Grease composition for hub unit bearing

Patent metadata

Field	Value
Publication number	US-10081778-B2
Application number	US-201314439250-A
Country	US
Kind code	B2
Filing date	Oct 30, 2013
Priority date	Oct 31, 2012
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

The invention provides a grease composition for hub unit bearing, having (a) as a base oil a mixture of a hydrocarbon synthetic oil and an ester type synthetic oil, with the content of the ester type synthetic oil being 20 to 50 parts by mass with respect to 100 parts by mass of the total of the hydrocarbon synthetic oil and the ester type synthetic oil, and the base oil having a kinematic viscosity at 40° C. of 20 to 80 mm 2 /s, and (b) as a thickener a urea compound.

First claim

The invention claimed is:

1. A grease composition for hub unit bearing, comprising;
(a) as a base oil a mixture of a hydrocarbon synthetic oil and an ester type synthetic oil, with the content of the ester type synthetic oil being 20 to 50 parts by mass with respect to 100 parts by mass of the total of the hydrocarbon synthetic oil and the ester type synthetic oil, and the base oil having a kinematic viscosity at 40° C. of 30 to 80 mm 2 /s,
(b) as a thickener at least one urea compound selected from the group consisting of the compounds represented by the following formulae:

and
(c) an additive

wherein the total content of the mixture of the hydrocarbon synthetic oil and the ester type synthetic oil in the base oil is 100 mass %,
wherein the hydrocarbon synthetic oil is a poly α-olefin and the ester type synthetic oil is an ester of trimethylolpropane, pentaerythritol or dipentaerythritol with an aliphatic straight or branched chain monocarboxylic acid having 2 to 36 carbon atoms,
wherein the content of the thickener in the grease composition is 5 to 25 mass %, and
wherein the content of the additive in the grease composition is 0.1 to 20 mass %.

2. The grease composition of claim 1 , wherein the ester type synthetic oil is an ester of pentaerythritol with a straight or branched chain fatty acid having 7 to 10 carbon atoms, or an ester of dipentaerythritol with a straight or branched chain fatty acid having 7 to 10 carbon atoms.

3. The grease composition of claim 1 , wherein a worked penetration of the grease composition is 280 to 325 when determined in accordance with JIS K2220.

4. The grease composition of claim 1 , wherein the additive comprises at least one rust inhibitor selected from the group consisting of carboxylic acids, derivatives thereof, and sulfonates.

5. The grease composition of claim 4 , wherein the content of the rust inhibitor in the grease composition is 0.25 to 3 mass %.

6. The grease composition of claim 1 , wherein the additive comprises an antioxidant having an amine functional group.

7. The grease composition of claim 6 , wherein the content of the antioxidant in the grease composition is 1 to 3 mass %.

8. The grease composition of claim 1 , wherein the additive comprises an extreme pressure agent.

9. The grease composition of claim 1 , wherein the ester type synthetic oil is an ester of dipentaerythritol with a straight or branched chain fatty acid having 7 to 10 carbon atoms.

Assignees

• Kyodo Yushi
• Honda Motor Co Ltd

Inventors

• Tsutsui Daisuke
• Sato Yuta
• Imai Junichi
• Kawamura Morinobu

Classifications

• C10N2040/02

  Bearings · CPC title

• C10N2030/36

  Seal compatibility, e.g. with rubber · CPC title

• F16C33/6633

  Grease properties or compositions, e.g. rheological properties · CPC title

• C10M169/00

  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 title

• C10M2215/1026

  used as thickening material · CPC title