JP2014005913A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing that can be easily made small and light with a simple structure.SOLUTION: A rolling bearing comprises: an inner ring 12 and an outer ring 14 relatively rotating to each other; plural rolling elements 15 interposed between the inner ring 12 and the outer ring 14; and a synthetic resin retainer 16 arranged between the inner ring 12 and the outer ring 14 and holding the rolling elements 15 at equal intervals in a circumferential direction. Metallic collor sections 20, 21 extending in a radial direction are provided on an inside diameter side and an outside diameter side at an axial end of the retainer 16. Recess grooves 24, 25 forming labyrinths 22, 23 together with the collar sections 20, 21 are provided at portions of the inner ring 12 and the outer ring 14 corresponding to the collar sections 20, 21.

Description

  The present invention relates to a rolling bearing in which a synthetic resin cage that holds a rolling element so as to roll freely is incorporated between an inner ring and an outer ring.

  For example, various rolling bearings such as deep groove ball bearings and angular ball bearings are widely used for gear support shafts of transmissions of vehicles having motors.

  This type of rolling bearing includes an inner ring having an inner race surface formed on the outer diameter surface, an outer ring disposed outside the inner ring and having an outer race surface formed on the inner diameter surface, and an inner race surface of the inner ring. A plurality of rolling elements interposed between the outer ring and the outer raceway surface of the outer ring, and a cage disposed between the inner ring and the outer ring and holding the rolling elements at equal intervals in the circumferential direction. The main part is composed. Either the inner ring or the outer ring is mounted on a fixed part such as a housing, and the other is mounted on a rotating part such as a rotating shaft.

  When this rolling bearing is used under oil bath lubrication, the rotating cage acts like a compressor of the pump, and the lubricating oil is excessively drawn into the bearing through between the inner and outer rings and the cage. Since the lubricating oil drawn in this way is stirred by the rolling elements and the cage inside the bearing, the torque (heat generation) of the bearing increases due to the stirring resistance. In particular, in an electric vehicle or a hybrid vehicle, since high-speed motor rotation is input, a rotating portion such as a rotating shaft tends to rotate at high speed. When rotating at a high speed in such a high temperature environment, the influence of the stirring resistance described above cannot be ignored.

  The present applicant has previously proposed a rolling bearing provided with a synthetic resin cage that can cope with high-speed rotation in a high-temperature environment (for example, see Patent Document 1).

  As shown in FIG. 5, this rolling bearing is arranged between the inner ring 112 and the outer ring 114, and can freely roll between the inner rolling surface 111 of the inner ring 112 and the outer rolling surface 113 of the outer ring 114. A cage 116 for holding the plurality of interposed rolling elements 115 at equal intervals in the circumferential direction is provided. This type of cage 116 is made of lightweight synthetic resin for the purpose of suppressing deformation due to centrifugal force under high speed rotation. The retainer 116 is formed with hemispherical pockets 119 for accommodating the rolling elements 115 at a plurality of locations in the circumferential direction on opposing surfaces 118 of the two annular members 117 facing in the axial direction, and the opposing surfaces 118 of the annular members 117. Are joined to each other so that two annular bodies 117 are joined.

  As described above, when used under oil bath lubrication, since the lubricant is excessively drawn into the bearing through the space between the inner and outer rings 112 and 114 and the retainer 116, the rolling bearing is connected to the inside of the bearing. The following structure is provided as means for restricting the inflow of the lubricant. On the inner diameter side and the outer diameter side of the axial end portion of the annular body 117, the flange portions 120 and 121 extending in the radial direction are integrally provided, and at portions corresponding to the flange portions 120 and 121 of the inner ring 112 and the outer ring 114, Grooves 120 and 121 form concave grooves 124 and 125 in which labyrinths 122 and 123 are formed. As described above, the labyrinths 122 and 123 formed by the flanges 120 and 121 of the cage 116 and the concave grooves 124 and 125 of the inner and outer rings 112 and 114 ensure that the lubricating oil flows excessively into the bearing. It can be suppressed.

JP 2012-67826 A

  By the way, the rolling bearing disclosed in Patent Document 1 employs a synthetic resin-made cage 116 as a whole, so that deformation of the cage 116 when a centrifugal force is applied under high-speed rotation is suppressed. Therefore, as shown in FIG. 6, the rigidity of the cage 116 is ensured by increasing the thickness t (axial dimension) of the bottom of the pocket 119. Further, in order to prevent the flanges 120 and 121 of the cage 116 from protruding outward in the axial direction from the bearing end surface, the axial dimensions of the inner ring 112 and the outer ring 114 are set to the axial dimensions of the cage 116 and the cage 116. It must be set larger than the sum of the pocket axial clearance and the bearing axial backlash (see FIG. 5).

  As described above, the bottom portion of the pocket 119 is made thick, and the axial dimensions of the inner ring 112 and the outer ring 114 must be set as described above, so that the axial dimension of the rolling bearing can be reduced. The current situation is that it is difficult to reduce the size and weight of rolling bearings.

  Accordingly, the present invention has been proposed in view of the above-described problems, and an object of the present invention is to provide a rolling bearing that can be easily reduced in size and weight with a simple structure.

  As technical means for achieving the above-mentioned object, the present invention is arranged between an inner ring and an outer ring that rotate relative to each other, a plurality of rolling elements interposed between the inner ring and the outer ring, and an inner ring and an outer ring. A rolling bearing provided with a synthetic resin cage that holds the rolling elements at equal intervals in the circumferential direction, and at least one of the axial end portion of the cage at the inner diameter side or the outer diameter side in the radial direction An extending metal collar is provided, and a groove in which a labyrinth is formed by the collar is provided at a portion corresponding to the collar of the inner ring or the outer ring. “At least one of the inner diameter side and the outer diameter side” means that when the collar portion is provided only on the inner diameter side, when the collar portion is provided only on the outer diameter side, the collar portion is provided on both the inner diameter side and the outer diameter side. It means to include all of the cases.

  In the present invention, since the metal collar is provided at the axial end of the cage made of synthetic resin, it becomes easy to secure the rigidity of the cage with the metal collar. It becomes easy to make the wall thickness (axial dimension) of the pocket bottom of the vessel thinner than the cage made of synthetic resin as a whole. As a result, it is easy to reduce the axial dimension of the rolling bearing, and the rolling bearing can be reduced in size and weight.

As for the collar part in this invention, it is desirable that the cyclic | annular metal plate is joined and integrated by the axial direction edge part of the cage | basket | carrier by insert molding of the cage | baskets made from a synthetic resin. If it does in this way, manufacture of the cage with a collar part which can secure the rigidity of a cage will become easy.
In the present invention, a structure in which the inner side surface of the flange portion located on the inner diameter side of the axial end portion of the cage is inclined so as to expand radially inward is desirable. In this way, an appropriate amount of lubricant can be supplied into the bearing by smoothly flowing the lubricant into the bearing from the radially inner side.

  In the present invention, a structure in which the inner side surface of the collar portion located on the outer diameter side of the axial end portion of the cage is inclined so as to expand outward in the radial direction is desirable. In this way, the increase in torque (heat generation) due to the stirring resistance under high-speed rotation can be suppressed by smoothly flowing the lubricant from the inside of the bearing to the outside in the radial direction.

  The cage according to the present invention is formed by forming hemispherical pockets for accommodating rolling elements at a plurality of locations in the circumferential direction on opposing surfaces of two annular members facing each other in the axial direction, and bringing the opposing surfaces into contact with each other to form two annular members. A structure in which the bodies are combined is desirable. If such a structure is adopted, when a centrifugal force is applied under high-speed rotation, the two annular members constituting the cage suppress the deformation of each other, thereby suppressing the deformation of the entire cage. It is possible to prevent the rolling element from falling out of the pocket and interfering with other parts such as inner and outer rings.

  The two annular bodies in the present invention preferably have a structure having the same shape symmetrical in the axial direction. With such a structure, it is possible to make one annular body and the other annular body by using a kind of annular body manufactured by one mold, and the product cost can be reduced.

  It is effective that the cage in the present invention is made of a synthetic resin in terms of weight reduction. In consideration of cost and oil resistance, any one selected from PPS, PA66, or PA46 is used. It is desirable to be molded with resin.

  According to the present invention, since the metal collar is provided at the axial end of the synthetic resin cage, it is easy to ensure the rigidity of the cage with the metal collar. The wall thickness (axial dimension) of the pocket bottom portion of the cage can be easily made thinner than the cage made of synthetic resin as a whole. As a result, it is easy to reduce the axial dimension of the rolling bearing, and the rolling bearing can be reduced in size and weight. A compact rolling bearing can be provided as an automotive application suitable for a high-speed rotary bearing used in an electric vehicle or a hybrid vehicle.

It is a fragmentary sectional view showing a rolling bearing in an embodiment of the present invention. It is a partial expanded sectional view which shows the holder | retainer of FIG. 1A is a sectional view showing two annular bodies before joining, and FIG. 1B is a sectional view showing two annular bodies after joining. The cage of the present invention is compared with a conventional cage, (A) is a partially enlarged sectional view showing the cage of the present invention, and (B) is a partially enlarged sectional view showing a conventional cage. It is a fragmentary sectional view which shows the conventional rolling bearing. It is a partial expanded sectional view which shows the holder | retainer of FIG.

  Embodiments of the rolling bearing according to the present invention will be described in detail below. The rolling bearing of this embodiment is particularly suitable for a high-speed rotary bearing for automobiles used under oil bath lubrication in an electric vehicle or a hybrid vehicle.

  As shown in FIG. 1, the rolling bearing of this embodiment has an inner ring 12 in which an inner rolling surface 11 is formed on an outer diameter surface, and an outer rolling surface 13 on an inner diameter surface that is disposed outside the inner ring 12. Between the formed outer ring 14, a plurality of rolling elements 15 movably interposed between the inner rolling surface 11 of the inner ring 12 and the outer rolling surface 14 of the outer ring 13, and between the inner ring 12 and the outer ring 13. The main part is comprised with the holder | retainer 16 which is distribute | arranged and hold | maintains each rolling element 15 at the circumferential direction equal intervals. Either the inner ring 12 or the outer ring 13 is attached to a fixed part such as a housing, and the other is attached to a rotating part such as a rotating shaft.

  The rolling bearing includes a lightweight synthetic resin cage 16 for the purpose of suppressing deformation of the cage 16 due to centrifugal force under high-speed rotation. The cage 16 can be molded from any one synthetic resin selected from PPS (polyphenylene sulfide), PA66 (polyamide 66) or PA46 (polyamide 46) in consideration of cost and oil resistance. It is valid. As other resin materials, PA9T (polyamide 9T), PEEK (polyetheretherketone) or phenol resin can be used.

  As shown in FIGS. 3A and 3B, the cage 16 in the rolling bearing has a hemispherical shape that accommodates the rolling elements 15 (see FIG. 1) on the opposing surfaces 18 of the two annular bodies 17 facing in the axial direction. Pockets 19 are formed at a plurality of locations in the circumferential direction, and each opposing surface 18 of the annular body 17 is abutted so that the two annular bodies 17 are joined together by a joining portion (not shown). The two annular bodies 17 can suppress the deformation of the entire cage 16 by suppressing the deformation of the retainer 16, so that the rolling element 15 falls off the pocket 19 or interferes with other parts such as the inner ring 12 and the outer ring 13. Can be avoided. As described above, the two annular bodies 17 have the same shape symmetrical in the axial direction. By adopting such a structure, it is possible to make one annular body 17 and the other annular body 17 by using a kind of annular body 17 manufactured by one mold, and the product cost can be reduced.

  As described above, as shown in FIG. 2, the retainer 16 composed of the two annular bodies 17 includes an axial end portion of the retainer 16, that is, an inner diameter side of an axially outer end portion of each annular body 17 and The flange portions 20 and 21 extending in the radial direction are provided on both the outer diameter sides, and the labyrinths 22 and 23 are formed by the flange portions 20 and 21 at portions corresponding to the flange portions 20 and 21 of the inner ring 12 and the outer ring 14. The recessed grooves 24 and 25 are provided (see FIG. 1).

  The aforementioned flange portions 20 and 21 are formed by inserting a thin annular metal plate 26 at the axial end portion of the retainer 16, that is, at the axially outer end portion of each annular body 17 by insert molding of the retainer 16 made of synthetic resin. It has an integrated structure. As a material of the metal plate 26 constituting the flanges 20 and 21, an SPCC steel plate having higher rigidity than the synthetic resin constituting the cage 16 is suitable. In insert molding of the cage 16, the hole 27 is filled with a synthetic resin by forming tapered holes 27 that expand outward in the axial direction at a plurality of locations in the circumferential direction of the metal plate 26. Thus, the bonding strength of the metal plate 26 to the synthetic resin is improved.

  On the other hand, the groove 24 on the inner ring side is formed such that the outer diameter axial end portion of the inner ring 12 is recessed in a step shape, and the outer groove side concave groove 25 forms a step shape on the inner diameter axial end portion of the outer ring 14. It is formed so as to be recessed. It should be noted that the positional relationship between the flange portions 20 and 21 of the cage 16 and the concave grooves 24 and 25 of the inner and outer rings 12 and 14 is a completely non-contact state that does not always contact.

  As described above, by providing the flange portions 20 and 21 made of the annular metal plate 26 at the axial end portion of the cage 16 made of synthetic resin, the metal plate 26 constituting the flange portions 20 and 21 is provided. It becomes easy to ensure the rigidity in the cage 16 made of synthetic resin. From this, as shown in FIGS. 4A and 4B, the thickness T (axial dimension) of the bottom portion of the pocket 19 of the cage 16 in this embodiment is set to the conventional cage (entirely made of synthetic resin). ) Of the bottom portion 19 of the pocket 19 (T <t). Thus, by making the wall thickness T of the bottom portion of the pocket 19 of the cage 16 thin, it is easy to reduce the axial dimension of the rolling bearing, and the rolling bearing can be reduced in size and weight.

  This rolling bearing, when used under oil bath lubrication, makes it easy to supply an appropriate amount of lubricant from the outside of the bearing to the inside of the bearing by centrifugal force due to high-speed rotation, and high-temperature lubricant from the inside of the bearing. It has the following structure that facilitates discharge to the outside. As shown in FIG. 2, the inner side surface 28 of the flange portion 20 located on the inner diameter side of the axial end portion of the cage 16 is inclined so as to expand radially inward at an inclination angle θ. Further, the inner side surface 29 of the flange portion 21 located on the outer diameter side of the axial end portion of the cage 16 is inclined so as to expand at an inclination angle θ toward the outer side in the radial direction.

  In this way, by inclining the inner side surfaces 28 and 29 of the flange portions 20 and 21, the flow of the lubricating oil can be intentionally and smoothly generated. That is, by inclining the inner side surface 28 of the flange portion 20 located on the inner diameter side of the axial end portion of the cage 16, the lubricant can smoothly flow into the bearing from the inner side in the radial direction. A sufficient amount of lubricant can be supplied. Further, by inclining the inner side surface 29 of the flange portion 21 located on the outer diameter side of the axial end portion of the cage 16, the lubricant can smoothly flow out from the inside of the bearing to the outer side in the radial direction, thereby reducing the rotation speed. The increase in torque (heat generation) due to the stirring resistance in the can be suppressed.

  In the above embodiment, the case where the flange portions 20 and 21 are provided on both the inner diameter side and the outer diameter side of the axial end portion of the cage 16 has been described, but the present invention is not limited to this, However, the flanges 20 and 21 may be provided only on either the inner diameter side or the outer diameter side of the axial end portion of the cage 16.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 12 Inner ring 14 Outer ring 15 Rolling body 16 Cage 17 Annular body 18 Opposite surface 19 Pocket 20,21 collar part 22,23 Labyrinth 24,25 Concave groove 26 Annular metal plate 28,29 Inner side surface of collar part

Claims (7)

An inner ring and an outer ring that rotate relative to each other, a plurality of rolling elements interposed between the inner ring and the outer ring, and the inner ring and the outer ring, the rolling elements are held at equal intervals in the circumferential direction. A rolling bearing provided with a synthetic resin cage;
At least one of the axial end portion of the cage in the inner diameter side or the outer diameter side is provided with a metal flange portion extending in the radial direction, and the flange portion is provided at a portion corresponding to the flange portion of the inner ring or the outer ring. A rolling bearing characterized in that a concave groove is formed in which a labyrinth is formed.   2. The rolling bearing according to claim 1, wherein the flange portion is formed by joining and integrating an annular metal plate to an axial end portion of the cage by insert molding of a cage made of synthetic resin.   The rolling bearing according to claim 1, wherein an inner side surface of a flange portion located on an inner diameter side of an axial end portion of the cage is inclined so as to expand radially inward.   The rolling bearing according to claim 1 or 2, wherein an inner side surface of the flange portion located on the outer diameter side of the axial end portion of the cage is inclined so as to expand outward in the radial direction.   The cage is formed by forming hemispherical pockets for accommodating rolling elements at a plurality of locations in the circumferential direction on opposing surfaces of two annular members facing in the axial direction, and abutting the opposing surfaces to form two annular members. The rolling bearing as described in any one of Claims 1-4 which couple | bonded these.   The rolling bearing according to claim 5, wherein the two annular bodies have the same shape symmetrical in the axial direction.   The rolling bearing according to any one of claims 1 to 6, wherein the cage is formed of any one synthetic resin selected from PPS, PA66, and PA46.

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