JP2018031465A - Ball bearing - Google Patents

Abstract

A ball bearing capable of suppressing a bearing torque to be low and maintaining a smooth riding comfort when a skateboard or the like slides can be provided.
SOLUTION: An outer ring 2, an inner ring 3 disposed on the inner side of the outer ring 2, a ball 4 disposed between the outer ring 2 and the inner ring 3, a cage 5 for holding the ball 4, In the ball bearing in which the lubricating oil is applied to the inside of the bearing, the average adhesion film thickness of the lubricating oil is 0.1 μm or more and 1.4 μm or less. The lubricating oil is a mixed oil composed of a base oil and a rust preventive oil.
[Selection] Figure 1

Description

  The present invention relates to a ball bearing capable of reducing rolling friction of wheels such as a skateboard and a roller skate.

Conventionally, a rotating part of a wheel such as a skateboard or a roller skate guides a rolling element between an outer ring and an inner ring, a rolling element disposed between opposing surfaces of the inner ring and the outer ring, and an outer ring and an inner ring. A small-diameter ball bearing composed of a cage is generally used in many cases. In particular, wheels such as skateboards for competition are required to have a low bearing torque in order to improve athlete performance.
Various greases and lubricating oils have been proposed to reduce the bearing torque, and oil lubrication is excellent for lowering the torque. For example, in Patent Document 1, for the purpose of rust prevention and torque reduction, grease containing sulfonate and containing 20% by weight or more of ether oil having a kinematic viscosity of 10 to 100 mm ² / s is adhered to the inside of the bearing. The amount of oil being used is described as a prescribed amount of 2-3 mg.

However, in the case of oil lubrication, the bearing torque varies greatly depending on the amount of oil inside the bearing, and the ride comfort changes.
Japanese Patent Laid-Open No. 7-179879

  An object of the present invention is to provide a ball bearing that can keep the bearing torque low and maintain a smooth riding comfort during sliding of a skateboard or the like.

In order to solve the above problems, a ball bearing according to a first invention comprises an outer ring, an inner ring disposed inward of the outer ring, a ball disposed between the outer ring and the inner ring, and a ball. A ball bearing provided with a retainer and coated with lubricating oil inside the bearing, wherein the lubricating oil has an average coating thickness of 0.1 μm or more and 1.4 μm or less. .
The ball bearing of the second invention is characterized in that the lubricating oil in the first invention is a mixed oil composed of a base oil and a rust preventive oil.
A ball bearing according to a third aspect is the ball bearing according to the first aspect, wherein the lubricating oil is composed of a base oil alone, or a base oil and an additive oil, and the most dynamic of the base oil alone or an additive oil added thereto. The kinematic viscosity of the high viscosity oil is 14 mm ² / s or less.
The ball bearing according to a fourth aspect of the present invention is the ball bearing according to the second aspect, wherein the lubricating oil has a kinematic viscosity of the base oil of 2.0 mm ² / s or less and a rust preventive oil having a kinematic viscosity of 14 mm ² / s or less. It is characterized by becoming.
The ball bearing of the fifth invention is characterized in that, in the second or fourth invention, the blending ratio of the rust preventive oil is 3% by volume or less.

  ADVANTAGE OF THE INVENTION According to this invention, the ball bearing which can suppress bearing torque low and can maintain the smooth riding comfort at the time of sliding of a skateboard etc. can be provided.

It is a schematic sectional drawing which shows partially one Embodiment of this invention ball bearing. It is a figure showing the relationship between the rotation time and the adhesion film thickness in the Example and comparative example of this invention.

The configuration of the ball bearing according to the embodiment of the present invention will be described below.
As shown in FIG. 1, the ball bearing 1 of the present embodiment includes an outer ring 2, an inner ring 3 disposed inside the outer ring 2, and a rolling element disposed between the outer ring 2 and the inner ring 3 and rolling. (Balls) 4 and a cage 5 for holding the rolling elements (balls) 4 are provided.
A sealing device (not shown) is used to seal the lubricating oil inside the bearing.

  The inner and outer rings 2, the inner ring 3 and the rolling element 4 are not particularly limited to the illustrated form, and can be modified within the scope of the present invention. These materials have the same physical properties as bearing steel. The material is not particularly limited.

  The retainer 5 is not particularly limited to the illustrated form, and the design can be changed within the scope of the present invention. In this embodiment, a crown retainer is adopted. The material of the cage 5 is not particularly limited, but a high-strength resin cage that has a high effect of reducing friction torque is preferable.

  The sealing device is not particularly limited, but a shield plate or a non-contact rubber seal is preferable in order to reduce torque. More preferably, a non-contact rubber seal that does not require paint or the like for improving the design property and can also improve the dust resistance is preferable. Further, the material of the shield plate and the contact rubber seal is not particularly limited, but is preferably a material capable of reducing torque.

Lubricating oil is applied to the surface of each component inside the bearing. In this case, the composition of the lubricating oil is not particularly limited, but it is preferable that the lubricating oil inside the bearing is applied with an average adhesion film thickness of 0.1 μm or more and 1.4 μm or less. More preferably, it is 0.1 μm or more and 0.4 μm or less. The average adhesion film thickness of the lubricating oil is the average value of the film thicknesses on the inner surface of the outer ring, the outer surface of the inner ring, the raceway surface of the inner and outer rings, the cage surface and the ball rolling surface.
If the thickness is less than 0.1 μm, a sufficient oil film is not formed, so that the possibility of early damage to the bearing is increased, and if it is 1.4 μm or more, a sufficient friction torque reduction effect cannot be obtained.

  The lubricating oil is composed of a base oil alone, or a base oil and an additive oil, and is a mixed oil obtained by mixing a base oil alone or a base oil with a predetermined additive oil. In this embodiment, white kerosene having a high degree of purification and low impurities (particularly sulfur content) is used as the base oil, and as the additive oil, a rust preventive oil capable of preventing the occurrence of rust inside the bearing is used.

Or it is more preferable that the kinematic viscosity of the oil with the highest kinematic viscosity among the oils added thereto is 14 mm ² / s or less. This is because by adding oil having a high kinematic viscosity, even if the average film thickness is equal or less, the viscosity resistance inside the bearing is increased, and it is difficult to obtain the effect of reducing the friction torque.

More preferably, the base oil has a kinematic viscosity of 2.0 mm ² / s or less and a rust preventive oil having a kinematic viscosity of 14 mm ² / s or less is preferably added. This is because the rust generated inside the bearing during transportation or storage can be reduced by adding rust preventive oil.

Moreover, it is more preferable that the mixture ratio of the rust preventive oil added to the base oil having a kinematic viscosity of 2.0 mm ² / s or less is 3% by volume or less. This is because if it exceeds 3% by volume, it is difficult to obtain a sufficient friction torque reduction effect.

Here, an example of the ball bearing of the present invention will be described in comparison with a comparative example (see Table 1 and FIG. 2).
The ball bearings used in the examples and comparative examples are deep groove ball bearings (outer diameter: 22 mm, inner diameter: 8 mm, width: 7 mm). The time until the bearing outer ring stops after rotating using energy that freely falls from 200 mm (bearing rotation time) is measured.

  As a method of applying the lubricating oil, the prepared mixed oil was applied to the surface inside the bearing before mounting the shield, and the average film thickness was defined as the average adhesion film thickness. That is, it is the average value of the oil film thickness on the inner peripheral surface of the outer ring, the outer peripheral surface of the inner ring, the raceway surface of the inner and outer rings and the rolling surface of the ball.

Example 1
The working condition is a deep groove ball bearing in which only white kerosene, which is a base oil having a kinematic viscosity at 40 ° C. of 2.0 mm ² / s or less, is applied with an average film thickness of 0.3 μm. Was adjusted to 0.8 mg.
(Example 2)
The working conditions were 99% by volume of white kerosene, which is a base oil having a kinematic viscosity at 40 ° C. of 2.0 mm ² / s or less, and 1% by volume of rust preventive oil having a kinematic viscosity of 14 mm ² / s at 40 ° C. The value of the oil adhesion amount inside the bearing was adjusted to 0.3 mg to 1.2 mg in a deep groove ball bearing in which the mixed oil blended at a ratio was applied to the surface with an average adhesion film thickness of 0.1 μm to 0.4 μm.
(Example 3)
The working conditions were 97% by volume of white kerosene, which is a base oil having a kinematic viscosity at 40 ° C. of 2.0 mm ² / s or less, and 3% by volume of rust preventive oil having a kinematic viscosity of 14 mm ² / s at 40 ° C. The value of the oil adhesion amount inside the bearing was adjusted to 2.9 mg to 4.1 mg in a deep groove ball bearing in which the mixed oil blended at a ratio was applied with an average adhesion film thickness of 1.0 μm to 1.4 μm.
(Comparative Example 1)
Implementation conditions were 90% by volume of white kerosene, which is a base oil having a kinematic viscosity at 40 ° C. of 2.0 mm ² / s or less, and 10% by volume of rust preventive oil having a kinematic viscosity of 14 mm ² / s at 40 ° C. The value of the oil adhesion amount inside the bearing was adjusted to 10.8 mg to 14.2 mg in a deep groove ball bearing in which the mixed oil blended at a ratio was applied with an average adhesion film thickness of 3.6 μm to 4.8 μm.
(Comparative Example 2)
Implementation conditions were 90% by volume of white kerosene, a base oil having a kinematic viscosity at 40 ° C of 2.0 mm ² / s or less, and RO460 (JX Nippon Mining Co., Ltd.), a lubricant having a kinematic viscosity of 460 mm ² / s at 40 ° C. This is a deep groove ball bearing with an average adhesion film thickness of 2.7 μm to 3.1 μm mixed with 10% by volume of FBK oil manufactured by Nisseki Energy Co., Ltd. Adjusted to 9.1 mg.

[Evaluation (see Fig. 2)]
In FIG. 2, ◆ indicates only the base oil of the example, ● indicates rust-preventing oil of Example 2 (diluted by 1% by volume), ▲ indicates anti-rust oil of Example 3 (diluted by 3% by volume), and ■ indicates Comparative Example 1. The rust preventive oil (diluted by 10% by volume) and □ represent the lubricating oil of Comparative Example 2 (diluted by 10% by volume).
In Examples 1 to 3, by setting the average adhesion film thickness of the mixed oil to 0.1 μm or more and 1.4 μm or less, the bearing rotation time was increased, and the effect of reducing the friction torque could be confirmed.
In Examples 1 to 3 and Comparative Example 1, the kinematic viscosity is 460 mm ² by setting the kinematic viscosity of the base oil to be applied alone or the oil having the highest kinematic viscosity to 14 mm ² / s or less. Compared with Comparative Example 2 to which / s was added, the bearing rotation time became longer even when the average adhered film thickness was thick, and the effect of reducing the friction torque could be confirmed.

  In Examples 2 and 3, the average adhesion film thickness of the oil can be reduced by setting the blending ratio of the rust preventive oil to 3% by volume or less as compared with the blending ratio of 10% by volume of the rust preventive oil of Comparative Example 1. As a result, the friction torque was reduced and the bearing rotation time was increased. Moreover, the rust which generate | occur | produces inside a bearing at the time of transportation or storage can be reduced by adding rust preventive oil.

1 Ball Bearing 2 Outer Ring 3 Inner Ring 4 Ball 5 Cage

Claims (5)

Provided with an outer ring, an inner ring disposed inside the outer ring, a rolling ball disposed between the outer ring and the inner ring, and a cage for holding the ball, and lubricating oil was applied to the inside of the bearing In ball bearings,
The ball bearing is characterized in that an average adhesion film thickness of the lubricating oil is applied at 0.1 μm or more and 1.4 μm or less.   The ball bearing according to claim 1, wherein the lubricating oil is a mixed oil composed of a base oil and an antirust oil. The lubricating oil is composed of a base oil alone or a base oil and an additive oil, and the kinematic viscosity of the oil having the highest kinematic viscosity among the base oil alone or the additive oil added to the base oil is 14 mm ² / s or less. The ball bearing according to claim 1. The ball according to claim 2, wherein the lubricating oil is formed by adding a rust preventive oil having a kinematic viscosity of 2.0 mm ² / s or less and a kinematic viscosity of 14 mm ² / s or less. bearing. The ball bearing according to claim 2 or 4, wherein a blending ratio of the rust preventive oil is 3% by volume or less.

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