JP6754384B2 - Wheel bearing device - Google Patents

Description

The present invention relates to a bearing device for a wheel. More specifically, the present invention relates to a wheel bearing device having improved sealing performance of an outer member.

Conventionally, there is known a wheel bearing device provided with a rotation speed detection device that rotatably supports wheels in a suspension device such as an automobile and detects the rotation speed of the wheels. In the wheel bearing device, the hub wheel connected to the wheel is rotatably supported via a rolling element. Further, the rotation speed detection device of the wheel bearing device is composed of an encoder ring and a magnetic sensor in which different magnetic poles are alternately magnetized in the circumferential direction. In the wheel bearing device, the encoder ring is fixed to the hub wheel, and the magnetic sensor is arranged in a portion that does not rotate together with the hub wheel. The wheel bearing device can detect the rotation speed of the wheel connected to the hub wheel from the interval of the change in magnetism when the encoder ring rotating with the hub wheel passes near the magnetic sensor.

Some bearing devices for wheels have a cover that protects the encoder ring in order to prevent damage to the encoder ring of the rotation speed detection device due to flying stones, etc., and false detection due to adhesion of mud, magnetic material, etc. .. The encoder ring is sealed inside the outer ring by covering the opening of the outer ring of the wheel bearing device with a non-magnetic cover. For example, as described in Patent Document 1.

The wheel bearing device described in Patent Document 1 includes a cylindrical protective cover that covers a pulsar ring (encoder ring), a rotation speed sensor (magnetic sensor), and a cylindrical sensor cap that supports the rotation speed sensor. A protective cover provided with a sealing member is fitted in the opening of the outer member on the pulsaring side, and a sensor cap is fitted on the outside thereof. As a result, the wheel bearing device not only protects the magnetic pulsaring of the rotation speed detection device from mud and magnetic materials by the highly airtight protective cover and sensor cap, but also reduces damage due to flying stones and the like. In the wheel bearing device, a fitting portion of the protective cover, a contact portion of the sealing member of the protective cover, and a fitting portion of the sensor cap are formed on the inner circumference of the opening of the outer member on the pulsaring side, and the inner diameters are sequentially increased. It is configured to be large. That is, a plurality of steps are formed on the inner circumference of the opening of the outer member on the pulsaring side. For this reason, in the wheel bearing device, when attaching the protective cover to the outer member, it is necessary to perform complicated processing on the inner circumference of the opening of the outer member so that the seal member will not be damaged even if it comes into contact with the step. It was.

Japanese Unexamined Patent Publication No. 2015-68454

The present invention has been made in view of the above circumstances, and prevents damage to the sealing member of the protective cover without performing complicated processing on the inner opening of the outer member, and improves the sealing performance of the protective cover. It is an object of the present invention to provide a bearing device for wheels that can be maintained.

That is, in the wheel bearing device, an outer member having a double row of outer rolling surfaces integrally formed on the inner circumference and a wheel mounting flange for mounting the wheel at one end thereof are integrally provided, and the outer circumference and other parts are provided. It consists of a hub wheel having a small-diameter step portion extending in the axial direction at the end and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and is a double-layered surface facing the outer rolling surface of the double-row. An inner member on which an inner rolling surface of a row is formed, a double-row rolling element rotatably housed between the rolling surfaces of the inner member and the outer member, and the outer member. A cylindrical protective cover that is fitted to the inner circumference of the inner opening of the member and is provided with an annular sealing member on the outer peripheral surface, and the protective cover that is the inner circumference of the inner opening of the outer member. In a wheel bearing device provided with a cylindrical sensor holder fitted to the outer side, the inner circumference of the inner side opening of the outer member is sequentially arranged from the inner side end toward the axial outer side. A sensor holder fitting portion into which the sensor holder is fitted, a seal portion with which the seal member of the protective cover comes into contact, and a protective cover fitting portion into which the protective cover is fitted are formed, and the inner diameter of the seal portion is formed. Is an inner diameter larger than the inner diameter of the protective cover fitting portion, the same inner diameter as the inner diameter of the sensor holder fitting portion, and the seal portion and the sensor holder fitting portion are adjacent to each other. is there.

In the wheel bearing device, the outer peripheral surface of the protective cover is formed of a large diameter portion, a tapered portion connected to the large diameter portion, and a small diameter portion connected to the tapered portion, and the tapered portion and the small diameter portion are formed. The seal member is formed to have an outer diameter larger than the inner diameter of the seal portion of the outer member, and the large diameter portion is fitted to the protective cover fitting portion of the outer member.

In a wheel bearing device, an annular protrusion that protrudes outward in the radial direction is formed on the seal member.

In the wheel bearing device, the annular protrusion of the seal member is formed in a lip shape.

In the wheel bearing device, a collar portion is formed in the middle of the outer peripheral surface of the sensor holder, the outer peripheral surface is fitted to the sensor holder fitting portion of the outer member, and the collar portion is the outer member. The fitting position of the sensor holder is determined by contacting the end face of the sensor holder.

As the effect of the present invention, the following effects are exhibited.

That is, according to the present invention, there is no step in the range through which the seal member of the protective cover passes on the inner peripheral surface of the inner side opening of the outer member. As a result, damage to the sealing member can be prevented without complicated processing of the inner opening of the outer member, and the sealing property of the protective cover can be maintained. Further, the outer diameter of the inner opening is formed to be small by reducing the sensor holder fitting portion of the inner opening toward the inside in the radial direction to eliminate the step. As a result, the weight of the outer member can be reduced.

According to the present invention, by connecting the large-diameter portion and the small-diameter portion of the protective cover with a tapered portion, an increase in rigidity on the small-diameter side of the large-diameter portion is suppressed, so that the shape of the large-diameter portion is inside the outer member. Easy to fit on the mating surface. As a result, damage to the sealing member can be prevented without complicated processing of the inner opening of the outer member, and the sealing property of the protective cover can be maintained.

According to the present invention, the frictional resistance generated when the seal member of the protective cover slides between the seal portion of the inner side opening of the outer member and the sensor holder fitting portion is suppressed. As a result, damage to the sealing member can be prevented without complicated processing of the inner opening of the outer member, and the sealing property of the protective cover can be maintained.

According to the present invention, it is not necessary to provide a step on the inner circumference of the outer member in order to determine the fitting position of the sensor holder. As a result, damage to the sealing member can be prevented without complicated processing of the inner opening of the outer member, and the sealing property of the protective cover can be maintained.

The perspective view which shows the whole structure in one Embodiment of the wheel bearing device which concerns on this invention. (A) A cross-sectional view showing an overall configuration according to an embodiment of a wheel bearing device according to the present invention, (b) an enlarged cross-sectional view of a portion A in FIG. 2 (a). (A) An enlarged partial cross-sectional view of a protective cover according to an embodiment of a wheel bearing device according to the present invention, and (b) an enlarged partial cross-sectional view of a sensor holder. The enlarged partial sectional view which shows the shape of the fitting hole of the outer ring in one Embodiment of the bearing device for a wheel which concerns on this invention. (A) An enlarged partial cross-sectional view showing a state in which a large diameter portion of the protective cover is inserted into the fitting hole of the outer ring in one embodiment of the wheel bearing device according to the present invention, and (b) the protective cover is also fitted in the fitting hole. An enlarged partial sectional view showing a state in which the seal portion is inserted into the wheel. (A) An enlarged partial cross-sectional view showing a state in which a large diameter portion of the protective cover is fitted in a fitting hole of an outer ring and a state in which a sensor holder is inserted in one embodiment of the wheel bearing device according to the present invention. b) Similarly, an enlarged partial cross-sectional view showing a state in which the protective cover and the sensor holder are fitted in the fitting holes.

Hereinafter, the wheel bearing device 1 which is an embodiment of the wheel bearing device according to the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, the wheel bearing device 1 rotatably supports wheels in a suspension device for a vehicle such as an automobile. The wheel bearing device 1 includes an outer ring 2 which is an outer member, a hub ring 3 which constitutes an inner member, an inner ring 4 (see FIG. 2) which constitutes an inner member, and two rows of one-side balls which are rolling rows. Row 5a (see FIG. 2), other side ball row 5b (see FIG. 2), seal member 6 (see FIG. 2), encoder ring 7 (see FIG. 2), protective cover 9 (see FIG. 2), sensor holder 11 and A magnetic sensor 12 is provided.

As shown in FIG. 2A, the outer ring 2 which is an outer member supports the inner member (hub ring 3 and inner ring 4). The outer ring 2 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a substantially cylindrical shape. A one-side opening 2a into which the protective cover 9 and the sensor holder 11 can be fitted is formed at one side (inner side) end of the outer ring 2. The other side (outer side) end on the wheel mounting flange 3b side of the outer ring 2 is formed with the other side opening 2b, which is an outer member opening into which the seal member 6 can be fitted.

The inner peripheral surface of the outer ring 2 is formed so that the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side, which are formed in an annular shape, are parallel to each other in the circumferential direction. The pitch circle diameters of the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side are configured to have the same size. The pitch circle diameters of the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side may be configured to have different sizes. A hardened layer having a surface hardness in the range of 58 to 64 HRC is formed on the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side by induction hardening. On the outer peripheral surface of the outer ring 2, a vehicle body mounting flange 2e for mounting on a knuckle of a suspension device (not shown) is integrally formed in the vicinity of the one-side opening 2a. The vehicle body mounting flange 2e is formed in a range including a portion facing the outer rolling surface 2c on one side of the outer ring 2. The one-side opening 2a of the outer ring 2 (the opening on the inner ring 4 side) is formed so that the protective cover 9 and the sensor holder 11 can be fitted to each other.

The hub wheel 3 constituting the inner member rotatably supports a wheel of a vehicle (not shown). The hub ring 3 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a bottomed cylindrical shape. A small diameter step portion 3a having a reduced diameter is formed on the outer peripheral surface at one side end portion (inner side) of the hub ring 3. A wheel mounting flange 3b for mounting a wheel is integrally formed at the other end (outer side) of the hub wheel 3. An annular inner rolling surface 3c and an annular seal sliding surface 3d are formed on the outer peripheral surface of the other side (wheel mounting flange 3b side) of the hub wheel 3 in the circumferential direction. The wheel mounting flange 3b is provided with hub bolts 3e at positions that are evenly distributed around the circumference.

The inner ring 4 constituting the inner member is press-fitted into the small diameter step portion 3a at one end of the hub ring 3. The inner ring 4 is made of high carbon chrome bearing steel such as SUJ2, and is hardened to the core in the range of 58 to 64 HRC by quenching. An annular inner rolling surface 4a is formed on the outer peripheral surface of the inner ring 4 in the circumferential direction. The inner ring 4 is integrally fixed to one side end of the hub ring 3 in a state where a predetermined preload is applied by press fitting. That is, on one side of the hub ring 3, the inner rolling surface 4a is formed by the inner ring 4. The surface hardness of the hub ring 3 is hardened in the range of 58 to 64 HRC by induction hardening from the small diameter step portion 3a on one side to the seal sliding surface 3d. As a result, the hub wheel 3 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 3b, and the durability of the hub wheel 3 is improved.

In the hub ring 3, the inner rolling surface 4a formed on the inner ring 4 at one side end faces the outer rolling surface 2c on one side of the outer ring 2, and the inner rolling surface 3c formed on the other side. Is arranged so as to face the outer rolling surface 2d on the other side of the outer ring 2. That is, in the inner member composed of the hub ring 3 and the inner ring 4, the inner ring 4 is arranged in the opening on one side of the outer ring 2, and the wheel mounting flange 3b of the hub ring 3 is arranged in the opening on the other side of the outer ring 2. There is.

The one-side ball row 5a and the other-side ball row 5b, which are rolling rows, rotatably support the hub wheel 3. In the one-side ball row 5a and the other-side ball row 5b, a plurality of balls, which are rolling elements, are held in an annular shape by a cage. The one-side ball row 5a and the other-side ball row 5b are made of high-carbon chrome bearing steel such as SUJ2, and are hardened to the core in the range of 58 to 64 HRC by quenching. The one-side ball row 5a is rotatably sandwiched between the inner rolling surface 4a formed on the inner ring 4 and the outer rolling surface 2c on one side of the outer ring 2 facing the inner rolling surface 4a. The other side ball row 5b is rotatably sandwiched between the inner rolling surface 3c formed on the hub ring 3 and the outer rolling surface 2d on the other side of the outer ring 2 facing the inner rolling surface 3c. .. That is, the one-side ball row 5a and the other-side ball row 5b rotatably support the hub ring 3 and the inner ring 4 with respect to the outer ring 2.

The wheel bearing device 1 is composed of an outer ring 2, a hub ring 3, an inner ring 4, a ball row 5a on one side, and a ball row 5b on the other side to form a double row angular contact ball bearing. In the present embodiment, the wheel bearing device 1 is configured with a double-row angular contact ball bearing, but the present invention is not limited to this, and a double-row conical roller bearing or the like may be used.

The seal member 6 closes the gap between the outer ring 2 and the hub ring 3. The sealing member 6 includes NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) with excellent heat resistance, EPDM (ethylene propylene rubber), and ACM (polyacrylic rubber) with excellent heat resistance and chemical resistance. , FKM (fluorine rubber), or a plurality of seal lips made of synthetic rubber such as silicon rubber are integrally joined to a core metal formed in a substantially cylindrical shape by vulture bonding. In the seal member 6, a core metal is fitted in the other side opening 2b of the outer ring 2, and a plurality of other side seal lips are in contact with the outer peripheral surface of the hub ring 3. The seal member 6 is configured to be slidable with respect to the hub ring 3 when the seal lip comes into contact with the outer peripheral surface of the hub ring 3 via the oil film. As a result, the seal member 6 prevents the lubricating grease from leaking from the other side opening 2b of the outer ring 2 and the intrusion of rainwater, dust, and the like from the outside.

As shown in FIG. 2B, in the encoder ring 7 (light black portion), synthetic rubber mixed with a magnetic powder such as ferrite is formed in an annular shape, and adheres to the magnetic poles N and S at equal pitches in the circumferential direction. It is magnetized. The encoder ring 7 is supported by the inner ring 4 via the support ring 8. The support ring 8 is a cylindrical member having a bent portion whose one side end is bent inward in the radial direction. The support ring 8 is made of a ferromagnetic steel plate, for example, a ferrite-based stainless steel plate (JIS standard SUS430 series, etc.) or a rust-preventive cold, in order to improve rust prevention and stability of detection accuracy. It is formed by press working from rolled steel sheet (JIS standard SPCC type, etc.). The encoder ring 7 is integrally joined to the bent portion of the support ring 8 by vulcanization adhesion. The inner ring 4 of the support ring 8 is press-fitted into the cylindrical portion at the other end. That is, the encoder ring 7 is arranged at a position inside the one-side opening 2a of the outer ring 2 and facing the end surface of the inner ring 4. As a result, the encoder ring 7 is configured to be rotatable integrally with the inner ring 4 via the support ring 8.

The protective cover 9 protects the encoder ring 7 by closing the one-side opening 2a, which is the inner-side opening of the outer ring 2. The protective cover 9 is formed into a cylindrical shape having a bottom surface by press working, and is made of a non-magnetic austenitic stainless steel plate (JIS standard SUS304 series or the like). The protective cover 9 is integrally provided with a seal member 10 on the side portion. As shown in FIG. 3A, the protective cover 9 has a protruding side portion and a central portion in which a cylindrical large-diameter portion 9a and a small-diameter portion 9c are connected by a tapered portion 9b having a predetermined angle θ. It is formed from a disk-shaped bottom 9d. In the protective cover 9, one end of the large diameter portion 9a and the other end of the small diameter portion 9c are connected via the tapered portion 9b, and the outer edge of the bottom portion 9d is integrally connected to the other end of the small diameter portion 9c. That is, the protective cover 9 has a bottom portion 9d formed on one side end and an opening on the other side end. The protective cover 9 has NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile / butadiene rubber), EPDM (ethylene propylene rubber), heat resistance, and chemical resistance on the tapered portion 9b and the small diameter portion 9c. An annular sealing member 10 made of synthetic rubber such as ACM (polyacrylic rubber), FKM (fluorine rubber), or silicon rubber, which is excellent in ACM (polyacrylic rubber), is integrally provided by vulture adhesion. The seal member 10 is integrally formed with an annular seal lip 10a, which is an annular protrusion, and a protrusion surface 10b.

The protective cover 9 is formed so that the seal outer diameter D2, which is the outer diameter of the annular seal lip 10a and the protruding surface 10b, is larger than the cover outer diameter D1 which is the outer diameter of the large diameter portion 9a. The protective cover 9 is fitted to the inner circumference of the one-side opening 2a of the outer ring 2. At this time, the protective cover 9 is fitted at a position where the entire protective cover 9 is inserted inside the outer ring 2 in order to bring the bottom portion 9d closer to the encoder ring 7. Further, the bottom portion 9d of the protective cover 9 is arranged so as to face the encoder ring 7 with a gap in a predetermined axial direction. The sealing member 10 of the protective cover 9 seals the gap between the one-side opening 2a of the outer ring 2 and the protective cover 9. As a result, the protective cover 9 closes the one-side opening 2a of the outer ring 2 and protects the encoder ring 7 arranged in the vicinity of the one-side opening 2a.

The seal member 10 of the protective cover 9 has a seal lip 10a and an annular protrusion surface 10b formed as annular protrusions, respectively, but is not limited to this, and only the seal lip 10a is formed. Alternatively, only the annular protruding surface 10b may be formed.

As shown in FIG. 2A, the sensor holder 11 holds the magnetic sensor 12. The sensor holder 11 is formed into a cylindrical shape having a bottom surface by pressing, and is treated with a ferritic stainless steel plate (JIS standard SUS430 series or the like), an austenitic stainless steel plate (JIS standard SUS304 series or the like), or rust prevention treatment. It is composed of cold-rolled steel sheets (JIS standard SPCC type, etc.). When the sensor holder 11 is made of an SPCC-based material, a rust preventive film is formed by cationic electrodeposition coating. In particular, cationic electrodeposition coating made of an epoxy resin or the like capable of forming a strong coating film having excellent rust prevention and adhesion is preferable. The cationic electrodeposition coating is an anion-type electrodeposition coating in which the positive electrode is energized with the product side as the negative electrode, but the negative electrode is energized with the product side as the positive electrode. Is also good. This anion-type electrodeposition coating has the characteristics that the stability of the coating color and the baking temperature can be set low.

As shown in FIG. 3B, the sensor holder 11 is formed of a cylindrical side portion 11a and a partially protruding disc-shaped bottom portion 11c. An annular collar portion 11b protruding outward in the radial direction is formed on the side portion 11a. A magnetic sensor mounting portion 11d is formed on the bottom portion 11c. The sensor holder 11 is formed so that the sensor holder outer diameter D3, which is the outer diameter of the side portion 11a, is larger than the cover outer diameter D1 of the protective cover 9 and smaller than the seal outer diameter D2 of the protective cover 9.

The sensor holder 11 is fitted to the inner circumference of the one-side opening 2a of the outer ring 2. At this time, the sensor holder 11 is fitted with the flange portion 11b in contact with one side end of the outer ring 2. That is, the sensor holder 11 is fitted to the one-side opening 2a so as to cover the protective cover 9 on the outer side (inner side) of the protective cover 9 fitted to the inner circumference of the one-side opening 2a of the outer ring 2. Has been done. As a result, the sensor holder 11 closes the one-side opening 2a of the outer ring 2 and determines the position in the axial direction with respect to the outer ring 2. Therefore, the sensor holder 11 can hold the magnetic sensor 12 attached to the magnetic sensor mounting portion 11d on the bottom 9d at an appropriate position with respect to the encoder ring 7.

As shown in FIG. 2A, the magnetic sensor 12 detects the magnetism of the encoder ring 7. The magnetic sensor 12 is provided on the outer ring 2 so that the detection surface thereof faces the encoder ring 7 by the sensor holder 11. The magnetic sensor 12 is held in the sensor holder 11 so as to have a predetermined air gap (axial clearance) from the encoder ring 7. The magnetic sensor 12 detects the passage time of each magnetism of the encoder ring 7 that alternately passes through the detection surface by rotating integrally with the hub ring 3.

In the wheel bearing device 1 configured as described above, a double-row angular contact ball bearing is composed of an outer ring 2, a hub ring 3, an inner ring 4, a one-side ball row 5a, and a other-side ball row 5b, and the hub wheel 3 is one. It is rotatably supported by the outer ring 2 via the side ball row 5a and the other side ball row 5b. Further, in the wheel bearing device 1, the gap between the one side opening 2a of the outer ring 2 and the inner ring 4 is closed by the protective cover 9 and the sensor holder 11, and the other side opening 2b of the outer ring 2 and the hub ring 3 The gap between the two is closed by the seal member 6. As a result, the wheel bearing device 1 protects the encoder ring 7 fixed to the inner ring 4 while preventing leakage of lubricating grease from the inside and intrusion of rainwater, dust, etc. from the outside by the protective cover 9. There is. Further, the wheel bearing device 1 holds the magnetic sensor 12 at an appropriate position with respect to the encoder ring 7 by the sensor holder 11.

Next, the shape of the inner circumference of the one-side opening 2a of the outer ring 2 will be described in detail with reference to FIG.

As shown in FIG. 4, the inner circumference of the one-side opening 2a of the outer ring 2 is configured as a fitting hole 13 into which the protective cover 9 and the sensor holder 11 are fitted. In the fitting hole 13, the protective cover fitting portion 13a (the darkest dark ink portion) into which the large diameter portion 9a of the protective cover 9 (see FIG. 3A) is press-fitted, and the protective cover 9 The sensor holder fitting portion 13c (see FIG. 3B) in which the seal portion 13b (third darkest light ink portion) in contact with the seal member 10 and the side portion 11a (see FIG. 3B) of the sensor holder 11 are press-fitted. The second darkest part) and is formed.

The sensor holder fitting portion 13c is formed from the inner side end (one side end of the outer ring 2) of the one side opening 2a toward the outer side in the axial direction. The sensor holder fitting portion 13c is formed as a hole having an axial length in which all the portions up to the flange portion 11b of the side portion 11a of the sensor holder 11 can be fitted. The seal portion 13b is formed adjacent to the outer side in the axial direction of the sensor holder fitting portion 13c. The seal portion 13b is formed as a hole having an axial length including all the small diameter portions 9c (see FIG. 3A) of the protective cover 9. The protective cover fitting portion 13a is formed adjacent to the outer side in the axial direction of the seal portion 13b. The protective cover fitting portion 13a is formed as a hole having an axial length into which the large diameter portion 9a of the protective cover 9 can be fitted at a position overlapping the outer ring 2 when viewed from the radial direction. That is, on the inner circumference of the one-side opening 2a of the outer ring 2, the sensor holder fitting portion 13c, the seal portion 13b, and the protective cover fitting portion 13a are sequentially arranged from the end surface of the one-side opening 2a toward the outer side in the axial direction. It is formed.

The fitting hole 13 is formed so that the outer inner diameter d3, which is the inner diameter of the sensor holder fitting portion 13c, is larger than the inner inner diameter d1 which is the inner diameter of the protective cover fitting portion 13a. Further, the fitting hole 13 is formed so that the inner diameter d2 of the seal portion, which is the inner diameter of the seal portion 13b formed between the protective cover fitting portion 13a and the sensor holder fitting portion 13c, has the same inner diameter as the outer inner diameter d3. Has been done. That is, the fitting hole 13 is composed of only a small-diameter portion in which the protective cover fitting portion 13a is formed and a large-diameter portion in which the seal portion 13b and the sensor holder fitting portion 13c are formed.

The protective cover fitting portion 13a of the fitting hole 13 is formed with an inner inner diameter d1 having a size that allows the large diameter portion 9a (see FIG. 3A) of the protective cover 9 to be press-fitted. The sensor holder fitting portion 13c of the fitting hole 13 is formed with an outer inner diameter d3 having a size capable of press-fitting the side portion 11a (see FIG. 3B) of the sensor holder 11. Further, the sensor holder fitting portion 13c has an outer inner diameter d3 having a size that allows the large diameter portion 9a of the protective cover 9 to pass through without contacting the inner peripheral surface of the sensor holder fitting portion 13c. The seal lip 10a (see FIG. 3A) and the protruding surface 10b (see FIG. 3A) of the sealing member 10 of the above contact the inner peripheral surface of the sensor holder fitting portion 13c while maintaining the sealing property. It is formed on the outer inner diameter d3 having a size that allows it to be moved. The seal portion 13b of the fitting hole 13 is a seal portion inner diameter d2 having a size that allows the large diameter portion 9a of the protective cover 9 to pass through without contacting the inner peripheral surface of the seal portion 13b, and is a seal of the protective cover 9. The seal lip 10a and the protruding surface 10b of the member 10 are formed on the inner diameter d2 of the seal portion having a size that allows the member 10 to come into contact with the inner peripheral surface of the seal portion 13b and move while maintaining the sealability.

Next, a mode in which the protective cover 9 and the sensor holder 11 are assembled to the fitting hole 13 of the outer ring 2 will be described with reference to FIGS. 5 and 6.

As shown in FIG. 5A, the protective cover 9 has a fitting hole 13 in a state where the axis of the protective cover 9 is aligned with the axis of the fitting hole 13 of the outer ring 2 which is the entrance of the fitting hole 13. Will be inserted into. The large diameter portion 9a of the protective cover 9 is inserted into the sensor holder fitting portion 13c of the fitting hole 13. At this time, the large diameter portion 9a having a cover outer diameter D1 smaller than the outer inner diameter d3 of the sensor holder fitting portion 13c does not come into contact with the inner peripheral surface of the sensor holder fitting portion 13c.

As shown in FIG. 5B, the protective cover 9 that is moved toward the inside (outer side) of the fitting hole 13 has a large diameter portion 9a inserted into the sealing portion 13b of the fitting hole 13 and is a sealing member. 10 is inserted into the sensor holder fitting portion 13c. At this time, the large diameter portion 9a having a cover outer diameter D1 smaller than the seal portion inner diameter d2 of the seal portion 13b does not come into contact with the inner peripheral surface of the seal portion 13b. On the other hand, in the seal member 10 having a seal outer diameter D2 (see FIG. 5A) larger than the outer inner diameter d3 of the sensor holder fitting portion 13c, the seal lip 10a and the protruding surface 10b are the sensor holder fitting portions 13c. It is moved toward the inside of the fitting hole 13 in a deformed state in contact with the inner peripheral surface.

As shown in FIG. 6A, in the protective cover 9 that is moved toward the inside of the fitting hole 13, the large diameter portion 9a is inserted into the protective cover fitting portion 13a of the fitting hole 13, and the seal member 10 Is inserted into the seal portion 13b. At this time, the large diameter portion 9a having a cover outer diameter D1 substantially the same as the inner inner diameter d1 of the protective cover fitting portion 13a is inside the fitting hole 13 in a state of being in contact with the inner peripheral surface of the protective cover fitting portion 13a. It is moved toward (press fit fitting). On the other hand, in the seal member 10 having a seal outer diameter D2 (see FIG. 5A) that is larger than the seal portion inner diameter d2 of the seal portion 13b, the seal lip 10a and the protruding surface 10b are the inner circumferences of the sensor holder fitting portion 13c. It is moved toward the inside of the fitting hole 13 in contact with the surface. The protective cover 9 is fixed to the outer ring 2 by press-fitting the large-diameter portion 9a to a predetermined position of the protective cover fitting portion 13a of the fitting hole 13, and the seal lip 10a and the protruding surface 10b of the seal member 10 are fixed. Contact the inner peripheral surface of the seal portion 13b to ensure the sealability between the fitting hole 13 and the protective cover 9.

As shown in FIG. 6A, the sensor holder 11 has the axis of the sensor holder 11 aligned with the axis of the fitting hole 13 from the one-side opening 2a of the outer ring 2 which is the entrance of the fitting hole 13. It is inserted into the fitting hole 13 in this state. The side portion 11a of the sensor holder 11 is inserted into the sensor holder fitting portion 13c of the fitting hole 13. At this time, the side portion 11a having the sensor holder outer diameter D3 substantially the same as the outer inner diameter d3 of the sensor holder fitting portion 13c is press-fitted in a state of being in contact with the inner peripheral surface of the sensor holder fitting portion 13c. .. As shown in FIG. 6B, the sensor holder 11 is moved toward the inside of the outer fitting hole 13 until the flange portion 11b of the side portion 11a comes into contact with one side end of the outer ring 2.

With this configuration, the seal member 10 of the protective cover 9 is fitted with a sensor holder having the same inner diameter between the sensor holder fitting portion 13c and the seal portion 13b at a predetermined position. It is moved in contact with the inner peripheral surface of the portion 13c and the inner peripheral surface of the seal portion 13b. That is, the seal member is on the inner peripheral surface of the fitting hole 13 while maintaining a constant contact state without passing through a step or the like from the sensor holder fitting portion 13c to the predetermined position of the seal portion 13b. Will be moved. Further, the fitting hole 13 is a protective cover fitting portion 13a and a sensor holder for fixing the protective cover 9 and the sensor holder 11 by press-fitting only by forming a small diameter portion and a large diameter portion on the inner peripheral surface. The fitting portion 13c and the sealing portion 13b for sealing the gap between the fitting hole 13 and the protective cover 9 are configured. As described above, the wheel bearing device 1 prevents damage to the sealing member of the protective cover 9 without performing complicated processing on the fitting hole 13 of the opening on the inner ring 4 side of the outer ring 2, and seals the protective cover 9. Can be maintained.

The protective cover 9 is a cover outer diameter D1 which is the outer diameter of the small diameter portion 9c and the outer diameter of the large diameter portion 9a when the large diameter portion 9a and the small diameter portion 9c are connected by the tapered portion 9b to be created by press working. The minimum dimension of the step with and can be reduced. That is, the protective cover 9 can expand the inner diameter of the small diameter portion 9c outward in the radial direction as compared with the case where the large diameter portion 9a and the small diameter portion 9c are connected by a step portion bent at a substantially right angle. it can. Further, since the encoder ring 7 is provided at the bent portion where one side end portion of the support ring 8 is bent inward in the radial direction, it is not necessary to secure a space for the encoder ring 7 on the radial outer side of the inner ring 4. .. Therefore, the wheel bearing device 1 can increase the shaft diameter of the hub wheel 3 and the inner ring 4, and increase the pitch circle diameter of the one-side ball row 5a and the other-side ball row 5b. As a result, the wheel bearing device 1 can improve the mechanical strength against the rotational bending load applied to the wheel mounting flange 3b and the rolling fatigue life.

As described above, according to the embodiment of the invention, the wheel bearing device 1 is a wheel bearing device 1 having a third generation structure in which the inner rolling surface 3c of the one-side ball row 5a is directly formed on the outer circumference of the hub wheel 3. Although it is configured, the structure is not limited to this, and a second generation structure in which a pair of inner rings 4 are press-fitted and fixed to the hub wheel 3 may be used. Further, the present invention is not limited to each embodiment, but is merely an example, and it goes without saying that the present invention can be further implemented in various forms without departing from the gist of the present invention. The scope of the present invention is indicated by the description of the scope of claims, and further includes the equal meaning described in the scope of claims, and all modifications within the scope.

1 Wheel bearing device 2 Outer ring 2a One side opening 3 Hub ring 3a Small diameter step part 4 Inner ring 9 Protective cover 10 Sealing member 11 Sensor holder 13a Protective cover fitting part 13b Sealing part 13c Sensor holder fitting part

Claims (4)

An outer member in which multiple rows of outer rolling surfaces are integrally formed on the inner circumference,
A hub wheel having a wheel mounting flange integrally provided at one end and a small diameter step portion extending in the axial direction at the other end of the outer circumference, and at least a press-fitted portion into the small diameter step portion of the hub ring. An inner member composed of one inner ring and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer circumference.
A double-row rolling element rotatably housed between the rolling surfaces of the inner member and the outer member, and
A cylindrical protective cover fitted to the inner circumference of the inner opening of the outer member and provided with an annular sealing member on the outer peripheral surface.
In a wheel bearing device provided with a cylindrical sensor holder that is the inner circumference of the inner side opening of the outer member and is fitted outside the protective cover.
The sensor holder fitting portion into which the sensor holder is fitted and the seal member of the protective cover come into contact with the inner circumference of the inner opening of the outer member in order from the inner end to the outer side in the axial direction. A seal portion and a protective cover fitting portion into which the protective cover is fitted are formed.
The axial length of the protective cover fitting portion, rather shorter than the axial length of the sensor holder fitting portion,
The outer peripheral surface of the protective cover is formed of a large diameter portion, a tapered portion connected to the large diameter portion, and a small diameter portion connected to the tapered portion, and the sealing member is formed on the tapered portion and the small diameter portion. A wheel bearing device that is formed to have an outer diameter larger than the inner diameter of the seal portion of the outer member, and the large diameter portion is fitted to the protective cover fitting portion of the outer member . The wheel bearing device according to claim 1, wherein an annular protrusion is formed on the seal member so as to project outward in the radial direction. The wheel bearing device according to claim 2 , wherein the annular protrusion of the seal member is formed in a lip shape. A flange portion is formed in the middle of the outer peripheral surface of the sensor holder, the outer peripheral surface is fitted to the sensor holder fitting portion of the outer member, and the collar portion comes into contact with the end surface of the outer member. The wheel bearing device according to any one of claims 1 to 3 , wherein the fitting position of the sensor holder is determined.

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