JPS6313046B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device in which a lubricant placed between an outer ring and an inner ring has good lubrication performance and also has good sealing performance.

In conventional rolling bearings, grease sealed within the bearing is sealed by a contact or non-contact seal fixed to the outer ring.

However, in the former case, the torque is high because the seal body and the inner ring are in contact with each other, and in the latter case, there are drawbacks such as easy grease leakage.

An object of the present invention is to provide a sealing device that has low torque, has good lubrication performance of a lubricant placed between an outer ring and an inner ring, and has good sealing performance.

Next, embodiments of the present invention will be described based on the drawings. In FIG. 1, the rolling bearing includes an outer ring 11, an inner ring 12, rolling elements 13, a cage 14, and a pair of magnetic fluid seals 15 and 16 fixed to the outer ring 11 on both sides of the cage 14. Therefore, the inner ring 12 is disposed on the inner peripheral side of the pair of magnetic fluid seals 15 and 16 fixed to the outer ring 11, and the outer ring 11 and the inner ring 1
A rolling element 13 is disposed between the two. One of the magnetic fluid seals 15 includes an annular permanent magnet 21 with opposite polarities on both side surfaces 18 and 19, and a pair of disc-shaped yokes 22 and 23 that are in close contact with both side surfaces 18 and 19 of the permanent magnet. and an elastic member 24 that is integrated with a permanent magnet 21 and a pair of yokes 22 and 23, and the pair of yokes 22 and 23 are configured symmetrically with respect to the permanent magnet 21. The elastic member 24 contacts the outer ring 11, and the permanent magnet 21 and the pair of yokes 22, 23 contact the outer ring 11.
It has become contactless. The elastic member 24 is not a ferromagnetic material, and the outer ring 11 and the pair of yokes 2
2, 23, and the inner ring 12 are all made of ferromagnetic material. A magnetic fluid exists in a seal gap 25 between the one magnetic fluid seal 15 and the inner ring 12, and a seal gap exists between the pair of magnetic fluid seals 15 and 16 between the outer ring 11 and the inner ring 12. A lubricant 26 that is not compatible with the solvent of the magnetic fluid in the magnetic fluid 25 and is not a magnetic fluid is contained.
Therefore, when silicone oil or polyhydric alcohol is used as a solvent for the magnetic fluid in the seal gap 25, mineral oil or synthetic oil is used as the lubricant 26 between the outer ring 11 and the inner ring 12, and When mineral oil or synthetic oil is used as the solvent for the magnetic fluid, silicone oil is used as the lubricant 26 between the outer ring 11 and the inner ring 12. The magnetic flux of the permanent magnet 21 passes from the N pole of the permanent magnet 21 to the S pole of the permanent magnet 21 through one yoke 22, the inner ring 12, and the other yoke 23.
The magnetic fluid in the seal gap 25 is in the seal gap 2.
The lubricant 26 between the outer ring 11 and the inner ring 12 is not compatible with the solvent of the magnetic fluid in the seal gap 25 and is not a magnetic fluid, so it is separated from the magnetic fluid in the seal gap 25. are doing. Therefore, the lubricant 2 between the outer ring 11 and the inner ring 12
6 is sealed by a magnetic fluid within a seal gap 25. The magnetic fluid in the seal gap 25 can be a magnetic fluid with good sealing performance, so the sealing performance is good, and the lubricant 26 between the outer ring 11 and the inner ring 12 is a lubricant with good lubricating performance. It has good lubrication performance. The illustrated rolling bearing is equipped with the sealing device of the present invention in the cage 14.
The sealing devices on both sides of the retainer 14 are constructed symmetrically with respect to the outer ring raceway 27, and have good lubrication performance and sealing performance.

FIG. 2 shows a spindle unit shown as a reference example, and the shaft member 112 has a groove 13 for generating dynamic pressure.
Receiving part 13 on the outer periphery of the conical surface having 1,132
3 and 134 are provided at two locations separated by a distance, and the receiving portions 133 and 134 on the outer periphery become smaller in diameter from both ends of the shaft member 112 toward the side between the two receiving portions 133 and 134 on the outer periphery. There is. Housing member 1
11 is provided with inner circumferential receivers 135, 136 that face and cooperate with outer circumferential receivers 133, 134, and magnetic fluid seals 115, 116 are fixed to both ends of this housing member 111, respectively. Therefore, the shaft member 112 is disposed on the inner peripheral side of the pair of magnetic fluid seals 115 and 116 fixed to the housing member 111.
is installed. One of the magnetic fluid seals 1
Seal clearance 125 between 15 and shaft member 112
There is a magnetic fluid in the magnetic fluid, and there is lubrication that is not compatible with the solvent of the magnetic fluid in the seal gap 125 between the pair of magnetic fluid seals 115 and 116, that is, between the housing member 111 and the shaft member 112, and is not a magnetic fluid. agent 126 is put therein. Therefore, the lubricant 1 between the housing member 111 and the shaft member 112
26 is sealed by a magnetic fluid within a seal gap 125. The magnetic fluid in the seal gap 125 can be a magnetic fluid with good sealing performance, so the sealing performance is good, and the lubricant 126 between the housing member 111 and the shaft member 112 is a lubricant with good lubrication performance. The lubrication performance is good because it can be used with The illustrated spindle unit is equipped with sealing devices at both ends of the housing member 111, and the sealing devices at both ends of the housing member 111 are configured symmetrically with respect to the center of the spindle unit, thereby improving lubrication performance and sealing performance. is in good condition.

According to the sealing device of the present invention, since the magnetic fluid seal 15 does not contact the inner ring 12, the torque is low, and since the magnetic fluid exists between the magnetic fluid seal 15 and the inner ring 12, the sealing performance is good. Furthermore, since a lubricant 26 that is not compatible with the solvent of the magnetic fluid in the seal gap 25 and is not a magnetic fluid is placed between the outer ring 11 and the inner ring 12,
The lubricant 26 between the inner ring 12 and the seal gap 2
Separated from the magnetic fluid in the seal gap 25, the magnetic fluid with good sealing performance can be used as the magnetic fluid in the seal gap 25, so the sealing performance is good, and the lubricant 26 between the outer ring 11 and the inner ring 12 Lubrication performance is good because a lubricant with good performance can be used. Furthermore, since the lubricant 26, which is not a magnetic fluid, is placed between the outer ring 11 and the inner ring 12, the cost of the lubricant 26 is low, and the overall cost is low.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rolling bearing equipped with a sealing device of the present invention, and FIG. 2 is a sectional view of a spindle unit shown as a reference example. In the figure, 11 is an outer ring, 12 is an inner ring, 13 is a rolling element, 15 is a magnetic fluid seal, 25 is a seal gap, and 26 is a lubricant.

Claims (1)

[Claims] 1. An inner ring of a rolling bearing is arranged on the inner circumferential side of a magnetic fluid seal fixed to an outer ring of a rolling bearing, and a magnetic fluid exists in a seal gap between the magnetic fluid seal and the inner ring, and a magnetic fluid exists between the outer ring and the inner ring. A rolling element is disposed between the outer ring and the inner ring, and a lubricant that is not compatible with the solvent of the magnetic fluid in the seal gap and is not a magnetic fluid is placed between the outer ring and the inner ring. A sealing device characterized by being sealed by a fluid.