前記ハブスピンドル３は、パイロット部８と、取付フランジ部９と、円筒面部１０と、段差面１１と、かしめ部１２とを有する。このうちのパイロット部８は、車輪及び制動用回転体（ブレーキロータ）を外嵌し、これら車輪及び制動用回転体の位置決めを図る為のもので、前記ハブスピンドル３の軸方向外端部に設けられている。前記取付フランジ部９は、前記車輪及び制動用回転体を支持固定する為のもので、前記ハブスピンドル３の外周面の軸方向外端寄り部分に設けられている。前記円筒面部１０は、このハブスピンドル３の外周面の軸方向中間部に設けられており、軸方向両端部（前記段差面１１及び前記かしめ部１２との連続部）を除き、軸方向に亙り直径が変化しない単一円筒面状である。前記段差面１１は、前記取付フランジ部９の軸方向内側面と前記円筒面部１０との間に、軸方向内側に向いた状態で形成されている。前記かしめ部１２は、前記ハブスピンドル３の軸方向内端部に径方向外方に折れ曲がった状態で形成されている。
The hub spindle 3 has a pilot portion 8, a mounting flange portion 9, a cylindrical surface portion 10, a step surface 11 and a caulking portion 12. Among them, the pilot portion 8 is for externally fitting a wheel and a braking rotor (brake rotor), and for positioning of the wheel and the braking rotor, at the axially outer end of the hub spindle 3. It is provided. The mounting flange portion 9 is for supporting and fixing the wheel and the rotating body for braking, and is provided at a portion near the axial direction outer end of the outer peripheral surface of the hub spindle 3. The cylindrical surface portion 10 is provided at an axially intermediate portion of the outer peripheral surface of the hub spindle 3 and is axially wound except at both axial end portions (a continuous portion with the step surface 11 and the caulking portion 12). It is a single cylindrical surface whose diameter does not change. The step surface 11 is formed between the axially inner surface of the mounting flange portion 9 and the cylindrical surface portion 10 so as to be directed inward in the axial direction. The caulking portion 12 is formed at the axially inner end portion of the hub spindle 3 in a state of being bent radially outward.
前記ハブスピンドル３ａは、パイロット部８と、取付フランジ部９と、円筒面部１０と、段差面１１と、かしめ部１２と、外側凹部１５と、内側凹部１６と、隔壁部１７とを備える。前記パイロット部８は、車輪及び制動用回転体を外嵌し、これら車輪及び制動用回転体の位置決めを図る為のもので、前記ハブスピンドル３ａの軸方向外端部に設けられている。前記取付フランジ部９は、前記車輪及び制動用回転体を支持固定する為のもので、前記ハブスピンドル３ａの外周面の軸方向外端寄り部分に設けられている。前記円筒面部１０は、このハブスピンドル３ａの外周面の軸方向中間部に設けられており、軸方向両端部（前記段差面１１及び前記かしめ部１２との連続部）を除き、軸方向に亙り直径が変化しない単一円筒面状である。前記段差面１１は、前記取付フランジ部９の軸方向内側面と前記円筒面部１０との間に、軸方向内側に向いた状態で設けられている。尚、図１に示す例では、前記段差面１１の外径を、前記１対の内輪４ａ、４ｂのうちの軸方向外側の内輪４ａの軸方向外端面の外径とほぼ同じとしている。但し、後述する実施の形態の第２例を示す図２の様に、前記段差面１１の外径を、前記かしめ部１２の軸方向内端面（軸方向内側の内輪４ｂとの接触面）の外径と同じとする事もできる。前記かしめ部１２は、前記ハブスピンドル３ａの軸方向内端部に径方向外方に折れ曲がった状態で設けられている。前記外側凹部１５は、前記ハブスピンドル３ａの中央部に、このハブスピンドル３ａの軸方向外端面にのみ開口する状態で設けられており、（底面と内周面との連続部である軸方向内端部を除いて、）軸方向に亙り内径Ｄ１５がほぼ一定（金型から取り出すのに必要な抜き勾配に就いては一定とみなし、この内径Ｄ１５は平均値を表す。前記内側凹部１６の内径Ｄ１６に関しても同じ。）である。尚、前記外側凹部１５の内周面と前記パイロット部８の内周面とは、軸方向外方に向かう程直径（内径）が大きくなる方向に傾斜した傾斜面部１８（図示の例では円すい凹面状）により連続されている。前記内側凹部１６は、前記ハブスピンドル３ａの中央部に、このハブスピンドル３ａの軸方向内端面にのみ開口する状態で設けられており、（底面と内周面との連続部である軸方向外端部を除いて、）軸方向に亙り内径Ｄ１６がほぼ一定である。前記隔壁部１７は、前記外側凹部１５の底面と前記内側凹部１６の底面との間に設けられている。
The hub spindle 3 a includes a pilot portion 8, a mounting flange portion 9, a cylindrical surface portion 10, a step surface 11, a caulking portion 12, an outer concave portion 15, an inner concave portion 16 and a partition portion 17. The pilot portion 8 is for externally fitting a wheel and a braking rotary body to position the wheel and the braking rotary body, and is provided at an axially outer end of the hub spindle 3a. The mounting flange portion 9 is for supporting and fixing the wheel and the rotating body for braking, and is provided at a portion near the axially outer end of the outer peripheral surface of the hub spindle 3a. The cylindrical surface portion 10 is provided at an axially intermediate portion of the outer peripheral surface of the hub spindle 3a, and except for both axial end portions (a continuous portion with the step surface 11 and the caulking portion 12) It is a single cylindrical surface whose diameter does not change. The step surface 11 is provided between the axially inner surface of the mounting flange portion 9 and the cylindrical surface portion 10 so as to be directed inward in the axial direction. In the example shown in FIG. 1, the outer diameter of the step surface 11 is substantially the same as the outer diameter of the axially outer end surface of the axially outer inner ring 4a of the pair of inner rings 4a and 4b. However, as shown in FIG. 2 showing a second example of the embodiment to be described later, the outer diameter of the step surface 11 is the axial inner end surface of the caulking portion 12 (contact surface with the inner ring 4 b in the axial direction). It can also be the same as the outer diameter. The caulking portion 12 is provided at the axially inner end portion of the hub spindle 3a in a state of being bent radially outward. The outer recess 15 is provided in the central portion of the hub spindle 3a so as to be open only at the outer end face in the axial direction of the hub spindle 3a. except for the end,) substantially constant inner diameter D 15 over axially (for the draft required to retrieve from the mold regarded as constant, the inner diameter D 15 represents the average value. the inner recess 16 The same is true for the inner diameter D 16 of The inner peripheral surface of the outer concave portion 15 and the inner peripheral surface of the pilot portion 8 are inclined surface portions 18 (conical concave surface in the example shown in the drawing) in a direction in which the diameter (inner diameter) becomes larger as it goes axially outward. ) Are continuous. The inner recess 16 is provided at the central portion of the hub spindle 3a so as to open only to the inner end face in the axial direction of the hub spindle 3a (an axial direction which is a continuous portion between the bottom and the inner circumferential surface) The inner diameter D 16 is substantially constant axially, except at the ends. The partition 17 is provided between the bottom of the outer recess 15 and the bottom of the inner recess 16.
上述の様な本例の車輪支持用複列転がり軸受ユニット１ｄによれば、前述の実施の形態の第１例の車輪支持用複列転がり軸受ユニット１ａの場合と同様に、前記車輪支持用複列転がり軸受ユニット１ｄの組み立てに伴う、前記１対の内輪４ａ、４ｂの変形量を小さく抑える事ができると共に、これら１対の内輪４ａ、４ｂの変形量を、これら１対の内輪４ａ、４ｂ同士の間でほぼ同じにする事ができる。この結果、これら１対の内輪４ａ、４ｂとして同じものを使用する事ができ、部品管理を容易化できて、前記車輪支持用複列転がり軸受ユニット１ｄの製造コストを低減する事ができる。
According to the wheel supporting double-row rolling bearing unit 1d of the present embodiment as described above, the wheel supporting double-row rolling bearing unit 1d is similar to the wheel supporting double-row rolling bearing unit 1a of the first example of the embodiment described above. The amount of deformation of the pair of inner rings 4a and 4b associated with the assembly of the row rolling bearing unit 1d can be reduced, and the amount of deformation of the pair of inner rings 4a and 4b can be reduced to the amount of deformation of the pair of inner rings 4a and 4b. It can be made almost the same between each other. As a result, these pair of inner rings 4a, can be used the same as 4b, made facilitate parts management, thereby reducing the manufacturing cost of the wheel supporting double row rolling rising bearing unit 1d.