Source: http://www.google.com/patents/US20050126005?dq=5083039
Timestamp: 2015-01-25 18:37:02
Document Index: 38826340

Matched Legal Cases: ['art 65', 'art 65', 'art 66', 'art 7', 'art 52', 'art 7', 'art 52', 'art 53', 'art 53', 'art 52', 'art 7', 'art 54', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 53', 'art 52', 'arts 54', 'art 7', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52', 'art 7', 'art 52']

Patent US20050126005 - Manufacturing method and manufacturing apparatus for wheel-support rolling ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsIn a manufacturing method and a manufacturing apparatus for a wheel-support rolling bearing unit, when forming a crimped portion 14 on an end (inside end) of a hub main body 8a, by rocking die forging using a die 26, while preventing enlargement of equipment, in order to prevent forming indentations...http://www.google.com/patents/US20050126005?utm_source=gb-gplus-sharePatent US20050126005 - Manufacturing method and manufacturing apparatus for wheel-support rolling bearing unitAdvanced Patent SearchPublication numberUS20050126005 A1Publication typeApplicationApplication numberUS 11/018,424Publication dateJun 16, 2005Filing dateDec 21, 2004Priority dateJun 24, 2002Also published asUS7121003, WO2004001247A1Publication number018424, 11018424, US 2005/0126005 A1, US 2005/126005 A1, US 20050126005 A1, US 20050126005A1, US 2005126005 A1, US 2005126005A1, US-A1-20050126005, US-A1-2005126005, US2005/0126005A1, US2005/126005A1, US20050126005 A1, US20050126005A1, US2005126005 A1, US2005126005A1InventorsMasahiro Yasumura, Nobuyuki Hagiwara, Shoji HorikeOriginal AssigneeMasahiro Yasumura, Nobuyuki Hagiwara, Shoji HorikeExport CitationBiBTeX, EndNote, RefManClassifications (30), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetManufacturing method and manufacturing apparatus for wheel-support rolling bearing unitUS 20050126005 A1Abstract In a manufacturing method and a manufacturing apparatus for a wheel-support rolling bearing unit, when forming a crimped portion 14 on an end (inside end) of a hub main body 8a, by rocking die forging using a die 26, while preventing enlargement of equipment, in order to prevent forming indentations in a second outer raceway 6a and a second inner raceway 12a, in the present invention, the outer ring 1a is turned by a motor 48, and the balls 32 are rotated. A difference is provided between the rotation speed of the balls 32 and an oscillation speed of the die 26. This difference is preferably at least 10 min−1. By rotating the balls 32 the formation of indentations in the second outer raceway 6a and the second inner raceway 12a is prevented. Moreover, by providing the difference between the rotation speed and the oscillation speed of the die 26, an increase in the torque required for rotation the outer ring 1a is suppressed. Images(12) Claims(5)
BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 and FIG. 2 show one example of an embodiment of the present invention. As explained above, when balls are employed as the rolling elements, indentations are readily formed in the surface of the raceway in association with formation of the crimped portion. That is to say, this effect is particularly apparent when the present invention is applied to a wheel-support rolling bearing unit employing balls as rolling elements. Therefore in the example shown in the figure, balls 32 are employed as the rolling elements. To match this, the cross-sectional shape of first and second inner raceways 11 a and 12 a formed on the outer peripheral surface of a hub 2 a comprising first and second outer raceways 5 a and 6 a of the inner peripheral surface of an outer ring 1 a, and a hub main body 8 a and an inner ring 9 a, are arc-shaped. Since the basic configuration of the wheel-support rolling bearing unit is the same as the aforementioned conventional structure shown in FIG. 8 apart from this point, the same reference symbols are applied to the same component elements and duplicate explanation is omitted, and the parts of the embodiment of the present invention are explained below. Moreover, the same reference symbols are applied to the same members in all drawings. Firstly, the configuration of the manufacturing apparatus is explained by FIG. 1 and FIG. 2. The manufacturing apparatus of the present invention has a ramp 33. This ramp 33 is fastened to the top end of an output rod 34 of a pressing apparatus (main part not shown in the drawings) such as a hydraulic cylinder and the like, and is pushed upwards by the pressing apparatus when forming the crimped portion 14. The top surface of this ramp 33 is provided with a slide table 35 moving horizontally in the front and rear directions of FIG. 1 and FIG. 2, and a support block 37 is mounted on this slide table 35 via a holder 36. A backup plate 39 is fastened between a pair of sliders 38 on the top surface of the ramp 33, and the top surface of this backup plate 39 slides against and in contact with, or in proximity to, the bottom surface of the slide table 35. The support block 37 supports the outside end (the end being the outside in the width direction when assembled in the vehicle, the bottom end in FIG. 1 and FIG. 2, and the other end disclosed in claims) of the hub main body 8 a constituting the hub 2 a being the inner diameter raceway member, and is provided with a support cylinder part 65 set at the center of the top surface. This support cylinder part 65 has an inner diameter able to freely fit inside with almost no play, a positioning cylinder part 66 provided on the outer end surface of the hub main body 8 a for fitting onto the inner peripheral edge part of the wheel, and a top end shape able to be freely in close contact with the outer surface of a flange 10 provided on the outer peripheral surface of the hub main body 8 a. Furthermore, a die 26 being the compression member for plastically deforming the cylindrical portion 16 formed on the inside end of the hub main body 8 a, is provided above of the support block 37. This die 26 is supported on the bottom part of a support head (not shown in drawings). As with the aforementioned conventional apparatus shown in the FIG. 10, the central axis α of the die is inclined at a small angle θ to the central axis β of the hub main body 8 a. When the crimped portion 14 is formed on the inner end of the hub main body 8 a, the die 26 is oscillated with its central axis a circulating around the central axis β of the hub main body 8. Then by pushing the ramp 33 upwards in this condition, the top edge of the cylindrical portion 16 is pressed against the bottom surface of the die 26. Loads are then applied from this die 26 to part around the peripheral direction of the cylindrical portion 16, outwards (downwards in FIG. 1, to the other end disclosed in claims) in relation to the axial direction, and outwards in relation to the diameter directions. The position wherein the load is applied to the cylindrical portion 16 in this manner changes continuously in relation to the peripheral direction of the cylindrical portion 16 in association with the oscillation of the central axis α. The die 26 is of high rigidity to ensure that damage such as cracking and the like due to the reaction associated with compression of this cylindrical portion 16 does not occur, and is of a tapered shape inclined in the direction of increasing diameter with distance from the tip part employed in forming the crimped portion (upwards). Moreover, a ring-shaped support frame 40 is provided around the die 26. A mortar-shaped through-hole 41 having an inner peripheral surface inclined in the direction wherein the inside diameter increases towards the top, is provided in the center of this support frame 40 to allow the oscillating movement of the die 26. Furthermore, a short approximately cylinder-shaped holding cylinder 42 is formed in the bottom surface of the support frame 40 in the part surrounding the through-hole 41. This holding cylinder 42 functions to prevent oscillation in the radial direction of the hub main body 8 a when the cylindrical portion 16 is formed into the crimped portion 14 with the die 26. Therefore the inner peripheral surface of the bottom end of the holding cylinder 42 has a stepped-shape to enable its free fitting onto the inner ring 9 a fitted onto the inside end of the hub main body 8 a. The support frame 40 is supported such that it is able to move freely up and down to a slight extent on part of the frame (not shown in drawings). Furthermore, a segmented cylinder-shaped retainer cylinder 44 is suspended and fastened on the part of the support frame 40 towards the outer periphery of the bottom surface via a top and bottom pair of connected rings 43 a and 43 b. This retainer cylinder 44 is fitted onto the holder 36 with the ramp 33 raised and the support frame 40 lowered. Moreover, a drive ring 45 being a rotating ring is supported on the inside of the connected ring 43 b by a roller bearing 46 such as to enable free rotation. As with a revolving ring, this roller bearing 46 has a structure able to bear freely radial loads and thrust loads. The drive ring 45 is for rotating the outer ring 1 a being the outer diameter raceway member, at the prescribed velocity when the crimped portion 14 is formed with the die 26, and is rotated by a motor 48 in a condition with an annular drive jig 47 being the rotating transmission member described in claims fitted onto a mounting part 7 provided on the outer peripheral surface of this outer ring 1 a. The drive jig 47 is able to move freely up and down to a slight extent in relation to this drive ring 45, and is assembled such that it is able to rotate freely synchronized with this drive ring 45. Therefore, in the case of this example, support holes 49 are formed parallel to the central axis of the drive ring 45 at a plurality of points (for example, 4 to 6 points) around the peripheral direction of the drive ring 45. Furthermore, the base end of guide pins 51 placed parallel with the central axis of the drive jig 47 are connected and fastened to the part matching each support hole 49 by part of the mounting flange 50 fastened to the top end of the outer peripheral surface of the drive jig 47. Then each of these guide pins 51 is inserted through the respective support holes 49, and a compression spring being a pressing member is provided between the top surface of the rim part formed on the bottom part of each of these guide pins 51, and the bottom surface of the mounting flange 50. The drive jig 47 according to this configuration, is supported such that when provided with a resilient force in the downwards direction, it is able to move freely up and down to a slight extent in relation to the drive ring 45, and rotate freely synchronized with the drive ring 45. A concave part 52 fitting in a non-circular manner with the outer peripheral edge of the mounting part 7 is formed on a part close to the inner periphery of the bottom surface of the drive jig 47. In this example, as shown in FIG. 3, a shape of the inner peripheral surface of the concave part 52 adopts a shape wherein part of the cylindrical surface is expanded radially inwards to give a bulged part 53. The bulged part 53, in a condition with the phase of the concave part 52 and the mounting part 7 matched, is connected to a concave edge part 54 existing in the outer peripheral edge part of the mounting part 7, so that the rotating force is freely transmitted from the drive jig 47 to the outer ring 1 a. Transmission of the rotating force from the drive ring 45 to the drive jig 47 may be performed by the guide pins 51. However if the connection between the inner peripheral surface of the drive ring 45 and the outer peripheral surface of the drive jig 47 is by non-circular engagement such as with a splined connection and the like, application of a large force to the guide pins 51 is prevented, and durability of the manufacturing apparatus is improved. On the other hand, the motor 48 (generally an electric motor, however a hydraulic motor may be used) which rotates the drive ring 45 is supported on and fastened to the outer peripheral surface of part of the retainer cylinder 44 by a connecting bracket 55 and a retainer bracket 56. The motor 48 is therefore raised and lowered together with the support frame 40. An output shaft 57 of the motor 48 and the drive ring 45 are connected by a reduction gear mechanism 58, to rotate the drive ring 45 freely in the prescribed direction at the prescribed speed. In this manner, the velocity of rotation of the output shaft 57 of the motor 48 is reduced by a speed-reduction apparatus such as the reduction gear mechanism 58 and the like, and the drive ring 45 which rotates the outer ring 1 a is rotated, and the motor 48 can be of a small size. Moreover, the outer ring 1 a is rotated at low velocity, thus reducing vibration of the manufacturing apparatus. To construct the reduction gear mechanism 58, an intermediate shaft 59 is supported so as to be freely rotatable on the connecting bracket 55, while positioned in parallel to the output shaft 57 and the central shaft of the drive ring 45. Furthermore, a major reduction gear 60 is fastened to the part close to the outer periphery of the bottom surface of the drive ring 45. This major reduction gear 60 and a minor reduction gear 61 fastened to the tip of the output shaft 57 (top end in drawings) are meshed via an intermediate gear 62 fastened to the top end of the intermediate shaft 59. With this configuration, the drive ring 45 is rotated freely in the same direction as the output shaft 57, and at a lower velocity than the output shaft 57. A holder rod 63 being a rotation limiting member is provided above the support block 37 so as to be freely movable back and forth in relation to the outer peripheral surface of the outer ring 1 a. In this example, therefore, an actuator 64 such as a pneumatic cylinder or the like is fastened to the part corresponding to a discontinuous part of the retainer cylinder 44 on the outer peripheral surface of the holder 36, and the holder rod 63 is able to be displaced freely in the radial direction of the outer ring 1 a by the actuator 64. When the concave part 52 of the drive jig 47 is fitted against the mounting part 7 while the drive jig 47 is lowered together with the drive ring 45 by an actuator such as a hydraulic cylinder (not shown in drawings) or the like, the drive jig 47 is immediately rotated in the prescribed direction by the motor 48. In this case, the holder rod 63 does not operate (displacement towards the outer peripheral surface of the outer ring 1 a), and remains separated from the outer peripheral surface of the outer ring 1 a. On the other hand, when the part separated from the concave part 52 on the bottom surface of this drive jig 47 is on the mounting part 7 when the drive jig 47 is lowered, the drive jig 47 is rotated by the motor 48 at low velocity (for example, between a few min−1 and few tens of min−1) in the reverse direction to the prescribed direction. In this case, the holder rod 63 is moved forward towards the outer peripheral surface of the outer ring 1 a as shown in FIG. 1 by the actuator 64, and the torque required to rotate the outer ring 1 a increases based on the frictional engagement between the tip of the holder rod 63 and the outer peripheral surface of the outer ring 1 a. The outer ring 1 a does not rotate together with the drive jig 47. On the other hand, when as shown in FIG. 2 the holder rod 63 is withdrawn from the outer peripheral surface of the outer ring 1 a, the torque required to rotate the outer ring 1 a decreases. Furthermore, it is desirable that a material being softer than the metal material (carbon steel) constituting the outer ring 1 a such as a hard rubber, synthetic resin, soft metal and the like is provided on the tip of the holder rod 63 to prevent damage to the outer peripheral surface of the outer ring 1 a. Next is a description of the action of plastically deforming the cylindrical portion 16 provided at the inside end of the hub main body 8 a to form the crimped portion 14, using the manufacturing apparatus configured as explained above. Firstly, the hub main body 8 a is mounted on the top surface of the support block 37, with the ramp 33 lowered and displaced in the front and rear direction in FIG. 1 and FIG. 2, and the support block 37 withdrawn from beneath the die 26. The inner ring 9 a is previously fitted onto the inside end of the hub main body 8 a. Next, the ramp 33 is inserted beneath the die 26 until the central shaft of the hub main body 8 a and the central shaft of the support frame 40 are aligned. The holding cylinder 42 is then lowered, and the bottom end of the holding cylinder 42 is fitted onto the inner ring 9 a as shown in FIG. 1. Moreover, the drive jig 47 is lowered together with the holding cylinder 42. When the concave part 52 of the drive jig 47 is fitted against the mounting part 7 when the drive jig 47 is lowered, a microswitch detects that the concave part 52 and the mounting part 7 are fitted together and that the drive jig 47 has been sufficiently lowered. Power is then supplied to the previously stopped motor 48, and the drive jig 47 is rotated in the prescribed direction. In this case, the holder rod 63 does not operate (displacement towards the outer peripheral surface of the outer ring 1 a), and remains separated from the outer peripheral surface of the outer ring 1 a. On the other hand, when the part separated from the concave part 52 on the bottom surface of this drive jig 47 is on the mounting part 7 when the drive jig 47 is lowered, lowering of the drive jig 47 is prevented, and the compression spring provided around the guide pins 51 is compressed. In this condition the microswitch does not detect lowering of the drive jig 47. Therefore, in this case the holder rod 63 is moved forward, and the tip of the holder rod 63 and the outer peripheral surface of the outer ring 1 a are frictionally engaged, and the drive jig 47 is rotated by the motor 48 at low velocity (for example, between a few min−1 and few tens of min−1) in the reverse direction to the prescribed direction, and through a prescribed angle (for example, approximately half a turn or less). As a result, in the condition with the phase of the concave part 52 and the mounting part 7 matched, the drive jig 47 is lowered and this lowering is detected by the microswitch. Since the rotation of the drive jig 47 is at low velocity, then provided the phase of the concave part 52 and the mounting part 7 match, the drive jig 47 can be reliably lowered, and the concave part 52 and the mounting part 7 can be fitted together. That is to say, in the condition with matching in the peripheral direction, of the phase of the bulged part 53 on the inner peripheral surface of the concave part 52 formed in the bottom surface of the drive jig 47, and one of the pair of concave edge parts 54 on the outer peripheral edge of the mounting part 7, the drive jig 47 is lowered under its own weight and the force of the compression springs positioned around the guide pins 51, and the mounting part 7 is fitted into the concave part 52. In this condition, the rotation of the drive jig 47 is transmitted freely to the outer ring 1 a. Therefore the holder rod 63 is withdrawn from the outer peripheral surface of the outer ring 1 a, and the motor 48 is stopped and then restarted to rotate the drive jig 47 in the prescribed direction. It is also possible that the drive jig 47 continues to rotate by a preset amount (approximately half a turn) after the mounting part 7 and the concave part 52 are fitted together. In this case, the tip of the holder rod 63 and the outer peripheral surface of the outer ring 1 a slide against each other and are subject to friction, and the drive torque required of the motor 48 increases. However, since the rotational velocity of the drive jig 47 in this condition is low, no particular problem arises. On the other hand, if configured as explained above, since fitting together of the mounting part 7 and the concave part 52 is detected by the microswitch, and the holder rod 63 is withdrawn immediately from the outer peripheral surface of the outer ring 1 a and the motor 48 is stopped temporarily, the situation of the tip of the holder rod 63 and the outer peripheral surface of the outer ring 1 a sliding against each other with friction is almost non existent. FIG. 1 shows the crimped portion 14 formed on the inner end of the hub main body 8 a. However in the initial stage of this crimped portion forming work shown in FIG. 1, as explained above in FIG. 9, the crimped portion 14 is not yet formed on the inner end of the hub main body 8 a. In any case, the mounting part 7 and the concave part 52 are fitted together and the outer ring 1 a is rotated freely by the drive jig 47 to complete preparations for lowering the crimped portion 14. Then the outer ring 1 a is rotated, for example, a few hundred min−1 by the motor 48 and the ramp 33 raised, and the cylindrical portion 16 formed on the end of the inside part of the hub main body 8 a is plastically deformed by the die 26. The crimped portion 14 is then formed, and the inner peripheral surface of the inner ring 9 a is held by the crimped portion 14. At this time, the central axis α of the die 26 is oscillated around the central axis β of the hub main body 8 a. The cylindrical portion 16 is pressed against the bottom surface of the die 26 oscillated in this manner, based on the rising force of the output rod 34 of the pressing apparatus such as the hydraulic cylinder and the like. At this time, since the hub main body 8 a provided with the cylindrical portion 16 does not rotate, load is applied to a part around the peripheral direction of the cylindrical portion 16, towards the other end (outside end) in the axial direction, and outwards in the radial direction, and the part to which this load is applied changes continuously in the peripheral direction of the cylindrical portion 16. As a result, this cylindrical portion 16 is plastically deformed continuously and gradually in the peripheral direction, forming the crimped portion 14. As the cylindrical portion 16 is formed into the crimped portion 14, the hub main body 8 a and the ramp 33 whereon the hub main body 8 a is mounted, the support frame 40, the motor 48, the reduction gear mechanism 58, and the like, gradually rise. As the crimped portion 14 is formed, the thrust load applied to the slide table 35 is borne by the output rod 34 via the backup plate 39. Therefore an excessive load does not act on the slider 38, and sufficient durability of the slider 38 can be ensured. In particular, in the case of the manufacturing method for a wheel-support rolling bearing unit of the present example, during formation of the crimped portion 14 from the cylindrical portion 16, the outer ring 1 a is rotated in one direction by the motor 48 with the hub main body 8 a remaining in a static condition. Moreover, while the balls 32 are rolling between the first and second outer raceways 5 a and 6 a, and the first and second inner raceways 11 a and 12 a, the cylindrical portion 16 is pressed with the die 26 to form the crimped portion 14. At this time, the rotational velocity nC [min−1] of the balls 32 and the rotational velocity (velocity of oscillation around the axis) nT [min−1] of the die 26 are made mutually different by appropriately controlling the direction and velocity of rotation of the motor 48 and the direction and velocity of oscillation of the die 26. The greater the difference between the rotational velocities nC and nT, the more the drive torque required to the motor 48 can be reliably reduced. Consequently, in terms of reducing this drive torque, it is desirable to ensure that the difference between the rotational velocities nC and nT is at least 10 min−1. As shown in FIG. 7 (A) and (B), if the distance from the center of the outer ring 1 a to the point of contact between the outer ring raceway and the rotating surface of the balls 32 is assumed as ro, and the distance from the center of the hub main body 8 a to the point of contact between the inner ring raceway and the rotating surface of the balls 32 is assumed as ri, it is well known that the relationship between the rotational velocity nC of the balls 32 and the rotational velocity no (rotating velocity) of the outer ring 1 a is nC={ro/(ro+ri) } no. Consequently the direction and velocity of rotation of the motor 48 are appropriately controlled by the relationship between the direction of oscillation and velocity of oscillation of the die 26, so that there is a difference between the rotational velocity nC [min−1] of the balls 32 and the rotational velocity (velocity of oscillation around the axis) nT [min−1] of the die 26 found with this equation, and furthermore, preferably so that the difference between the rotational velocities nC and nT (|nC−nT|) is at least 10 min−1. The direction of oscillation of this die 26 and the direction of rotation of the balls 32 may be the same or opposite. Essentially, it is necessary that the difference between the rotational velocities nC and nT (|nCnT|) is at least 10 min−1, and more preferably at least 50 min−1. In this case, values are set such that |nC|−|nT|>10 or |nT|−|nC|>10 to ensure that the direction of rotation of the die 26 and the direction of rotation of each of the balls 32 match, and values are set such that |nC|+|nT|>10 to ensure that the directions do not match (opposite directions). In this case, if the direction of rotation of the die 26 and the direction of rotation of each of the balls 32 are opposite, then without increasing the absolute values of the rotational velocities nC and nT, the difference in these two rotational velocities nC and nT is |nC|+|nT|, which can be much greater than the difference |nC|−|nT| for when the directions are matched. Therefore there is an advantage in that while controlling the rotation velocity of the output shaft 57 of the motor 48, the drive torque of the drive ring 45 for rotating the outer ring 1 a is kept low. The aforementioned difference has no particular upper limit. It is determined by design in consideration of the need for efficiency in forming the crimped portion 14, the need for durability of the manufacturing apparatus, and manufacturing cost, and the like. In any case, the work of plastically deforming the crimped portion 14 with the die 26 is conducted while oscillating the central axis of the die 26. Consequently, the contact part (forming part) between the tip surface of the die 26 and the tip surface part of the cylindrical portion 16 moves around the peripheral direction of the cylindrical portion 16 while rotating. However, when commencing forming work, if the tip surface of the die 26 and the tip of the cylindrical portion 16 are displaced relative to each other at the instant the tip surface of the die 26 and the tip of the cylindrical portion 16 come into contact, welding may occur at the contact part. Therefore in order to eliminate the relative displacement of the tip surface of the die 26 and the tip part of this cylindrical portion 16 at the instant of contact, preferably the ramp 33 is raised with the die 26 stopped, and the tip surface of the die 26 and the tip part of this cylindrical portion 16 are contacted. Oscillation of the die 26 around the central axis is commenced following contact (light contact is desirable) with the part to be formed. In the present example, as explained above, since the balls 32 are continuously rotated and the cylindrical portion 16 is plastically deformed by the die 26, damage such as indentations and the like do not occur on the first outer raceway 5 a and the first inner raceway 11 a far from the cylindrical portion 16, nor on the second outer raceway 6 a and the second inner raceway 12 a close to the cylindrical portion 16. That is to say, since the velocity of movement (rotation) in the peripheral direction, of the part where the die 26 presses the cylindrical portion 16, and the rotational velocity of the balls 32 differ (for example, at least 10 min−1), each of the balls 32 move in the peripheral direction in relation to the pressing part. It has been found by experiment by the inventor of the present invention that the indentations and the like do not occur when the outer ring 1 a is rotated and each ball 32 is rolled continuously during the work of forming the cylindrical portion 16 into the crimped portion 14. This is thought to be due to the fact that the part receiving a large load in association with the work of forming the crimped portion 14 is continuously changing. Moreover, it has also been verified by experiment by the inventor of the present invention that, if a difference between the rotational velocities nC and nT is provided (a difference in |nC−nT| of at least 10 min−1 is particularly desirable), the torque required to rotate the outer ring 1 a does not become excessively large. This point is explained with reference to FIG. 4 through FIG. 6. FIG. 4 through FIG. 6 show the relationship between the rotational velocity nC of the balls 32 and the torque required to rotate the outer ring 1 a, with the velocity of oscillation of the die 26 around the central axis (rocking rotation velocity=rotational velocity nT) constant. FIG. 4 shows the velocity of oscillation around the central axis as 400 min−1, FIG. 5 shows it as 800 min−1, and FIG. 6 shows it as 1200 min−1. As is clear from FIG. 4 through FIG. 6, when the rotational velocity nT of the die 26 and the rotational velocity nC of the balls 32 match, the torque required to rotate the outer ring 1 a becomes extremely large. If a difference is provided between the rotational velocities nT and nC, the torque rapidly becomes small. Moreover this torque is reduced as the difference between the rotational velocities nT and nC increases. In particular, if the difference between the rotational velocities nC and nT (|nC−nT|) is at least 10 min−1, the outer ring 1 a can be rotated sufficiently, and this outer ring 1 a can be more readily rotated if this difference is at least 50 min−1 (particularly at least 100 min−1). Industrial Applicability According to the manufacturing method and manufacturing apparatus for a wheel-support rolling bearing unit of the present invention as explained above, the formation of indentations on each raceway in association with the work of forming the crimped portion 14 as with the previous invention can be prevented. Therefore a wheel-support rolling bearing unit having low vibration and noise in operation, and excellent durability can be obtained. Furthermore, with the present invention, an excessive increase in the torque required to rotate the outer ring can be prevented, and in particular, the work of manufacturing the wheel-support rolling bearing unit can be stabilized without the use of a large apparatus. Classifications U.S. Classification29/898.061, 29/509, 29/898.04International ClassificationB23P11/00, B21K25/00, F16C43/04, B60B27/00, F16C35/063, B21J9/02, F16C19/00, F16C19/38, F16C33/64, B21K23/04Cooperative ClassificationF16C19/186, B21K23/04, B21J9/025, B21K25/00, F16C33/64, B23P11/00, F16C43/04, B60B27/00European ClassificationF16C19/38T2O, B23P11/00, B21J9/02R, B21K25/00, F16C33/64, B21K23/04, F16C43/04, F16C19/00, B60B27/00Legal EventsDateCodeEventDescriptionMar 19, 2014FPAYFee paymentYear of fee payment: 8Apr 8, 2010FPAYFee paymentYear of fee payment: 4Mar 23, 2005ASAssignmentOwner name: NSK LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YASUMARA, MASAHIRO;HAGIWARA, NOBUYUKI;HORIKE, SHOJI;REEL/FRAME:015811/0393Effective date: 20050106RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services