Method and apparatus for assembling rolling bearing

A rolling bearing assembling method includes: providing a subassembly member in which a cage and an outer ring raceway of an outer ring are combined with each other; disposing a rotary member that includes groove portions formed on an outer circumference thereof, concentrically with the outer ring so that the plurality of groove portions confront respectively pockets of the cage; disposing a guide member including a guide hole, above the rotary member; supplying tapered rollers from the guide hole between the pockets and the groove portions, respectively; rotating the rotary member by a predetermined angle so that the tapered rollers are pushed radially outward by raised portions between the adjacent groove portions thereby accommodating the tapered rollers into the pockets, respectively; providing the seal ring on the inner ring raceway; and assembling the hub main body together with the outer ring.

BACKGROUND OF THE INVENTION

The present invention relates to a method and apparatus for assembling a rolling bearing, and more particularly to a method and apparatus for assembling a double row tapered roller bearing.

A wheel of a motor vehicle is supported rotatably relative to a suspension system on a body side by a rolling bearing, and a wheel of a heavy vehicle such as a bus or a truck in motor vehicles is normally supported by a double row tapered bearing in which tapered rollers are arranged in double rows.

Incidentally, rolling bearings having a construction referred to as a so-called third generation hub unit have been proposed with a view to reducing the number of constituent components to thereby reduce production costs. As is shown inFIG. 10, this hub unit includes a hub main body51, an inner ring52fixedly fitted on one end portion of the hub main body51, an outer ring53provided on an outside diameter side of the inner ring52and the hub main body51, a first row of tapered rollers54aand a second row of tapered rollers54bwhich are provided rollingly between an outer circumferential surface of the inner ring52and the hub main body51and an inner circumferential surface of the outer ring53and a first seal ring55aand a second seal ring55bwhich are adapted to form a seal between inner circumferential surfaces of both end portions of the outer ring53and the outer circumferential surface of the hub main body51and an outer circumferential surface of an end portion of the inner ring52which confronts an inner side of the vehicle (a right-hand side as viewed inFIG. 10). In addition, a flange56for mounting a wheel (not shown) is provided at an end portion of the hub main body51which confronts an outer side of the vehicle, and on an outer circumferential surface of an intermediate portion of the hub main body, a first inner ring raceway58ais formed in such a manner as to confront, of the two raceways, that is, the first outer ring raceway57aand the second outer ring raceway57b, the first outer ring raceway57awhich is disposed on the outer side of the vehicle (a left-hand side as viewed inFIG. 10). In addition, a second inner ring raceway58bis formed in such a manner as to confront the second outer ring raceway57bon an outer circumferential surface of the inner ring52fitted on to be fixed to an end portion of the hub main body51which confronts the outer side of the vehicle.

The vehicle outer side tapered rollers54are arranged circumferentially at equal intervals between the first outer ring raceway57aand the first inner ring raceway58aby a cage60a, and the vehicle inner side tapered rollers54barranged circumferentially at equal intervals between the second outer ring raceway57band the second inner ring raceway58bby a cage60b. In addition, inFIG. 10, reference numeral59denotes a splined hole formed in a central portion of the hub main body51with which an end portion of a drive shaft or axle (not shown) of the vehicle is brought into spline engagement.

In the hub unit constructed as has been described above, since the flange portion56is formed at the vehicle outer side end portion of the hub main body51, the vehicle outer side seal ring55aneeds to be provided on an inner circumferential surface of the vehicle outer side end portion of the outer ring53before the hub main body51is inserted into the outer ring53. Consequently, being different from a conventional double row tapered roller bearing, this hub unit is assembled by a method described, for example, in JP-A-2004-257553.

Namely, as is shown inFIG. 11, firstly, a subassembly member70is prepared in which the vehicle outer side cage60aand the tapered rollers54aare combined with each other, and this subassembly member70is then combined with the outer ring53. More specifically, the subassembly member70is set on the first outer ring raceway57a.

Following this, the seal ring55ais fitted in to be fixed to the inner circumferential surface of the vehicle outer side end portion of the outer ring53(refer toFIG. 12), and the vehicle inner side end portion of the hub main body51is inserted from a vehicle outer side opening of the outer ring53in such a state, and the first tapered rollers54aretained by the cage60aare provided on the outer circumferential surface of the second inner ring raceway58b(refer toFIG. 13). Then, although illustration is omitted, the inner ring52in which the second tapered rollers54bare provided on the second inner ring raceway58bis inserted from the vehicle inner side opening of the outer ring53, and the inner ring52is fitted on to be fixed to the outer circumferential surface of the vehicle inner side end portion of the hub main body51. Thereafter, the seal ring55bis fitted in to be fixed to the inner circumferential surface of the vehicle inner side end portion of the outer ring53, whereby the hub unit can be obtained.

In addition, it is described in Patent Document No. 1 that when assembling the hub unit in the way described above, a cylindrical support table is used to support the tapered rollers54afrom below in the steps shown inFIGS. 11 to 12with a view to shorten the assembling time and to give a proper preload to the rollers.

According to the assembling method and apparatus described in JP-A-2004-257553, although the assembling time of the hub unit can be shortened more than the other conventional methods and apparatuses, when mounting the tapered rollers on the cage, the worker needs to place a plurality of tapered rollers in pockets of the cage one by one, and this increases the production costs and imposes a limitation on to the efforts to shorten the assembling time.

SUMMARY OF THE INVENTION

The invention has been made in view of these situations, and an object there of is to provide a rolling bearing assembling method and apparatus which enable the automation of assembling work of double row tapered roller bearings so as to enable an efficient and short-time assemblage of such tapered roller bearings.

According to an aspect of the invention, there is provided a method of assembling a double row tapered roller bearing which includes; an outer ring including a first outer ring raceway and a second outer ring raceway on an inner circumferential surface thereof; a hub main body including a first inner ring raceway which confronts the first outer ring raceway and including a radially outwardly projecting flange at one end portion thereof; an inner ring that includes a second inner ring raceway which confronts the second outer ring raceway and is fitted on an outer circumferential surface of the other end portion of the hub main body; a row of tapered rollers which are provided rollably between the first inner ring raceway and the first outer ring raceway; a cage that includes a plurality of pockets for arranging the row of tapered rollers at equal intervals along a circumferential direction; and a seal ring provided on an inner circumferential surface of an end portion of the outer ring which lies on a side close to the first outer ring raceway, the method comprising:

providing a subassembly member in which the cage and the first outer ring raceway of the outer ring are combined with each other;

disposing a rotary member that includes a plurality of groove portions formed on an outer circumference thereof, concentrically with the outer ring so that the plurality of groove portions confront respectively inner circumferential sides of the pockets;

disposing a guide member including a guide hole, above the rotary member;

supplying the tapered rollers through the guide hole between the pockets and the groove portions, respectively;

rotating the rotary member by a predetermined angle so that the tapered rollers are pushed radially outward by raised portions between the adjacent groove portions thereby accommodating the tapered rollers into the pockets, respectively;

providing the seal ring on the inner circumferential surface of the end portion of the outer ring; and

assembling the hub main body together with the outer ring so that the tapered rollers are rollably disposed between the first inner ring raceway and the first outer ring raceway.

In the rolling bearing assembling method of the aspect of the invention, in the first step in which the subassembly member in which the first case and the first outer ring raceway of the outer ring are combined with each other and the first row of tapered rollers are combined together into the first step member, the rotatably rotary member in which the plurality of groove portions are formed on the outer circumference thereof is provided concentrically with the outer ring and in such a manner that the plurality of groove portions confront respectively the inner circumferential sides of the plurality of pockets of the first cage into which the tapered rollers are accommodated. Following this, the guide member in which the guide hole is formed through which the tapered rollers are supplied is provided above the rotary member, so that the tapered rollers are supplied from the guide hole between the pockets and the guide grooves. By causing the tapered rollers to move downwards through the guide hole formed in the guide member in that way, the tapered rollers can be supplied into spaces lying close to the pockets of the cage.

In addition, in the assembling method of the invention, the rotary member is caused to rotate by the predetermined angle to push radially outwards the tapered rollers so supplied by the raised portions formed between the adjacent groove portions, whereby the tapered rollers are accommodated inside the pockets. The supply of the tapered rollers into the guide hole can automatically be implemented using, for example, a parts feeder, and by rotating the rotary member by a suitable driving device after the tapered rollers are supplied into the respective guide holes, the tapered rollers can be provided within the pockets of the cage. In this way, according to the assembling method of the invention, the provision of tapered rollers into the pockets of the case, which has been manually implemented, can be automated, thereby making it possible not only to simplify the bearing assembling work but also to shorten the working time.

In addition, according to another aspect of the invention, there is provided an apparatus for use in assembling a double row tapered roller bearing which includes: an outer ring including a first outer ring raceway and a second outer ring raceway on an inner circumferential surface thereof; a hub main body including a first inner ring raceway which confronts the first outer ring raceway and including a radially outwardly projecting flange at one end portion thereof; an inner ring that includes a second inner ring raceway which confronts the second outer ring raceway and is fitted on an outer circumferential surface of the other end portion of the hub main body; a row of tapered rollers which are provided rollably between the first inner ring raceway and the first outer ring raceway; a cage that includes a plurality of pockets for arranging the row of tapered rollers at equal intervals along a circumferential direction; and a seal ring provided on an inner circumferential surface of an end portion of the outer ring which lies on a side close to the first outer ring raceway, the apparatus comprising:

a support member on which the outer ring is placed with the first outer ring raceway side thereof oriented upwards; and

a supply member disposed above the support member and adapted to supply the tapered rollers onto the outer ring,

wherein the support member includes:an outer cylindrical portion including a first annular stepped portion on which the outer ring is to be placed and which is formed on an outer circumferential surface at an upper end portion thereof; anda cylindrical support portion that is disposed so as to move axially in an interior of the outer cylindrical portion and includes a second annular stepped portion formed on an outer circumferential surface at an upper end portion thereof on which the tapered rollers are to be placed, and

wherein the supply member includes;a guide member including a guide hole through which the tapered rollers are transferred; anda rotary member disposed concentrically with the support portion below the guide member, and including an engagement portion which is brought into engagement with the upper end portion of the support portion, and a plurality of groove portions formed on an outer circumferential surface thereof, wherein the rotary member is configured to be rotated relative to the guide member so that raised portions between the adjacent groove portions push radially outwards the tapered rollers disposed on the second stepped portion.

In the assembling apparatus of the invention, by causing the tapered rollers to move downwards through the guide hole formed in the guide member, the tapered rollers can be supplied to the spaces lying close to the pockets of the cage. In addition, the rotary member is caused to rotate by the predetermined angle to push radially outwards the tapered rollers so supplied by the raised portions formed between the adjacent groove portions, whereby the tapered rollers are accommodated inside the pockets. The supply of the tapered rollers into the guide hole can automatically be implemented using, for example, a parts feeder, and by rotating the rotary member by a suitable driving device after the tapered rollers are supplied into the respective guide holes, the tapered rollers can be provided within the pockets of the cage. In this way, according to the assembling apparatus of the invention, the provision of tapered rollers into the pockets of the case, which has been manually implemented, can be automated, thereby making it possible not only to simplify the bearing assembling work but also to shorten the working time.

According to the tolling bearing assembling method and apparatus of the invention, the automation of assembling work of double row tapered roller bearings can be enabled, thereby making it possible to assemble double row tapered roller bearings with good efficiency and within a short period of time.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, referring to the accompanying drawings, embodiments of a rolling bearing assembling method and assembling apparatus according to an embodiment of the invention will be described in detail.

Structure of Assembling Apparatus

Firstly, the structure of a rolling bearing assembling apparatus according to an embodiment of the invention will be described.

Note that since a basic structure of a rolling bearing that is to be assembled by an assembling apparatus of the invention is similar to that shown inFIG. 10, reference numerals given to constituent components thereof will be also used for description.

In addition, since the assembling apparatus of the invention is such as to perform assembling steps of assembling, in the plurality of components which make up the rolling bearing shown inFIG. 10, the hub main body51, the outer ring53, the tapered roller bearings54a, the cage60a, and the seal ring55a, the description of the constituent components of the rolling bearing other than the components described above will be omitted.

A rolling bearing that is assembled by the assembling apparatus of the invention has an outer ring53having on an inner circumferential surface thereof an outer ring raceway57a(a first outer ring raceway) and an outer ring raceway57b(a second outer ring raceway), a hub main body51having an inner ring raceway58a(a first inner ring raceway) which confronts the outer ring raceway57aand having a radially outwardly projecting flange56at one end portion thereof, a plurality of tapered rollers54a(a first row of tapered rollers) which are provided rollingly between the inner ring raceway58aand the outer ring raceway57a, a cage60a(a first cage) which includes a plurality of pockets for arranging the tapered rollers circumferentially at equal intervals and a seal ring55a(a first seal ring) provided on an inner circumferential surface of an end portion of the outer ring which lies on a side close to the outer ring raceway57a.

As is shown inFIGS. 1 to 6, the assembling apparatus of the embodiment includes a support member A on which the outer ring53of the rolling bearing is placed with its outer ring raceway side oriented upwards and a supply member B disposed above the support member A and adapted to supply the tapered rollers54ato the outer ring53.

As is shown inFIG. 1, the support member A is formed into a short cylindrical body and is made up of an outer cylindrical portion3which is provided on a base, not shown, in such a manner that an axis of the short cylindrical body extends along a vertical axis and a support portion5which is disposed in such a manner as to move axially in an interior of the outer cylindrical portion3.

A first annular stepped portion4is formed on an outer circumferential surface of an upper end portion of the outer cylindrical portion3, and the outer ring53is placed on this annular stepped portion4. This stepped portion4is formed in such a manner that an inner circumferential surface of a vehicle inner side end portion of the outer ring53is brought into abutment with a side4aof the stepped portion4. In addition, the stepped portion4is formed by selecting its axial position such that the whole of the outer ring raceway57aprojects further outwards than an upper end3aof the outer cylindrical portion3.

The support portion5is provided concentrically with the outer cylindrical portion3in such a manner as to slide along an inner circumferential surface of the outer cylindrical portion3. The support portion5is made up of a disc-shaped base portion5aand a cylindrical placing portion5bwhich is provided along a circumferential edge of an upper surface of the base portion5ain such a manner as to erect therefrom. A leading end of a piston6ain a hydraulic cylinder6is brought into connection with a center of a lower surface of the base portion5a, and the support portion5is made to be moved along an axial direction thereof by driving the piston6ain the hydraulic cylinder6.

A second annular stepped portion7is formed on an outer circumferential surface of an upper end portion of the placing portion5bof the support portion5, and the tapered rollers54aare adapted to be place on this second annular stepped portion7. An upper surface7aof the second annular stepped portion7is made into a sloping surface which descends outwards. The tapered rollers are supplied from guide holes in a guide member, which will be described later, to thereby be accommodated in a space defined above the stepped portion7.

In addition, the supply member B is made up of a guide member9in which guide holes9aare formed through which the tapered rollers54aare transferred (supplied) and a rotary member8disposed concentrically with the support portion5below the guide member9.

The rotary member8is made up of a rotatable disk-shaped member, and an annular notched portion8ais formed on an outer circumference of a lower portion thereof. This notched portion8ais formed in such a manner as to be brought into engagement with a thin portion5c(an upper portion) at a distal end of the placing portion5b. In addition, a plurality of groove portions10are formed circumferentially at equal intervals and each of the groove portions10is formed into a shape which corresponds to a circumferential surface of the tapered roller54a. As is shown inFIGS. 4A and 4B, a section of the groove portion10which is vertical to an axial direction thereof is formed into a substantially arc shape which corresponds to the circumferential surface of the tapered roller54a. In addition, the cross sectional shape of the groove portion which is vertical to the axial direction is not limited to the substantially arc shape shown inFIGS. 4A and 4Band hence may be formed into other shapes, for example, into a substantially V shape as is shown inFIG. 5Aor into a substantially rectangular shape as is shown inFIG. 5B, provided that the groove portion10can position the tapered roller54which falls down along the guide hole9aand push the tapered roller54outwards.

The guide member9is made up of a short cylindrical member which is provided concentrically with the rotary member8, and a plurality of guide holes9a, through which the tapered rollers54acan move vertically along the axial direction, are formed circumferentially at equal intervals. The number of pockets60cin the cage60is the same as those of the guide holes9aand the groove portions10.

In addition, a mounting hole21is formed in the guide member9in such a manner as to pass therethrough in the axial direction, and a rotational shaft20adapted to impart a rotating force to the rotary member8is mounted in this mounting hole21. The rotational shaft20is rotatably supported by a bearing22in this mounting hole21.

The rotary member8and the guide member9can move along the axial direction. Relative to the support member A which is made up of the outer cylindrical portion3and the support member5, it is configured such that the rotary member8is firstly provided above the support member5, and following this, the guide member9is provided above the rotary member8. The position where the cage60ais provided on the outer ring raceway57ais set such that the groove portion10formed on the outer circumferential surface of the rotary member8and pockets62of the cage60aconfront each other. In addition, the guide holes9a, the groove portions10and the spaces above the stepped portion7are made to communicate vertically with each other, and the position of the rotary member8and the guide member9about the axis is set such that the tapered rollers54afalling down along the guide holes9apass through the groove portions10to thereby be accommodated in the spaces above the stepped portion7in a smooth fashion.

Assembling Steps of Bearing

Next, an embodiment of a rolling bearing assembling method of the invention will described.

An assembling method of the invention includes a first step for assembling a subassembly member70in which the cage60aand the outer ring raceway57aare combined with each other, and the tapered rollers54atogether so as to be formed into a first step member1(FIGS. 1 to 6), a second step in which the seal ring55ais provided on the first step member1so as to be formed into a second step member2(FIG. 7) and a third step in which the second step member2is combined with the hub main body51(FIGS. 8 to 9). Hereinafter, the first to third steps will be described sequentially.

Firstly, in the first step, the cage60aand the outer ring raceway57aare combined together into the subassembly member70(refer toFIG. 1). In the invention, there is no specific limitation imposed on the cage60a, and hence, a cage can be adopted which is normally used in a double row tapered roller bearing. For example, as is shown inFIG. 14, a cage can be used which is made up of a pair of spaced apart annular portions, that is, a large annular portion61awhich lies on a large diameter side and a small annular portion61bwhich lies on a small diameter side, and a plurality of pillar portions61cwhich are provided in such a manner as to extend between both the annular portions61a,61b, and an annular rib portion61dwhich is provided in such a manner as to extend radially inwards from a radially inward end portion of the small annular portion61b, to thereby exhibit a substantially conical surface shape. In addition, in this cage60a, a plurality of trapezoidal window-like pockets62are provided between the adjacent pillar portions61cat equal intervals in such a manner that the tapered rollers54acan be accommodated therein.

The outer ring53is provided on an outer circumference of an upper portion of the outer cylindrical portion3in such a manner that the outer ring raceway is positioned on an upper side thereof. More specifically, the outer ring53is provided in such a manner that an inner circumferential surface of a vehicle inner side end portion of the outer ring53is brought into abutment with the side4aof the first annular stepped portion4on the outer cylindrical portion3.

Following this, after the subassembly member70is prepared by providing the cage60aon the outer ring raceway57aof the outer ring53, as is shown inFIG. 2, the rotary member8and the guide member9are provided in this order above the support portion5. Namely, after the step shown inFIG. 1is completed, the rotary member8is provided above the support member5, and the guide member9is then provided above the rotary member8. As this occurs, the position where the cage60ais provided on the outer ring raceway57ais set such that the groove portions10formed on the outer circumferential surface of the rotary member8and the pockets62of the cage60aconfront each other. In addition, the guide holes9a, the groove portions10and the spaces above the second stepped portion7are made to communicate vertically with each other, and the position of the rotary member8and the guide member9about the axis is set such that the tapered rollers54afalling down along the guide holes9apass through the groove portions10to thereby be accommodated in the spaces above the stepped portion7in a smooth fashion.

As is shown inFIG. 2, after the rotary member8and the guide member9have been provided above the support portion5, when the tapered rollers54aare supplied into the guide holes9ain the guide member9by means of a parts feeder (not shown) or the like, the tapered rollers54aare accommodated in the space above the second stepped portion7by way of the guide holes9aand the groove portions10(refer toFIG. 3). As this occurs, as is shown inFIG. 4A, the tapered rollers54aare in such a state that part of a circumferential surface thereof is fitted in the groove portion10.

Following this, when the rotary member8is caused to rotate by a predetermined angle (for example, an angle corresponding to one half of the pitch of the groove portions10), the tapered roller54ais, as is shown inFIG. 4B, then pushed out radially outwards by a raised portion11defined between the adjacent groove portions10, so as to be accommodated within the pocket60cof the cage60a(refer toFIG. 6). In this way, the first step member1is completed in which the tapered rollers54aare accommodated, respectively, in the pockets60cof the cage60adisposed on the outer ring raceway57a, and the first step of the invention ends.

In this first step, as has been described before, the tapered rollers54acan be supplied to the space above the stepped portion7which lies close to the pockets60cof the cage60aby causing the tapered rollers54ato fall down along the guide holes9aformed in the guide member9. In addition, the tapered rollers54aso supplied are pushed out radially outwards by the raised portions11defined between the adjacent groove portions10so as to allow the tapered rollers54ato be accommodated in the pockets60cby causing the rotary member8to rotate by the predetermined angle. In this way, according to the assembling method of the invention, the provision of the tapered rollers54ainto the pockets60cof the cage60a, which has been manually implemented in the conventional assembling methods, can be automated, there by making it possible not only to simplify the assembling work of roller bearings but also to shorten the working time.

After the first step has been completed, the rotary member8and the guide member9are withdrawn upwards, and as is shown inFIG. 7, the seal ring55ais provided on an inner circumferential surface of an upper end of the outer ring53which is made to open, and the second step member2is completed (the second step).

Following this, the hub main body51is inserted from above the outer ring53into the outer ring53in such a state that a vehicle inner end portion of the hub main body51is oriented downwards (the third step,FIGS. 8 to 9). As this occurs, an inside diameter of the placing portion5bis set such that an outer circumferential surface of a vehicle inner side small diameter portion51aof the hub main body51can slide against an inner surface of the placing portion5bof the support portion5, whereby the positioning between the hub main body51and the second step member2can be implemented with high accuracy.

When the hub main body51is lowered, a boundary surface between the small diameter portion51aand a large diameter portion51bof the hub main body51are brought into abutment with an upper end face5dof the placing portion5bof the support portion5. In addition, when it is detected by detection devices (not shown) provided on the support portion5and the hydraulic cylinder6such as a displacement sensor, a proximity sensor and a load cell that the boundary surface51has reached the abutment position with the upper end face5d, the hydraulic cylinder6is driven by the detection signal so as to drive to withdraw the piston6ain synchronism with the lowering action of the hub main body51. Note that the hub main body51may be pushed in with a larger force than the supporting force of the hydraulic cylinder6without driving to withdraw the hydraulic cylinder6in response to the detection signal from the detection device.

In addition, as the device for moving the support portion5in the axial direction, a pneumatic cylinder or a mechanism in which a motor is combined with a ball screw can be used in place of the hydraulic cylinder6. Furthermore, without using the drive device, the support portion may be configured to be supported while being biased from below by means of an elastic device such as a coil spring. In this case, the state shown inFIGS. 1 to 7is taken as the reference position (a state in which the weight of the support member is balanced with the biasing force of the spring), and in the state shown inFIGS. 8 to 9, the hub main body51is lowered downwards against the biasing force of the spring.

In addition, when the tapered rollers54aare brought into contact with the inner ring raceway57aand the hub main body51is lowered to the position where the large diameter side end faces54cof the tapered rollers54aare brought into abutment with a large collar surface58cof the inner ring raceway58a,the hub main body51and the support portion5come to a halt, and the third step is completed.

Following this, only the support portion5is withdrawn further downwards, although not shown, the inner ring52in which the tapered rollers54bare disposed on the inner ring raceway58bis inserted into a space that is produced on an outer circumference of the small diameter portion51aof the hub main body51by the further withdrawal of the support portion5, and the inner ring52is fitted on to be fixed to the outer circumference of the small diameter portion51a, thereafter, the seal ring55bbeing fitted in to be fixed to the inner circumferential surface of the vehicle inner side end portion of the outer ring53, the rolling bearing being thereby obtained.

In addition, in the third step, the support portion5and the hub main body51may be lowered while being caused to rotate about the center axis relative to the outer cylindrical portion3. By this structure, when the tapered rollers54aand the inner ring raceway58aare brought into contact with each other, the contact surfaces of both the members are allowed to be in contact comfortably to thereby prevent the damage that would otherwise be made to the surfaces of both the members.

In addition, the assembling method and assembling apparatus of the invention can be applied to not only the bearing for the driving wheel but also to a bearing for a driven wheel.