JP2013040664A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device having improved durability by preventing creep while attaining lightweighting, compactifying, and cost reduction.SOLUTION: In the wheel bearing device having the first-generation structure which includes a wheel bearing 2 for bearing a wheel to be rotatable, a hub ring 1 is formed with a fitted part 10 into which the wheel bearing 2 is pressed and a positioning part 11 which is gradually reduced in inner diameter from the fitted part 10 toward one end of a base part 4 of the hub ring 1, on an inner circumferential surface of the base part 4 of the hub ring 1, where the another end being the press-in entrance, and an outer ring 15 of the wheel bearing 2 is formed with an outer diameter surface part 15b, a small diameter surface part 15c formed in a slightly small diameter in comparison with the diameter of the outer diameter surface part 15b, and a positioning part 30 which is gradually reduced in inner diameter via the small diameter surface part 15c, on an end part of an outer circumference surface of the outer ring 15. These positioning parts 11, 30 each have a tapered surface of an inclined angle θ in a range of 5 to 45 degrees, and the base part 4 of the hub ring 1 and the outer ring 15 of the wheel bearing 2 are mutually fitted along the tapered surfaces to position the outer ring 15 in the axial direction with respect the hub ring 1.

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of a vehicle such as an automobile, and more particularly, for a wheel having improved durability by preventing creep while reducing the cost while reducing the weight and size. The present invention relates to a bearing device.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and both an inner ring rotation method and an outer member rotation method are generally used for driven wheels. This wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double-row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device, and an outer member. 2nd generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the wheel, 3rd generation structure with one inner rolling surface formed directly on the outer periphery of the hub wheel, or constant speed with the hub wheel It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the universal joint.

  In these wheel bearing devices, in recent years, there are severe demands for improving fuel efficiency in terms of resource saving or pollution. In automobile parts, in particular, weight reduction of a wheel bearing device has been attracting attention and strongly desired as a factor to meet such demands. On the other hand, it is conceivable to make the hub wheel have a hollow structure in order to reduce the weight, but the rigidity is reduced as the weight is reduced. That is, the hub wheel is deformed when a large load is applied, and abnormal vibration, early separation of the inner raceway surface, or so-called creep occurs in which the hub wheel and the inner ring press-fitted into the hub wheel rotate relative to each other. Sometimes. Here, creep refers to a phenomenon in which the bearing surface slightly moves in the circumferential direction due to lack of mating squealing or poor mating surface processing accuracy, and the mating surface becomes a mirror surface, and in some cases, seizure or welding occurs with galling. Say.

  As a solution to these problems, a wheel bearing device as shown in FIG. 10 is known. This wheel bearing device mainly includes a hub wheel 60, a wheel bearing 50, and a shaft 57. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 10), and the side closer to the center is referred to as the inner side (right side in FIG. 10).

  The hub wheel 60 is made of gray cast iron such as FC25 or spheroidal graphite cast iron such as FCD45, and integrally has a wheel mounting flange 62 for attaching a wheel (not shown) to one end of a cylindrical base 61. Bolt holes 63 for hub bolts for fixing the wheels at the circumferentially equidistant positions of the mounting flange 62 are planted. A cylindrical brake drum 64 extending in the axial direction from the outer end of the wheel mounting flange 62 is provided continuously, and a shoe surface 65 is formed on the inner periphery thereof. A wheel bearing 50 is fitted to the inner peripheral portion of the base portion 61 of the hub wheel 60, and the wheel is rotatably supported on the shaft 57.

  The wheel bearing 50 includes an outer ring 51 having double-row outer rolling surfaces 51a and 51a formed on the inner periphery, and an inner rolling surface 52a facing the double-row outer rolling surfaces 51a and 51a on the outer periphery. A pair of formed inner rings 52, 52, double-row balls 54, 54 accommodated between the rolling surfaces of the inner ring 52 and the outer ring 51 via cages 53, 53, and the outer ring 51 And the seals 55 and 55 attached to the opening of the annular space formed between the inner ring 52 and the inner ring 52. The end faces on the small diameter (front) side of the inner rings 52, 52 are brought into contact with each other in a butted state to constitute a so-called back-to-back type double row angular ball bearing.

  The outer ring 51 and the inner ring 52 are formed by pressing or rolling (hereinafter referred to as plastic working) a steel plate made of carburized steel such as SCr420 or SCM415 having a relatively small amount of carbon. And the surface hardness is hardened in the range of 50 to 64 HRC by carburizing and quenching.

  Here, serrations (or splines) 56, 56 are formed on the inner peripheral surfaces 52 b, 52 b of the pair of inner rings 52, 52. Then, when the pair of inner rings 52, 52 are press-fitted into the shaft portion 58 of the shaft 57, the serrations 56, 56 bite into the shaft portion 58, and creep can be reliably prevented over a long period of time. Durability can be improved.

  The shaft 57 integrally has a vehicle body attachment flange 66 for attachment to a vehicle body (not shown), and a shaft portion 58 that protrudes in the axial direction from the vehicle body attachment flange 66 via a shoulder portion 67 is projected. A screw part 59 is formed at the end of the shaft part 58.

  A fitting portion 68 into which the wheel bearing 50 is fitted is formed on the inner periphery of the base portion 61 of the hub wheel 60, and a flange portion 69 is formed at the inner end of the fitting portion 68. A retaining ring 70 is attached to the end, and the outer ring 51 of the wheel bearing 50 is positioned and fixed in the axial direction while being sandwiched between the retaining ring 70 and the flange 69. On the other hand, the inner rings 52 and 52 of the wheel bearing 50 are press-fitted into the shaft portion 58 of the shaft 57 and are positioned and fixed in the axial direction while being sandwiched between the shoulder portion 67 of the shaft 57 and the fixing nut 71 ( For example, see Patent Document 1.)

JP 2008-267519 A

  However, in the conventional wheel bearing device, by forming the flange portion 69 on the base portion 61 of the hub wheel 60, the base portion 61 itself becomes longer in the axial direction and restricts the wheel space. In particular, since the front wheel has not only a brake device but also a steering function, it is desirable to store the bearing portion in a space-saving as much as possible.

  As a structure for positioning in the axial direction other than those described above, there are a bearing with a retaining ring and a bearing having a flange integrally on the outer periphery of the outer ring, but in this type of positioning structure, there is a possibility that the fitting portion is worn by creep. . As a method of preventing this creep, it is common to increase the squeeze between the housing and the outer ring, but by increasing the squeeze, the internal clearance of the bearing is reduced and the bearing preload after final assembly becomes excessive. There was a risk of becoming a short life.

  In particular, in large-diameter wheel bearings for trucks, the tolerance of the mating housing and the outer diameter of the outer ring are larger than those of wheel bearings for passenger cars. There is a possibility of preload.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device in which creep is prevented and durability is improved while achieving cost reduction as well as light weight and compactness. It is said.

  In order to achieve such an object, the invention according to claim 1 of the present invention is a hub wheel integrally having a wheel mounting flange for mounting a wheel to one end of a cylindrical base, and a wheel for mounting to a vehicle body. A shaft integrally including a vehicle body mounting flange; and a wheel bearing that is fitted between the shaft and the base and rotatably supports the wheel. An outer ring formed integrally with the outer rolling surface, a pair of inner rings formed with an inner rolling surface opposed to the outer rolling surface of the double row on the outer periphery, and between the rolling surfaces of the inner ring and the outer ring In a wheel bearing device comprising a double row rolling element housed in a freely rotatable manner via a cage, a fitting portion into which the wheel bearing is press-fitted into the inner periphery of the base portion of the hub wheel, A positioning portion is formed which is reduced in diameter from the fitting portion to the inner side. A positioning part that gradually decreases in diameter to the inner side is formed on the outer periphery of the inner side end of the outer ring, and these positioning parts are formed and fitted on a tapered surface having a predetermined inclination angle, and are attached to the hub wheel. The outer ring is positioned in the axial direction.

  Thus, in the wheel bearing device of the first generation structure provided with the wheel bearing for rotatably supporting the wheel, the fitting portion in which the wheel bearing is press-fitted into the inner periphery of the base portion of the hub wheel, and the fitting Positioning portions that are reduced in diameter from the joint portion to the inner side are formed, positioning portions that are gradually reduced in diameter to the inner side are formed on the outer periphery of the inner side end of the outer ring, and these positioning portions are tapered with a predetermined inclination angle. Formed on the surface and fitted, and the outer ring is positioned in the axial direction with respect to the hub ring, so it is possible to reduce the cost and weight and make it compact, and the wedge effect increases creep resistance and durability It is possible to provide a wheel bearing device with improved performance.

  Preferably, if the inclination angle θ of the positioning portion is set to 5 ° ≦ θ ≦ 45 ° as in the invention described in claim 2, the radial component force of the load applied to the positioning portion is It is possible to prevent the creep resistance from deteriorating due to an increase in size, and to function as a guide surface during assembly to the hub wheel, and to ensure axial positioning accuracy during assembly to the hub wheel.

  Further, as in the invention according to claim 3, if a small diameter portion formed slightly smaller from the outer diameter surface of the outer ring is formed, and the positioning portion is formed through the small diameter portion, the small diameter The portion becomes a relief portion, and the fitting state with the hub wheel can be improved.

  Further, when the outer ring surface of the outer ring and the connecting part of the positioning part are formed in an arc shape having a predetermined radius of curvature as in the invention described in claim 4, when the outer ring is press-fitted into the hub ring. Therefore, stable assembly can be performed by preventing the occurrence of galling or the like.

  Preferably, as in the invention described in claim 5, if the curvature radius Ro of the joint portion is set to 0.5R ≦ R ≦ 5.0R, simultaneous grinding while dressing a forming grindstone with a diamond dresser In this case, it is possible to prevent sagging of the grindstone, to stably form the size and shape, and to secure the tapered surface of the positioning portion without increasing the width of the outer ring, thereby reducing the weight and size. it can.

  Further, as in the invention described in claim 6, if the outer diameter surface of the outer ring and the positioning portion are ground simultaneously by the overall grinding wheel, the coaxiality of the outer diameter surface and the positioning portion is ensured, and the outer ring Positioning accuracy can be enhanced, dimensions and shapes can be stabilized, and galling can be prevented.

  Further, as in the invention according to claim 7, if an annular relief portion is formed in the vicinity of the positioning portion of the hub wheel or the outer ring and an elastic member is attached to the relief portion, It is possible to prevent intrusion of foreign substances such as, and to improve airtightness.

  In addition, as in the invention according to claim 8, if grease or a sealing agent is applied to the contact surfaces of the positioning portion of the hub wheel and the positioning portion of the outer ring, foreign matter such as rainwater is applied to the fitting portion. Intrusion can be prevented, airtightness can be improved, and creep resistance is improved.

  According to a ninth aspect of the present invention, an annular groove is formed in the fitting portion of the hub wheel, and a retaining ring is attached to the annular groove, and the retaining ring and the positioning portion The outer ring of the wheel bearing may be positioned and fixed in the axial direction while being sandwiched.

  Further, as in the invention described in claim 10, the inner ring of the wheel bearing is press-fitted into the shaft portion of the shaft, and a thread portion is formed at an end portion of the shaft portion, and the inner ring is connected to the shaft. If the preload is applied to the wheel bearing by tightening the fixing nut with a predetermined tightening torque, the bearing rigidity is fixed. And the rolling fatigue life can be improved.

  A wheel bearing device according to the present invention includes a hub wheel integrally including a wheel mounting flange for mounting a wheel on one end of a cylindrical base, a shaft integrally including a vehicle body mounting flange for mounting to a vehicle body, The wheel bearing is fitted between the shaft and the base and rotatably supports the wheel, and the wheel bearing has a double row outer rolling surface formed integrally on the inner periphery. An outer ring, a pair of inner rings formed with an inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and freely rollable via a cage between both rolling surfaces of the inner ring and the outer ring In the wheel bearing device including the accommodated double row rolling elements, a fitting portion in which the wheel bearing is press-fitted into an inner periphery of the base portion of the hub wheel, and a diameter of the fitting portion is reduced from the fitting portion to the inner side. A positioning portion is formed, and the outer side of the outer ring is outside the end portion. In addition, a positioning portion that gradually decreases in diameter on the inner side is formed, and these positioning portions are formed and fitted on a tapered surface having a predetermined inclination angle, and the outer ring is positioned in the axial direction with respect to the hub wheel. Therefore, it is possible to provide a wheel bearing device that can be reduced in cost, reduced in weight and compact, and improved in creep resistance and improved in durability due to the wedge effect.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a longitudinal cross-sectional view which shows the wheel bearing of FIG. (A) is an expanded sectional view showing one seal unit of FIG. 2, and (b) is an enlarged sectional view showing the other seal unit of FIG. It is a principal part enlarged view which shows the positioning part of FIG. It is explanatory drawing which shows the grinding process of the outer ring | wheel of FIG. It is a principal part enlarged view which shows the modification of FIG. It is explanatory drawing which shows the grinding process of the outer ring | wheel of FIG. It is a principal part enlarged view which shows the other modification of FIG. It is a principal part enlarged view which shows the other modification of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

  A hub wheel integrally having a wheel mounting flange for mounting a wheel on one end of a cylindrical base, a shaft integrally having a vehicle mounting flange for mounting on a vehicle body, and a fit between the shaft and the base. A wheel bearing for rotatably supporting the wheel, the wheel bearing comprising an outer ring integrally formed with an outer circumferential surface of a double row on an inner circumference, and an outer side of the double row on an outer circumference. A pair of inner rings formed with an inner rolling surface facing the rolling surface, and a double row rolling element accommodated between the rolling surfaces of the inner ring and the outer ring via a cage. In the wheel bearing device provided, a fitting portion into which the wheel bearing is press-fitted on the inner periphery of the base portion of the hub wheel, and a positioning portion that reduces the diameter from the fitting portion to the inner side are formed. Slightly smaller diameter from the outer diameter surface on the outer periphery of the inner end And a positioning portion that gradually decreases in diameter toward the inner side through the small diameter portion, and the positioning portion has a tapered surface with an inclination angle θ set to 5 ° ≦ θ ≦ 45 °. The outer ring is positioned in the axial direction with respect to the hub ring.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is a longitudinal sectional view showing a wheel bearing of FIG. 1, and FIG. 3 (a) is one of FIG. FIG. 4 is an enlarged cross-sectional view showing the seal alone, FIG. 4B is an enlarged cross-sectional view showing the other seal single piece of FIG. 2, FIG. 4 is an enlarged view of the main part showing the positioning portion of FIG. FIG. 6 is an enlarged view of an essential part showing a modification of FIG. 4, FIG. 7 is an explanatory view showing the grinding process of the outer ring of FIG. 6, and FIG. 8 is another modification of FIG. The principal part enlarged view which shows an example, FIG. 9 is a principal part enlarged view which shows the other modification of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is for a driven wheel, and has a hub wheel 1, a wheel bearing 2, and a shaft 3 as main components. The hub wheel 1 is made of gray cast iron such as FC25 or spheroidal graphite cast iron such as FCD45, and integrally has a wheel mounting flange 5 for mounting a wheel (not shown) on the outer end of the cylindrical base 4. The wheel bearing 2 is fitted to the inner peripheral portion of the base portion 4 to rotatably support the wheel with respect to the shaft 3.

  The shaft 3 integrally has a vehicle body mounting flange 6 for mounting to a vehicle body (not shown), and a shaft portion 8 extending in the axial direction from the vehicle body mounting flange 6 via a shoulder portion 7 is projected. A threaded portion 9 is formed at the end of the portion 8.

  The shaft 3 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S45C, and the surface hardness is set to a range of 50 to 64 HRC by induction hardening from the shoulder portion 7 to the shaft portion 8. Has been. Thereby, it has sufficient mechanical strength with respect to the bending load applied to the axial part 7 grade | etc., And the fretting resistance of the fitting part of the wheel bearing 2 improves.

  A fitting portion 10 into which the wheel bearing 2 is fitted is formed on the inner periphery of the base portion 4 of the hub wheel 1, and a positioning portion 11 which will be described later is formed at the inner end of the fitting portion 10. A retaining ring 13 is mounted in an annular groove 12 formed at the end of the side, and the outer ring 15 of the wheel bearing 2 is positioned and fixed in the axial direction while being sandwiched between the retaining ring 13 and the positioning portion 11. Yes.

  On the other hand, the inner rings 16 and 17 of the wheel bearing 2 are press-fitted into the shaft portion 8 of the shaft 3 and positioned and fixed in the axial direction while being sandwiched between the shoulder portion 7 of the shaft 3 and the fixing nut 14. Here, a predetermined bearing preload is applied by tightening the fixing nut 14 with a predetermined tightening torque. Note that an end cap (not shown) is attached to the end opening on the outer side of the hub wheel 1 to prevent rainwater, dust and the like from entering the wheel bearing 2 from the outside.

  As shown in FIG. 2 in an enlarged manner, the wheel bearing 2 is an outer ring (outer member) in which tapered double-row outer rolling surfaces 15a and 15a that are outwardly opened on the inner circumference are integrally formed. 15, a pair of inner races 16, 17 in which a tapered inner raceway surface 16 a facing the double row outer raceway surfaces 15 a, 15 a is formed on the outer periphery, and a cage 18 between both the raceway surfaces. And two rows of rolling elements (conical rollers) 19 and 19 accommodated so as to be freely rollable. A large collar portion 16b for guiding the rolling element 19 is formed on the large diameter side of the inner raceway 16a of the inner rings 16, 17, and a small collar for preventing the rolling element 19 from falling off on the small diameter side. A portion 16c is formed. And it sets in the state by which the small diameter side end surface of a pair of inner ring | wheels 16 and 17 was faced | matched, and comprises the bearing for wheels of a back-to-back type.

  Here, the pair of inner rings 16 and 17 basically have the same specifications such as dimensions and shapes, but the structures on the large diameter side of the inner rings 16 and 17 are different. Specifically, the inner diameter chamfered portion of the inner side inner ring 17 is different from the outer side inner ring 16. Thereby, the chamfer dimension of the shoulder part 7 of the shaft 3 can be set large, and sufficient mechanical strength can be ensured with respect to the bending load applied to the shaft part 7 (see FIG. 1).

  Seals 20 and 21 are attached to the openings of the annular space formed between the outer ring 15 and the pair of inner rings 16 and 17, and leakage of the lubricating grease sealed inside the bearing to the outside, rainwater and Dust and the like are prevented from entering the bearing.

  As shown in an enlarged view in FIG. 3A, the outer seal 20 is integrally joined to the core 22 pressed into the inner periphery of the outer end of the outer ring 15 by vulcanization adhesion. It is comprised by the integral seal | sticker which consists of the sealed member 23 made. The cored bar 22 is formed into a substantially L-shaped section by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). Has been. The seal member 23 is made of a synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and integrally includes bifurcated radial lips 23a and 23b that are in sliding contact with the outer diameter of the inner ring 16 via a predetermined radial shimeshiro.

  On the other hand, the seal 21 on the inner side is a so-called pack seal composed of an annular seal plate 24 and a slinger 25 which are formed in a substantially L-shaped cross section and are arranged to face each other as shown in an enlarged view in FIG. Is configured. The seal plate 24 includes a cored bar 26 that is press-fitted into the inner periphery of the inner ring side end of the outer ring 15, and a seal member 27 that is integrally vulcanized and bonded to the cored bar 26. The core metal 26 has a substantially L-shaped cross section by press working from an austenitic stainless steel plate or a cold-rolled steel plate treated with rust.

  The seal member 27 is made of a synthetic rubber such as NBR, and is formed with a pair of side lips 27a and 27b that are formed to be inclined outward in the radial direction, and an inner diameter side of the side lip 27b that is inclined to the inner side of the bearing. And a grease lip 27c.

  The slinger 25 is formed of an austenitic stainless steel plate or a cold-rolled steel plate that has been rust-proofed by a press process, and a cylindrical portion 25a that is press-fitted into the outer diameter of the inner ring 17; It comprises a standing plate portion 25b extending radially outward from the cylindrical portion 25a. The pair of side lips 27a and 27b of the seal member 27 are slidably contacted with the upright plate portion 25b via a predetermined axial squeeze, and the grease lip 27c is slid with respect to the cylindrical portion 25a via a predetermined radial nip. It is touched. Reference numeral 28 denotes a packing member joined to the outer side surface of the upright plate portion 25b, which enhances the airtightness of the fitting portion between the slinger 25 and the outer diameter of the inner ring 17.

  In addition to NBR, the seal members 23 and 27 are made of, for example, HNBR (hydrogenated acrylonitrile-butadiene rubber), EPDM (ethylene / propylene rubber), ACM (polyacrylic rubber) having excellent heat resistance. ), FKM (fluoro rubber), silicon rubber, or the like.

  The outer ring 15, the inner rings 16, 17 and the rolling element 19 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching. Further, annular grooves 16d and 16d are formed at the small diameter side ends of the pair of inner rings 16 and 17, and a connecting ring 29 is attached to the annular grooves 16d. This connecting ring 29 is formed by pressing a steel plate such as tool steel or spring steel into a substantially U-shaped cross-section, and as a whole in a ring shape with an end, and the surface is tempered or quenched to a range of 40 to 55 HRC. A curing process is applied. In addition, although the wheel bearing 2 comprised by the double row tapered roller bearing which used the tapered roller for the rolling element 19 was illustrated as the wheel bearing 2 here, it is not restricted to this, The double row which uses the ball for the rolling element An angular ball bearing may be used.

  Here, in the present embodiment, as shown in FIG. 4, a positioning portion 11 is formed on the inner periphery of the end portion on the inner side of the hub wheel 1. The positioning portion 11 is formed on a tapered surface having a predetermined inclination angle θ that gradually decreases in diameter from the fitting portion 10 toward the inner side. On the other hand, the outer ring 15 is formed on the outer periphery of the inner side end portion so as to be in a good fitting state with the hub wheel 1 with a slightly smaller diameter from the outer diameter surface 15b fitted to the fitting portion 10 of the hub wheel 1. A small-diameter portion 15c serving as the escape portion is formed, and a positioning portion 30 that gradually decreases in diameter from the small-diameter portion 15c to the inner side is formed. The positioning portion 30 is formed in a tapered surface having a predetermined inclination angle θ, is fitted to the positioning portion 11 of the hub wheel 1, and is sandwiched between the retaining ring 13 attached to the outer end of the hub wheel 1. In this state, the outer ring 15 is positioned and fixed in the axial direction with respect to the hub wheel 1 (see FIG. 1).

  Thus, in this embodiment, since the hub wheel 1 and the outer ring 15 are provided with the positioning portions 11 and 30 to which the hub wheel 1 and the outer ring 15 are respectively taper-fitted, it is possible to reduce the cost and reduce the weight and the size, and to achieve the wedge effect. It is possible to provide a wheel bearing device with improved creep resistance and improved durability.

  The inclination angle θ is set to 45 ° or less, preferably 5 ° ≦ θ ≦ 45 °. When the inclination angle θ exceeds 45 °, the radial component force of the load applied to the positioning portions 11 and 30 is reduced, the creep resistance is lowered, and the function as a guide surface during assembly to the hub wheel 1 is achieved. Decreases. In addition, when the inclination angle θ is less than 5 °, the positioning accuracy in the axial direction is deteriorated when the hub wheel 1 is assembled.

  Further, in the present embodiment, as shown in FIG. 5, the outer diameter surface 15 b of the outer ring 15 and the positioning portion 30 are simultaneously formed by the grinding with the total-type grindstone 32. Thereby, the coaxiality of the outer diameter surface 15b and the positioning part 30 is ensured, the assemblability is improved, and the positioning accuracy of the outer ring 15 can be increased.

  FIG. 6 is a modification of FIG. As in the above-described embodiment, the positioning portion 11 is formed on the inner periphery of the inner end of the hub wheel 31. The positioning portion 11 is formed on a tapered surface having a predetermined inclination angle θ that gradually decreases in diameter from the fitting portion 10 to the inner side through an annular relief portion 31a. On the other hand, the outer ring 33 is formed with a positioning portion 30 that gradually decreases in diameter toward the inner side from the outer diameter surface 15b fitted to the fitting portion 10 of the hub wheel 31 on the outer periphery of the end portion on the inner side. The positioning portion 30 is formed on a tapered surface having a predetermined inclination angle θ and is fitted to the positioning portion 11 of the hub wheel 31.

  In the present embodiment, the outer diameter surface 15b of the outer ring 33 and the connecting portion 33a of the positioning portion 30 are formed in an arc shape having a predetermined curvature radius Ro. As a result, when the outer ring 33 is press-fitted into the hub wheel 31, it is possible to prevent the occurrence of galling or the like and perform stable assembly.

  Further, as shown in FIG. 7, the outer diameter surface 15b of the outer ring 33, the positioning portion 30 and the connecting portion 33a are simultaneously formed by grinding with a general-purpose grindstone 32 '. As a result, the coaxiality between the outer diameter surface 15b and the positioning portion 30 is secured, the positioning accuracy of the outer ring 33 can be increased, and the dimensions and shape of the connecting portion 33a are stabilized, and it is ensured that galling or the like occurs. Can be prevented.

  In addition, the curvature radius Ro of the connection part 33a is set to 0.5R <= R <= 5.0R. If the radius of curvature Ro of the joint portion 33a is less than 0.5, when the grinding wheel is simultaneously ground while being dressed with a diamond dresser, the grinding wheel may sag and the size and shape may not be stably molded. On the other hand, if it exceeds 5.0, the taper surface of the positioning portion 30 cannot be secured, the width dimension of the outer ring 33 is increased, and this is not preferable because it impedes weight reduction and compactness.

  FIG. 8 shows another modification of FIG. This embodiment differs from the above-described embodiment basically only in that the elastic member 34 is attached to the small-diameter portion 15c of the outer ring 15, but the same parts are the same parts or parts or parts having the same function. Are denoted by the same reference numerals and detailed description thereof is omitted.

  The positioning portion 11 is formed on the inner periphery of the inner side end of the hub wheel 1, and the positioning portion 30 fitted to the positioning portion 11 is connected to the outer periphery of the inner side end through the small diameter portion 15 c from the outer diameter surface 15 b of the outer ring 15. Is formed. An elastic member 34 made of an O-ring or the like is mounted in an annular space formed between the hub wheel 1 and the small diameter portion 15 c of the outer ring 15. Thereby, it can prevent that foreign materials, such as rain water, penetrate | invade into a fitting part, and can improve airtightness.

  FIG. 9 is another modification of FIG. This embodiment basically differs from the above-described embodiment only in the configuration of the positioning portion, and the same reference numerals are given to the same parts or parts having the same function, and detailed description is omitted. To do.

  The positioning portion 11 is formed on the inner periphery of the inner side end of the hub wheel 1, and the positioning portion 30 fitted to the positioning portion 11 is connected to the outer periphery of the inner side end through the small diameter portion 15 c from the outer diameter surface 15 b of the outer ring 15. Is formed. Grease is applied to the contact surface between the positioning portion 11 of the hub wheel 1 and the positioning portion 30 of the outer ring 15 (indicated by a two-dot chain line in the figure). Thereby, it is possible to prevent foreign matters such as rainwater from entering the fitting portion, thereby improving airtightness and improving creep resistance.

  In addition, instead of grease, the sealing agent 35 is applied not only between the contact surfaces of the positioning portion 11 of the hub wheel 1 and the positioning portion 30 of the outer ring 15 but also on the end surface 1 a of the hub wheel 1 and the end surface 15 d of the outer ring 15. You may do it. Thereby, the airtightness of a fitting part can be improved further.

  Examples of the sealing agent 35 include epoxy resin-based, phenol resin-based, polyurethane-based, and polyethylene-based adhesives. Moreover, what is called a liquid gasket may be used. This is a paste-like non-drying property containing a modified ester resin as a main component and can close the fitting portion without peeling (trade name; ThreeBond 1121). In addition to those based on modified ester resins, for example, those based on phenol-based, acrylic-based, or silicon-based resins may be used. Furthermore, a curing putty such as a steel putty or an uncured elastic putty such as a silicone sealing agent may be used.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention is a first-generation wheel bearing device in which a wheel is rotatably supported regardless of inner ring rotation or outer ring rotation, and the outer ring and the inner ring include wheel bearings made of press. Applicable. Of course, the present invention can be applied even when the outer ring and the inner ring are not made of press, and can also be applied to a wheel bearing device having a second generation structure.

DESCRIPTION OF SYMBOLS 1, 31 Hub wheel 2 Wheel bearing 3 Shaft 4 Hub wheel base 5 Wheel mounting flange 6 Car body mounting flange 7 Shoulder part 8 Shaft part 9 Screw part 10 Fitting part 11, 30 Positioning part 12, 16d Annular groove 13 Retaining ring 14 Fixing nuts 15, 33 Outer ring 15a Outer rolling surface 15b Outer ring outer diameter surface 15c Outer ring small diameter part 15d Outer ring end face 16, 17 Inner ring 16a Inner rolling surface 16b Large collar part 16c Small collar part 18 Cage 19 Rolling element 20 Seal on outer side 21 Seal on inner side 22, 26 Core metal 23, 27 Seal member 23a, 23b Radial lip 24 Seal plate 25 Slinger 25a Cylindrical portion 25b Standing plate portion 27a, 27b Side lip 27c Grease lip 28 Packing member 29 Connection Ring 31a Escape portions 32, 32 'Total grinding wheel 34 Elastic member 35 Sealing agent 50 Wheel bearing 51 Wheel 51a Outer rolling surface 52 Inner ring 52a Inner rolling surface 52b Inner ring inner peripheral surface 53 Cage 54 Ball 55 Seal 56 Serration 57 Shaft 58 Shaft portion 59 Screw portion 60 Hub wheel 61 Base portion 62 Wheel mounting flange 63 Bolt hole 64 Brake drum 65 Shoe surface 66 Car body mounting flange 67 Shoulder portion 68 Fitting portion 69 鍔 portion 70 Retaining ring Ro Curvature radius θ of connecting portion Inclination angle of positioning portion

Claims (10)

A hub wheel integrally having a wheel mounting flange for mounting a wheel on one end of a cylindrical base;
A shaft integrally having a vehicle body mounting flange for mounting to the vehicle body;
A wheel bearing fitted between the shaft and the base and rotatably supporting the wheel;
This wheel bearing has an outer ring in which a double row outer rolling surface is integrally formed on the inner periphery,
A pair of inner rings formed on the outer periphery with an inner rolling surface facing the double row outer rolling surface;
In a wheel bearing device comprising a double row rolling element that is slidably accommodated via a cage between both rolling surfaces of the inner ring and the outer ring,
A fitting portion into which the wheel bearing is press-fitted on the inner periphery of the base portion of the hub wheel, and a positioning portion that reduces the diameter from the fitting portion to the inner side are formed, and are gradually formed on the outer periphery of the inner side end portion of the outer ring. Positioning portions that are reduced in diameter on the inner side are formed, and these positioning portions are formed and fitted on a tapered surface having a predetermined inclination angle, and the outer ring is positioned in the axial direction with respect to the hub wheel. A wheel bearing device characterized by that.   The wheel bearing device according to claim 1, wherein an inclination angle θ of the positioning portion is set to 5 ° ≦ θ ≦ 45 °.   The wheel bearing device according to claim 1, wherein a small-diameter portion that is slightly smaller in diameter than the outer-diameter surface of the outer ring is formed, and the positioning portion is formed through the small-diameter portion.   The wheel bearing device according to claim 1, wherein a connecting portion between the outer diameter surface of the outer ring and the positioning portion is formed in an arc shape having a predetermined radius of curvature.   The wheel bearing device according to claim 4, wherein a curvature radius Ro of the joint portion is set to 0.5R ≦ R ≦ 5.0R.   The wheel bearing device according to claim 1, wherein an outer diameter surface and a positioning portion of the outer ring are simultaneously ground by a grindstone.   The wheel bearing device according to claim 1, wherein an annular relief portion is formed in the vicinity of the positioning portion of the hub wheel or the outer ring, and an elastic member is attached to the relief portion.   The wheel bearing device according to claim 1, wherein grease or a sealing agent is applied to contact surfaces of the hub wheel positioning portion and the outer ring positioning portion.   An annular groove is formed in the fitting portion of the hub wheel, and a retaining ring is attached to the annular groove, and the outer ring of the wheel bearing is sandwiched between the retaining ring and the positioning portion in the axial direction. The wheel bearing device according to claim 1, wherein the wheel bearing device is positioned and fixed to the wheel.   The inner ring of the wheel bearing is press-fitted into the shaft part of the shaft, and a threaded part is formed at the end of the shaft part. The inner ring is sandwiched between the shoulder part of the shaft and the fixing nut in the axial direction. The wheel bearing device according to claim 1, wherein a predetermined preload is applied to the wheel bearing by tightening the fixing nut with a predetermined tightening torque.

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