Grease, rolling bearing, rolling bearing device, and information recording and reproducing apparatus

Abstract

Provided are grease containing a base oil and a thickener, a rolling bearing including the grease, a rolling device 6, and an information recording and reproducing apparatus 1. The base oil contains mineral oil and poly-alpha-olefin, a proportion of the mineral oil is 10% by mass to 40% by mass in 100% by mass of the base oil, and a kinematic viscosity v1 of the mineral oil at 40 DEG C is higher than a kinematic viscosity v2 of the poly-alpha-olefin at 40 DEG C.

Description

technical field

[0001] The present invention relates to lubricating grease, rolling bearing, rolling bearing device and information recording and reproducing device.

[0002] This application claims priority based on Japanese Patent Application No. 2015-009485 filed in Japan on January 21, 2015, and Japanese Patent Application No. 2015-236921 filed in Japan on December 3, 2015, the contents of which are incorporated herein. Background technique

[0003] Information recording and reproducing devices such as hard disk drives (HDDs) are known as devices for magnetically or optically recording and reproducing various types of information on a disc. This information recording and reproducing device usually has: the swing arm of the magnetic head gimbal assembly (magnetic head) that records and reproduces signals in the disc is provided at the front end, the rolling bearing device that becomes the fulcrum of the swing arm's rotation, and the swing arm that rotates. actuator. By ...

Examples

Embodiment 1

[0182] Refined mineral oil (classified as Group III mineral oil in the API base oil category with a mass ratio of 3:7. The kinematic viscosity is ν 1 =47mm 2 / s (40°C), mineral oil with a flash point above 250°C) and PAO (a mixture of 3-5 polymers of α-olefins with 8-12 carbon atoms, the kinematic viscosity is ν 2 =30mm 2 / s(40℃)) mixed as base oil (kinematic viscosity ν=34mm 2 / s(40℃)).

[0183] Next, using the above-mentioned base oil and a cycloaliphatic diurea compound as a thickener, it is greased, and an antioxidant and a rust inhibitor are added and mixed. The ratio of each component was 86.0 mass % of base oil, 12.5 mass % of thickener, 0.5 mass % of antioxidant, and 1.0 mass % of rust inhibitor with respect to 100 mass % of grease.

Embodiment 2

[0185] The above-mentioned base oil and a cycloaliphatic diurea compound as a thickener were used for greasing, and a mixed extreme pressure agent was further added in addition to the antioxidant and rust inhibitor, and the same implementation as in Example 1 was carried out. The ratio of each component is: 85.0% by mass of base oil, 12.5% ​​by mass of thickener, 0.5% by mass of antioxidant, 1.0% by mass of rust inhibitor, and 1.0% by mass of extreme pressure agent, based on 100% by mass of grease. quality%.

reference example 1

[0193] As the grease, a commercially available rolling bearing grease α for an information recording and reproducing device was prepared. In addition, grease α contains a urea compound as a thickener.

[0194] Table 1 shows the results of outgassing measurement, durability test, and grease bump test in each of Examples and Comparative Examples. In addition, the results of the low-temperature torque test of the greases of Example 2 and Reference Example 1 are shown in Table 2, and the results of the long-term evaporation loss test are shown in Figure 7~9 middle.

[0195] [Table 1]

[0196]

[0197] [Table 2]

[0198]

[0199] As shown in Tables 1 and 2, including kinematic viscosity ν used at the ratio of the present invention 1 kinematic viscosity ν of PAO 2 The greases of Examples 1 and 2, which are high mineral oil base oils, had a small amount of outgassing. In addition, in Examples 1 and 2, there was little variation in torque in any of the durability test and...

technical field

[0001] The present invention relates to lubricating grease, rolling bearing, rolling bearing device and information recording and reproducing device.

[0002] This application claims priority based on Japanese Patent Application No. 2015-009485 filed in Japan on January 21, 2015, and Japanese Patent Application No. 2015-236921 filed in Japan on December 3, 2015, the contents of which are incorporated herein. Background technique

[0003] Information recording and reproducing devices such as hard disk drives (HDDs) are known as devices for magnetically or optically recording and reproducing various types of information on a disc. This information recording and reproducing device usually has: the swing arm of the magnetic head gimbal assembly (magnetic head) that records and reproduces signals in the disc is provided at the front end, the rolling bearing device that becomes the fulcrum of the swing arm's rotation, and the swing arm that rotates. actuator. By ...

Examples

Embodiment 1

[0182] Refined mineral oil (classified as Group III mineral oil in the API base oil category with a mass ratio of 3:7. The kinematic viscosity is ν 1 =47mm 2 / s (40°C), mineral oil with a flash point above 250°C) and PAO (a mixture of 3-5 polymers of α-olefins with 8-12 carbon atoms, the kinematic viscosity is ν 2 =30mm 2 / s(40℃)) mixed as base oil (kinematic viscosity ν=34mm 2 / s(40℃)).

[0183] Next, using the above-mentioned base oil and a cycloaliphatic diurea compound as a thickener, it is greased, and an antioxidant and a rust inhibitor are added and mixed. The ratio of each component was 86.0 mass % of base oil, 12.5 mass % of thickener, 0.5 mass % of antioxidant, and 1.0 mass % of rust inhibitor with respect to 100 mass % of grease.

Embodiment 2

[0185] The above-mentioned base oil and a cycloaliphatic diurea compound as a thickener were used for greasing, and a mixed extreme pressure agent was further added in addition to the antioxidant and rust inhibitor, and the same implementation as in Example 1 was carried out. The ratio of each component is: 85.0% by mass of base oil, 12.5% ​​by mass of thickener, 0.5% by mass of antioxidant, 1.0% by mass of rust inhibitor, and 1.0% by mass of extreme pressure agent, based on 100% by mass of grease. quality%.

reference example 1

[0193] As the grease, a commercially available rolling bearing grease α for an information recording and reproducing device was prepared. In addition, grease α contains a urea compound as a thickener.

[0194] Table 1 shows the results of outgassing measurement, durability test, and grease bump test in each of Examples and Comparative Examples. In addition, the results of the low-temperature torque test of the greases of Example 2 and Reference Example 1 are shown in Table 2, and the results of the long-term evaporation loss test are shown in Figure 7~9 middle.

[0195] [Table 1]

[0196]

[0197] [Table 2]

[0198]

[0199] As shown in Tables 1 and 2, including kinematic viscosity ν used at the ratio of the present invention 1 kinematic viscosity ν of PAO 2 The greases of Examples 1 and 2, which are high mineral oil base oils, had a small amount of outgassing. In addition, in Examples 1 and 2, there was little variation in torque in any of the durability test and...

Images