Method of manufacturing a bearing ring

• US 9,540,705 B2
• Filed: 03/19/2009
• Issued: 01/10/2017
• Est. Priority Date: 03/19/2009
• Status: Active Grant

• Current Assignee: ABet SKF
• Original Assignee: ABet SKF
• Inventors: Vissers, Cornelius Petrus Antonius, Kapaan, Hendrikus Jan, Van De Sanden, Johannes Franciscus, Zwarts, Jacobus
• Primary Examiner(s): Roe, Jessee
• Assistant Examiner(s): WU, JENNY R
• Application Number:
  US13/201,290
• Publication Number:
  US 20120055587A1
• Time in Patent Office: 2,854 Days
• Field of Search: 148/516, 420557-562
• US Class Current: 1/1
• CPC Class Codes: B22D 19/00 Casting in, on, or around objects which form part of the product B22D23/04 takes precedence; alumino-thermic welding B23K23/00; coating by casting molten material on the substrate C23C6/00
• CPC Class Codes: B22D 21/04 Casting aluminium or magnesium no material; see B22D21/007
• CPC Class Codes: B22D 27/20 Measures not previously mentioned for influencing the grain structure or texture; Selection of compositions therefor
• CPC Class Codes: C21D 1/06 Surface hardening
• CPC Class Codes: C21D 1/18 Hardening C21D1/02 takes precedence; Quenching with or without subsequent tempering quenching devices C21D1/62
• CPC Class Codes: C21D 9/40 for rings; for bearing races
• CPC Class Codes: F16C 19/525 related to temperature and heat, e.g. insulation
• CPC Class Codes: F16C 2202/24 Insulating
• CPC Class Codes: F16C 2220/04 by injection-moulding
• CPC Class Codes: F16C 33/60 divided or split, e.g. comprising two juxtaposed rings
• CPC Class Codes: F16C 33/64 Special methods of manufacture
• CPC Class Codes: Y10T 29/49636 Process for making bearing or component thereof

Abstract

The present invention resides in a method of manufacturing a bearing ring (101) for a rolling element bearing, wherein the bearing ring comprises a bearing race (102) made of a bearing grade steel and an overmolded part (106) that is preferably made of a lightweight metal such as aluminum or a thermoplastic material such as polyamide. According to the invention, the method comprises a step of hardening at least a raceway surface (103) of the bearing race prior to a step of joining the overmolded part (106) to the bearing race (102) in a molding process. In a further development, the method comprises a step of temperature control, to ensure that the temperature of the raceway surface (103) is kept below a predetermined value during the molding process.

Claims

1. A method of manufacturing a bearing ring for a rolling element bearing, the method comprising:

producing a bearing race of the bearing ring from a bearing grade steel, the bearing race being of annular shape and having a raceway surface adapted to serve as a raceway for rolling elements of the rolling element bearing;

providing an overmoulded part configured to be secured over the bearing race over a surface radially opposite from the raceway surface, the overmoulded part and the bearing race being configured to be axially aligned and configured to rotate relative to a second bearing raceway;

hardening at least the raceway surface of the bearing race;

after the hardening, providing a thermal barrier on a surface of the bearing race radially opposite from the raceway surface such that the thermal barrier lies between the bearing race and the overmoulded part;

after providing the thermal barrier, joining the overmoulded part to the bearing race in a moulding process that includes one of a molten and semi-molten material being shaped around the bearing race, wherein a temperature of the molten or semi-molten material is greater than a predetermined value and the molten or semi-molten material contains a heat energy sufficient to cause the raceway surface to exceed the predetermined value during the moulding process, the predetermined value being a maximum temperature of the raceway surface which can be withstood by the raceway surface without adversely affecting raceway hardness;

wherein the thermal barrier is configured such that heat energy transferred to the raceway surface by the molten or semi-molten material is insufficient to cause the temperature of the raceway surface to exceed the predetermined value; and

wherein the thermal barrier consists of a material with a melting point lower than the temperature of the molten or semi-molten material such that the thermal barrier is configured to at least partially melt away during the moulding process.

2. A method according to claim 1, wherein the step of hardening further comprises a martensitic heat treatment, and wherein,

at least the raceway surface of the bearing race is heated to an austenitic phase transformation temperature that is rapidly cooled in a quenching medium and then reheated for a period of time at a tempering temperature.

3. A method according to claim 1, wherein the step of hardening comprises subjecting at least the raceway surface of the bearing race to a bainitic hardening process.

4. A method according to claim 1, wherein a layer of one of a bismuth alloy and an indium alloy is provided on the bearing race.

5. A method according to claim 1, wherein the overmoulded part is formed from one of an aluminium and an aluminium alloy and is joined to the bearing race in a semi-solid metal process, being one of a rheocasting process, a rheoforming process, a rheomoulding process, a thixocasting process, a thixoforming process and a thixomoulding process.

6. A method according to claim 1, further comprising the step of determining the heat energy required to raise the temperature of the raceway surface to the predetermined value.