Rolling Bearing

• US 20090103844A1
• Filed: 12/05/2006
• Published: 04/23/2009
• Est. Priority Date: 01/05/2006
• Status: Active Grant

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Lee, Sun woo, Kobayashi, Takuji, Takiuchi, Hiroshi, Mori, Masatsugu
• Granted Patent: US 7,874,733 B2
• Time in Patent Office: Days
• US Class Current: 384/462
• CPC Class Codes: F16C 19/163 with angular contact
• CPC Class Codes: F16C 19/26 with a single row of rollers
• CPC Class Codes: F16C 19/364 with tapered rollers, i.e. rollers having essentially the shape of a truncated cone
• CPC Class Codes: F16C 19/548 in O-arrangement
• CPC Class Codes: F16C 2322/39 General buildup of machine tools, e.g. spindles, slides, actuators
• CPC Class Codes: F16C 33/585 of raceways, e.g. ribs to guide the rollers
• CPC Class Codes: F16C 33/6607 Retaining the grease in or near the bearing
• CPC Class Codes: F16C 33/6625 Controlling or conditioning the grease supply
• CPC Class Codes: F16C 33/6674 related to the amount supplied, e.g. gaps to restrict flow of the liquid
• CPC Class Codes: F16C 37/007 of rolling bearings
• CPC Class Codes: F16N 2210/14 Bearings

Abstract

To provide a rolling bearing assembly, in which a grease filled within the bearing assembly is utilized to achieve a high speed feature, a long life and a maintenance-free and a lubricant oil can be stably supplied from a minute gap, a stepped face continued from the raceway surface is provided in a stationary raceway ring unit of an inner and outer ring units in a direction away from rolling elements. A gap forming piece having a free end confronting the stepped face is provided to define therebetween a flow passage and a grease reservoir communicated with the flow passage. The rolling bearing assembly is so designed that a heat cycle can be induced in the grease reservoir and, base oil of the grease can be urged to flow out from the gap by the effect of a pressure variation caused by the temperature rise.

Claims

1. A rolling bearing assembly which comprises:

an inner ring unit forming a raceway ring unit;

an outer ring unit forming another raceway ring unit;

a plurality of rolling elements interposed between respective raceway surfaces of the inner and outer ring units;

a stepped face continued from the raceway surface provided in one of the inner ring unit and the outer ring unit that serves as a stationary raceway ring unit, in a direction away from the rolling elements;

a gap forming piece having a free end confronting the stepped face to define a gap therebetween, and a peripheral wall cooperating with the stationary raceway ring unit to define a flow passage therebetween; and

a grease reservoir communicated with the flow passage and subjected to a heat cycle of ascent and descent of a temperature.

2. The rolling bearing assembly as claimed in claim 1, wherein the gap between the stepped face and the gap forming piece is selected to be within the range of 0.05 to 0.1 mm.

3. The rolling bearing assembly as claimed in claim 1, further comprising a grease reservoir cooling liquid recirculating passage, through which a cooling liquid for cooling a member in contact with the stationary raceway ring unit is recirculated around the grease reservoir, wherein the heat cycle of ascent and descent of the temperature is applied to the grease reservoir generated by a time-dependent change of an amount of the cooling liquid flowing through the grease reservoir cooling liquid recirculating passage.

4. The rolling bearing assembly as defined in claim 3, wherein the stationary raceway ring unit is the outer ring unit and the member in contact with the stationary raceway ring unit is a housing accommodating the outer ring.

5. The rolling bearing assembly as claimed in claim 1, wherein the rolling bearing assembly is an angular contact ball bearing for supporting a machine tool spindle.

6. The rolling bearing assembly as claimed in claim 1, wherein the rolling bearing assembly is a cylindrical roller bearing for supporting a machine tool spindle.

7. The rolling bearing assembly as claimed in claim 1, wherein the rolling bearing assembly is a tapered roller bearing for supporting a machine tool spindle.

8. A method of using a rolling bearing assembly that includes an inner ring unit forming a raceway ring unit;

an outer ring unit forming another raceway ring unit;

a plurality of rolling elements interposed between respective raceway surfaces of the inner and outer ring units;

a stepped face continued from the raceway surface provided in one of the inner ring unit and the outer ring unit that serves as a stationary raceway ring unit, in a direction away from the rolling elements;

a gap forming piece having a free end confronting the stepped face to define a gap therebetween selected to be within the range of 0.05 to 0.1 mm, and a peripheral wall cooperating with the stationary raceway ring unit to define a flow passage therebetween; and

a grease reservoir communicated with the flow passage,

the method comprising using the roller bearing assembly under an environment in which a heat cycle of ascent and descent of a temperature is applied to the grease reservoir.