JPH02164241A - Pre-load quantity detector for angular contact type duplex ball bearing - Google Patents

Abstract

PURPOSE:To cause an apparatus to have an interchangeability and a low-cost structure by fitting a spacer ring inserted between outer rings with a pre-load quantity detecting sensor connected with a strain gauge. CONSTITUTION:A rotating shaft 1 is supported by a bearing housing 3 via a pair of angular contact type ball bearings 2. In the bearing 2, a spacer ring 4 is inserted between a pair of outer rings 2a and the end face of one inner ring 2b is tightened via the spacer ring 4 and outer rings 2a by a ring-nut 5 so that the end face of the other inner ring 2b is biased and fixed to the stepped part 1a of the rotating shaft 1. In this case, the outer periphery of the spacer ring 4 is provided with an axial groove 4a and a strain sensor 10 connected with a strain gauge to detect the pre-load quantity between the inner ring 2b and outer ring 2a is embedded in the groove 4a. That is, the pre-load quantity brings about a strain corresponding to the elastic modulus and dimension of the spacer ring 4 in the pipe 4 and the strain is detected by the strain sensor 10 so that the pre-load quantity is measured by the strain gauge. Therefore, an apparatus can have interchangeability and can be formed into a low-cost structure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an improved detection device that can easily detect the amount of preload applied between the inner ring and the outer ring in an angular contact type back-to-back combination ball bearing. Regarding.

[Conventional technology]

In angular contact type back-to-back ball bearings, a cylindrical spacer tube and a slightly longer spacer tube are generally inserted between the pair of inner and outer rings in order to apply an appropriate preload between the inner and outer rings. The inner ring was then tightened to the stepped portion of the rotating shaft with a ring nut to apply preload.

[Problem to be solved by the invention]

Such a structure has the disadvantage that it is not only expensive but also lacks compatibility, since it is necessary to ensure the length accuracy of the spacer tube and to assemble it with the actual bearing.

In order to eliminate the above-mentioned drawbacks, the present invention has developed an angular motor that can easily detect the amount of preload and apply an appropriate preload between the inner ring and the outer ring without requiring special length accuracy of the spacer tube. An object of the present invention is to provide a preload amount detection device for a contact type combination ball bearing.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention has an inner ring of a pair of Angiela contact type ball bearings which are assembled back to back through a cylindrical spacer tube and is tightened with a ring nut to a stepped part of a rotating shaft. The bearing is mounted so as to apply a preload, and the bearing is supported by a cylindrical bearing housing, and a strain sensor connected to a strain gauge to detect the amount of preload is attached to a spacer tube inserted between the outer ring. It is.

[Effect]

The amount of preload causes a strain in the spacer tube that corresponds to the elastic modulus and dimensions of the material of the spacer tube, and this strain can be detected by a strain sensor and the amount of preload can be measured with a strain gauge.

Measurements can be taken both during assembly and during operation.

〔Example〕

The figure shows an embodiment of the present invention, in which a rotating shaft 1 is supported by a cylindrical bearing housing 3 via a pair of angular contact type ball bearings 2 which are assembled back to back. In the bearing 2, a cylindrical spacer tube 4 is inserted between a pair of outer rings 2a, and by tightening the end face of one inner ring 2b with a ring nut 5 through the spacer tube 4 and the outer ring 2a, the other inner ring 2b is tightened. The end face is pressed against the stepped portion 1a of the rotating shaft 1 and fixed.

The ring nut 5 is a screw of the rotating shaft 1, and the ring nut 5
In order to prevent uneven contact of the inner ring 2b against the end surface due to errors in machining accuracy of the threads and end surfaces, the inner ring 2b is tightened through a cylindrical collar 6, and loosened by a washer 7 with a claw. The bearing 2 and the ring nut 5 are surrounded by bearing covers 8 and 9 attached to both end faces of the bearing housing 3.

An axial groove 4a is provided on the outer circumference of the spacer tube 4,
A strain gauge (not shown) is connected to the inner ring 2b in this groove 4a.
A strain sensor 10 is embedded therein to detect the amount of preload between the outer ring 2a and the outer ring 2a. Strain sensor 10 connected to a strain gauge
The connecting wire 11 passes through the bearing housing 3 in the radial direction and is drawn out. Strain gauges are only connected when measuring the amount of preload.
It may be connected to All. The strain sensor 10 is connected to the spacer tube 4
Alternatively, the spacer tube itself may be made of a material whose electrical resistance or electromotive force changes with pressure.

According to the embodiment, a preload can be applied between the inner ring 2b and the outer ring 2a of the bearing 2 by tightening the ring nut 5, and since this preload causes strain in the spacer tube 4, the amount of strain can be measured by the strain sensor 10 and If detected with a strain gauge, the amount of preload can be easily read directly as a value proportional to this.

Therefore, if you tighten the ring nut 5 while reading the strain gauge reading before installing the bearing cover 8, you can improve the length accuracy of the spacer tube 4, the threading accuracy of the ring nut 5 and the rotating shaft 1, and the rotation of the inner ring 2b of the bearing 2. Appropriate preload can be applied between the inner ring 2b and the outer ring 2a without being affected by the fitting interference of the shaft 1 or variations in the friction coefficient, etc.
As a result, the pair of combined bearings 2 can be made inexpensive and have compatibility that does not require actual matching.

In addition, changes in the amount of preload due to temperature differences between related parts during operation, periodic changes in the amount of preload when damage occurs to the rolling parts of the bearing 2, etc. can be retrieved as electrical signals from the strain sensor 10 and monitored remotely. Bearing 2 due to abnormal preload or damage to rolling parts
Burnout accidents can be prevented by adjusting the amount of preload or replacing the bearing 2. Furthermore, since the spacer tube between the pair of inner rings 2b explained in the conventional example can be omitted, the cost can be reduced accordingly.

〔Effect of the invention〕

According to this invention, in a preload amount detection device for an angular contact type combination ball bearing, a strain sensor is attached to a spacer tube between a pair of bearing outer rings assembled back to back, and the strain sensor is connected to a strain gauge through a cylindrical bearing housing. Since the amount of preload can be easily detected by connecting the parts, it is possible to create an appropriate connection between the inner ring and the outer ring with an inexpensive structure that is compatible and does not require special processing precision of each related part or actual combination. The effect of being able to apply preload is obtained.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of an embodiment of the invention. ■...Rotating shaft, 1a...Stepped part, 2...Bearing,
2a...Outer ring, 2b...Inner ring, 3...Bearing housing, 4...

Claims (1)

[Claims] 1) The inner rings of a pair of angular contact ball bearings that are assembled back to back via a cylindrical spacer tube are tightened with a ring nut to the stepped part of the rotating shaft so that a preload is applied between them and the outer rings, and the bearings are An angular contact type combination ball supported by a cylindrical bearing housing, characterized in that a strain sensor connected to a strain gauge to detect the amount of preload is attached to a spacer tube inserted between the outer rings. Bearing preload amount detection device.