defines the shape of the elongated hole of the cage to be a substantially H-shaped, a substantially I-shaped, a substantially drum-shaped, and a rectangular shape with protrusions, respectively. . Even in such a long hole shape, the force for skewing the rolling elements is reduced, the forced skew can be suppressed, and the wear of the race can be reduced.

The hermetic compressor according to claim 5 comprises a housing, a fixing member fixed to the housing, and a working chamber for sucking and compressing fluid together with the fixing member, and by rotating with respect to the fixing member, The swivel member that expands and contracts the volume of the working chamber, and receives a thrust force orthogonal to the swivel direction of the swivel member among the compression reaction forces acting on the swivel member, and supports the swivel member in a turnable manner. The thrust receiving mechanism according to any one of the above is provided. Thereby, the forced skew of a rolling element can be suppressed and the hermetic compressor which can reduce abrasion of a race can be provided.
The hermetic compressor according to claim 6 is specified as a scroll compressor.

The hermetic compressor according to claim 7 defines the fluid to be used as a refrigerant, and the hermetic compressor according to claim 8 is limited to one in which the refrigerant is used at a critical pressure or higher. This can be applied to a refrigeration cycle in which the discharge pressure of the machine exceeds the critical pressure of the refrigerant.
The hermetic compressor according to claim 9 stipulates that carbon dioxide can be used as the refrigerant.

  Hereinafter, a thrust receiving mechanism according to an embodiment of the present invention and a hermetic compressor including the thrust receiving mechanism will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the overall configuration of a hermetic compressor including a thrust receiving mechanism of the present invention. This hermetic compressor is a compressor in which a scroll compression mechanism that sucks and compresses refrigerant and an electric motor (DC brushless motor) that drives the scroll compression mechanism are integrated.

  An outline of the electric motor will be described. An electric motor 2 that is a drive unit is disposed in the housing 1. That is, a permanent magnet synchronous motor is constituted by a stator 2a fixed inside the housing 1 and a rotor 2b composed of a plurality of permanent magnets arranged inside the stator 2a. The rotor 2b is fixed to a shaft 5 that is rotatably supported via bearings 6a and 6b disposed in the housing 1 and the middle housing (thrust receiving portion) 15.

  The end 5 a of the shaft 5 transmits the driving force of the motor connected to the scroll type compression mechanism via the revolution driving unit 10. That is, the revolution drive unit 10 is formed by the crank portion at the end of the shaft 5, the bush 7, the bearing 8, the boss portion 9 a of the orbiting scroll (orbiting member) 9 and the thrust receiving portion 15, and the orbiting scroll 9 is fixedly scrolled (fixed). Member) 11 is swung.

  Here, the scroll type compression mechanism will be described. The fixed scroll 11 that is a fixed member is fixed to a thrust receiving portion 15 that is a middle housing, and constitutes a space together with the middle housing. The fixed scroll 11 protrudes toward the middle housing side on the middle housing side. A spiral tooth portion 28 is formed. Further, between the middle housing 15 and the fixed scroll 11, there is a revolving scroll 9 that is a revolving member in which a spiral tooth portion 29 that forms the working chamber 12 is formed in contact with the tooth portion 28 of the fixed scroll 11. The orbiting scroll 9 orbits with respect to the fixed scroll 11 to expand and reduce the volume of the working chamber 12 and compress the refrigerant (fluid) by suction.

  The orbiting scroll 9 is connected via a needle roller bearing 8 to a crank portion formed at the end portion 5a of the shaft 5 with a boss portion 9a formed at the substantially center thereof. Since the crank portion of the end portion 5 a of the shaft 5 is formed at a position eccentric to the radially outward side from the rotation center of the shaft 5, when the shaft 5 is rotated by the electric motor 2, the orbiting scroll 9 is moved around the shaft 5. Make a swivel motion. Incidentally, the bush 7 slidably connects the orbiting scroll 9 to the crank portion of the shaft 5 and constitutes a driven crank mechanism that increases the contact surface pressure between both the tooth portions 28 and 29. The orbiting scroll 9 is slightly displaced with respect to the crank portion by the force in the turning direction of the compression reaction force acting on the contact force 9, thereby increasing the contact surface pressure between the tooth portions 28 and 29.

  By the way, since the working chamber 12 is formed by the orbiting scroll 9 and the fixed scroll 11, the compressor can be compressed by the rotation of the electric motor 2, and the orbiting can be performed by the internal pressure (compression reaction force) in the working chamber 12. The scroll 9 receives a thrust force. In other words, the compression reaction force acting on the orbiting scroll 9 receives a force (this force is called a thrust force) in a direction orthogonal to the orbiting direction of the orbiting scroll 9 (a direction parallel to the longitudinal direction of the shaft 5). The thrust receiving mechanism 21 is a mechanism that receives the thrust force of the orbiting scroll 9 and supports the orbiting scroll 9 so as to be orbitable.

  FIG. 2 shows an exploded view of the thrust receiving mechanism 21. The thrust receiving mechanism 21 includes a substantially cylindrical first roller 18s that is a rolling element that is rotatably held in one direction (up and down direction in the drawing), and a direction (left and right direction in the drawing) that is orthogonal to the one direction. ) And a substantially cylindrical second roller 18m which is a rolling element held rotatably. The first roller 18s is rotatably held by the first holder 17s, and the second roller 18m is rotatably held by the second holder 17m. As shown in FIG. 4, the first and second cages 17 s and 17 m are annular first and second holding casings having a substantially U-shaped cross section formed by pressing a metal plate material. 40a and 40b are joined by projection welding.

  The first and second rollers 17s and 17m are fitted in the plurality of holding slots 20s and 20m formed in the first and second holding casings 40a and 40b, respectively. , 40b so as to be rotatable.

A first race plate 19 s formed between the first cage 17 s and the orbiting scroll 9 and formed with an annular raceway surface that contacts the first roller 18 s, and between the second cage 17 m and the middle housing 15. The second race plate 19m formed with an annular raceway surface that is in contact with the second roller 18m and the first and second rollers 18s, There is provided a third race plate 16 in which an annular raceway surface that contacts 18 m is formed on both sides. The first and second cages 17s and 17m and the first to third race plates 19s, 19m, and 16 are disposed substantially parallel to each other. Incidentally, the first and second rollers 18s, 18m are made of high carbon chromium bearing steel (SVJ) heat-treated so that the surface hardness is H _R C59-64, and the first to third race plates 19s, The track surfaces of 19 m and 16 are made of high carbon chromium bearing steel (SVJ) that has been heat-treated to have a surface hardness H _R C59-64.

  As shown in FIGS. 3 and 4, the holding elongated holes 20s, 20m and the first and second rollers 18s, 18m have the same dimensions as the first roller 18s. The second roller 18m is selected so that a predetermined gap is formed between the first cage 17s and the raceway surfaces of the first and third race plates 19s, 16 without falling off from the first roller 17m. The second roller 18m does not fall off from the second cage 17m, and a predetermined gap is formed between the second cage 17m and the raceway surfaces of the second and third race plates 19m, 16. Selected.

  The first pin 30s is press-fitted and fixed to the orbiting scroll 9 to position the first race plate 19s with respect to the orbiting scroll 9. The second pin 30m is press-fitted and fixed to the middle housing 15 to be the second race plate 19m. Is fixed with respect to the middle housing 15. The first and second pins 30s and 30m are columnar straight pins that do not have a stepped portion. The first retainer 17s and the third race plate 16 are formed with elongated holes 31s and 32s having a long diameter dimension in a direction orthogonal to the axial direction of the first roller 18s, and the second retainer 17m and the third race plate. The plate 16 is formed with long holes 31m and 32m having a long diameter dimension in a direction perpendicular to the axial direction of the second roller 18m. The first pin 30 s can move relative to the long holes 31 s and 32 s in the long-diameter direction in a state of being inserted through the long holes 31 s and 32 s. Similarly, the second pin 30m can move relative to the long holes 31m and 32m in the long diameter direction in a state of being inserted through the long holes 31m and 32m.

  For this reason, when the orbiting scroll 9 is turned, the orbiting scroll 9 and the first race plate 19s are integrally rotated with respect to the first cage 17s and the third race plate 16 in the rotation direction of the first roller 18s (the long diameter of the long hole 32m). On the other hand, the third race plate 16 and the second retainer 17m are displaced in the rotational direction of the second roller 18m (the long diameter direction of the long hole 32s) with respect to the middle housing 15, so that the orbiting scroll 9 Moves freely relative to the middle housing 15 (fixed scroll 11) without rotating with respect to the crank portion.

  Thereby, the orbiting scroll 9 can freely move in the depth and the vertical direction of FIG. 1 by the thrust receiving mechanism 21, and the revolving motion is provided by the rotation preventing mechanism provided in the orbiting scroll 9 and the fixed scroll 11. Is possible.

  The rear housing 25 is fixed to the middle housing 15 with bolts together with the fixed scroll 11, and constitutes a discharge chamber 23 that smoothes the refrigerant discharged from the working chamber 12 together with the fixed scroll 11. A discharge port that communicates the working chamber 12 and the discharge chamber 23 located substantially in the center of the fixed scroll 11 is provided, and the refrigerant discharged into the discharge chamber 23 is operated on the discharge chamber 23 side of the discharge port. A reed valve-like discharge valve 17 that prevents backflow into the chamber 12 and a stopper 19 that restricts the maximum opening of the discharge valve are provided.

  Since the operation of the hermetic type compressor (scroll type compressor) configured as described above is the same as the conventional one, the description thereof is omitted.

  FIG. 5 shows the relationship between the long hole 20m (20s) of the conventional cage 17m (17s) and the cylindrical roller 18m (18s) when cut along the YY line in FIG. . In the prior art, the shape of the long hole 20m (20 s) of the cage that holds the cylindrical roller is substantially rectangular. FIGS. 5A, 5B, and 5C show a case where there is no inclination of the cylindrical roller 18m (18s) and a case where there is an inclination of the cylindrical roller 18m (18s), respectively. When the speed of the roller 18m (18s) is greater than the speed of the cage 17m (17s) (b) or smaller (c), the conventional cylindrical roller 18m (18s) and the cage 17m (17s) The positional relationship is shown. In FIG. 5, M is the width of the conventional long hole 20m (20s), and P is the width of the cylindrical roller 18m (18s) cut along the YY line. The distance between the point (action point) Q at which the long hole 20m (20s) and the cylindrical roller 18m (18s) are in contact with the fulcrum R of the roller 18m (18s) is L1 and L2, and relative to the cage 17m (17s) The inclination angles θ1 and θ2 of the cylindrical roller 18m (18s) are set.

  Even when the cylindrical roller 18m (18s) is not inclined with respect to the cage 17m (17s) as shown in FIG. 5A in the initial state, the cylindrical roller 18m (18s) is not moved during the operation of the compressor. Due to some influence, the cage 17m (17s) is inclined with respect to the long hole 20m (20s) and comes into contact with the cage 17m (17s) as shown in FIGS. In this case, when the speed of the cylindrical roller 18m (18s) is larger than the speed of the cage 17m (17s), it is inclined as shown in FIG. 5B, and the speed of the cylindrical roller 18m (18s) is When it is smaller than the speed of the cage 17m (17s), it tilts as shown in FIG. When such an inclination occurs, an external force from the cage 17m (17s) is applied to the contact point Q of the cylindrical roller 18m (18s) with the cage 17m (17s), and the cylindrical roller 18m (18s). ) Generates a rotational force (slip) around the center of the fulcrum R, and the cylindrical roller 18m (18s) attempts to return to a stable state (θ = 0 °). This forced slip (skew) causes the race board to wear.

  Therefore, in the present invention, forced slip is suppressed by improving the shape of the long hole 20m (20s) of the cage 17m (17s) holding the cylindrical roller 18m (18s). FIG. 6 shows the shape of the long hole 20m (20s) of the cage 17m (17s) according to the embodiment of the present invention. In the present embodiment, the shape of the long hole 20m (20s) of the cage 17m (17s) is a non-rectangular substantially H shape or substantially I shape. 6 (a), 6 (b), and 6 (c) show a cylindrical roller 18m (18s) in a non-rectangular shape in which both ends of the long hole 20m (20s) holding the cylindrical roller 18m (18s) are wide. ) And the cage 17m (17s). That is, the width N1 of both ends of the long hole 20m (20s) is larger than the width M of the normal rectangular long hole 20m (20s), and the long hole 20m (20s) is substantially H-shaped or substantially I-shaped. It is in shape. In such a case, when the cylindrical roller 18m (18s) comes into contact with the cage 17m (17s), the cylindrical roller 18m (18s) is inclined, as shown in FIGS. 6 (a) and 6 (b). To come into contact. Since the inclination angles θ3 and θ4 of the cylindrical roller 18m (18s) with respect to the cage 17m (17s) are larger than the conventional inclination angles θ1 and θ2, the inclination angle of the cylindrical roller 18m (18s) is The degree of freedom increases. Furthermore, the contact point (action point) Q between the cage 17m (17s) and the cylindrical roller 18m (18s) is closer to the inner side than the conventional one, that is, the fulcrum R of the cylindrical roller 18m (18s). Since the distances L3 and L4 between the action point Q and the fulcrum R are smaller than the conventional distances L1 and L2, the force (moment force) for skewing the cylindrical roller 18m (18s) is also reduced. Forced skew can be suppressed and wear of the race board can be reduced.

  FIG. 7 shows the shape of a long hole 20m (20 s) according to a modification of the present invention. In the embodiment of FIG. 6, the case where the width N1 of both ends of the long hole 20m (20s) of the cage 17m (17s) is increased is described, but in the modification of FIG. 7, the long hole 20m (20s) The width N2 of the central portion in the longitudinal direction is made smaller than the width M of the conventional long hole, which is a substantially H shape or a substantially I shape. Even in this case, as shown in FIG. 7B, the inclination angle θ5 of the cylindrical roller 18m (18s) with respect to the cage 17m (17s) is larger than the conventional inclination angles θ1, θ2, and the cage 17m. Since the contact point Q between (17s) and the cylindrical roller 18m (18s) approaches the fulcrum R of the cylindrical roller, the same effect that the moment force at the time of contact can be reduced is obtained.

  From the above, the shape of the elongated hole for holding the cylindrical roller (rolling element) of the cage is made larger at the width at both ends than at the center, or the width at the center is greater than the width at both ends. Since the forcible skew can be suppressed by reducing the width, the wear of the race board can be reduced.

FIGS. 8A and 8B show still another embodiment of the present invention. In the embodiment of FIG. 8A, the shape of the long hole 20m (20s) of the cage 17m (17s) is formed in a substantially drum shape. Thus, even if the long hole 20m (20s) is made substantially drum-shaped, when the cylindrical roller 18m (18s) is tilted and contacts the cage 17m (17s), the tilt angle can be increased, and the contact point Q Can be brought close to the fulcrum R of the cylindrical roller, the forced skew of the cylindrical roller can be suppressed, and the wear of the race board can be reduced.
In the embodiment of FIG. 8B, two projections A on one side are provided on both sides for supporting a cylindrical roller 18m (18s) of a conventional rectangular long hole 20m (20s). Even in this case, when the cylindrical roller 18m (18s) and the cage 17m (17s) are in contact with each other, the contact point Q between the cylindrical roller 18m (18s) and the long hole 20m (20s) is set to the cylindrical roller. It can be brought close to the fulcrum (R), the moment force at the time of contact can be reduced, forced skew can be suppressed, and wear of the race board can be reduced.

It is a longitudinal cross-sectional view which shows the whole structure of the hermetic type compressor (scroll type compressor) of this invention. It is an exploded view of a thrust receiving mechanism. It is a top view which shows the relationship between the long hole of a holder | retainer, and a cylindrical roller (rolling body). It is sectional drawing along the XX line of FIG. 3 which shows the relationship between a holder | retainer and a cylindrical roller (rolling body). It is sectional drawing along the YY line | wire of FIG. 4 which shows the positional relationship (a), (b), (c) of the long hole of a conventional holder | retainer, and a cylindrical roller (rolling body). Sectional drawing along the YY line of FIG. 4 which shows the positional relationship (a), (b), (c) of the long hole of a holder | retainer which is an Example of this invention, and a cylindrical roller (rolling element) It is. It is a figure which shows the positional relationship (a), (b) of the long hole of the holder | retainer which is a modification of the Example of this invention, and a cylindrical roller (rolling element). The positional relationship of the long hole of the holder | retainer which is another Example (a) of this invention, and (b), and a cylindrical roller (rolling element) is shown.

Explanation of symbols

9 ... Orbiting scroll (orbiting member)
11 ... Fixed scroll (fixed member)
15 ... Middle housing (thrust receiving part)
17s, 17m ... 1st, 2nd retainers 18s, 18m ... 1st, 2nd roller (rolling element)
19s, 19m, 16 ... 1st-3rd race board 20s, 20m ... Long hole 21 ... Thrust receiving mechanism

Claims (9)

A thrust receiving mechanism that supports a revolving swivel member while receiving a force in a thrust direction orthogonal to the revolving direction, the thrust receiving mechanism,
A rolling element composed of a substantially cylindrical first roller held rotatably in one direction and a substantially cylindrical second roller held rotatably in another direction different from the one direction;
A cage having an elongated hole for holding the rolling element;
A plate-like race formed with a raceway surface in rolling contact with the rolling elements;
With
A thrust receiving mechanism, wherein the shape of the elongated hole of the cage is non-rectangular.   The thrust receiving mechanism according to claim 1, wherein the non-rectangular shape of the elongated hole is substantially H-shaped or substantially I-shaped.   The thrust receiving mechanism according to claim 1, wherein the non-rectangular shape of the elongated hole is a substantially drum shape.   The thrust receiving mechanism according to claim 1, wherein the non-rectangular shape of the elongated hole is a shape obtained by adding a projection to a rectangle. A hermetic compressor that sucks and compresses fluid,
A housing, a fixing member fixed to the housing, and a working chamber that sucks and compresses fluid together with the fixing member are configured, and the volume of the working chamber is expanded and reduced by rotating with respect to the fixing member. The swivel member to be rotated and a thrust force orthogonal to the swivel direction of the swivel member among the compression reaction force acting on the swivel member, and the swivel member are supported so as to be swivelable. A hermetic compressor comprising the thrust receiving mechanism described in 1.   6. The hermetic compressor according to claim 5, wherein a model of the hermetic compressor is a scroll compressor.   The hermetic compressor according to claim 5 or 6, wherein the fluid used is a refrigerant.   The hermetic compressor according to claim 7, wherein the refrigerant is used at a critical pressure or higher. The hermetic compressor according to claim 8, wherein carbon dioxide (CO ₂ ) is used as the refrigerant.

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