Grease for high-speed bearing

Abstract

A grease for a high-speed bearing which can sufficiently accommodate high-speed rotation with a dmN value of 1,700,000 or above and which enables compactification of machine tools and operating cost reduction, more specifically, a grease for high-speed bearings which comprises both a urea grease containing a urea compound as the thickening agent and a non-urea grease containing a composite amide lithium soap having an amide linkage in the molecule as the thickening agent, wherein the urea compound is a compound prepared by reacting a polyisocyanate component with a monoamine component, with the monoamine component containing an aliphatic monoamine in an amount of 46% by mole or above of the whole monoamine component.

Description

technical field [0001] The present invention relates to a high-speed bearing grease used for rolling bearings that support high-speed rotating shafts such as machine tool spindles. Background technique [0002] The spindle of a machine tool is preferably a spindle that rotates at a high speed in order to improve machining efficiency, and various lubrication techniques are used in this bearing. As a lubrication method suitable for a high-speed rotating spindle, for example, methods such as oil mist lubrication, air oil mist lubrication, and jet lubrication are known. However, these lubricating methods require auxiliary equipment such as compressed air or oil feeder, which is one of the reasons for the increase in the original cost and operating cost of the machine tool. On the other hand, grease lubrication can be said to be the preferred lubrication method since maintenance is less necessary. For example, as a high-speed rolling bearing that supports a rotating shaft rotat...

AI Technical Summary

Problems solved by technology

[0010] (b) With regard to low torque performance (inhibition of temperature rise), the existing grease for high-speed bearings, as mentioned above, should suppress the viscosity of the base oil to a low value, but there is a problem that when the bearing rotates at high speed, Viscosity decreases significantly due to temperature rise, and an oil film with the thickness necessary for lubrication cannot be formed

With the increase in the rotational speed of such bearings, it is difficult to fully satisfy the performance required by the bearings with existing greases.

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