本例の場合、第一、第二各保持器２０、２１ａはそれぞれ、前述の図８〜９に示した従来構造の場合と同様、それぞれ複数個ずつの第一、第二各円すいころ５、６を保持した状態で、これら各円すいころ５、６が直径方向外方に脱落するのを防止する構造を有する。又、上記第二保持器２１ａは、その内端部外周面に径方向外方に突出する突出部３０を、全周に亙り、或は周方向複数個所（３個所以上）等間隔位置に形成している。図２に詳示する様に、この突出部３０の自由状態での外径Ｄ30は、上記各第二円すいころ６、６の転動面を上記第二内輪軌道１５に当接させると共に、これら各第二円すいころ６、６の大径側端面を上記第二内輪軌道１５の大径側端部に形成した大鍔部２９の内側面に当接させた状態での、上記各第二円すいころ６、６の大径側端部の外接円の直径ｄ6 よりも大きく（Ｄ30＞ｄ6 ）している。
In the case of this example, the first and second cages 20 and 21a respectively have a plurality of first and second tapered rollers 5, respectively, as in the case of the conventional structure shown in FIGS. In the state of holding 6, the tapered rollers 5, 6 have a structure to prevent them from dropping outward in the diameter direction. Further, the second retainer 21a is formed with projecting portions 30 which project radially outward on the outer peripheral surface of the inner end portion, all around the circumference or at a plurality of circumferential locations (three or more locations) at equal intervals. doing. As shown in detail in FIG. 2, an outer diameter D 30 in the free state of the projection 30 makes the rolling surface of each of the second tapered rollers 6, 6 abut on the second inner ring raceway 15 , Each of the second tapered rollers 6, 6 in the state where the large diameter side end face of each of the second tapered rollers 6, 6 is in contact with the inner surface of the large flange portion 29 formed at the large diameter side end of the second inner ring raceway 15. The diameter d 6 of the circumscribed circle of the large diameter side end portion of the tapered rollers 6 is larger (D 30 > d 6 ).
次いで、図４に示す様に、複数個の第二円すいころ６、６を、前記第二保持器２１ａにより、内輪３の外周面に設けた第二内輪軌道１５の周囲に脱落不能に保持した状態で、この内輪３を上記ハブ本体２の小径段部１２に外嵌する作業を行なう。そして、この様な外嵌作業を行なう事により、上記各第二円すいころ６、６を上記第二内輪軌道１５と上記外輪４の内半部内周面に形成した第二外輪軌道１８との間に組み付ける。特に、本例の場合には、この内輪３の外嵌作業を、案内治具３１を使用して行なう。
Then, as shown in FIG. 4, a plurality of second circle tapered roller 6,6, by the second retainer 21 a, so as not to fall off the periphery of the second inner ring raceway 15 which is provided on the outer peripheral surface of the inner ring 3 holding In this state, the inner ring 3 is externally fitted to the small diameter step portion 12 of the hub body 2. And, by performing such an outer fitting operation, between the second inner ring raceway 15 and the second outer ring raceway 18 formed on the inner peripheral surface of the inner half portion of the outer ring 4 each of the second tapered rollers 6, 6 Assemble to In particular, in the case of this example, the outer fitting operation of the inner ring 3 is performed using the guide jig 31.
この案内治具３１は、全体を円筒状に形成すると共に、一端部（図３〜４の下端部）に外径が小さい薄肉の嵌合筒部３３を設けている。又、この案内治具３１の内周面は、それぞれが円筒面状で互いに同心の大径部３４（内径Ｄ34）及び小径部３５｛内径ｄ35（＜Ｄ34）｝と、これら大径部３４と小径部３５との軸方向端縁同士を連続させる円すい凹面（テーパ面）状の連続部３６とから成る。使用時に挿入側開口部で上側となる上記大径部３４の内径Ｄ34は、上記第二保持器２１ａの内端部外周面に設けた突出部３０の外径Ｄ30以上（Ｄ34≧Ｄ30）としている。一方、上記小径部３５の内径ｄ35は、上記第二保持器２１ａの突出部３０の外径Ｄ30よりも僅かに小さく（ｄ35＜Ｄ30）、且つ、上記各第二円すいころ６、６の大径側端部の外接円の直径ｄ6 以上（ｄ35≧ｄ6 ）としている。この様な案内治具３１は、上記外輪４に対し、図３〜４に示す様に、上記嵌合筒部３３をこの外輪４の内端部にがたつきなく内嵌すると共に、この嵌合筒部３３の基端部に設けた段差面３７を上記外輪４の内端面に突き当てた状態で装着する。
The entire guide jig 31 is formed in a cylindrical shape, and a thin fitting cylinder portion 33 having a small outer diameter is provided at one end (the lower end in FIGS. 3 to 4). Further, the inner peripheral surface of the guide jig 31 has a large diameter portion 34 (inside diameter D 34 ) and a small diameter portion 35 {inside diameter d 35 (<D 34 )} which are cylindrical surfaces and concentric with each other, It consists of a conical concave (taper surface) -like continuous part 36 which makes the axial direction edges of the part 34 and the small diameter part 35 continue. The inner diameter D 34 of the large diameter portion 34 which is the upper side at the insertion side opening in use is the outer diameter D 30 or more of the projecting portion 30 provided on the outer peripheral surface of the inner end portion of the second cage 21 a (D 34 ≧ D 30 ). On the other hand, the inner diameter d 35 of the small diameter portion 35 is slightly smaller than the outer diameter D 30 of the projecting portion 30 of the second cage 21 a (d 35 <D 30 ), and each second tapered roller 6 , Diameter d 6 or more of the circumscribed circle of the large diameter end of 6 (d 35 d d 6 ). As shown in FIGS. 3 and 4, the guide jig 31 as described above fits the fitting cylindrical portion 33 into the inner end portion of the outer ring 4 without rattling, as shown in FIGS. It mounts in the state where the level difference side 37 provided in the base end part of the combined cylinder part 33 abuts on the inner end face of the above-mentioned outer ring 4.
上記内輪３を上記ハブ本体２の小径段部１２に外嵌する作業は、図４に示す様に、この内輪３の内端面（組立作業時の上端面）を押圧治具３８により下方に押圧しつつ、この内輪３を、上記案内治具３１の内側を通過させつつ行なう。この様にして内輪３を通過させる際に、上記第二保持器２１ａの内端部外周面に設けた突出部３０は、上記案内治具３１の内周面に設けた大径部３４の内側から小径部３５の内側に、円すい凹面状の連続部３６に案内されつつ進入する。この小径部３５の内径ｄ35は、上記突出部３０の外径Ｄ30よりも僅かに小さい（ｄ35＜Ｄ30）為、上述の様に突出部３０を小径部３５の内側の進入させると、この突出部３０の外周縁がこの小径部３５に、全周に亙り弾性的に（締め代を持って）当接する。尚、本例の場合、上記内輪３を上記小径段部１２に圧入する直前に、上記突出部３０が上記小径部３５の内側に進入する様に、各部の寸法を規制している。又、上記小径部３５の内径ｄ35は、上記各第二円すいころ６、６の大径側端部の外接円の直径ｄ6 以上（ｄ35≧ｄ6 ）である為、これら各第二円すいころ６、６の大径側端部が上記小径部３５に弾性的（締め代を持って）に当接する事はない。
In the work of externally fitting the inner ring 3 to the small diameter step portion 12 of the hub main body 2, as shown in FIG. 4, the inner end face (upper end face at the time of assembling work) of the inner ring 3 is pressed downward by a pressing jig 38. While doing this, the inner ring 3 is passed through the inside of the guide jig 31. Thus, when passing the inner ring 3, the projecting portion 30 provided on the outer peripheral surface of the inner end portion of the second cage 21 a is the large diameter portion 34 provided on the inner peripheral surface of the guide jig 31. While being guided by the conical concave continuous portion 36 from the inside to the inside of the small diameter portion 35, it enters. The inner diameter d 35 of the small diameter portion 35 is slightly smaller (d 35 <D 30) than the outer diameter D 30 of the projection 30 for, when the projection 30 is entering the inside of the small-diameter portion 35 as described above The outer peripheral edge of the projecting portion 30 abuts on the small diameter portion 35 elastically (with an interference) around the entire circumference. In the case of this example, the dimensions of each portion are regulated so that the projecting portion 30 enters the inside of the small diameter portion 35 immediately before press-fitting the inner ring 3 into the small diameter step portion 12. Further, since the inner diameter d 35 of the small diameter portion 35 is equal to or larger than the diameter d 6 of the circumscribed circle of the large diameter side end portion of each of the second tapered rollers 6 6 (d 35 6 d 6 ) The large diameter side end portions of the tapered rollers 6, 6 do not contact the small diameter portion 35 elastically (with an interference).
上述の様に突出部３０を小径部３５の内側に進入させた状態から更に、上記内輪３を上記小径段部１２に向けて押し込むと、上記突出部３０の外周縁と上記小径部３５との当接部に、摺動に基づく摩擦力が作用する。そして、この摩擦力に基づき、上記第二保持器２１ａ及びこの第二保持器２１ａにより保持した上記各第二円すいころ６、６が上記内輪３に対し、この内輪３の押し込み方向後方に相対変位し、これら各第二円すいころ６、６の大径側端面が、前記第二内輪軌道１５の大径側端部に形成した大鍔部２９の内側面と当接する。そして、この状態で、上記内輪３を上記小径段部１２に外嵌する事により、上記各第二円すいころ６、６を、上記第二内輪軌道１５と前記外輪４の内半部内周面に設けた第二外輪軌道１８との間に組み付ける。この様に、本例の場合には、上記各第二円すいころ６、６の大径側端面を上記大鍔部２９の内側面に当接させた状態で、これら各第二円すいころ６、６を上記第二内輪軌道１５と上記第二外輪軌道１８との間に組み付ける事ができる。この為、組み付けを行なう際に、上記各第二円すいころ６、６が、不正規位置に存在したまま、上記第二内輪軌道１５と上記第二外輪軌道１８との間にくさび状に食い付く事を防止できる。
When the inner ring 3 is further pushed toward the small diameter step 12 from the state where the projection 30 is made to enter the inside of the small diameter part 35 as described above, the outer peripheral edge of the projection 30 and the small diameter part 35 A frictional force based on the sliding acts on the contact portion. Then, based on this frictional force, the second retainer 21 a and the second retainer 21 above the second circle which is held by a tapered roller 6,6 to the inner ring 3, the push-in direction behind the inner ring 3 Relatively displaced, the large diameter side end faces of the respective second tapered rollers 6 abut against the inner side surface of the large collar portion 29 formed at the large diameter side end of the second inner ring raceway 15. Then, in this state, by externally fitting the inner ring 3 to the small diameter step portion 12, the second tapered rollers 6, 6 are formed on the inner peripheral surface of the second inner ring raceway 15 and the inner half portion of the outer ring 4. It assemble | attaches between the provided 2nd outer ring | wheel raceways 18. As shown in FIG. Thus, in the case of this example, with the large diameter side end faces of the second tapered rollers 6, 6 being in contact with the inner side surface of the large collar portion 29, the respective second tapered rollers 6, 6, 6 can be assembled between the second inner ring raceway 15 and the second outer ring raceway 18. Therefore, when assembling, the respective second tapered rollers 6, 6 are wedged between the second inner ring raceway 15 and the second outer ring raceway 18 while being present at an irregular position. You can prevent things.
