Heat-resistant, high-speed, high-load rolling bearing and grease composition

• US 20030027731A1
• Filed: 06/28/2002
• Published: 02/06/2003
• Est. Priority Date: 06/28/2001
• Status: Abandoned Application

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Mikami, Hidenobu, Kawamura, Takayuki, Asao, Mitsunari
• Application Number:
  US10/183,168
• Publication Number:
  US 20030027731A1
• Time in Patent Office: Days
• US Class Current: 508/552
• CPC Class Codes: C10M 169/00 Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
• CPC Class Codes: C10M 2201/08 Inorganic acids or salts thereof of phosphorus C10M2201/085, of chromium C10M2201/086, of boron C10M2201/087; metal carbonates or bicarbonates C10M2201/062
• CPC Class Codes: C10M 2201/082 containing nitrogen nitrides C10M2201/061
• CPC Class Codes: C10M 2201/083 nitrites
• CPC Class Codes: C10M 2201/085 Phosphorus oxides, acids or salts
• CPC Class Codes: C10M 2201/086 Chromium oxides, acids or salts
• CPC Class Codes: C10M 2207/0406 used as base material
• CPC Class Codes: C10M 2207/2855 used as base material
• CPC Class Codes: C10N 2030/08 Resistance to extreme temperature
• CPC Class Codes: C10N 2040/02 Bearings
• CPC Class Codes: C10N 2040/14 Electric or magnetic purposes
• CPC Class Codes: C10N 2050/10 Semi-solids; greasy

Abstract

A heat-resistant, high-speed, high-load rolling bearing for automotive accessories and electric part is provided which develops no abnormal flaking and is sufficiently long in life and superior in durability. It is a heat-resistant, high-speed, high-load rolling bearing in which is sealed a grease composition which comprises a base oil which is a mixture alkyldiphenyl ether oil and aromatic ester oil at the ratio (in weight) of 50:50 to 80:20, a diurea compound expressed by the following formula as a thickening agent, and 0.1 to 5 wt % of a passivating agent.

(wherein R₂ is an aromatic hydrocarbon group having a carbon number of 6-15, R₁ and R₃ are an aromatic hydrocarbon groups having a carbon number of 6-12 or a cycloaliphatic hydrocarbon group having a carbon number of 6-20. R₁ and R₃ may be identical to or different from each other.)

Claims

1. A heat-resistant, high-speed, high-load rolling bearing in which is sealed a grease composition which comprises a base oil which is a mixture alkyldiphenyl ether oil and aromatic ester oil at the ratio (in weight) of 50:

50 to 80;

20, a diurea compound expressed by the following formula as a thickening agent, and 0.1 to 5 wt % of a passivating agent.

2. The heat-resistant, high-speed, high-load rolling bearing as claimed in claim 1 wherein the rate of the aromatic hydrocarbon group relative to the total amount of R₁ and R₃ is 50-100 mol %.

3. The heat-resistant, high-speed, high-load rolling bearing as claimed in claim 1 or 2 wherein said aromatic ester oil has a dynamic viscosity at 40°

C. of 20 to 150 mm²/s.

4. A grease composition for rolling bearings for use in automotive accessories or electric parts, the grease composition comprising a base oil which is a mixture alkyldiphenyl ether oil and aromatic ester oil at the ratio (in weight) of 50:

50 to 80;

20, a diurea compound expressed by the following formula as a thickening agent, and 0.1 to 5 wt % of a passivating agent.

5. The grease composition as claimed in claim 4 wherein the rate of the aromatic hydrocarbon group relative to the total amount of R₁ and R₃ is 50-100 mol %.

6. The grease composition for a rolling bearing as claimed in claim 4 or 5 wherein said accessory or electric part is an alternator, electromagnetic clutch, tension pulley or one-way clutch.

7. The grease composition as claimed in claim 4 or 5 wherein said aromatic ester oil has a dynamic viscosity at 40°

C. of 20 to 150 mm²/s.