JP2018165562A - Rolling bearing for automobile electric equipment and auxiliary equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing for an automobile electric equipment and an auxiliary equipment capable of preventing cooling-time noises at the cooling time.SOLUTION: A rolling bearing 1 for an automobile electric equipment and an auxiliary equipment rotatably supporting a rotation shaft rotary-driven by an engine output to a stationary member has: an inner ring 2 and an outer ring 3 as bearing rings; plural rolling elements 4 interposed between the inner ring 2 and the outer ring 3; a retainer 5 for retaining the rolling elements 4; and grease filled around the rolling elements 4. The retainer 5 is fixed to an implanting body 6 including plural fibers on at least one face selected from its inside and outside diameter faces, and tips of fibers of the implanting body 6 are in contact with surfaces of the bearing rings (inner ring 2, outer ring 3).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing, and more particularly, to a rolling bearing for an automobile electrical component such as a pulley, an alternator, an electromagnetic clutch for a car air conditioner, a fan coupling device, and an electric fan motor, and an auxiliary machine component.

  In automobile engines, electrical parts and auxiliary parts that are driven to rotate by engine output are used. Such automobile electrical equipment / auxiliary machines include alternators, pulleys, car air conditioner electromagnetic clutches, fan coupling devices, electric fan motors, and the like. For example, an idler pulley for an automobile is used as a belt tensioner for a drive belt that transmits engine rotation to an auxiliary machine of the automobile. This pulley functions as a pulley for applying tension as a tensioner to the belt when the distance between the shafts is fixed, and is used to change the running direction of the belt or to avoid obstacles. It also has a function as an idler that reduces the volume. Rolling bearings used in the rotating parts of these parts are mainly lubricated with grease.

  When driving a pulley of equipment driven by an automobile engine in cold weather (for example, -20 ° C or lower), depending on the pulley specifications and operating conditions, a singular sound (whispering sound) in cold weather, so-called cold noise may be heard. May occur. This cold noise is presumed to be caused by the self-excited vibration of the rolling elements due to the oil film unevenness of the grease. In other words, during cold weather, oil film unevenness on the raceway surface (rolling surface) is likely to occur due to an increase in the base oil viscosity of the grease, but if there is oil film unevenness, the friction coefficient between the rolling element and the raceway surface is very small. This causes a change, which causes a self-excited vibration in the rolling element. It is considered that the pulley system resonates due to this self-excited vibration, and the outer ring vibrates in the axial direction (translational movement), resulting in generation of cold noise.

  In recent years, with the demand for miniaturization and high performance of automobile electrical equipment and auxiliary equipment, for example, grease having excellent high-temperature durability and the like is used for the rolling bearing used in the rotating part of these devices. . On the other hand, in such a grease, the viscosity of the grease is likely to increase during cold weather, and the above abnormal noise is likely to occur.

  Conventionally, as a countermeasure, a rolling bearing has been proposed that optimizes base oil and thickener to prevent the occurrence of abnormal noise during cold and maintain high-temperature durability (Patent Literature). 1, Patent Document 2). The rolling bearing of Patent Document 1 is formed by applying a lubricating oil such as poly-α-olefin (hereinafter referred to as PAO) oil to the friction surface inside the bearing, and the rolling bearing of Patent Document 2 is a PAO. An oil is used as a base oil, a urea compound having a predetermined structure is used as a thickener, and a grease having an unmixed consistency of 200 or more at −20 ° C. is used.

Japanese Patent Laid-Open No. 5-149343 JP 2006-225519 A

  However, when eliminating cold abnormal noise by improving lubricants such as grease, it is not easy to have other characteristics at the same time, and the manufacturing cost increases, so if possible use general-purpose grease etc. It is desirable to eliminate cold noises with other simpler configurations. Further, if grease or lubricating oil cannot be used effectively due to leakage of lubricant from the bearing or uneven distribution inside the bearing, a sufficient effect may not be expected. In particular, in the case of oil lubrication, oil is easily released to the outside of the bearing. In addition, during cold weather, the viscosity of the grease (base oil) increases and the torque tends to increase, so it is also desired to suppress this.

  The present invention has been made in order to cope with such problems, and does not depend largely on the characteristics of a lubricant such as grease, and can prevent the generation of cold abnormal noise during cold weather. An object is to provide a rolling bearing for a machine.

  The rolling bearing for automobile electrical equipment / auxiliary machine according to the present invention is a rolling bearing that rotatably supports a rotating shaft that is driven to rotate by an engine output on a stationary member, and the rolling bearing includes an inner ring and an outer ring that are raceways. A plurality of rolling elements interposed between the inner ring and the outer ring, a cage for holding the rolling elements, and grease sealed around the rolling elements, the cage having an inner surface and an outer surface. A flocked body composed of a plurality of fibers is fixed to at least one surface selected from the radial surfaces, and the tip of the fibers of the flocked body is in contact with the surface of the raceway.

  The tip of the fiber of the flocked body is curved in an arc shape.

  The fibers of the flocked body are synthetic resin fibers, and the flocked body is bonded and fixed to the cage by electrostatic flocking.

  The rolling bearing is a bearing used in an environment of −20 ° C. or lower.

  In the rolling bearing for automobile electrical equipment / auxiliary machine of the present invention, a flocked body composed of a plurality of fibers is fixed to at least one surface selected from an inner diameter surface and an outer diameter surface of the cage, and the tips of the fibers of the flocked body Since the portion is in contact with the surface of the raceway ring, grease wrinkles present on the raceway ring can be scraped off with fibers. Further, the base oil is present on the fiber surface where the grease is caught, and the base oil continues to be supplied to the raceway due to the capillary phenomenon. As a result, even when the temperature is low or cold (for example, −20 ° C. or lower), the occurrence of oil film unevenness on the raceway surface can be prevented, and the occurrence of abnormal noise during cold can be prevented.

  In addition, since the tip of the fiber of the flocked body is curved in an arc shape, sliding resistance can be reduced and torque can be reduced even when the race and the fiber tip are in contact.

  In addition, since the fiber of the flocked body is a synthetic resin fiber, and the flocked body is bonded and fixed to the cage by electrostatic flocking, it is difficult to swell and dissolve with oil and is chemically stable and homogeneous. It can be a flocked body that is closely bonded.

It is a partial cross section figure of the rolling bearing which concerns on one Example of this invention. FIG. 2 is a partial perspective view of the cage in FIG. 1. It is a partial enlarged view of the part (cage) which provided the flocked body. It is sectional drawing which shows the alternator using the bearing of this invention. It is sectional drawing which shows the idler pulley using the bearing of this invention.

  An example of a rolling bearing for automobile electrical equipment and auxiliary equipment of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of a deep groove ball bearing incorporating a crown-shaped cage as a rolling bearing of the present invention, and FIG. 2 is a partial perspective view of the crown-shaped cage. As shown in FIG. 1, in the rolling bearing 1, an inner ring 2 having a raceway surface 2a on an outer peripheral surface and an outer ring 3 having a raceway surface 3a on an inner peripheral surface are arranged concentrically. A plurality of rolling elements 4 are disposed between the raceway surface 2a of the inner ring and the raceway surface 3a of the outer ring. The plurality of rolling elements 4 are held by a crown-shaped cage 5. Further, the rolling bearing 1 includes annular seal members 12a and 12b provided at openings in both axial ends of the inner and outer rings, and is constituted by an inner ring 2, an outer ring 3, a cage 5, and seal members 12a and 12b. It is lubricated by grease (not shown) sealed in the bearing inner space. In this embodiment, the flocked body 6 is fixed to the inner and outer diameter surfaces of the cage 5.

  As shown in FIG. 2, the crown-shaped cage 5 is formed with a pair of opposed holding claws 8 on the upper surface of the annular main body 7 at a constant pitch in the circumferential direction, and the opposed holding claws 8 approach each other. And a pocket 9 for holding a ball as a rolling element between the holding claws 8 is formed. A flat portion 10 serving as a rising reference surface of the holding claw 8 is formed between the back surfaces of the holding claws 8 adjacent to each other formed at the edge of the adjacent pocket 9. As shown in the figure, the flocked body 6 is fixed to the outer diameter surface 5 a of the cage 5 and the inner diameter surface 5 b of the cage 5.

  As shown in FIG. 1, in the flocked body 6 provided in the cage 5, the tip of the fiber is in contact with the surface of the race ring (the inner ring 2 and the outer ring 3). In order to reduce an increase in torque due to contact, it is preferable to adjust the length of the fiber, which will be described later, so that the contact between the race and the fiber tip is as light as possible. Grease ridges are formed on the shoulder portion of the raceway ring, which is the portion where the flocked body 6 contacts. In the present invention, this can be scraped off by the flocked body 6. Furthermore, since the scraped grease (base oil) is supplied to the raceway surface via the flocked body 6, the occurrence of oil film unevenness on the raceway surface can be prevented, and the occurrence of abnormal noise during cold can be prevented. Normally, when the temperature is low or cold, the oil supply to the rolling elements is not smooth due to an increase in the viscosity of the base oil in the grease, and oil film unevenness tends to occur on the raceway surface. Is suppressed.

  Based on FIG. 3, the suitable form of the flocked body provided in a holder | retainer is demonstrated. FIG. 3 is a partially enlarged cross-sectional view (a cross section perpendicular to the axial direction) of the cage provided with the flocked body in FIG. 1. As shown in FIG. 3, it is preferable that the flocked body 6 has a shape in which the tip portion 6a of the fiber constituting the curved body is curved in an arc shape. The tip 6a of the curved fiber is in contact with the surface (inner diameter surface) of the outer ring 3 which is the counterpart member. Further, the flocked body 6 is in a state where the root of the main body portion 6 b is fixed to the outer diameter surface 5 a of the cage 5 by the adhesive 11 and is raised. By making the front end portion 6a of the fiber constituting the flocked body 6 into a curved shape (convex curved shape) as described above, the flocked body is formed from straight hair-shaped fibers in which the front end portion 6a is on the straight extension of the main body portion 6b. Compared with the case where it is configured, since there is less catching between the tip portion 6a and the mating member surface, the resistance is low, the torque can be reduced, and the wear of the fiber tip portion is also reduced.

  Moreover, as shown in FIG. 3, in the front-end | tip part 6a of the fiber of the flocked body 6, it goes to the front end side (front-end | tip part 6a side) from the fixed side (main body part 6b side) of the some fiber which comprises this flocked body 6. The torque can be further reduced by setting the direction of the arcuate curve to the same direction (clockwise in the figure). In particular, as shown in FIG. 3, the direction of the bending of the fiber tip 6a of the flocked body 6 is such that the fixed side (main body 6b side) is the rotational direction with respect to the rotational direction of the mating member (black arrow in the figure). It is preferable that the front end side (the front end portion 6a side) on the upstream side is oriented to be the downstream side in the rotation direction. Here, the “rotation direction” is a relative rotation direction with respect to the bearing constituent member provided with the flocked body in the counterpart member. In FIG. 3, the outer ring 3 rotates relative to the cage 5 in the direction of the black arrow in the figure by rotating with respect to the outer ring 3 to which the cage 5 is fixed. Will do. In this way, by setting the direction of bending to the direction along the rotation direction of the mating member, the resistance due to the contact between the flocked body and the mating member is further reduced, and the torque can be further reduced.

  Further, as shown in FIG. 1, the flocked body 6 is also fixed to the surface of the seal member 12a on the bearing inner side. Thereby, the amount of grease held inside the bearing can be increased. The oil held in the flocked body of the seal member is supplied to the raceway surface from the contact portion with the outer ring through the shoulder of the outer ring by surface tension. Moreover, although the flocked body 6 is provided in the radial direction whole range of the sealing member 12a, it is good also as a form provided in a part of radial direction. Similarly, the circumferential direction can be provided in the entire circumferential range or a partial range.

  As described above, the flocked body 6 can be provided on the surface of a cage or a seal member. Moreover, in one rolling bearing, you may provide a flocking body in the some member which comprises this, respectively. The examples shown in FIGS. 1 and 2 are crown-shaped cages. However, in the rolling bearings for automobile electrical equipment and auxiliary equipment according to the present invention, the cage is a corrugated cage, a ball cage, a roller cage, or the like. It is good also as a form which fixes a flocked body. Moreover, about the material of a holder | retainer, arbitrary materials, such as a metal material and a resin material, are employable. The crown-shaped cage shown in FIG. 2 is made of resin. For example, a polyamide resin such as polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) resin, thermoplastic polyimide resin, polyamideimide resin, nylon 66 resin, nylon 46 resin is used as a resin base material, and carbon fiber, glass fiber, etc. It is manufactured by injection molding using a resin composition containing reinforced fibers and other additives.

  The bearing type of the rolling bearing for automobile electrical equipment and auxiliary equipment of the present invention is not particularly limited, and in addition to the above deep groove ball bearing, angular ball bearing, thrust ball bearing, cylindrical roller bearing, needle roller bearing, thrust cylindrical roller bearing, The present invention can be applied to any type of rolling bearing such as a thrust needle roller bearing, a tapered roller bearing, a thrust tapered roller bearing, a self-aligning ball bearing, a self-aligning roller bearing, and a thrust self-aligning roller bearing. Moreover, the presence or absence of a seal member (shield plate) can be applied to these rolling bearings.

  The flocked body in the present invention is formed by flocking fibers (short fibers). As a method for flocking, there are electrostatic flocking and electrostatic flocking, and a known method can be adopted. Electrostatic flocking uses a base material (mainly a cage) to which an adhesive is applied as a counter electrode, creates an electrostatic field with a high-voltage electrode, and forms an electrostatic field by flying short fibers with the electrostatic attractive force. This is a method of raising hair. In addition to this electrostatic attraction force, electrostatic spraying is a method of flocking a forming portion to which an adhesive is applied while forcing short fibers to fly with air. In any method, a drying step, a finishing step, etc. are performed after flocking. Moreover, after fixing the straight-hair-shaped fiber by these methods, the flocked body in which the tip portion is curved can be formed by pressing the pressing member against the tip portion. Moreover, the same flocked body can be formed by curving the tip of the fiber before flocking and flocking the fiber.

  The short fiber used for flocking is not particularly limited as long as it can be used as a short fiber for flocking. For example, (1) polyolefin resin such as polyethylene and polypropylene, polyamide resin such as nylon, aromatic polyamide resin, polyethylene terephthalate, Polyester resin such as polyethylene naphthalate, polyethylene succinate, polybutylene terephthalate, synthetic resin fiber such as acrylic resin, vinyl chloride, vinylon, (2) inorganic fiber such as carbon fiber, glass fiber, (3) rayon, acetate, etc. And natural fibers such as cotton, silk, hemp and wool. These may be used independently and 2 or more types may be used together. It is preferable to use synthetic resin fiber among the above because it is difficult to cause swelling and dissolution with oil, is chemically stable, can produce a large amount of homogeneous fibers, and can be obtained at low cost.

  The shape of the short fiber is not particularly limited as long as the shape of the tip portion can be realized. As a specific shape, for example, those having a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex are preferable, and the density of short fibers of the flocked body is occupied by fibers per planted area. A ratio of 1 to 30% is preferable. The cross-sectional shape of the short fiber includes a circular shape and a polygonal shape. By using the short fibers having a polygonal cross section, the surface area can be made larger than that of the short fibers having a circular cross section, and the grease can be more easily retained. Further, as in the case shown in FIG. 1, the short fiber length of the flocked body provided in the cage is set to such a length that the fiber tip comes into contact with the raceway.

  Examples of the adhesive include an adhesive mainly composed of urethane resin, epoxy resin, acrylic resin, vinyl acetate resin, polyimide resin, silicone resin and the like. For example, urethane resin solvent adhesive, epoxy resin solvent adhesive, vinyl acetate resin solvent adhesive, acrylic resin emulsion adhesive, acrylate-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive , Urethane resin emulsion adhesive, epoxy resin emulsion adhesive, polyester emulsion adhesive, ethylene-vinyl acetate copolymer adhesive and the like. These may be used independently and 2 or more types may be used together.

  In the rolling bearing for automobile electrical equipment / auxiliary machinery according to the present invention, grease is sealed in the space between the inner and outer rings, and lubricated by being interposed on the raceway surface while being partially held by the flocked body. Moreover, it is good also as a form lubricated only with lubricating oil. In this case, since the fiber scrapes off the oil existing in the raceway and retains the oil with the surface tension on the fiber surface, sufficient oil for lubrication is continuously supplied to the raceway. As a result, as in the case of grease, oil film unevenness is eliminated, and generation of abnormal noise during cold can be prevented.

  As the grease and lubricating oil, those used for rolling bearings can be used without particular limitation. Here, the present invention prevents the occurrence of cold abnormal noise without depending on the type of grease, etc., depending on the configuration of the predetermined flocked body, but is suitable for preventing the occurrence of known cold abnormal noise. Grease can be used in combination. For example, examples of the base oil constituting the grease include synthetic hydrocarbon oil (PAO oil), perfluoroether oil, alkyl diphenyl ether oil, ester oil, and fluorine oil. Examples of the thickener constituting the grease include aliphatic, alicyclic, and aromatic diurea compounds and metal soaps. Moreover, you may mix | blend a predetermined | prescribed antioxidant, extreme pressure agent, polymethacrylate, etc. as an additive.

  An automobile alternator to which the rolling bearing is applied will be described with reference to FIG. FIG. 4 is a sectional view of the structure of the alternator. In the alternator, a rotor rotating shaft 23 having a rotor 22 mounted on a pair of frames 21a and 21b forming a housing which is a stationary member is rotatably supported by a pair of rolling bearings 1 and 1 (see FIG. 1). Yes. A rotor coil 24 is attached to the rotor 22, and a three-turn stator coil 26 is attached to the stator 25 disposed on the outer periphery of the rotor 22 at a phase of 120 °. The rotor rotating shaft 23 is rotationally driven with a rotational torque transmitted by a belt (not shown) to a pulley 27 attached to the tip thereof. The pulley 27 is attached to the rotor rotating shaft 23 in a cantilever state, and vibration is also generated as the rotor rotating shaft 23 rotates at high speed. Therefore, the rolling bearing 1 that supports the pulley 27 side in particular receives a severe load. .

  An example of an idler pulley to which the rolling bearing is applied is shown in FIG. FIG. 5 is a sectional view of the structure of the idler pulley. This idler pulley is used as a belt tensioner for an auxiliary drive belt of an automobile. This pulley includes a pulley body 28 made of a steel plate press and a single row rolling bearing 1 ″ (see FIG. 4) fitted to the inner diameter of the pulley body 28. This rolling bearing 1 ″ rotates the outer ring. The pulley main body 28 includes an inner diameter cylindrical portion 28a, a flange portion 28b extending from one end of the inner diameter cylindrical portion 28a to the outer diameter side, an outer diameter cylindrical portion 28c extending in the axial direction from the flange portion 28b, and an inner diameter cylindrical portion 28a. This is an annulus composed of a flange portion 28d extending from the other end to the inner diameter side. The outer ring 3 of the rolling bearing 1 '' is fitted into the inner diameter of the inner diameter cylindrical portion 28a, and the outer peripheral diameter of the outer diameter cylindrical portion 28c is provided with a pulley peripheral surface 28e that contacts a belt driven by the engine. . By bringing the pulley peripheral surface 28e into contact with the belt, the pulley functions as an idler.

  Even when such a pulley or the like is used in a cold state, for example, at a temperature of −20 ° C. or higher (particularly in the case of −40 ° C.), oil is applied to the raceway surface from the cage flock by a centrifugal force applied during rotation. As a result, oil film unevenness on the raceway surface can be prevented and cold noise can be prevented.

  The rolling bearing for automobile electrical equipment and auxiliary equipment according to the present invention can prevent the occurrence of cold noise during cold weather, so automobile electrical parts such as pulleys, alternators, car air conditioner electromagnetic clutches, fan coupling devices, electric fan motors, etc. And can be suitably used as a rolling bearing for auxiliary machine parts, in particular, a rolling bearing used in cold districts and low temperature conditions.

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner ring 3 Outer ring 4 Rolling body 5 Cage 6 Flocking body 7 Cage body 8 Holding claw 9 Pocket 10 Flat part 11 Adhesive 12a, 12b Seal member 21a, 21b Frame 22 Rotor 23 Rotor rotating shaft 24 Rotor coil 25 Stator 26 Stator coil 27 Pulley 28 Pulley body

Claims (4)

A rolling bearing for automobile electrical equipment and auxiliary equipment that rotatably supports a rotating shaft that is driven to rotate by engine output on a stationary member, and the rolling bearing is provided between an inner ring and an outer ring that are raceways, and between the inner ring and the outer ring. A plurality of intervening rolling elements, a cage for holding the rolling elements, and grease sealed around the rolling elements;
The retainer has a flocked body composed of a plurality of fibers fixed to at least one surface selected from an inner diameter surface and an outer diameter surface thereof,
A rolling bearing for automobile electrical equipment / auxiliary machinery, wherein a tip portion of a fiber of the flocked body is in contact with a surface of the raceway.   The rolling bearing for automobile electrical equipment / auxiliary machinery according to claim 1, wherein a tip portion of the fiber of the flocked body is curved in an arc shape.   The rolling for automobile electrical equipment and auxiliary equipment according to claim 1 or 2, wherein the fibers of the flocked body are synthetic resin fibers, and the flocked body is bonded and fixed to the cage by electrostatic flocking. bearing.   The rolling bearing for automobile electrical equipment / auxiliary machinery according to any one of claims 1 to 3, wherein the rolling bearing is a bearing used in an environment of -20 ° C or lower.

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