JP5169503B2 - Drive wheel bearing device - Google Patents

Description

  The present invention relates to a bearing device for a drive wheel mainly used in an automobile.

  In general, an automobile includes a drive wheel bearing device for rotatably supporting a drive wheel rotated by a drive shaft. Such a drive wheel bearing device includes an outer ring fixed to a vehicle body, a hub ring to which the drive wheel is attached, a plurality of rolling elements, and an outer ring via the rolling elements to rotate the hub ring. And a drive shaft that rotates relative to the drive shaft.

  Also, in order to connect the shaft, which is the axle connected to the engine, and the drive shaft through a constant velocity universal joint (constant velocity joint), the drive shaft and the joint member which is a component of the constant velocity universal joint are integrated. Further, there is known a drive wheel bearing device in which a drive shaft and an inner ring of a rolling bearing are integrated. Such a bearing device for a drive wheel further includes a plurality of balls for connecting to the shaft, and a track groove in which the balls are disposed and a raceway surface on which the rolling elements roll are formed on the drive shaft. (For example, refer to Patent Document 1).

More specifically, as shown in FIG. 4, the drive wheel bearing device 101 is configured as a rolling bearing B, and includes an outer ring 102, a hub ring 103 corresponding to an inner ring rotatable with respect to the outer ring 102, A plurality of rolling elements 105 and 106 are provided. The outer ring 102 is fixed to a vehicle body (not shown), and the hub wheel 103 is attached with a drive wheel and a brake rotor (both not shown). The drive wheel bearing device 101 includes a drive shaft 104 that rotates with respect to the outer ring 102 via a rolling element 106 to rotate the hub wheel 103, and a shaft that connects the drive shaft 104 to an engine (not shown). Further, a plurality of balls 109 for connection to 107 are provided. Since the drive shaft 104 is formed by integrating an outer joint member that is a component of the constant velocity universal joint J and an inner ring that is a component of the rolling bearing B, a ball 109 is disposed on the drive shaft 104. A track groove 104g and a raceway surface 104d for rolling the rolling element 106 are formed. A joint member 108 is fixed to the shaft 107, and a ball 109, which is a spherical torque transmission member, is fitted in a track groove 104 g formed in the drive shaft 104 and a track groove 108 b formed in the joint member 108. Has been. In this manner, the torque of the shaft 107 is configured to be transmitted to the drive shaft 104 via the joint member 108 and the ball 109.
JP 2002-356101 A

  By the way, when the torque transmitted by the shaft 107 is too large (that is, when excessive torque is generated), the shaft 107 is greatly inclined with respect to the center line C of the drive shaft 104 (that is, the constant velocity universal joint J operates at a high speed). When a secondary couple is generated (in the corner), an excessive stress is generated in the drive shaft 104 integrated with the outer joint member via the ball 109. When such excessive stress is generated in the drive shaft 104, when the six balls 109 are arranged in the track groove 104g formed in the drive shaft 104, the track surface 104d that should have a circular cross section is formed. 5, the raceway surface 104d is deformed so as to have six peaks (that is, the number of peaks corresponding to the number of the balls 109). If the raceway surface 104d is deformed in such a manner as described above, there is a problem that vibrations and abnormal noise are generated when the rolling element 106 rolls on the raceway surface 104d.

  The present invention has been made in view of such a situation, and the purpose thereof is to allow the rolling element to roll on the raceway surface even when the raceway surface formed on the drive shaft is deformed so as to swell. An object of the present invention is to provide a drive wheel bearing device capable of suppressing generated vibrations and abnormal noise.

(1) This means is “a bearing device for a driving wheel that supports a driving wheel, and the driving wheel bearing device includes an outer ring, a hub wheel, a driving shaft, a row of rolling elements on a vehicle body side, and a rolling element on a wheel side. And the outer ring is a component fixed to the vehicle body and surrounds a part of the outer periphery of the drive shaft and a part of the outer periphery of the hub wheel, and the vehicle body side outer peripheral raceway surface and the wheel. The outer peripheral raceway surface, the drive shaft is a portion that rotates with respect to the outer ring, and includes a stepped portion, a caulking portion, an opening, and a vehicle body side inner peripheral raceway surface. A component to which a drive wheel is attached, which is fixed to the drive shaft by the step portion and the caulking portion, has a wheel side inner raceway surface, and the vehicle body side outer raceway surface is formed on an inner circumference of the outer ring. The wheel side outer peripheral raceway surface is formed on the vehicle body side in the inner periphery of the outer ring. Formed on the wheel side portion of the circumferential raceway surface, the vehicle body side inner raceway surface is formed on the vehicle body side portion of the stepped portion on the outer periphery of the drive shaft, and the wheel side inner raceway surface is Formed on the outer periphery of the hub wheel, the row of rolling elements on the vehicle body side is formed between the vehicle body side outer circumferential raceway surface and the vehicle body side inner circumferential raceway surface, and the row of rolling elements on the wheel side is It is formed between the wheel side outer peripheral raceway surface and the wheel side inner peripheral raceway surface, and the caulking portion is formed at the wheel side end portion of the drive shaft and is pressed against the wheel side side surface of the hub wheel. The step portion is formed in a portion between an end portion of the drive shaft on the wheel side and an end portion of the drive shaft on the vehicle body side, a side surface of the hub wheel on the vehicle body side is pressed, and the opening portion is A portion into which the axle is inserted and formed at the end of the drive shaft on the vehicle body side, and a plurality of track grooves The track groove is formed on an inner periphery of the opening, and the ball is disposed in an inner space of the opening, is fitted in the track groove, the row of rolling elements on the vehicle body side, and the The plurality of balls satisfy the relationship of “n × Z + 2 ≦ Y ≦ (n + 1) × Z−2”, where “Y” indicates the number of rolling elements constituting the row of rolling elements on the vehicle body side, and “Z "Represents the number of the balls, and" n "represents a drive wheel bearing device indicating an arbitrary positive integer. "including.
  (2) One form of the above means is that the drive shaft has a large diameter shaft portion and a small diameter shaft portion in addition to the stepped portion, the caulking portion, the opening portion, and the vehicle body side inner circumferential raceway surface. The step portion is formed at a boundary portion between the large-diameter shaft portion and the small-diameter shaft portion, and the large-diameter shaft portion is formed on the vehicle body side with respect to the step portion in the axial direction of the drive shaft, The small-diameter shaft portion is formed on the wheel side with respect to the stepped portion in the axial direction of the drive shaft, and the hub wheel has a hub wheel main body portion and a flange portion in addition to the wheel side inner circumferential raceway surface. The hub wheel body portion surrounds the outer periphery of the small diameter shaft portion and is fixed to the drive shaft by being sandwiched between the stepped portion and the caulking portion, and the flange portion is a portion to which the drive wheel is attached. The hub wheel book as the wheel side end of the hub wheel The vehicle body side inner raceway surface is formed on the outer circumference of the large-diameter shaft portion, and the wheel side inner circumference raceway surface is the hub wheel as the outer circumference of the hub wheel. Drive wheel bearing device formed on the outer periphery of the main body. "

  According to this configuration, when the number of balls is Z, the number of rolling elements is Y, and an arbitrary positive integer is n, the relationship of n × Z + 2 ≦ Y ≦ (n + 1) × Z−2 is satisfied. For this reason, the number of rolling elements can be made different from a multiple of the number of balls, a number obtained by adding 1 to a multiple of the number of balls, and a number obtained by subtracting 1 from the multiple of the number of balls. Therefore, even if the raceway surface is deformed to have peaks corresponding to the number of balls due to excessive stress generated on the drive shaft via the balls, the number of rolling elements and the number of peaks on the raceway surface Therefore, when the rolling element rolls on the raceway surface, the occurrence of resonance can be suppressed. As a result, even if the raceway surface formed on the drive shaft is deformed so as to swell, by suppressing the occurrence of resonance, vibrations and abnormalities that occur when the rolling element rolls on the raceway surface are suppressed. Sound can be suppressed.

  According to the present invention, even when the raceway surface formed on the drive shaft is deformed so as to swell, it is generated when the rolling element rolls on the raceway surface by suppressing the occurrence of resonance. Vibration and abnormal noise can be suppressed.

  The present invention will be described below with reference to the drawings. An arrow A in the figure indicates an axial direction that is a direction parallel to the center line C of the drive shaft, and an arrow R in the figure indicates a radial direction that is a direction perpendicular to the center line C of the drive shaft. ing.

  FIG. 1 is a schematic configuration diagram of a drive wheel bearing device 1 according to an embodiment of the present invention. The drive wheel bearing device 1 is mainly used in an automobile to rotatably support a drive wheel (not shown). It is a rolling bearing device (a so-called hub unit) used, in which a rolling bearing B and a constant velocity universal joint (constant velocity joint) J are integrated.

  That is, in the present embodiment, the rolling bearing B is composed of the outer ring 2, the hub ring 3 corresponding to the inner ring, the drive shaft 4 in which the inner ring is integrated, the rolling elements 5, 6 and the like. The quick universal joint J includes a drive shaft 4 in which an outer joint member is integrated, an inner joint member 8, a ball 9, and the like.

  A flange portion (not shown) fixed to the vehicle body using a bolt (not shown) is provided on the outer periphery 2a of the outer ring 2 formed in a substantially cylindrical shape, and an inner periphery 2b of the outer ring 2 is Ring-shaped track surfaces 2c and 2d are formed along the inner periphery 2b of the outer ring 2 so as to form two rows at intervals in the axial direction A. A hub wheel 3 and a drive shaft 4 are provided in the outer ring 2.

  An end portion 3A on the wheel side of the annular hub wheel 3 is provided with a flange portion 3a projecting outward in the radial direction R and a guide portion 3b projecting toward the wheel side in the axial direction A. . The guide portion 3b is an annular projection for guiding a brake rotor (not shown) to the flange portion 3a, and guides the brake rotor to the flange portion 3a by moving the brake rotor along the guide portion 3b. The brake rotor and the drive wheel are attached to the flange portion 3a using bolts (not shown).

  An annular raceway surface 3d is formed on the outer periphery 3c on the vehicle body side of the hub wheel 3 so as to face the row of raceway surfaces 2c, and a drive shaft 4 is inserted into the inner periphery 3e of the hub wheel 3. ing. That is, the hub wheel 3 is fitted to the outer periphery 4a of the drive shaft 4, and the teeth and tooth grooves (both not shown) formed on the inner periphery 3e of the hub wheel 3 and the outer periphery 4a of the drive shaft 4 are engaged. Thus, the hub wheel 3 and the drive shaft 4 are configured to rotate integrally.

  In the end 4A on the wheel side of the drive shaft 4, a caulking portion that abuts on the side surface 3f on the wheel side of the hub wheel 3 in order to fix the hub wheel 3 fitted to the outer periphery 4a to the drive shaft 4. 4b is provided on the outer periphery 4a of the drive shaft 4 in order to hold the hub wheel 3 together with the caulking part 4b. Accordingly, the end portion 4A of the drive shaft 4 formed in a cylindrical shape is plastically deformed outward in the radial direction R to form the caulking portion 4b, thereby being fitted to the drive shaft 4 by the stepped portion 4c and the caulking portion 4b. The hub wheel 3 is sandwiched and the hub wheel 3 is fixed to the drive shaft 4.

  Further, in the present embodiment, since the raceway surface 4d on which the rolling element 6 rolls is formed on the outer periphery 4a of the drive shaft 4 on the vehicle body side with respect to the stepped portion 4c, the drive shaft 4 is a rolling bearing. The shaft member is integrated with the inner ring of B. A plurality of rolling elements 5 and a plurality of rolling elements 6 are arranged in the axial direction A so as to form two rows between the outer ring 2 and the hub ring 3 and the drive shaft 4 configured as described above. Is provided.

  The rolling elements 5 and 6 are balls having a spherical rolling surface, and one row of rolling elements 5 provided on the wheel side is disposed between the outer ring 2 and the hub ring 3, and the raceway surface of the outer ring 2. It is configured to roll in contact with 2c and the raceway surface 3d of the hub wheel 3. Further, as shown in FIG. 2, the rolling element 6 provided on the vehicle body side is disposed between the outer ring 2 and the drive shaft 4 and is in contact with the raceway surface 2 d of the outer ring 2 and the raceway surface 4 d of the drive shaft 4. It is configured to roll. Note that the intervals between the plurality of rolling elements 5 and the intervals between the plurality of rolling elements 6 in the rolling direction are each maintained by a cage (not shown).

  Furthermore, in the present embodiment, the end 4B on the vehicle body side of the drive shaft 4 is provided with an opening 4e formed in a bottomed cylindrical shape, and an inner periphery 4f of the opening 4e has a shaft A plurality of track grooves 4g extending in the direction A are formed. A shaft 7 that is an axle connected to an engine (not shown) that is an internal combustion engine of an automobile is inserted into the opening 4 e of the drive shaft 4.

  An annular joint member 8 is fixedly provided on the outer periphery 7 a of the shaft 7, and the outer periphery 8 a of the joint member 8 extends to face the track groove 4 g of the drive shaft 4. A plurality of track grooves 8b are formed. As shown in FIG. 3, a plurality of balls 9 are provided between the drive shaft 4 and the shaft 7 configured as described above.

  A ball 9 which is a spherical torque transmitting member is disposed by being fitted in a track groove 4g formed in the drive shaft 4 and a track groove 8b formed in the joint member 8, and the ball 9 includes the track grooves 4g and 8b. It is held by the cage 10 so that it does not fall out.

  As described above, the torque of the shaft 7 is configured to be transmitted to the drive shaft 4 via the joint member 8 and the ball 9. Accordingly, in the present embodiment, the inner periphery 4f of the opening 4e of the drive shaft 4 is formed with a track groove 4g in which the ball 9 for transmitting the rotational force of the shaft 7 is fitted. However, the shaft member is integrated with the outer joint member of the constant velocity universal joint J.

  As described above, the drive wheel bearing device 1 includes the outer ring 2 that is fixed to the vehicle body, the hub wheel 3 to which the drive wheel is attached, the plurality of rolling elements 6, and the rolling wheel for rotating the hub wheel 3. A drive shaft 4 that rotates with respect to the outer ring 2 via a moving body 6 and a plurality of balls 9 for connecting the drive shaft 4 to a shaft 7 are provided. The drive shaft 4 is formed with a track groove 4g in which the ball 9 is disposed and a raceway surface 4d on which the rolling element 6 rolls.

  Here, in this embodiment, as shown in FIGS. 2 and 3, when the number of balls 9 is Z, the number of rolling elements 6 is Y, and an arbitrary positive integer is n, n × Z + 2 ≦ Y ≦ (n + 1) × Z−2 (hereinafter referred to as “Formula (1)”) is a feature. More specifically, in the present embodiment, as shown in FIG. 2, the number of balls 9 is 6 and the number of rolling elements 6 is 8. Therefore, when n, which is an arbitrary positive integer, is 1, the relationship of Expression (1) is satisfied.

  As long as the relationship of Formula (1) is satisfied as described above, the number of rolling elements 6 is calculated based on a multiple of the number of balls 9, a multiple of the number of balls 9, and a multiple of the number of balls 9. It can be different from the number minus one. For this reason, an excessive stress is generated in the drive shaft 4 integrated with the outer joint member via the ball 9, so that the raceway surface 4d is deformed so as to have six peaks corresponding to the number of the balls 9. Even in this case, the difference between the number of rolling elements 6 and the multiple of the number of peaks of the raceway surface 4d is large. That is, since the difference between the number of rolling elements 6 and the number of peaks of the raceway surface 4d can be 2 or more, the occurrence of resonance is suppressed when the rolling element 6 rolls on the raceway surface 4d. be able to.

According to the drive wheel bearing device 1 of the above embodiment, the following effects can be obtained.
(1) When the number of balls 9 is Z, the number of rolling elements 6 is Y, and an arbitrary positive integer is n, the rolling elements satisfy the relationship of n × Z + 2 ≦ Y ≦ (n + 1) × Z−2. The number of 6 can be made different from a multiple of the number of balls 9, a multiple of the number of balls 9 plus 1 and a multiple of the number of balls 9 minus 1. Therefore, it is possible to suppress the occurrence of resonance when the rolling element 6 rolls on the raceway surface 4d. As a result, even when the raceway surface 4d formed on the drive shaft 4 is deformed, By suppressing the occurrence of resonance, it is possible to suppress vibration and abnormal noise that occur when the rolling element 6 rolls on the raceway surface 4d.

  In addition, this invention is not limited to the said embodiment, A various design change is possible based on the meaning of this invention, and they are not excluded from the scope of the present invention. For example, you may change the said embodiment as follows.

  In the above embodiment, the number of rolling elements 6 is 8, but the number of rolling elements 6 may be changed as appropriate. That is, even when the number of rolling elements 6 is 9 or 10, when n, which is an arbitrary positive integer, is 1, the relationship of Expression (1) is satisfied. Further, for example, even if the number of rolling elements 6 is 14, 15, or 16, when n, which is an arbitrary positive integer, is 2, the relationship of Equation (1) is satisfied and the number of rolling elements 6 is Even in the case of 20, 21, and 22, when n, which is an arbitrary positive integer, is 3, the relationship of Expression (1) is satisfied.

  In the above embodiment, the number of balls 9 is 6, but the number of balls 9 may be changed as appropriate. That is, for example, even when the number of balls 9 is 5, when n, which is an arbitrary positive integer, is 1, the relationship of Expression (1) is satisfied. Further, for example, even if the number of balls 9 is 7, if the number of rolling elements 6 is 9, 10, 11 or 12, the formula (1) ) And the number of rolling elements 6 is 16, 17, 18, or 19, the relationship of Formula (1) is satisfied when n, which is an arbitrary positive integer, is 2.

  That is, as long as the number of rolling elements 6 and balls 9 satisfies the relationship of formula (1), the drive shaft 4, the cage 10 that holds the balls 9, and the track grooves 8 b in which the balls 9 are arranged are formed. It may be changed as appropriate in accordance with the design of the joint member 8 made.

The schematic block diagram which shows the bearing apparatus for drive wheels which concerns on embodiment of this invention. Sectional drawing of the S1-S1 part of FIG. Sectional drawing of the S2-S2 part of FIG. The schematic block diagram which shows the conventional bearing apparatus for driving wheels. Sectional drawing of the S3-S3 part of FIG.

Explanation of symbols

  A ... axial direction, R ... radial direction, B ... rolling bearing, J ... constant velocity universal joint, 1 ... driving wheel bearing device, 2 ... outer ring, 3 ... hub wheel, 4 ... drive shaft, 4d ... raceway surface, 4g ... Track groove, 5, 6 ... Rolling element, 7 ... Shaft (axle), 8 ... Joint member, 9 ... Ball, 10 ... Cage.

Claims (2)

  A bearing device for a drive wheel that supports the drive wheel,
  The drive wheel bearing device has an outer ring, a hub wheel, a drive shaft, a row of rolling elements on the vehicle body side, a row of rolling elements on the wheel side, and a plurality of balls.
  The outer ring is a component fixed to the vehicle body, surrounds a part of the outer periphery of the drive shaft and a part of the outer periphery of the hub wheel, and has a vehicle body side outer peripheral raceway surface and a wheel side outer peripheral raceway surface,
  The drive shaft is a portion that rotates with respect to the outer ring, and has a step portion, a caulking portion, an opening portion, and a vehicle body side inner circumferential raceway surface,
  The hub wheel is a component to which a drive wheel is attached, and is fixed to the drive shaft by the stepped portion and the caulking portion, and has a wheel side inner circumferential raceway surface,
  The vehicle body side outer peripheral raceway surface is formed on the inner periphery of the outer ring,
  The wheel side outer peripheral raceway surface is formed in a portion on the wheel side of the vehicle body side outer peripheral raceway surface in the inner periphery of the outer ring,
  The vehicle body side inner circumferential raceway surface is formed in a portion on the vehicle body side of the stepped portion on the outer periphery of the drive shaft,
  The wheel side inner raceway surface is formed on the outer circumference of the hub wheel,
  The row of rolling elements on the vehicle body side is formed between the vehicle body side outer peripheral raceway surface and the vehicle body side inner peripheral raceway surface,
  The row of rolling elements on the wheel side is formed between the wheel side outer peripheral raceway surface and the wheel side inner peripheral raceway surface,
  The caulking portion is formed at the wheel side end of the drive shaft, and is pressed against the wheel side surface of the hub wheel,
  The step portion is formed in a portion between an end portion on the wheel side of the drive shaft and an end portion on the vehicle body side of the drive shaft, and a side surface on the vehicle body side of the hub wheel is pressed,
  The opening is a portion into which an axle is inserted, is formed at an end of the drive shaft on the vehicle body side, and has a plurality of track grooves,
  The track groove is formed on the inner periphery of the opening,
  The ball is disposed in the internal space of the opening, and is fitted into the track groove.
  The row of rolling elements on the vehicle body side and the plurality of balls satisfy the following relationship:

    n × Z + 2 ≦ Y ≦ (n + 1) × Z−2

  “Y” indicates the number of rolling elements constituting the row of rolling elements on the vehicle body side,
  “Z” indicates the number of the balls,
  “N” represents any positive integer
  Drive wheel bearing device.   The drive shaft has a large-diameter shaft portion and a small-diameter shaft portion in addition to the stepped portion, the caulking portion, the opening, and the vehicle body-side inner circumferential raceway surface,
  The step portion is formed at a boundary portion between the large-diameter shaft portion and the small-diameter shaft portion,
  The large-diameter shaft portion is formed on the vehicle body side with respect to the stepped portion in the axial direction of the drive shaft,
  The small diameter shaft portion is formed on the wheel side with respect to the stepped portion in the axial direction of the drive shaft,
  The hub wheel has a hub wheel main body part and a flange part in addition to the wheel side inner circumferential raceway surface,
  The hub wheel main body portion surrounds the outer periphery of the small-diameter shaft portion, and is fixed to the drive shaft by being sandwiched between the stepped portion and the caulking portion,
  The flange portion is a portion to which the driving wheel is attached, and is formed at a wheel side end portion of the hub wheel main body portion as a wheel side end portion of the hub wheel,
  The vehicle body side inner peripheral raceway surface is formed on the outer periphery of the large-diameter shaft portion,
  The wheel side inner raceway surface is formed on an outer periphery of the hub wheel main body as an outer periphery of the hub wheel.
  The drive wheel bearing device according to claim 1.

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