JP2020050267A - Wheel bearing device - Google Patents

Abstract

To provide a wheel bearing device of an outer ring rotation type which can give face deflection accuracy to a flange face of a wheel fitting flange of an outer member.SOLUTION: A wheel bearing device 1 comprises: an inner member 2 as a stationary side member; an outer member 3 as a rotation side member which has a wheel fitting flange 14 for fitting a wheel to an outer periphery thereof, and has an annular pilot part 15 which projects to an out-board side from a base end part on an inner diameter side of the wheel fitting flange 14; and rolling elements 4, 5 of two rows which are so accommodated between the inner member 2 and the outer member 3 as to be capable of freely rolling. In the device, the pilot part 15 has a concaved notch part 20 which is opened to the out-board side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bearing device for a wheel, particularly to a so-called outer ring rotating type in which an outer member rotates together with a wheel.

  A wheel bearing device that supports wheels of an automobile or the like includes an inner member and an outer member that are relatively rotatable via rolling elements, and one of the inner member and the outer member is fixed to the vehicle body. The other is a rotating side member attached to the wheel.

  The inner member is a rotating member, and the outer member is a fixed member. The inner member is a rotating member. The inner member is a fixed member and the outer member is a rotating member. Called. In the case of the inner ring rotating type, a wheel mounting flange for mounting a wheel is provided on the inner member, and in the case of the outer ring rotating type, the wheel mounting flange is provided on the outer member.

  There are two types of wheel bearing devices, one for driving wheels and the other for driven wheels. For structural reasons, inner ring rotating type is adopted for driving wheels, and both inner ring rotating type and outer ring rotating type are used for driven wheels. Is adopted.

  Here, in the case of a wheel bearing device mounted on a luxury car or the like, it is important to suppress the occurrence of brake judder which adversely affects the steering stability and silence of the vehicle. One of the causes of the occurrence of brake judder is the runout of the wheel mounting flange. Therefore, in order to suppress the occurrence of brake judder due to the runout, a high runout accuracy is required for the flange surface of the wheel mounting flange.

  In order to satisfy such demands, in an inner ring rotation type wheel bearing device, after assembling an inner member, an outer member and a rolling element, a flange of a wheel mounting flange of the inner member is rotated while rotating the inner member. In some cases, a surface is turned (for example, see Patent Document 1). Thereby, the surface runout accuracy of the flange surface can be improved.

  Similarly, in order to satisfy the above requirements, even in an outer ring rotating type wheel bearing device, after assembling the inner member, the outer member and the rolling element, the wheel mounting flange of the outer member is rotated while rotating the outer member. Turning the flange surface is conceivable, but it is more difficult than the inner ring rotation type for structural reasons.

  Therefore, Patent Literature 2 discloses that a rib is provided on an inner diameter surface of a pilot portion that protrudes to the outboard side from a base end portion on the inner diameter side of a wheel mounting flange of an outer member. The rib functions as a rivet for receiving a rotational driving force. When turning the flange surface of the wheel mounting flange of the outer member, the driving jig can be hooked on the rib to apply the rotational driving force to the outer member. . As a result, since the flange surface of the wheel mounting flange of the outer member can be turned while rotating the outer member, the runout accuracy of the flange surface of the wheel mounting flange can be improved even in the case of the outer ring rotating type.

JP 2007-0445305 A JP 2015-189267 A

  The rib disclosed in Patent Document 2 protrudes radially inward from the inner diameter surface of the pilot portion. Therefore, when applying a rotational driving force by the driving jig, there is a possibility that stress concentration occurs at the root portion of the rib (the connection portion between the rib and the pilot portion). As a result, if the ribs are damaged, it becomes difficult to rotate the outer member when turning the flange surface of the wheel mounting flange, and it becomes impossible to impart high surface runout accuracy to the flange surface.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an outer ring rotation type wheel bearing device capable of imparting high surface runout accuracy to a flange surface of a wheel mounting flange of an outer member.

  The present invention created to solve the above-described problem has an inner member serving as a fixed side member, and a wheel mounting flange for mounting a wheel on the outer periphery, and from a base end portion on the inner diameter side of the wheel mounting flange. An outer member which has an annular pilot portion protruding toward the outboard side, and serves as a rotating member, and a double-row rolling element rotatably accommodated between the inner member and the outer member, In the wheel bearing device provided, the pilot portion has a concave cutout portion opened to the outboard side. With this configuration, in a state where the wheel bearing device is assembled, the driving member for turning can be attached to the notch provided in the pilot portion, and the outer member can be rotated. That is, in a state where the wheel bearing device is assembled, the flange surface of the wheel mounting flange of the outer member can be turned while rotating the outer member, so that high run-out accuracy can be imparted to the flange surface. The notch is a concave portion formed in the pilot portion, and is not a convex portion that protrudes inward in the radial direction like a rib. For this reason, when applying a rotational driving force by the driving jig, a situation in which stress is generated in the notch portion and the outer member is damaged is less likely to occur. Since the weight of the outer member lightened by the notch portion is reduced by the amount of the notch portion, the moment of inertia when the outer member is rotated can be reduced. Therefore, improvement in the running performance and fuel efficiency of the vehicle can be expected.

  In the above configuration, it is preferable that a plurality of notches are provided at intervals in the circumferential direction of the pilot portion. With this configuration, when turning the flange surface of the wheel mounting flange of the outer member, the rotational jig of the driving jig and the outer member can be easily and quickly aligned in a short time.

  In the above configuration, it is preferable that the notch is provided at a position facing the diametrical direction of the pilot portion. With this configuration, the rotational driving force from the driving jig can be evenly transmitted to the outer member.

  In the above configuration, it is preferable that the connecting portion between the side wall surface of the notch portion and the outer diameter surface of the pilot portion is chamfered. With this configuration, it is possible to prevent burrs from being generated on the outer diameter surface of the pilot portion due to an impact when the drive jig is attached to the cutout portion. If burrs are generated on the outer diameter surface of the pilot portion, the assemblability of the wheels and the brake rotor may be deteriorated. However, with the above configuration, the occurrence of burrs can be prevented. Can be maintained.

  In the above configuration, it is preferable that the connection between the side wall surface of the notch portion and the inner diameter surface of the pilot portion is chamfered. With this configuration, it is possible to prevent burrs from being generated on the inner diameter surface of the pilot portion due to an impact when the driving jig is attached to the cutout portion.

  In the above configuration, it is preferable that the connecting portion between the side wall surface of the notch portion and the distal end surface of the pilot portion is chamfered. In this way, when the driving jig is inserted into the cutout from the outboard side, it is possible to prevent the driving jig from hitting the cutout and causing a dent or a scratch.

  ADVANTAGE OF THE INVENTION According to this invention, the outer ring rotation type wheel bearing device which can provide high runout accuracy to the flange surface of a wheel mounting flange can be provided.

It is a longitudinal section of a bearing device for wheels showing an embodiment of the present invention. FIG. 2 is a view taken in the direction of arrow A in FIG. 1 and shows a pilot unit of the wheel bearing device according to the present embodiment. FIG. 2 is a view taken in the direction of arrow A in FIG. 1 and shows a pilot portion of a wheel bearing device according to a modification of the present embodiment. FIG. 3 is an enlarged view of a region B in FIG. 2, showing a cutout portion of a pilot portion of the wheel bearing device according to the present embodiment and the vicinity thereof. FIG. 3 is a view taken in the direction of arrow C in FIG. 2, showing a cutout portion of a pilot portion of the wheel bearing device according to the present embodiment and the vicinity thereof. It is a longitudinal cross-sectional view which shows the process of turning the flange surface of the wheel mounting flange of the wheel bearing apparatus which shows embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the side closer to the outside of the vehicle when assembled to the vehicle is referred to as the outboard side (left side in FIG. 1), and the side closer to the center is referred to as the inboard side (right side in FIG. 1).

  As shown in FIG. 1, a bearing device 1 for a wheel is a third-generation bearing device for a driven wheel (outer ring rotating type), and includes an inner member 2 serving as a fixed member and an outer member serving as a rotating member. It has a member 3 and two rows of rolling elements 4 and 5 rotatably accommodated between the inner member 2 and the outer member 3.

  The inner member 2 includes a hub wheel 6 and an inner ring 7 separate from the hub wheel 6.

  The hub wheel 6 has a large-diameter portion 8 formed on the inboard side, and a small-diameter portion 9 formed on the outboard side and connected to the large-diameter portion 8 via a step. An inner raceway surface 10 on the inboard side is formed on the outer periphery of the large diameter portion 8.

  The inner race 7 is press-fitted (tightly fitted) to the outer periphery of the small-diameter portion 9, and the end face on the inboard side is abutted against the shoulder 11 rising from the inboard side of the outer periphery of the small-diameter portion 9 in the radial direction. I have. In this state, the inner race 7 is fixed in the axial direction by a caulking portion 12 formed by plastically deforming the end of the small diameter portion 9 on the outboard side. An inner raceway surface 13 on the outboard side is formed on the outer periphery of the inner race 7.

  The outer member 3 has a wheel mounting flange 14 on the outer periphery of an end on the outboard side, and an annular pilot portion protruding from the base end (root portion) on the inner diameter side of the wheel mounting flange 14 to the outboard side. 15 The outer member 3 has a cylindrical hollow structure, and has an inner periphery thereof facing an inboard side outer race surface 22 facing the inner race surface 10 of the hub wheel 6 and an inner race surface 13 of the inner race 7. The outer raceway surface 23 on the outboard side is formed. Further, a pulsar ring 28, which is a component of a wheel rotation speed detection sensor, is attached to an end of the outer member 3 on the inboard side.

  The wheel mounting flange 14 is for mounting a wheel (not shown). Therefore, a plurality of bolt holes 16 for fixing a hub bolt (not shown) are formed in the wheel mounting flange 14, and a thick rib 17 is formed around the bolt hole 16. The ribs 17 can reduce the weight and increase the rigidity of the outer member 3, and can secure sufficient strength even when a large bending moment load is applied to the wheel mounting flange 14.

  The outer peripheral surface of the pilot portion 15 is a stepped cylindrical shape, and the small diameter portion 18 plays a role of guiding and centering when mounting the wheel, and the large diameter portion 19 guides and centering when mounting the brake disc. Play a role.

  The pilot portion 15 is formed with a concave cutout portion 20 which is open to the outboard side. Since the outer member 3 can be rotated by hooking the driving jig X in the notch portion 20, after assembling the wheel bearing device 1, the flange surface 21 of the wheel mounting flange 14 is turned to form a flange surface. 21 can be given high surface runout accuracy (for example, see FIG. 6). That is, the notch 20 has a function of receiving a rotational driving force when turning the flange surface 21. In addition, the depth and width (dimension in the circumferential direction) of the cutout portion 20 can be arbitrarily set as long as the function of receiving the rotational driving force from the driving jig X can be maintained.

  The rolling element 4 on the inboard side is accommodated between the inner raceway surface 10 of the inner member 2 (hub wheel 6) and the outer raceway surface 22 of the outer member 3 on the inboard side, and is rolled by the retainer 24. It is movably held. The rolling element 5 on the outboard side is accommodated between the inner raceway surface 13 of the inner member 2 (the inner race 7) and the outer raceway surface 23 of the outer member 3 on the outboard side, and is rolled by the retainer 25. It is freely held.

  The pitch circle diameter of the rolling elements 5 on the outboard side is smaller than the pitch circle diameter of the rolling elements 4 on the inboard side. Therefore, although the sizes of the rolling elements 4 and 5 are the same, the number of the rolling elements 4 on the inboard side is larger than the number of the rolling elements 5 on the outboard side due to the difference in pitch circle diameter.

  Each of the rolling elements 4 and 5 is an angular contact and constitutes a back-to-back double row angular contact ball bearing. Therefore, a radial load and an axial load in both directions can be applied.

  A seal 26 is attached to an opening on the inboard side of the annular space formed between the inner member 2 and the outer member 3. Inner circumference of outer member 3 (more specifically, inner circumference of outer member 3 located on the inboard side of pilot portion 15 and on the outboard side of the end of inner member 2 on the outboard side) ), A hub cap 27 is attached. The seal 26 and the hub cap 27 prevent the lubricant (grease) sealed in the bearing from leaking to the outside, and prevent rainwater, dust, and the like from entering the bearing from the outside.

  Here, a mortar-shaped recess 29 is formed at the inboard end of the large diameter portion 8 of the hub wheel 6. The depth of the concave portion 29 is set to be near the shoulder portion 11, and the large diameter portion 8 of the hub wheel 6 has a substantially uniform thickness. This makes it possible to reduce the weight while maintaining the strength of the hub wheel 6. In the present embodiment, the large diameter portion 8 is a vehicle body attachment portion, and the large diameter portion 8 has a plurality of bolt holes 30 formed therein. These bolt holes 30 are for fastening the inner member 2 to a vehicle body side such as a knuckle (housing) using a fixing bolt.

  As shown in FIG. 2, the notch portion 20 of the pilot portion 15 has a pair of side wall surfaces 20 a facing in the circumferential direction of the pilot portion 15 (the rotation direction of the outer member 3), and a bottom wall surface connecting these side wall surfaces 20 a. 20b. In the present embodiment, the notches 20 are provided at two locations in the circumferential direction of the pilot portion 15. The notch portions 20 provided at two locations face each other in the diametrical direction of the pilot portion 15. In this way, since a plurality of notches 20 are provided, when turning the flange surface 21 of the wheel mounting flange 14, the rotational jig of the driving jig X and the outer member 3 can be easily and shortly aligned. Can be done in time. In addition, since the notch portion 20 is provided at a position facing the diametrical direction of the pilot portion 15, the rotational driving force from the driving jig X can be evenly transmitted to the outer member 3.

  The number of the cutout portions 20 is not particularly limited as long as the cutout portions 20 are formed in at least one portion of the pilot portion 15. For example, as shown in FIG. 3, the cutout portions 20 may be formed at three or more locations of the pilot portion 15. In the illustrated example, the cutout portions 20 are formed at four positions in the circumferential direction of the pilot portion 15, and the cutout portions 20 formed at two of the cutout portions 20 are in the first direction which is the diametric direction of the pilot portion 15. The notch portions 20 formed at the remaining two locations are in the diametric direction of the pilot portion 15 and face each other in a second direction orthogonal to the first direction. That is, when a plurality of cutouts 20 are provided, it is advantageous to arrange the cutouts 20 at equal intervals in the circumferential direction (in the illustrated example, every central angle of 90 degrees) in consideration of the rotational balance of the outer member 3. .

  The shape of the driving jig X is not particularly limited as long as it can be engaged with the notch 20. In the present embodiment, the tip of the driving jig X can be inserted into the notch 20. It has a plate shape. More specifically, the thickness of the plate-shaped distal end of the driving jig X is smaller than the circumferential dimension of the bottom wall surface 20 b of the notch 20.

  As shown in FIG. 4, a connection portion 31 between the side wall surface 20 a of the notch portion 20 and the outer diameter surface 15 a of the pilot portion 15 and a connection portion 32 between the side wall surface 20 a of the notch portion 20 and the inner diameter surface 15 b of the pilot portion 15. Are preferably chamfered. Of course, as in the illustrated example, the entire side wall surface 20a including the connection portions 31 and 32 may be an R surface. By doing so, it is possible to prevent burrs from being generated on the outer diameter surface 15a and the inner diameter surface 15b of the pilot portion 15 due to an impact when the driving jig X is attached to the notch portion 20. In particular, when burrs are generated on the outer diameter surface 15a of the pilot portion 15, there is a possibility that the assemblability of the wheels and the brake disc may be deteriorated. Therefore, the outer diameter side connection portion 31 is preferably chamfered as described above. . Note that the chamfers of the connection portions 31 and 32 are not limited to the R chamfers, but may be other chamfer shapes such as C chamfers. In addition, the connection part 31 and / or the connection part 32 may be configured, for example, as a right angle part without chamfering.

  As shown in FIG. 5, in the present embodiment, the connecting portion 33 between the side wall surface 20a of the notch portion 20 and the distal end surface (outboard side end surface) 15c of the pilot portion 15 is chamfered. In this way, when the driving jig X is inserted into the notch 20 from the outboard side, it is possible to prevent the driving jig X from hitting the notch 20 and causing dents and scratches. Note that the chamfering of the connection portion 33 is not limited to the R chamfering, but may be another chamfering shape such as a C chamfering. Further, the connection portion 33 may be formed of, for example, a right angle portion without being chamfered. Further, the connecting portion between the side wall surface 20a and the bottom wall surface 20b of the notch portion 20 is formed as a right angle portion in the present embodiment, but may be formed in an R shape.

  Next, a method of manufacturing the wheel bearing device 1 configured as described above will be described.

  The manufacturing method of the wheel bearing device 1 includes a process of forming the notch portion 20 in the pilot portion 15, a process of assembling the wheel bearing device 1, and a process of turning the flange surface 21 of the wheel mounting flange 14. Prepared in order.

  The step of forming the notch 20 is preferably performed simultaneously with the step of forging the outer member 3. That is, in the process of forging the outer member 3, it is preferable that the notch portion 20 is also forged at the same time. The notch 20 is not limited to the case where the outer member 3 is formed by forging, but may be formed by cutting, for example.

  In the step of assembling the wheel bearing device 1, the outer member 3, the inner member 2, the rolling elements 4, 5, and the like are assembled in a predetermined procedure. An example of the assembling procedure includes the following procedure.

  First, the inboard-side rolling elements 4 and the retainer 24 are assembled to the inboard-side outer raceway surface 22 of the outer member 3. Next, the hub wheel 6 is inserted through the inside of the assembled rolling element 4 with the small-diameter portion 9 side as the head, and the rolling element 4 is seated on the inner raceway surface 10 of the hub wheel 6. After that, the retainer 25 is arranged on the outer raceway surface 23 on the outboard side of the outer member 3, and the rolling element 5 on the outboard side is incorporated. In this state, the inner ring 7 is press-fitted into the small-diameter portion 9 of the hub wheel 6, and the end of the small-diameter portion 9 is plastically deformed to form a caulked portion 12. Fix it.

  In the step of turning the flange surface 21, as shown in FIG. 6, the flange surface 21 of the wheel mounting flange 14 is turned while the wheel bearing device 1 is assembled as described above. Specifically, in a state where the inner member 2 is fixed by the fixing jig Y, the outer member 3 is rotated by the driving jig X. At this time, as shown in FIGS. 2 and 3, the driving jig X is hooked on the notch 20 of the pilot portion 15, and the rotational driving force is applied so that the outer member 3 rotates in the direction of the arrow in the drawing. introduce. Then, while rotating the outer member 3 in this manner, the cutting tool Z is fed in the radial direction of the wheel mounting flange 14 to turn the flange surface 21 of the wheel mounting flange 14.

  By turning the flange surface 21 of the wheel mounting flange 14 in the state where the wheel bearing device 1 is assembled in this way, regardless of the dimensional errors and the assembly errors of the components of the wheel bearing device 1, the wheel bearings are turned. The axial runout (plane runout) of the flange surface 21 of the wheel mounting flange 14 during rotation of the device 1 can be sufficiently reduced. Since the flange surface 21 is a surface on which the brake disk is mounted, the runout of the pad sliding surface of the brake disk can be extremely reduced.

  Further, the notch 20 is not shaped so that stress concentration is likely to occur at the root portion like a member protruding inward in the radial direction, so that when the driving jig X applies the rotational driving force, the notch 20 , The outer member 3 is unlikely to be damaged.

  Furthermore, since the weight of the outer member 3 can be reduced by the amount corresponding to the notch portion 20, the moment of inertia of the outer member 3 during rotation of the wheel bearing device 1 is reduced, and the running performance and fuel efficiency of the vehicle are improved. Can be expected. Further, when the notch 20 is forged, for example, the material can be reduced by the amount corresponding to the notch 20, so that the material cost can be reduced.

  The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described operation and effect. The present invention can be variously modified without departing from the gist of the present invention.

  In the above embodiment, the case where each of the rolling elements 4 and 5 is a ball has been described. However, the present invention is not limited to this, and may be, for example, tapered rollers. Of course, the shape of the raceway surface is appropriately changed according to the shape of the rolling element.

DESCRIPTION OF SYMBOLS 1 Wheel bearing device 2 Inner member 3 Outer member 4 Rolling element 5 Rolling element 6 Hub wheel 7 Inner ring 14 Wheel mounting flange 15 Pilot section 20 Notch section 21 Flange surface X Drive jig Y Fixing jig Z Cutting tool

Claims (6)

An inner member serving as a fixed side member,
An outer member that has a wheel mounting flange for mounting a wheel on the outer periphery, has an annular pilot portion that protrudes toward the outboard side from a base end portion on the inner diameter side of the wheel mounting flange, and a rotating side member,
A double-row rolling element rotatably housed between the inner member and the outer member,
A bearing device for a wheel, wherein the pilot portion has a concave cutout portion that opens to the outboard side.   2. The wheel bearing device according to claim 1, wherein a plurality of the notches are provided at intervals in a circumferential direction of the pilot portion. 3.   The wheel bearing device according to claim 2, wherein the notch portion is provided at a position facing the pilot portion in a diametrical direction.   The wheel bearing device according to any one of claims 1 to 3, wherein a connecting portion between a side wall surface of the notch portion and an outer diameter surface of the pilot portion is chamfered.   The wheel bearing device according to any one of claims 1 to 4, wherein a connecting portion between a side wall surface of the notch portion and an inner diameter surface of the pilot portion is chamfered.   The wheel bearing device according to any one of claims 1 to 5, wherein a connection portion between a side wall surface of the notch portion and a front end surface of the pilot portion is chamfered.

Images