JPH0245047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealed rolling bearing in which a permanent magnet member is used as a seal body for sealing the bearing.

In conventional sealed 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 raceway 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 sealed rolling bearing that has good sealing performance, low torque, and is inexpensive.

Next, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a first embodiment, in which a sealed rolling bearing includes an outer ring 1, an inner ring 2, rolling elements 3, and a cage 4.
and a pair of seal bodies 5 and 6 fixed to both ends of an outer ring, that is, both ends of one bearing ring, and both the outer ring 1 and the inner ring 2 are made of a ferromagnetic material. The pair of seal bodies 5, 6 each have a rectangular cross section, and the pair of seal bodies 5,
6, the fixing parts 7 and 8 to one bearing ring are N.
The pole parts 11 and 12 near the inner ring, that is, the parts 11 and 12 near the other bearing ring, are S-pole permanent magnets. Therefore, each of the pair of seal bodies 5, 6 has fixed parts 7, 8 to one raceway ring and proximate parts 11, 12 to the other raceway ring.
and are permanent magnetic members with different polarities, and the fixed part 7 of the seal body on one side to one raceway ring and the fixed part 8 of the seal body on the other side to one raceway ring are of the same polarity. It's summery. Seal surface 1 of the other raceway ring
3 and 14 are both cylindrical, and have a seal gap 15 between the sealing surface 13 and the sealing surface 13 of the sealing body on the other side. A magnetic fluid is in each case present in the other sealing gap 16 between the vicinity 12 to the other raceway and the other sealing surface 14 .
A lubricant that is not compatible with the solvent of the magnetic fluid existing in the seal gaps 15 and 16 and is not a magnetic fluid is placed between the pair of seal bodies 5 and 6. The magnetic flux of the seal body 5 on one side flows from the N pole of the seal body 5 on one side through one raceway 1, the rolling elements 3, and the raceway ring 2 on the other side, as shown by the dotted line in FIG. The magnetic flux of the seal body 6 on the other side passes from the N pole of the seal body 6 on the other side to the one raceway 1, the rolling elements 3, and the other raceway ring. 2 to the S pole of the seal body 6 on the other side. The lubricant placed between the pair of seal bodies 5 and 6 is sealed by the magnetic fluid present in the seal gap 15 on one side and the magnetic fluid present in the seal gap 16 on the other side.

FIG. 2 shows a second embodiment, which is a modification of the first embodiment, in which the pair of seal bodies 5, 6 are fixed to one raceway ring with the fixing portions 7, 8 attached to the inner surface of the seal body. 21 and 22, and fixing portions 7 and 8 to one of the bearing rings protrude inside the bearing and contact one of the bearing rings 1. the pair of seal bodies 5;
6 are both adjacent parts 11 and 12 to the other bearing ring.
on the inner peripheral side of the inner surfaces 21 and 22 of the seal body,
Portions 11 and 12 adjacent to the other bearing ring protrude inside the bearing. The pair of seal bodies 5 and 6 are both permanent magnets in which the fixing parts 7 and 8 to one raceway are north poles and the parts 11 and 12 near the other raceway are south poles. 5 and 6 are permanent magnet members in which fixed portions 7 and 8 to one bearing ring and adjacent portions 11 and 12 to the other bearing ring have different polarities. The sealing surfaces 13 and 14 of the other bearing ring are both flat and parallel to the side surface of the other bearing ring 2, and the adjacent parts 11 and 1 to the other bearing ring are
A magnetic fluid is present in seal gaps 15 and 16 between seal surfaces 13 and 14 of the bearing ring 2 and the other bearing ring, respectively.

Making the sealing surfaces 13 and 14 planar in this manner is effective when sealing is desired on a surface parallel to the side surface of the other bearing ring 2.

FIG. 3 shows a third embodiment, which is a modification of the first embodiment, in which a pair of seal bodies 5, 6 are both connected to permanent magnets 31, 32 and a peripheral surface 33 of the permanent magnet on the side opposite to the fixed part. , 34 fixed to the ferromagnetic yoke 3
5, 36, and these yokes 35, 36 form the vicinity portions 11, 12 to the other bearing ring.
The pair of seal bodies 5 and 6 are both permanent magnet members in which the fixing parts 7 and 8 to one bearing ring are north poles, and the parts 11 and 12 near the other bearing ring are south poles, and The sealing surfaces 13 and 14 of the bearing rings are both flat and parallel to the side surface of the other bearing ring 2. The magnetic fluid is present in the seal gaps 15, 16 between the adjacent portions 11, 12 to the other bearing ring and the seal surfaces 13, 14 of the other bearing ring, respectively.

If the yokes 35 and 36 are in the vicinity of the other bearing ring in this way, the magnetic flux density of the seal gap 15 and 16 is made by tapering the vicinity of the other bearing ring. can be increased.

Although not shown, if a circumferential groove is provided on the seal surfaces 13 and 14 of the other raceway, the magnetic flux density in the seal gaps 15 and 16 will be increased.

Further, the seal bodies 5 and 6 are fixed to one of the raceway rings 7 and 8 and the other raceway to the vicinity parts 11 and 12.
If the other parts are coated with a material other than ferromagnetic material, the strength of the seal bodies 5 and 6 will be reinforced.

Furthermore, although the seal bodies 5 and 6 are fixed to the outer ring 1 in the illustrated embodiment, the seal bodies 5 and 6 may not be fixed to the outer ring 1 but may be fixed to the inner ring 2.

In addition, a magnetic fluid serving as a lubricant is put between the pair of seal bodies 5 and 6, and the pair of seal bodies 5 and 6 are
The same magnetic fluid as that between seal gaps 15 and 16 may be present in the seal gaps 15 and 16.

According to the sealed rolling bearing of the present invention, the seal body is made of a permanent magnet member in which the portion fixed to one raceway ring and the portion near the other raceway ring have different polarities, and the fixed portions have the same polarity. Since the magnetic fluid exists in the seal gap between the vicinity of the other bearing ring and the sealing surface of the other bearing ring, a magnetic circuit passing through the rolling elements is formed. Therefore, the magnetic flux in the seal portion increases, and the seal performance (pressure resistance performance) increases. Therefore, the lubricant placed between the pair of seal bodies is well sealed by the magnetic fluid existing in the seal gap, increasing sealing performance.
Furthermore, since the pair of seal bodies does not contact the other raceway, the torque is low. Furthermore, the seal body has a simple structure because the part fixed to one bearing ring and the part near the other bearing ring are permanent magnetic members with different polarities.
Cost is low. Further, since the pair of seal bodies has good sealing performance, a lubricant with low viscosity can be used between the pair of seal bodies, and this has the effect that a sealed rolling bearing with lower torque can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a sealed rolling bearing showing one embodiment of the invention, and FIGS. 2 and 3 are sectional views of sealed rolling bearings showing other embodiments of the invention. Explanation of symbols of main parts, 1...Outer ring, 2...Inner ring, 5, 6...Seal body, 7, 8...Fixing part, 1
1, 12... Near the other bearing ring, 13, 1
4... Seal surface, 15, 16... Seal clearance.

Claims (1)

[Scope of Claims] 1. First and second bearing rings made of magnetic materials having different diameters and arranged radially opposite to each other, and a rolling element of magnetic material interposed between both of the bearing rings. and fixed to both axial ends of the first bearing ring,
extending in the radial direction to the vicinity of the corresponding end of the second bearing ring;
a pair of disc-shaped seal bodies made of permanent magnet members, the fixed part and the neighboring part having different polarities, and the fixed parts having the same polarity, and the corresponding end of the second bearing ring and a seal gap is formed between the sealing gap and the corresponding ends and center portions of the seal body and the first bearing ring, and the center portion and the corresponding end portion of the rolling element and the second bearing ring. A sealed rolling bearing comprising a magnetic fluid held by a magnetic flux passing through an end thereof.