Wheel-support rolling bearing unit
First Claim
1. A wheel-support rolling bearing unit comprising;
- an inner member having an inner raceway on an outer peripheral surface, an outer member having an outer raceway on an inner peripheral surface, a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway, and a flange provided on the peripheral surface of at least one member of said inner member and said outer member, for fastening to a part of a suspension device or a wheel,wherein in a portion being a part of at least one member of said inner member and said outer member and including said inner raceway or said outer raceway, a hardened layer is formed by induction hardening, andat least one member of said inner member and said outer member is made from an alloy steel containing 0.5 to 0.65 weight % of C, 0.3 to 1.5 weight % of Mn, 0.1 to 1.0 weight % of Si, and 0.01 to 0.5 weight % of Cr, and the S content is kept to 0.035 weight % or less, and further including any one type or more selected from 0.01 to 0.2 weight % of V, 0.01 to 0.15 weight % of Nb, and 0.01 to 0.15 weight % of Ti, with the rest being Fe and inevitable impurities, and the oxygen contents of the alloy steel is 15 ppm or less, andfor at least one member of said inner member and said outer member, the surface hardness of the inner raceway or the outer raceway formed with the hardened layer, is between Hv 650 and 780, and for at least one member of the inner member and the outer member, the surface hardness of a portion not formed with the hardened layer is between Hv 230 and 300.
1 Assignment
0 Petitions
Accused Products
Abstract
In a wheel-support rolling bearing unit, in order to made a flange 6 thinner and thus lighten the bearing unit without impairing fatigue strength, machinability, and workability after forging, the composition of the alloy steel constituting the flange attached member (hub ring 2), the surface hardness of the root portion 14 on the axial outside surface side of the flange 6, and the surface roughness, are stipulated to thereby improve the durability ratio (fatigue limit strength/tensile strength) of the flange 6. In one aspect, the member is made from an alloy steel containing C: 0.5 to 0.65 weight %, Mn: 0.3 to 1.5 weight %, Si: 0.1 to 1.0 weight %, Cr: 0.01 to 0.5 weight %, S: 0.35 weight % or less, and any one type or more selected from 0.01 to 0.2 weight % of V, 0.01 to 0.15 weight % of Nb, and 0.01 to 0.15 weight % of Ti, with the rest being Fe and inevitable impurities, and the oxygen contents is 15 ppm or less. Moreover, the surface hardness of the inner raceway 7a formed with the hardened layer, is between Hv 650 and 780, and the surface hardness of a portion not formed with the hardened layer is between Hv 230 and 300.
33 Citations
30 Claims
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1. A wheel-support rolling bearing unit comprising;
- an inner member having an inner raceway on an outer peripheral surface, an outer member having an outer raceway on an inner peripheral surface, a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway, and a flange provided on the peripheral surface of at least one member of said inner member and said outer member, for fastening to a part of a suspension device or a wheel,
wherein in a portion being a part of at least one member of said inner member and said outer member and including said inner raceway or said outer raceway, a hardened layer is formed by induction hardening, and at least one member of said inner member and said outer member is made from an alloy steel containing 0.5 to 0.65 weight % of C, 0.3 to 1.5 weight % of Mn, 0.1 to 1.0 weight % of Si, and 0.01 to 0.5 weight % of Cr, and the S content is kept to 0.035 weight % or less, and further including any one type or more selected from 0.01 to 0.2 weight % of V, 0.01 to 0.15 weight % of Nb, and 0.01 to 0.15 weight % of Ti, with the rest being Fe and inevitable impurities, and the oxygen contents of the alloy steel is 15 ppm or less, and for at least one member of said inner member and said outer member, the surface hardness of the inner raceway or the outer raceway formed with the hardened layer, is between Hv 650 and 780, and for at least one member of the inner member and the outer member, the surface hardness of a portion not formed with the hardened layer is between Hv 230 and 300. - View Dependent Claims (2)
- an inner member having an inner raceway on an outer peripheral surface, an outer member having an outer raceway on an inner peripheral surface, a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway, and a flange provided on the peripheral surface of at least one member of said inner member and said outer member, for fastening to a part of a suspension device or a wheel,
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3. A wheel-support rolling bearing unit comprising:
- a stationary ring which is supported on a suspension device during use and does not rotate;
a rotating ring disposed concentric with said stationary ring, and which is fastened to a wheel during use and which rotates together with said wheel;
an outer raceway provided on an inner peripheral surface of an outer diameter side bearing ring of one of said rotating ring and said stationary ring which exists radially outwards;
an inner raceway provided on an outer peripheral surface of an inner diameter side bearing ring of the other of said rotating ring and said stationary ring which exists radially inwards;
a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway; and
a flange provided on the outer peripheral surface of said rotating ring, for fastening a wheel,wherein at least a portion of said rotating ring that is provided with said flange is made from a carbon steel containing 0.5 to 0.8 weight % of C, and in this rotating ring, at least the hardness of the surface of a root portion on an axial outside surface side of said flange is between 24 and 35 by Rockwell hardness C scale, that is between 260 and 345 by Vickers hardness. - View Dependent Claims (4)
- a stationary ring which is supported on a suspension device during use and does not rotate;
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5. A wheel-support rolling bearing unit comprising:
- a stationary ring which is supported on a suspension device during use and does not rotate;
a rotating ring disposed concentric with said stationary ring, and which is fastened a wheel during use and which rotates together with said wheel;
an outer raceway provided on an inner peripheral surface of an outer diameter side bearing ring of one of said rotating ring and said stationary ring which exists radially outwards;
an inner raceway provided on an outer peripheral surface of an inner diameter side bearing ring of the other of said rotating ring and said stationary ring which exists radially inwards;
a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway; and
a flange provided on the outer peripheral surface of said rotating ring, for fastening a wheel,wherein in said rotating ring, at least the surface roughness of a root portion on an axial outside surface side of said flange is between 0.1 and 1.0 μ
m by arithmetic average roughness Ra.
- a stationary ring which is supported on a suspension device during use and does not rotate;
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6. A wheel-support rolling bearing unit comprising:
- a stationary ring which is supported on a suspension device during use and does not rotate;
a rotating ring disposed concentric with said stationary ring, and which is fastened a wheel during use and which rotates together with said wheel;
an outer raceway provided on an inner peripheral surface of an outer diameter side bearing ring of one of said rotating ring and said stationary ring which exists radially outwards;
an inner raceway provided on an outer peripheral surface of an inner diameter side bearing ring of the other of said rotating ring and said stationary ring which exists radially inwards;
a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway; and
a flange provided on the outer peripheral surface of said rotating ring, for fastening a wheel,wherein in said rotating ring, at least the surface roughness of a root portion on an axial outside surface side of said flange is 10 μ
m or less by maximum height Ry.
- a stationary ring which is supported on a suspension device during use and does not rotate;
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7. A flanged bearing unit comprising:
- an inner member having a raceway surface on an outside surface;
an outer member having a raceway surface facing the raceway surface of said inner member on an inner surface and arranged on the outside of said inner member;
rolling elements rotatably arranged between said raceway surfaces; and
a flange provided at least on one of said inner member and said outer member, wherein at least the member provided with said flange is made from a carbon steel having a carbon content between 0.45 weight % and 0.65 weight %, and an area ratio of pro-eutectoid ferrite of at least said flange is between 3 and 15%. - View Dependent Claims (8, 9, 10, 11, 19)
- an inner member having a raceway surface on an outside surface;
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12. A method of manufacturing a flanged bearing unit wherein a plurality of rolling elements are arranged between an inner member and an outer member having a flange for attaching at least one member of said inner member and said outer member on a fixed side or a rotation side, and having a hardened layer made by induction hardening at least in the vicinity of a raceway portion, and at least the member provided with said flange is formed by hot forging using an alloy steel containing C, 0.45 to 0.65 weight %, Mn:
- 0.3 to 1.5 weight %, Si;
0.1 to 1.0 weight %, Cr;
0.01 to 0.5 weight %, S≦
0.025 weight %, O≦
15 ppm, and the rest being Fe and inevitable impurities, and the material heating temperature at the time of said hot forging is between 900 and 1050°
C., and the temperature at the time of finishing forge stamping is 800°
C. or more. - View Dependent Claims (13, 14, 15)
- 0.3 to 1.5 weight %, Si;
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16. A method of manufacturing a flanged bearing unit wherein a plurality of rolling elements are arranged between an inner member and an outer member having a flange for attaching at least one member of said inner member and said outer member on a fixed side or a rotation side, and having a hardened layer made by induction hardening at least in the vicinity of a raceway portion, and at least the member provided with said flange is formed by hot forging using an alloy steel containing C, 0.45 to 0.65 weight %, Mn:
- 0.3 to 1.5 weight %, Si;
0.1 to 1.0 weight %, Cr;
0.01 to 0.5 weight %, S≦
0.025 weight %, O≦
15 ppm, and the rest being Fe and inevitable impurities, and the material heating temperature at the time of said hot forging is between 900 and 1050°
C., and the average cooling rate from the temperature at the time of finishing forge stamping until reaching 600°
C. is between 0.5 and 5°
C./sec.
- 0.3 to 1.5 weight %, Si;
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17. A wheel-support flanged bearing unit having a plurality of rolling elements arranged between an inner member and an outer member, and a flange for attaching at least one member of said inner member and said outer member on a vehicle body side or a wheel side, and having a hardened layer made by induction hardening at least in the vicinity of a raceway portion, wherein at least the member provided with said flange is formed from an alloy steel containing C, 0.45 to 0.50 weight %, Si:
- 0.3 to 1.5 weight %, V;
0.03 to 0.3 weight %, Mn≦
1.5 weight %, Cr≦
1.0 weight %, S≦
0.035 weight %, O≦
15 ppm, and the rest being Fe and inevitable impurities, and the C+0.2Si+0.5V value satisfies between 0.55 and 0.75, and the raceway portion surface hardness of the hardened layer made by said induction hardening is between Hv 630 and Hv 750, and the hardness of the portion which is not subjected to hardening treatment by said induction hardening is between Hv 220 and Hv 300. - View Dependent Claims (18)
- 0.3 to 1.5 weight %, V;
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20. A wheel-support rolling bearing unit comprising:
- an inner member having an inner raceway on an outer peripheral surface;
an outer member having an outer raceway on an inner peripheral surface; and
a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway, wherein a member being at least one member of said inner member and said outer member and comprising a flange on the outer peripheral surface, is made from a steel containing 0.45 to 0.60 weight % of C, and has a hardened layer formed by induction hardening, on the raceway portion provided on the peripheral surface, and the hardness of a portion at a depth of 0.1 mm from the surface of this hardened layer is Hv 670 or more, and a prior austenite grain size of the metal structure of this hardened layer is 8 or more in grain size number according to JIS G 0551. - View Dependent Claims (21, 22)
- an inner member having an inner raceway on an outer peripheral surface;
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23. A wheel-support rolling bearing unit comprising:
- a stationary ring which is supported on a suspension device during use and does not rotate;
a rotating ring disposed concentric with said stationary ring, and which is fastened a wheel during use and which rotates together with said wheel;
an outer raceway provided on an inner peripheral surface of an outer diameter side bearing ring of one of said rotating ring and said stationary ring which exists radially outwards;
an inner raceway provided on an outer peripheral surface of an inner diameter side bearing ring of the other of said rotating ring and said stationary ring which exists radially inwards;
a plurality of rolling elements rotatably provided between said inner raceway and said outer raceway; and
a flange provided on the outer peripheral surface of said rotating ring, for fastening a wheel,wherein said rotating ring is made from a carbon steel containing 0.45 to 0.60 weight % of C, and in this rotating ring, at least a root portion on the axial outside surface side of said flange is made from a pro-eutectoid ferrite wherein a prior austenite grain size number is 4 or more in JIS G0551, and the area ratio is between 3 and 15%. - View Dependent Claims (24, 25, 26, 27, 28, 29)
- a stationary ring which is supported on a suspension device during use and does not rotate;
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30. A wheel-support rolling bearing unit comprising;
- an inner ring, an outer ring, a plurality of rolling elements rotatably provided between said inner ring and said outer ring, and a hub ring made from steel having said inner ring integrally fixed by swaging, wherein
said steel contains manganese and 0.45 to 0.65 mass % of carbon, and manganese segregation degree determined by the following equation is 0.6 or less if the manganese content [Mn0] is 0.5 mass % or more, and is (2.8−
2×
[Mn0]/3 or less if the manganese content [Mn0] is less than 0.5 mass %;manganese segregation degree=([Mn]−
[Mn0])/[Mn0]where [Mn] is the maximum manganese concentration of the steel;
the unit is mass %.
- an inner ring, an outer ring, a plurality of rolling elements rotatably provided between said inner ring and said outer ring, and a hub ring made from steel having said inner ring integrally fixed by swaging, wherein
Specification