JP2004278804A - Rolling bearing unit for wheels - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a small, lightweight and practical structure.
SOLUTION: A female spline groove 28 formed on a partial inner peripheral surface of a first inner ring member 3a is engaged with a male spline groove 29 formed on a partial outer peripheral surface of a second inner ring member 4a. The cylindrical portion 8a of the first inner ring member 3a is swaged radially outward to form a swaged portion 26, and the first and second inner ring members 3a, 4a are joined together. The remaining inner peripheral surface of the first inner ring member 3a and the remaining outer peripheral surface of the second inner ring member 4a are fitted to each other in the axial direction on both sides in the axial direction of the engaging portion between the two spline grooves 28 and 29 by fitting. I have.
[Selection diagram] Fig. 1

Description

  The rolling bearing unit for a wheel according to the present invention is a rear wheel of an FR vehicle (front-engine rear-wheel drive vehicle), a front wheel of an FF vehicle (front-engine front wheel drive vehicle), and all wheels of a 4WD vehicle (four-wheel drive vehicle). And the like are used to rotatably support the drive wheels with respect to the suspension device.

  In order to rotatably support the wheels with respect to the suspension device, various types of rolling bearing units for wheels are used in which an outer ring and an inner ring are rotatably combined via rolling elements. In addition, a rolling bearing unit for a wheel for supporting the front wheel of an FF vehicle or a 4WD vehicle that is both a steering wheel and a driving wheel is combined with a constant velocity joint, regardless of the steering angle given to the wheel. It is necessary to transmit the rotation of the drive shaft to the wheels smoothly (with constant speed). Further, a rolling bearing unit for a wheel that supports rear wheels of an FR car and a 4WD car may be combined with a constant velocity joint in some cases. A rolling bearing unit for a wheel that can be configured to be relatively small and lightweight in combination with such a constant velocity joint is disclosed in Japanese Patent Application Laid-Open No. H11-163873.

  FIG. 12 shows a conventional structure described in Patent Document 1. The outer ring 1 which is not rotated while being supported by the suspension device in a state of being assembled to the vehicle, has a first mounting flange 2 for supporting the suspension device on the outer peripheral surface, and a double-row outer ring raceway 23 on the inner peripheral surface. 23. Inside the outer ring 1, a hub 5 formed by combining the first and second inner ring members 3, 4 is arranged. The first inner ring member 3 has a second mounting flange 6 for supporting a wheel at one end (leftward in FIG. 12) of the outer peripheral surface, and a second mounting flange 6 at the other end (rightward in FIG. 12). The first inner raceway 7 is formed in a cylindrical shape provided for each. Further, on one end face (left end face in FIG. 12) of the first inner ring member 3, a positioning for positioning the wheel with respect to the hub 5 when the wheel is mounted on the second mounting flange 6. A cylindrical portion 22 is provided. On the other hand, the second inner ring member 4 integrally formed with the drive shaft member has one end (the left end in FIG. 12) as a cylindrical portion 8 for externally fixing the first inner ring member 3. The other end (the right end in FIG. 12) is a housing 9 serving as an outer ring of the constant velocity joint, and a second inner raceway 10 is provided on the outer peripheral surface of the intermediate portion. By providing a plurality of rolling elements 11, 11 between the outer raceways 23, 23 and the first and second inner raceways 7, 10, the hub is provided inside the outer race 1. 5 is rotatably supported.

  At positions where the inner peripheral surface of the first inner race member 3 and the outer peripheral surface of the second inner race member 4 are aligned with each other, locking grooves 12 and 13 are formed, and a retaining ring 14 is formed. The first inner ring member 3 is provided so as to be bridged between the locking grooves 12 and 13 to prevent the first inner ring member 3 from coming out of the second inner ring member 4. Further, a weld 16 is attached to an outer peripheral edge of one end surface (left end surface in FIG. 12) of the second inner race member 4 and an inner peripheral edge of a step portion 15 formed on the inner peripheral surface of the first inner race member 3. The first and second inner ring members 3 and 4 are connected and fixed to each other.

  On the other hand, between the openings at both ends of the outer race 1 and the outer peripheral surface of the intermediate portion of the hub 5, a substantially cylindrical cover 19a, 19b made of metal such as a stainless steel plate and an elastic material made of rubber, elastomer or the like are provided. An annular seal ring 20a, 20b is provided. The covers 19a, 19b and the seal rings 20a, 20b block the portion where the plurality of rolling elements 11, 11 are installed from the outside, and prevent the grease existing in this portion from leaking to the outside. Prevents foreign matter such as rainwater and dust from entering the part. Further, a partition plate portion 21 for closing the inside of the second inner ring member 4 is provided inside the intermediate portion of the second inner ring member 4 so as to secure the rigidity of the second inner ring member 4. Prevents foreign matter that has entered the inside of the second inner ring member 4 from the opening (the left end in FIG. 12) of the second inner ring member 4 from reaching the constant velocity joint provided inside the housing portion 9. are doing.

  When assembling the rolling bearing unit for a wheel configured as described above to a vehicle, the outer ring 1 is supported on the suspension by the first mounting flange 2, and the front wheel, which is also a driving wheel, is firstly mounted by the second mounting flange 6. To the inner ring member 3. Further, a tip end of a driving force transmission shaft (not shown), which is rotationally driven by the engine via a transmission, is spline-engaged with the inside of an inner ring 17 constituting a constant velocity joint. When the automobile is running, the rotation of the inner wheel 17 is transmitted to the hub 5 including the second inner wheel member 4 via the plurality of balls 18 to rotate the front wheel.

JP-A-7-317754

The present invention can be applied to a case where a fitting portion formed at an inner end portion of an outer ring is fitted into a mounting hole of a knuckle constituting a suspension device, and the inner half of the hub can be inserted into the mounting hole of the knuckle. It has been invented to provide a simple rolling bearing unit for wheels.

  The rolling bearing unit for a wheel according to the present invention includes an outer ring, first and second inner ring members, and a plurality of rolling elements, similarly to the above-described conventional rolling bearing unit for a wheel. The outer ring has a first mounting flange for supporting the suspension on the outer peripheral surface, and a double-row outer raceway on the inner peripheral surface. Further, the first inner race member has a second mounting flange for supporting a wheel on an outer peripheral surface of a portion protruding from the outer race, and is opposed to an outer raceway of one end portion of the double row outer raceways. The first inner raceway is provided on the outer peripheral surface of the portion to be formed. The second inner race member has a second inner raceway at an intermediate portion or a portion near one end of the outer peripheral surface, and a housing portion serving as an outer race of a constant velocity joint at the other end. The plurality of rolling elements are provided between the outer raceway and the first and second inner raceways, respectively. Further, a cylindrical portion is formed in at least a part of the inner ring member of the first and second inner ring members in the axial direction, and a cylindrical portion is formed in at least a part of the inner ring member of the other inner ring member. In addition, the first and second inner ring members are connected to each other in a state where the cylindrical portion and the cylindrical portion are fitted to each other.

In particular, in the wheel rolling bearing unit of the present invention, the outer diameter of the housing portion is equal to or less than the outer diameter of the fitting portion for fitting into the mounting hole of the suspension device formed at the end of the outer ring. It is .

In the case of the wheel rolling bearing unit of the present invention configured as described above, when the fitting portion formed at the inner end of the outer ring is fitted into the mounting hole of the knuckle constituting the suspension device, Since the inner half can be inserted into the mounting hole of the knuckle , a compact and lightweight structure can be provided, and a practical rolling bearing unit for a wheel can be provided.

When implementing the present invention, preferably, as described in claim 2, the constant velocity joint is assembled to the housing portion, and the rolling bearing unit for a wheel is mounted to the suspension with the dustproof boot mounted. Further, preferably as described in claim 3, for fitted the ends of the dustproof boot the open end of the housing portion, the coupling sleeve having an outer diameter smaller than the outer diameter of the fitting portion, the opening Fit and fix to the end .

1 to 4 show a first example of a reference example according to the present invention . The outer ring 1, which is fixed to the suspension device and does not rotate when used, has a first mounting flange 2 for supporting the suspension device on the outer peripheral surface, and double-row outer ring raceways 23, 23 on the inner peripheral surface. A hub 5a is arranged inside such an outer ring 1 in the diameter direction. The hub 5a is formed by connecting first and second inner ring members 3a and 4a. The first inner ring member 3a has a second mounting flange 6 for supporting a wheel (not shown) on an outer peripheral surface of a portion (substantially the center portion in the axial direction in the illustrated example) protruding from the outer ring 1. The outer raceway 23 of the double row of outer raceways 23, 23 near the one end (in the illustrated example, the outer raceway near the outer end, which is the outer side in the width direction when assembled to the vehicle, and on the left side in FIG. 1). A first inner raceway 7 is provided on an outer peripheral surface of a portion (the right side portion in FIG. 1) opposed to. In addition, the second inner race member 4a has a second inner raceway 10 at an intermediate portion of the outer peripheral surface, and another end (in the illustrated example, an inner end that is located at the center in the width direction when assembled to a vehicle). In other words, a housing portion 9 serving as an outer ring of the constant velocity joint is provided at the right end of FIG. 1). A plurality of rolling elements 11, 11 are provided between the outer raceways 23, 23 and the first and second inner raceways 7, 10, respectively, and the hub 5a is provided inside the outer race 1. It is rotatably supported.

  The first inner ring member 3a and the second inner ring member 4a have a cylindrical portion 24 at the center in the diameter direction of the first inner ring member 3a, and a half portion near one end in the axial direction of the second inner ring member 4a (see FIG. In the left half of FIG. 1, a rod-shaped portion 25 is formed. A step 27 is formed at the boundary between the housing 9 and the cylindrical portion 25. The first and second inner ring members 3a and 4a fit the cylindrical portion 24 and the cylindrical portion 25 together, and the other end surface (the right end surface in FIG. 1) of the cylindrical portion 24 In a state where it abuts against the step portion 27, it is connected and fixed to each other.

For this purpose, a cylindrical portion 8a is formed at the tip of the cylindrical portion 25. Then, in order to connect and fix the first and second inner ring members 3a and 4a to each other, the distal end portion (the left end portion in FIG. 1) of the cylindrical portion 8a is plastically deformed radially outward to form a caulking portion 26. And Then, the caulked portion 26 is brought into contact with the inner peripheral edge of one end face (the left end face in FIG. 1) of the first inner ring member 3a, and the caulked portion 26 directs the cylindrical portion 24 toward the step portion 27. Strongly restrained. The position and the like of the step 27 are regulated so that an appropriate preload is applied to the rolling elements 11 with the other end surface of the cylindrical portion 24 abutting against the step 27 in this manner. are doing. In order to allow one end surface of the first inner ring member 3a to come into close contact with the step portion 27 over the entire circumference, the radius of curvature r ₂₇ (of the cross section of the inner peripheral edge portion of the step portion ₂₇ ) 4) is smaller (r ₂₇ <r ₂₄ ) than the radius of curvature r ₂₄ (see FIG. 2) of the cross section of the inner peripheral edge at the other end of the cylindrical portion 24 to prevent interference of the portion. I have.

A female spline groove 28 is formed on the inner peripheral surface of the cylindrical portion 24 over the entire length of the inner peripheral surface. The diameter R ₁ (see FIG. 2) of the inscribed circle on the tooth bottom surface of the female spline groove 28 does not change over the entire length, but the diameters R ₂ and R ₃ of the inscribed surface of the tooth tip surface are varied on the way. ing. That is, the diameter R ₂ of the tooth tip surface at one end portion of the cylindrical portion 24 is slightly smaller than the diameter R ₃ of the tooth tip surface at the intermediate portion and the other end portion (R ₂ <R _3). )are doing.

On the other hand, a male spline groove 29 that engages with the female spline groove 28 is formed at an axially intermediate portion of the outer peripheral surface of the cylindrical portion 25. Further, a pair of cylindrical outer peripheral surface portions 30a and 30b are formed at one end and the other end of the cylindrical portion 25 sandwiching the male spline groove 29 from both sides in the axial direction. The diameter D ₁ (see FIG. 4) of the circumscribed circle of the tooth tip surface of the male spline groove 29 is smaller than the diameter R ₁ of the inscribed circle of the tooth bottom surface of the female spline groove 28 (D ₁ <R ₁ ). ing. The diameter D ₂ of the circumscribed circle on the tooth bottom surface of the male spline groove 29 is larger than the diameter R ₂ of the inscribed circle on the tooth tip surface at a portion near one end of the female spline groove 28, and the middle part and the other parts. smaller than the diameter R ₃ of the inscribed circle of at tooth crest on the end portion closer are _{(R 2 <D 2 <R} 3). The outer diameter D ₃ of the cylindrical outer peripheral surface portion 30 a formed at one end of the cylindrical portion 25 of the cylindrical outer peripheral surface portions 30 a and 30 b is closer to one end of the cylindrical portion 24. slightly larger than the diameter R ₂ of the tooth crest is (D _3> R _2). Further, the outer diameter D ₄ of the cylindrical outer peripheral surface portion 30b which is formed at the other end of the circular rod-shaped portion 25 is slightly than the diameter R ₃ of at tip surfaces to near the other end portion of the cylindrical portion 24 (D ₄ > R ₃ ).

  The operation of connecting and fixing the first inner ring member 3a having the cylindrical portion 24 and the second inner ring member 4a having the cylindrical portion 25, each of which is configured as described above, is performed as follows. In a state before the coupling, the caulking portion 26 is not formed at the tip of the cylindrical portion 8a, and the tip of the cylindrical portion 8a is present on the single cylindrical surface with the cylindrical outer peripheral surface 30a at the one end. I do. The lid 31 is not fitted to the wheel insertion guide cylindrical portion 22 formed on one end surface of the first inner ring member 3a, and one end side of the first inner ring member 3a is opened. In this state, the cylindrical portion 25 is pushed into the cylindrical portion 24 from the other end opening side of the cylindrical portion 24 until the step portion 27 abuts against the other end surface of the cylindrical portion 24, and The spline groove 28 and the male spline groove 29 are engaged. In addition, the female spline groove 28 and the male spline groove 29 are engaged with each other, and the cylindrical outer peripheral surface portions 30a and 30b are respectively fitted to the tooth tip surfaces at both axial ends of the female spline groove 28 by interference fitting. Fit.

Then, in a state where the first and second inner ring members 3a and 4a are combined with each other, the distal end of the cylindrical portion 8a is plastically deformed radially outward to form a caulking portion 26, and the first and second inner ring members 3a and 4a are caulked. The second inner ring members 3a, 4a are joined. Finally, the lid 31 is fitted to the cylindrical portion 22. The lid 31 prevents rainwater or the like from entering the inside of the first inner ring member 3a, and prevents the engaging portion between the female spline groove 28 and the male spline groove 29 from rusting. Before the first and second inner ring members 3a, 4a are connected and fixed to each other as described above, a plurality of rolling elements 11 each held by a retainer 32 are provided inside the outer ring 1. , 11 and the seal rings 20a, 20b. In the case of this embodiment , the inner diameters of both ends of the outer ring 1 and the first and second inner ring members 3a and 4a are used so that the same type of seal rings 20a and 20b can be used. The outer diameter and the shape of the portion of the outer peripheral surface of the intermediate portion where the inner peripheral surfaces of both ends of the outer ring 1 face each other are the same (the shape is symmetric). A bank-like projection 35 is formed over the entire circumference at a portion corresponding to the base of the housing portion 9 at the intermediate portion of the second inner ring member 4a. Then, the edge of the projection 35 and the peripheral edge of the opening of the outer ring 1 are brought close to each other to form a labyrinth gap in this portion, thereby improving the sealing performance of the opening at the other end of the outer ring 1. .

Also, the portion shown by the oblique lattice in FIG. 2 on the inner peripheral surface of the cylindrical portion 24 and the portion shown by the oblique lattice in FIG. A hardening process such as quenching is performed to increase the hardness of the portion to a necessary level. A relief groove 33 is formed over the entire circumference at the boundary between the male spline groove 29 and the cylindrical outer peripheral surface 30b at the other end on the outer peripheral surface of the intermediate portion of the cylindrical portion 25. Has formed. The bottom portion of the diameter D ₃₃ of the relief groove 33 is smaller (D ₃₃ <D ₂₎ than the diameter D ₂ of the circumscribed circle of the tooth bottom of the male spline grooves 29. In the case of this example , by forming such a relief groove 33, the processing of the male spline groove 29 can be easily performed.

In the case of the rolling bearing unit for a wheel of the present example configured as described above, the caulking portion 26 prevents separation of the first and second inner ring members 3a and 4a. Further, the torque transmission between the first and second inner ring members 3a, 4a is performed by an engaging portion between the female spline groove 28 and the male spline groove 29. Further, the moment load applied at the time of turning is supported by the fitting portions between the cylindrical outer peripheral surface portions 30a and 30b, which are the cylindrical surface portions on one end side and the other end side, and the tooth tip surfaces at both ends of the female spline groove 28. Therefore, even when used for a long time, the first inner ring member 3a and the second inner ring member 4a can be held in a state in which the relative rotation is reliably prevented, and can be held via the constant velocity joint. The rotation of the wheels can be reliably performed.

  That is, only the force for coupling the first and second inner ring members 3a and 4a is applied to the caulking portion 26, and the force based on the torque transmitted between the two inner ring members 3a and 4a is applied. Also, no force based on the moment load is applied. Therefore, a force in the direction of reducing the diameter of the caulked portion 26 is not applied to the caulked portion 26, and the coupling force between the inner ring members 3a, 4a by the caulked portion 26 is maintained for a long period of time. Can hold enough. Further, the engaging portion between the female spline groove 28 and the male spline groove 29 performs only torque transmission between the first and second inner ring members 3a, 4a, and supports the moment load. Therefore, the bending rigidity of the hub 5a formed by connecting the inner ring members 3a, 4a can be sufficiently ensured. This point will be described with reference to FIGS.

At the time of turning of the vehicle incorporating the wheel rolling bearing unit, the hub 5a has a direction (bending direction) in which the center axis of the first inner ring member 3a is shifted from the center axis of the second inner ring member 4a. Moment load is applied. This moment load is supported by a fitting portion between the cylindrical portion 24 and the cylindrical portion 25. In the case of this example , the moment load is applied to a pair of cylindrical outer peripheral surface portions 30a and 30b provided at positions spaced apart in the axial direction, and a pair of fittings of the tooth tip surfaces at both ends of the female spline groove 28. Joint part supports. Since the pair of fitting portions are disposed on both sides in the axial direction with the spline engaging portion interposed therebetween, the distance L between the centers of these fitting portions (see FIG. 5) is sufficiently large. Since a part of the surface exists in a direction perpendicular to the direction in which the moment load acts, the bending rigidity can be increased. On the other hand, the female spline groove 28 extends over the entire length (without providing the pair of cylindrical outer peripheral surface portions 30a, 30b) at the fitting portion between the cylindrical portion 24 and the cylindrical portion 25. And the male spline groove 29, the bending rigidity cannot be increased.

That is, in order to enable the engagement between the female spline groove 28 and the male spline groove 29, the space between the tooth bottom surface and the tooth tip surface of the female spline groove 28 and the male spline groove 29 is as shown in FIG. In this case, some gaps 34a and 34b must be interposed. Further, in order to transmit a large torque based on the engagement between the female spline groove 28 and the male spline groove 29, the inclination angle θ between the circumferential side surfaces of both spline grooves 28 and 29 and the diametric direction is small. Must. Therefore, the rigidity of the engaging portion between the female spline groove 28 and the male spline groove 29 with respect to the radial load cannot be so large. As a result, as described above, when the female spline groove 28 and the male spline groove 29 are formed over the entire length in the fitting portion between the cylindrical portion 24 and the cylindrical portion 25, Flexural rigidity cannot be increased. In the case of this example, the bending rigidity is sufficiently increased by providing the pair of cylindrical outer peripheral surface portions 30a and 30b.

7 to 10 show a second example of the reference example according to the present invention . In the case of the present example , contrary to the case of the above-described first example , the cylindrical portion 25a is provided on the inner half (the right half in FIG. 7) of the first inner ring member 3b, and the second inner ring member is provided. A cylindrical portion 24a is formed in the outer half of 4b (the left half in FIG. 7). Then, the caulking portion 26a formed at the distal end portion (the right end portion in FIG. 7) of the cylindrical portion 25a is caulked toward the step portion 36 formed on the inner peripheral surface of the intermediate portion of the second inner ring member 4b. The first and second inner ring members 3b, 4b are connected and fixed to each other. The installation positions of the cylindrical portion 25a and the cylindrical portion 24a are reversed. As a result, the positions of the constituent parts of the connecting portion between the inner ring members 3b and 4b are reversed inside and outside in the width direction of the vehicle. Is similar to that of the first example described above, the same reference numerals are given to the same parts, and the duplicate description will be omitted.

FIG. 11 shows an embodiment of the present invention. In the case of the present embodiment, the fitting portion 37 formed at the inner end portion (one end portion on the center side in the width direction when mounted on the vehicle, which is the right end portion in FIG. 11) which is one end portion of the outer race 1 is When fitting into a mounting hole (not shown) of a knuckle constituting a suspension device, an inner half of a hub 5b composed of a first inner ring member 3c and a second inner ring member 4c (right half of FIG. 11) ) Can be inserted through the mounting hole of the knuckle. For this reason, the outer diameter D _9a of the housing portion 9a formed in the inner half portion of the second inner ring member 4c that is closer to one end is set to be equal to or less than the outer diameter D ₃₇ of the fitting portion 37 (D _9a ≦ D _{9a). 37} ). At the opening end of the housing portion 9a, a smaller-diameter mounting portion 38 is formed over the entire periphery, and the mounting portion 38 is provided with a coupling cylinder 39 made of a corrosion-resistant metal plate such as a stainless steel plate. The base half 40 is externally fitted and fixed. The coupling cylinder 39 is formed in a cylindrical shape with a crank-shaped cross section by connecting a large-diameter base half portion 40 and a small-diameter first half portion 41 at a step portion 42. In such a coupling cylinder 39, the step portion 42 abuts against the distal end surface of the mounting portion 38, and the distal edge of the base half portion 40 is the outer periphery of the base end portion (left end portion in FIG. 11) of the mounting portion 38. The second inner ring member 4c is fixed to the inner end of the second inner ring member 4c by caulking in a locking groove 43 formed on the surface. An O-ring 44 is provided between the inner peripheral surface of the base half 40 and the outer peripheral surface of the mounting portion 38, and the rainwater flows into the second inner ring member 4c between the two peripheral surfaces. Etc. are prevented from entering.

In an assembled state to a vehicle, an end of a boot 45 for dustproof and waterproofing is externally fitted and fixed to the first half 41 of the connecting cylinder 39 as described above. That is, the end of the boot 45 is fitted over the first half 41, and the outer peripheral surface of the end is pressed down by the band 46. A concave groove 47 or a ridge is formed on the outer peripheral surface of the intermediate portion of the first half portion 41, and the concave groove 47 or the ridge is engaged with the inner peripheral surface of the end of the boot 45, thereby forming an end of the boot 45. The part is prevented from coming off from the first half part 41. The outer diameter D ₃₉ of the coupling sleeve 39 also has a less outer diameter D ₃₇ of the fitting portion _{37 (D 39 ≦ D 37)} . Although not shown, the constant velocity joint is used not only on the wheel side but also on the reduction gear (differential gear) side. If these two constant velocity joints and the bearings are assembled into a vehicle in an integrated state, assembly by an automobile manufacturer becomes easy. In this case, since a state of assembling the boot 45 and the band 46, the diameter of the circumscribed circle of the band 46 must also be below the outer diameter D ₃₇ of the fitting portion 37. Further, the inner peripheral surface of the mounting portion 38 has a curved shape near the intersection of the ball groove of the constant velocity joint, and the thickness of the locking groove 43 is limited to the extent that the ball can be incorporated into the constant velocity joint. Is as thick as possible. When the length to the tip of the connecting cylinder is increased as in the present embodiment, the joint angle of the constant velocity joint cannot be increased. However, in the case of the rear wheel, a large joint angle is not required. The embodiment is an effective structure for not increasing the outer diameter.

Further, in the illustrated embodiment , a circular concave portion 48 is formed concentrically with the housing portion 9a at the back end of the housing portion 9a. The inner diameter R ₄₈ of the circular recess 48, the outer diameter of the first inner ring member 3c and to couple the second inner ring member 4c, crimping portions 26 formed in the outer end portion of the second inner ring member 4c D is greater than _{26 (R 48> D 26)} . A pedestal (not shown) is fitted into such a circular concave portion 48 at the time of forming the caulked portion 26, and the thrust applied to the second inner ring member 4c when the caulked portion 26 is formed. Receive a load. Because it has the inner diameter R ₄₈ is larger than the outer diameter D _26, carried by Me move rocking the processing of the crimped portion 26, a part the thrust load in the circumferential direction of the second inner ring member 4c Even when only the second inner ring member 4c is added, it is possible to reliably prevent the second inner ring member 4c from being inclined, and to form the high-quality caulked portion 26. Other configurations and operations are the same as those of the first embodiment of the above-described reference example . Therefore, the same reference numerals are given to the same parts, and the duplicate description will be omitted.

Sectional drawing which shows the 1st example of the reference example regarding this invention. FIG. 2 is a partial cross-sectional view showing only a first inner ring member taken out from a portion A in FIG. 1. The figure seen from the left of FIG. FIG. 2 is a partial cross-sectional view showing only a second inner ring member taken out from a portion A in FIG. 1. FIG. 5 is a partial cross-sectional view for explaining a state in which rigidity against a moment load can be secured. FIG. 6 is a sectional view taken along line BB of FIG. 5. Sectional drawing which shows the 2nd example of the reference example regarding this invention. FIG. 8 is a partial cross-sectional view showing only a first inner ring member taken out of a portion C in FIG. 7. FIG. 8 is a partial cross-sectional view showing only a second inner ring member taken out from a portion C in FIG. 7. The figure seen from the right of FIG. FIG. 2 is a partial cross-sectional view showing an embodiment of the present invention. FIG. 7 is a partial cross-sectional view showing one example of a conventional structure.

Explanation of reference numerals

Reference Signs List 1 outer ring 2 first mounting flange 3, 3a, 3b, 3c first inner ring member 4, 4a, 4b, 4c second inner ring member 5, 5a, 5b hub 6 second mounting flange 7 first inner ring track 8, 8a Cylindrical part 9, 9a Housing part 10 Second inner ring raceway 11 Rolling element 12 Locking groove 13 Locking groove 14 Retaining ring 15 Step 16 Welding 17 Inner ring 18 Ball 19a, 19b Cover 20a, 20b Seal ring 21 Separation Plate portion 22 Cylindrical portion 23 Outer ring raceway 24, 24a Cylindrical portion 25, 25a Cylindrical portion 26, 26a Caulking portion 27 Step portion 28 Female spline groove 29 Male spline groove 30a, 30b Cylindrical outer peripheral surface portion 31 Lid 32 Cage 33 Evacuation groove 34a, 34b Gap 35 Projection 36 Step 37 Fitting part 38 Attachment part 39 Joining cylinder 40 Base half 41 First half 42 Step 43 Stop groove 44 O-ring 45 Boot 46 Band 47 Groove 48 Circular concave

Claims (2)

  A first mounting flange for supporting the suspension on the outer peripheral surface, an outer ring having a double row of outer ring tracks on the inner peripheral surface, and a second for supporting the wheel on the outer peripheral surface of a portion protruding from the outer ring. A first inner ring member provided with a second mounting flange, a first inner ring member on an outer peripheral surface of a portion of the double row outer ring member facing the outer ring member near one end, and an intermediate member between the outer peripheral surface. A second inner ring member having a second inner raceway at a portion or a portion near one end, and a housing portion serving as an outer race of a constant velocity joint at the other end, the respective outer raceways and the first and second inner races. A plurality of rolling elements respectively provided between the raceway, a cylindrical portion in at least a part of the inner ring member in the axial direction of one of the first and second inner ring members, the other inner ring member At least partly in the axial direction, a cylindrical part In the rolling bearing unit for a wheel connecting the first and second inner ring members with the cylindrical portion and the cylindrical portion fitted to each other, A cylindrical portion is formed at the tip of the portion, and a female spline groove is provided at least in the axial center of the inner peripheral surface of the cylindrical portion, and at least in the axial center of the outer peripheral surface of the cylindrical portion. Male spline grooves that engage with the female spline grooves are formed, respectively, and at least one of the inner peripheral surface of one end of the cylindrical portion and the outer peripheral surface of one end of the rod-shaped portion has A cylindrical surface on one end side is formed so as to fit without looseness with the peripheral surface on the other side, and at least one of the inner peripheral surface on the other end of the cylindrical portion and the outer peripheral surface on the other end of the cylindrical portion is formed. On the other side, the other end side cylindrical surface that fits without looseness on the mating peripheral surface The first inner ring member and the second inner ring member are formed so that the female spline groove and the male spline groove engage with each other, and the one end cylindrical surface and the mating peripheral surface are separated from each other by the other With the end cylindrical surface and the mating peripheral surface fitted to each other, the distal end of the cylindrical portion is plastically deformed diametrically outward to form a caulked portion, and the caulked portion serves as the one inner ring member. A rolling bearing unit for a wheel, characterized in that a part of the rolling bearing unit is directed toward the other inner ring member in the axial direction. The outer diameter of the housing part that becomes the outer ring of the constant velocity joint is smaller than the outer diameter of a part of the outer ring closer to the other end than the first mounting flange, and the end of the dustproof boot is located at the open end of the housing part. The wheel according to claim 1, wherein a connecting cylinder having an outer diameter smaller than an outer diameter of a portion closer to the other end than the first mounting flange is fitted and fixed in a part of the outer ring in order to externally fit. Rolling bearing unit.

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