JP2007224978A - Double row thrust roller bearing - Google Patents

Abstract

[PROBLEMS] To obtain a high rated capacity and stable bearing performance in a rotating part even under a higher temperature and pressure environment.
Retainers 16 and 18 having a plurality of pockets 12 and 14 arranged concentrically in two rows in the radial direction and formed in a single row in the circumferential direction, and shafts stored and held in the respective pockets of the respective cages A plurality of rollers 24 and 26 sandwiched by a pair of races from both sides in the direction, the inner diameter side cage is guided by one race, and the outer diameter side cage is guided by the other race. Constitution.
[Selection] Figure 1

Description

  The present invention relates to a double row thrust roller bearing that is installed in a rotating portion of a compressor (refrigerant compressor) such as an air conditioner for an automobile and is suitable for supporting a thrust load applied to the rotating portion.

  The thrust roller bearing includes a plurality of rollers arranged radially and equally in the circumferential direction, and a cage that is formed in an annular shape and holds the plurality of rollers in a freely rolling manner. It is configured to be clamped by a race (orbital ring) from both sides in the direction. Such thrust roller bearings have come to be used in high temperature and high pressure environments due to recent usage applications, and higher rated capacity and more stable bearing performance than ever are required.

  For example, some air conditioner compressors for automobiles use alternative fluorocarbons such as hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) as the refrigerant from the viewpoint of environmental problems such as prevention of ozone layer destruction. In order to obtain a thrust roller bearing, a double-row thrust roller bearing of a type in which the rollers are double-rowed and each roller is housed in one pocket has already been proposed (see Patent Document 1).

  However, the above-mentioned alternative chlorofluorocarbons have a new environmental problem of global warming, and there is no destruction of the ozone layer. In addition, carbon dioxide, a natural refrigerant, is used as an alternative chlorofluorocarbon, which has an extremely low global warming effect compared to these alternative chlorofluorocarbons. I am trying to do. In the case of carbon dioxide, unlike the above-mentioned conventional alternative chlorofluorocarbon, which is liable to be liquefied at low pressure, in order to liquefy it is necessary to liquefy at high pressure, so the pressure inside the compressor increases greatly. Therefore, a double row thrust roller bearing used for supporting the internal rotating portion of a compressor using carbon dioxide as an alternative chlorofluorocarbon refrigerant is required to have a higher rated capacity than ever before.

  In particular, when carbon dioxide is used as the refrigerant, the sliding pressure and rolling contact pressure between the double-row thrust roller bearing and each part in the compressor inevitably increase as the pressure inside the compressor increases. The amount of heat generated in the portion also increases, and the viscosity of the lubricating oil of the bearing decreases, resulting in a poor lubricating environment.

  In addition, since compression and expansion are repeated inside the compressor, the lubricating oil is also repeatedly liquefied and vaporized, and there is an environment where the amount of lubricating oil decreases due to the mixing of refrigerant, so that the lubricating oil for general machinery is lubricated. Compared with, the oil film formation state is poor, and peeling is likely to occur at an early stage. When carbon dioxide is used as an alternative chlorofluorocarbon refrigerant in such a compressor environment, the environment becomes more severe.

  As described above, a double row thrust roller bearing incorporated in a compressor using carbon dioxide as an alternative chlorofluorocarbon refrigerant is required to have a higher rated capacity and a more stable high bearing performance.

  Therefore, the present applicant has conducted various studies such as increasing the roller diameter, increasing the roller length, and increasing the number of rollers used. However, simply increasing the roller diameter of the roller increases the weight of the roller itself, which causes the problem that the cage window is subject to drilling wear. Increased sliding is likely to cause roller skewing and surface-origin separation at the race rolling edge, and simply increasing the number of rollers used will waste space on the inner diameter side of the thrust roller bearing. Will increase. Furthermore, although it has been considered to arrange the rollers in a single row in a single cage, the roller rolling advances and delays between the rollers in each row, and torque loss due to an increase in rotational torque increases.

In the above examination, even if the rated capacity can be improved, the bearing performance is deteriorated, and it is difficult to achieve both.
JP 2004-316930 A

  Therefore, the problem to be solved by the present invention is to obtain a high rated capacity and a stable bearing performance in a rotating part even in a higher temperature and high pressure environment such as a compressor using carbon dioxide as an alternative chlorofluorocarbon refrigerant as a use application. A double row thrust roller bearing is provided.

  The double-row thrust roller bearing according to the first aspect of the present invention includes two rows of cages arranged separately in two rows in the radial direction and each having a plurality of circumferential pockets in a single row, and each of the cages in each row. A plurality of rollers housed and held in a pocket, the inner diameter side retainer is guided by an inner diameter at its inner diameter end, and the outer diameter side retainer is guided by an outer diameter at its outer diameter end. It is characterized by becoming.

  According to the first aspect of the present invention, the use environment is carbon dioxide as an alternative chlorofluorocarbon refrigerant, so that even in a high temperature and high pressure environment such as a compressor, one roller is placed in each pocket of each radial double row cage. Since the structure is housed one by one, the rated capacity can be improved to the same extent as one cage in which rollers are arranged in double rows. In particular, according to the first aspect of the present invention, the rated capacity can be improved without increasing the roller diameter, increasing the roller length, or increasing the number of rollers used. The rated capacity can be improved without affecting the bearing performance. In the first aspect of the present invention, on the other hand, in addition to the rollers being held in the pockets of the cage separated separately on the inner diameter side and the outer diameter side, the inner diameter side cage is guided by one race. Since the outer diameter side cage is guided by the other race, the outer race is guided by the advance and delay even if it is likely to cause a delay in rolling of the rollers between the rollers of both cages. The occurrence of torque loss can be suppressed, and the bearing performance is improved accordingly.

  As described above, according to the first aspect of the present invention, it is possible to provide a thrust roller bearing capable of supporting a rotating portion with a high rated capacity and stable bearing performance even under a higher temperature and pressure environment.

  In the above case, the inner diameter side retainer is guided by the inner diameter end by the annular flange extending annularly from the inner diameter side end of the one race, and the outer diameter side retainer has the outer diameter end portion of the other end of the other race. It is preferable that the outer diameter is guided by an annular flange extending annularly from the outer diameter side end of the race.

  In the above case, at least one of the cages may be a split type cage that is divided into a plurality of circumferential directions. In such a case, the assembly of the bearing can be facilitated.

  A thrust roller bearing according to a second aspect of the present invention includes a double row cage that is arranged separately in two rows in the radial direction and has a plurality of circumferential pockets in a single row and is race-guided, and each of the rows. A plurality of rollers that are housed and held in respective pockets of each of the cages, the cage on the inner diameter side is guided by an inner diameter by an annular flange provided at the inner diameter end of the race, and the cage on the outer diameter side is The outer diameter is guided by an annular flange provided at the outer diameter end.

  The second aspect of the present invention can provide a double row thrust roller bearing capable of supporting the rotating portion with a high rated capacity and stable bearing performance even in a higher temperature and high pressure environment as in the first aspect of the present invention.

  In the first and second embodiments of the present invention, it is preferable that the outer diameter side end portion of the inner diameter side cage and the inner diameter side end portion of the outer diameter side cage are assembled so as to be separable from each other. In such a case, the inner diameter side and outer diameter side cages can be easily assembled and can be prevented from interfering with each other after the assembly.

  In the first and second embodiments of the present invention, it is preferable that the rollers held by both cages are provided with crowning. In such a case, the differential slip can be reduced in a poorly lubricated or lean lubricated environment, and the surface-origin type damage can be suppressed, and the durability as a bearing can be increased. In particular, the crowning of the rollers of the outer diameter side cage is preferably made smaller than the crowning shape of the rollers of the inner diameter side cage.

  In the first and second embodiments of the present invention, a solid lubricant film is formed on the surface of each cage on the inner diameter side and the outer diameter side to improve wear resistance, non-seizure property, and initial conformability. preferable.

  In the first and second embodiments of the present invention, the roller length is preferably within twice the roller diameter. Differential slip on the raceway surface of the roller can be effectively suppressed, and edge stress between the roller edge and the race is less likely to occur. Peeling is less likely to occur. This increases the rated capacity of the double-row thrust roller bearing and improves the life characteristics.

  In the first and second embodiments of the present invention, it is preferable that the number of pockets of the outer diameter side cage is set larger than the number of pockets of the inner diameter side cage. In such a case, the load capacity on the outer diameter side can be made larger than that on the inner diameter side. In this case, during rotation, the lubricating oil inside the bearing becomes rich on the outer diameter side due to the rotational centrifugal force, so even if the number of pockets in the outer diameter side row is increased, heat generation does not occur as much as the inner diameter side row. .

  The double-row thrust roller bearing described above is preferably used to support the rotating portion of a compressor that uses carbon dioxide as an alternative chlorofluorocarbon refrigerant. In such a case, even if incorporated in the compressor, the high rated capacity and bearing performance as described above can be exhibited.

  According to the present invention, as a use application, for example, a compressor using carbon dioxide as an alternative chlorofluorocarbon refrigerant, a double row that can obtain a high rated capacity and a stable bearing performance in a rotating part even in a higher temperature and high pressure environment. Thrust roller bearings can be provided.

  Hereinafter, a thrust roller bearing for an automotive air conditioner compressor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this compressor, the refrigerant is carbon dioxide. Further, the assembled state of the double-row thrust roller bearing to the compressor is not shown.

  The double row thrust roller bearing of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the double row thrust roller bearing, and FIG. 2 is a sectional view taken along the line AA of FIG. However, FIG. 2 shows the state incorporated in the race. Referring to these drawings, this double-row thrust roller bearing 10 has two rows of retainers 16 which are arranged separately in two rows in the radial direction and are respectively provided with a plurality of circumferential pockets 12 and 14 in a single row. , 18 and a plurality of rollers 24, 26 that are stored and held in the pockets 12, 14 of the cages 16, 18 in each row and are sandwiched by a pair of first and second races 20, 22 from both sides in the axial direction. I have. The pockets 12, 14 are circumferentially unequal with respect to each other.

  An inner diameter end of the inner diameter side cage 16 is guided by an annular flange 20a that rises annularly from an inner diameter side end portion of the first race 20, and the outer diameter side cage 18 has an outer diameter end portion of the second race. The outer diameter is guided by an annular flange 22a that falls in an annular shape from the outer diameter side end portion of 22.

  The inner diameter side retainer 16 includes two annular portions 16a and 16b that are concentric in the radial direction, and a plurality of column portions 16c that are disposed at equal intervals in the circumferential direction between the annular portions 16a and 16b. Pockets 12 are formed in the holes between the opposing portions of the portion 16c in the circumferential direction, and one roller 24 is stored in each pocket 12. In the column portion 16c, a pair of column end portions 16c1 on both sides in the radial direction and a column center portion 16c2 are positioned on both sides in the axial direction with respect to the roller PCD, and the column end portion 16c1 and the column center portion 16c2 are inclined connection bars 16c3. As a result, the column shape is M-shaped. The column end portion 16c1 and the column center portion 16c2 are respectively formed with roller stoppers that protrude into the pocket 12 and prevent the rollers 24 from coming off. In addition, the code | symbol is not taken for the roller stopper in order to eliminate the complexity of illustration.

  The outer diameter side retainer 18 includes two annular portions 18a and 18b that are concentric in the radial direction, and a plurality of column portions 18c that are disposed at equal intervals in the circumferential direction between the annular portions 18a and 18b. Pockets 14 are formed in the holes between the circumferential ends of the column portions 18 c, and one roller 26 is stored in each pocket 14. In the column portion 18c, a pair of column end portions 18c1 on both sides in the radial direction and a column center portion 18c2 are positioned on both sides in the axial direction with respect to the roller PCD. The column end portion 18c1 and the column center portion 18c2 are inclined connection bars 18c3. As a result, the column shape is M-shaped. The column end portion 18c1 and the column center portion 18c2 are formed with roller stoppers that protrude into the pocket 14 and prevent the rollers 26 from coming off. In addition, the code | symbol is not taken for the roller stopper in order to eliminate the complexity of illustration.

  In the double row thrust roller bearing of the first embodiment having the above configuration, the rollers 24 and 26 are accommodated one by one in the pockets 12 and 14 of the radial direction double row cages 16 and 18, respectively. The rated capacity can be improved to the same extent as a single cage in which rollers are arranged in double rows.

  In the first embodiment, the inner diameter side retainer 16 which is one retainer separated separately from the inner diameter side and the outer diameter side is guided by the first race 20 and the outer diameter side retainer 18 which is the other retainer. Since the outer diameter is guided by the second race 22, even if a delay occurs in the rolling of the rollers 24 and 26 of the retainers 16 and 18, torque loss due to the advance and delay is generated. Therefore, the bearing performance is improved accordingly.

  In addition, it is good also as a structure which arrange | positions the division | segmentation holder | retainer 181 and 182 which divided | segmented the outer diameter side holder | retainer 18 into two in the circumferential direction like FIG.

  In addition, as shown in FIGS. 4 and 5, the retainers 16 and 18 on the inner diameter side and the outer diameter side may be temporarily assembled at a plurality of locations in the circumferential direction or at one location.

  In FIG. 4, the outer diameter side annular portion 16b of the inner diameter side retainer 16 is extended in the outer diameter direction, the inner diameter side annular portion 18a of the outer diameter side retainer 18 is extended in the inner diameter direction, and these 16b and 18a are moved in the axial direction. By overlapping, both the cages 16 and 18 can be transported in a temporarily assembled state in the assembly process and separated after the assembly.

  In FIG. 5, the outer diameter side annular portion 16b of the inner diameter side retainer 16 and the inner diameter side annular portion 18a of the outer diameter side retainer 18 have a U-shaped cross section, and both retainers 16, 18 are assembled in the assembly process. It can be transported in a temporarily assembled state and separated after assembly.

  Further, as shown in FIG. 6, it is preferable to coat the surfaces of both the cages 16 and 18 with solid lubricant films 28 and 30 for improving wear resistance, non-seizure property, and initial conformability. Examples of the solid lubricant include thermosetting resins such as polyamideimide, polyimide, and epoxy resin, polymer resins such as polytetrafluoroethylene and polyimide, and other than the above resins, copper, silver, gold, aluminum, tin, There are zinc and the like, and alloys thereof, soft metals such as graphite, lead oxide, tungsten disulfide, molybdenum disulfide, and the like. Examples of coating methods for these films include sputtering, vapor deposition, and ion plating.

  Further, it is preferable to provide crowning at both ends 24a and 26a of the rollers 24 and 26 of the inner diameter side cage 16 and the outer diameter side cage 18 as shown in FIG. By forming crowning on the rollers 24 and 26, the differential slip can be reduced by reducing the load on the edge portion and shortening the straight central portions 24b and 26b which are effective lengths of the rollers. Further, the crowning of the roller 26 of the outer diameter side retainer 18 shown in FIG. 7B is made smaller than the crowning shape of the roller 24 of the inner diameter side retainer 16 shown in FIG. The contact surface pressure of the roller 26 of the outer diameter side cage 18 can be suppressed more than the roller 24 of the cage 16, and the outer diameter separation of the roller 26 of the outer diameter side cage 18 and the separation of the race outer diameter side can be prevented. And the life can be improved. In this case, only the roller 26 of the outer diameter side cage 18 may be a straight roller.

  The roller lengths of the roller 24 of the inner diameter side retainer 16 and the roller 26 of the outer diameter side retainer 18 are preferably within twice the respective roller diameters. By shortening the roller length, the differential slip on the raceway surface of the rollers 24 and 26 is suppressed, and the edge stress between the rollers 24 and 26 at the edge portion is less likely to be generated. It is possible to make it difficult for surface-origin separation to occur at the edge of the rolling part. In addition, the rated capacity increases and the life characteristics are improved. Furthermore, by making the roller length of the roller 24 of the inner diameter side retainer 16 shorter than the roller length of the roller 26 of the outer diameter side retainer 18, the load capacity on the outer diameter side than the inner diameter side is increased. The outer diameter separation and the race outer diameter side peeling can be prevented, and the differential sliding of the inner diameter side rollers can be reduced, and the life can be improved.

  Further, it is preferable to set the number of pockets 14 of the outer diameter side cage 18 larger than the number of pockets 12 of the inner diameter side cage 16. With this setting, it is possible to make the load capacity of the roller 14 of the outer diameter side cage 18 larger than that of the roller 12 of the inner diameter side cage 16.

  Further, as shown in FIG. 8, either one of the races 20 and 22, for example, the first race 20 is provided with annular flanges 20a and 20a on both sides in the radial direction, and both retainers 16 and 18 are provided. , The inner diameter side retainer 16 is guided by an annular flange 20 a provided at the inner diameter end of the first race 20, and the outer diameter side retainer 18 is provided by an annular flange 20 a provided at the outer diameter end of the first race 20. An outer diameter guide may be used.

FIG. 1 is a plan view of a double row thrust roller bearing for an automotive air conditioner compressor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the double row thrust roller bearing taken along line AA in FIG. FIG. 3 is a plan view of a double row thrust roller bearing for an automotive air conditioner compressor according to another embodiment of the present invention. FIG. 4 is a sectional view of a double row thrust roller bearing for an automotive air conditioner compressor according to still another embodiment of the present invention. FIG. 5 is a cross-sectional view of a double row thrust roller bearing for an automotive air conditioner compressor according to still another embodiment of the present invention. FIG. 6 is a sectional view of a double row thrust roller bearing for an automotive air conditioner compressor according to still another embodiment of the present invention. FIG. 7 is a cross-sectional view of a roller used in a double row thrust roller bearing for an automotive air conditioner compressor according to still another embodiment of the present invention. FIG. 8 is a cross-sectional view corresponding to FIG. 2 of a double row thrust roller bearing for an automotive air conditioner compressor according to still another embodiment of the present invention.

Explanation of symbols

10 Double-row thrust roller bearing 12, 14 Pocket 24, 26 Roller 16, 18 Cage

Claims (8)

Two rows of cages that are separately arranged concentrically in two rows in the radial direction and each have a plurality of circumferential pockets in a single row, and a plurality of rollers that are stored and held in the respective pockets of the cages of each row. The double row thrust is characterized in that the inner diameter side retainer is radially guided at its inner diameter end, and the outer diameter side retainer is guided at the outer diameter end. Roller bearing. The inner diameter side retainer has an inner diameter end portion guided by an annular flange provided at the inner diameter end of one race, and the outer diameter side retainer has an outer diameter end portion provided at the outer diameter end of the other race. The double row thrust roller bearing according to claim 1, wherein an outer diameter is guided by an annular flange.   The double row thrust roller bearing according to claim 1, wherein at least one of the cages is a split type cage divided into a plurality of circumferential directions.   The outer diameter side end portion of the inner diameter side cage and the inner diameter side end portion of the outer diameter side cage are assembled so as to be separable from each other. Double row thrust roller bearing.   5. The double row thrust roller bearing according to claim 1, wherein a solid lubricant film is formed on the surface of each of the inner diameter side and outer diameter side cages.   The double row thrust roller bearing according to any one of claims 1 to 5, wherein a roller length of the roller is within twice a roller diameter.   The double row thrust roller bearing according to any one of claims 1 to 6, wherein the number of pockets of the outer diameter side cage is larger than the number of pockets of the inner diameter side cage.   The double-row thrust roller bearing according to any one of claims 1 to 7, wherein the double-row thrust roller bearing is used to support a rotating portion of a compressor using carbon dioxide as an alternative chlorofluorocarbon refrigerant.

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