JPH08334425A - Fluid pressure detecting device for bearing surface - Google Patents

Abstract

PURPOSE: To provide a fluid pressure detecting device by which the internal fluid pressure of a bearing for supporting a turning shaft can be accurately detected with high responsiveness causing little failure. CONSTITUTION: The pressure detector 40 having a small diameter cylindrical part 43 and a large diameter cylindrical part 44 is inserted into a stepped cylindrical hole that has been provided to a turning shaft 10. A hollow hole is formed in the large diameter cylindrical part 44 from the end thereof, and a strain gauge 42 is fixed thereto by means of a resin adhesive. A metallic plate 50 of a conical and cylindrical shape is inserted so that the end parts thereof are abutted both on the stepped outside diametral end part B of the stepped cylindrical hole and on the stepped part A of the pressure detector, and it is supported by a hollow cylindrical sleeve 41. The fluid is hermetrically sealed by the metallic plate 50 of a conical and cylindrical shape which is hardly deformed by the pressure, and is transmitted to the strain gauge 42 as an axial strain without attenuating its pressure, so that it can be detected with good responsiveness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure detecting device used to detect the internal fluid pressure of a bearing that supports a rotating shaft such as a main shaft of a turbomachine.

[0002]

2. Description of the Related Art A conventional example of a fluid pressure detecting device for a bearing surface is shown in FIG. In FIG. 3, 1 is a rotating shaft, 2 is a casing, and 3 is a bearing attached to the casing to support the rotating shaft 1. A lubricating fluid W is provided between the rotating shaft 1 and the bearing 3.
There is.

Due to the rotation N of the rotary shaft 1, a fluid pressure is generated on the inner surface of the bearing 3, and a pressure detector 4 for detecting the pressure is rotated by a mounting sleeve 6 via a seal 5 for sealing the fluid pressure. Embedded in shaft 1. The output signal of the pressure detector 4 is taken out by the lead wire 7 and input to a measurement signal processor (not shown).

The fluid W is guided to the surface of the pressure detector 4 through a pressure guide hole 8 formed in the rotary shaft 1 at the tip of the pressure detector 4, and the surface diaphragm of the detector 4 is deformed. It is converted into an electric signal by a strain gauge or the like.

[0005]

As described above, in the conventional pressure detector device, a diaphragm surface is formed on the surface of the pressure detector 4 which is in contact with the fluid pressure, and the deformation of the diaphragm due to the fluid pressure is strain gauge. Etc., and the electric signal was taken out to the outside. Since this diaphragm is a very thin film, it will be damaged if it comes into contact with other metals or the like, so that great care must be taken in handling.

Further, since the diaphragm of the fluid contact surface of the detector 4 has such a small strength that it cannot be post-processed, it cannot be attached to the rotary shaft or the bearing surface, and the fluid to be detected is introduced into the diaphragm by the pressure guide hole 8. I needed to reach you.

However, when the lubricating fluid film on the surface of the bearing reaches a level of several microns, the volume of the pressure guiding hole 8 becomes relatively large and the fluid pressure is not compressed and propagated, resulting in poor pressure detection due to insufficient response. was there.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure detecting device capable of detecting the internal fluid pressure of a bearing supporting a rotating shaft with high responsiveness and high accuracy and causing less failure.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems in a pressure detecting device for measuring a fluid pressure on a bearing surface generated by the rotation of a rotary shaft supported by the bearing device, the present invention has the following fluid pressure. A detection device is provided.

First, the fluid pressure detecting device according to the present invention is
A pressure detector, which is composed of a small-diameter cylindrical portion and a large-diameter cylindrical portion, has a hollow hole formed in the large-diameter cylindrical portion from the end surface, and is inserted into a stepped cylindrical hole bored in the rotating shaft or the bearing, A pressure detector having a strain gauge for axial strain detection fixed with a resin adhesive is provided in the hollow hole of the same detector.

Further, the fluid pressure detecting device according to the present invention is
The detector has an inner diameter slightly larger than the outer diameter of the small-diameter cylindrical portion and an outer diameter larger than the outer diameter of the large-diameter cylindrical portion, and the stepped portion formed by the both cylindrical portions has an inner diameter side thereof. The tip is in contact with the stepped outer diameter end of the stepped cylindrical hole, and the tip on the outer diameter side is placed in contact with the stepped parallel conical metal plate, and the large diameter column of the detector. It has a hollow cylindrical sleeve which is inserted outside and one end surface of which is in contact with the outer diameter portion of the metal plate.

[0012]

The fluid pressure detecting device according to the present invention has the above-mentioned structure. According to this, the oil film pressure acting on the tip of the detector is determined by the rotating shaft or bearing in which the detector is embedded and the tip of the detector. Although it also acts on the gap formed by the outer diameter of the cylindrical part, the tip of the angle parallel cone-shaped metal plate on the inner diameter side contacts the stepped part formed by the large and small diameter cylindrical parts of the detector, and the metal Since the tip of the plate on the outer diameter side is supported and mounted by a hollow cylindrical sleeve so that it contacts the stepped outer end of the stepped cylindrical hole of the rotating shaft or bearing, the oil film pressure is sealed and the angled parallel cone Since the shaped plate is made of metal, it will not be greatly deformed like rubber even when oil film pressure is applied.

In the fluid pressure detecting device according to the present invention, the oil film pressure is thus sealed, so that the oil film pressure acts on the tip of the detector and is detected by the strain gauge embedded in the detector as an axial force. To be done. Further, since this strain gauge is fixed in the pressure detector with an adhesive, the tip of the detector can be surface-processed together with the embedded rotary shaft or bearing, and the surface of the detector can be formed so as not to have irregularities.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fluid pressure detecting device according to the present invention will be described below with reference to FIG.
It will be specifically described based on the embodiment shown in FIG. In FIG. 1, a rotating shaft 10 is supported by the casing 20 via a bearing 30.

The rotary shaft 10 is provided with a stepped cylindrical hole that opens toward the inner surface of the bearing 30, and a pressure detector 40 is fixed in the stepped cylindrical hole by a mounting sleeve 60. A specific fastening method such as a screw is omitted for the mounting sleeve 60.

The pressure detector 40 is composed of a small-diameter column portion 43 and a large-diameter column portion 44, and a hollow hole is formed in the large-diameter column portion 44 from the end surface. A hollow cylindrical sleeve 41 is inserted into the pressure detector 40, and a mountain-shaped parallel conical metal plate 50 is attached between the pressure detector 40 and the rotary shaft 10.

The metal plate 50 has a cylindrical portion 4 whose inner diameter is small.
3 has an inner diameter slightly larger than the outer diameter of 3 and also has an outer diameter larger than the outer diameter of the large-diameter cylindrical portion 44,
The inner diameter side tip contacts the stepped portion A of the detector 40 formed by 3, 44, and the outer diameter side tip contacts the stepped outer diameter end portion B of the stepped cylindrical hole of the rotary shaft 10. It is arranged.

The upper end surface of the hollow cylindrical sleeve 41 is in contact with the outer diameter portion of the metal plate 50. The above structure prevents the fluid W between the bearing 30 and the rotary shaft 10 from leaking to the lead wire 70 side.

A strain gauge 42 for detecting the axial force of the pressure detector 40 is fixed in the hollow hole of the pressure detector 40 with a resin adhesive or the like (not shown). The output of the strain gauge 42 is taken out by the lead wire 70. The rotating shaft 10 is supported by a bearing 30 fixed to a casing 20 such as a pump, and is given a rotation N.

In the pressure detecting device constructed as described above, the pressure of the fluid W inside the bearing 30 generated by the rotation of the rotary shaft 10 is detected by the pressure receiving area portion at the tip of the pressure detector 40, and the strain gauge is used as the axial force. Detected by 42, the output is taken out by the lead wire 70. In addition, in order to prevent the fluid pressure from leaking to the lead wire 70 side, the angled parallel conical metal plate 5
0 is supported by the sleeve 41 and functions as a sealing device.

FIG. 2 illustrates a processing mode of the rotary shaft 10 in which the pressure detector 40 described in FIG. 1 is inserted into the stepped cylindrical hole. In FIG. 2, the grinding wheel 80 is a grinding spindle 81.
And is rotated in the rotation direction G to process the surface of the rotating shaft 10.

The pressure detector 40 is made of the same material as the rotary shaft 10, and can be machined together with the surface of the rotary shaft 10. Detector 4 slightly protruding from the stepped cylindrical hole of the rotating shaft 10
The upper end of the cylindrical portion 43 of 0 is rotated by the grinding wheel 80.
Since it is ground into one body with the surface of
No unevenness is formed, and a volume that causes insufficient pressure response is not formed.

The hollow hole formed in the large diameter cylindrical portion 44 of the detector 40 for mounting the strain gauge 42 is a pressure detector 40.
It is processed so that it does not come out to the shaft surface side from the tip stepped portion A, and the strain gauge 42 is tightened by the external pressure of the fluid pressure, and the output sensitivity does not become poor.

The present invention has been specifically described above based on the illustrated embodiments, but the present invention is not limited to these embodiments, and within the scope of the present invention shown in the claims, the specific structure thereof. It goes without saying that various changes may be added to the.

For example, in the above-mentioned embodiment, the stepped cylindrical hole is formed in the rotary shaft 10 and the pressure detector 40 is inserted therein. However, the stepped cylindrical hole is formed in the bearing 30, and the pressure detector 40 is inserted therein. May be attached to detect the pressure of the fluid W in the same manner as described above.

[0026]

As described above, in the fluid pressure detecting device of the present invention, a pressure detector which can be co-machined with the same material as the rotating shaft or the bearing so as not to form irregularities on the surface for detecting the fluid pressure. Due to the configuration adopted and the principle of detecting the fluid pressure as axial force strain, there is no volume of the pressure guide hole and the like, and therefore the pressure response does not become insufficient.

Further, since the main body of the detector is composed of a cylindrical portion made of metal or the like, there is no fear of damage to the diaphragm or the like, and the handleability is good. Further, since the fluid is sealed by the seal of the chevron-shaped conical metal plate with almost no pressure deformation, the fluid is transmitted to the strain gauge as axial strain without pressure attenuation.

Further, since the outer diameter portion of the chevron parallel-conical metal plate is supported by the hollow cylindrical sleeve, the fixing is reliable, and the force acting on the chevron parallel-conical metal plate is also supported by the hollow cylindrical sleeve. Therefore, there is also an effect that there is almost no pressure detection error in the strain gauge.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a fluid pressure detecting device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the fluid pressure detection device shown in FIG. 1 is incorporated and processed.

FIG. 3 is a vertical cross-sectional view showing an example of a conventional fluid pressure detection device.

[Explanation of symbols]

 40 Pressure Detector 41 Hollow Cylindrical Sleeve 42 Strain Gauge 43 Small Diameter Cylindrical Section 44 Large Diameter Cylindrical Section 50 Angled Parallel Cone Metal Plate 60 Mounting Sleeve 80 Grinding Wheel 81 Grinding Spindle

Claims (1)

[Claims] 1. A fluid pressure detection device for measuring a fluid pressure on a bearing surface generated by rotation of a rotating shaft supported by a bearing device, comprising a small-diameter column portion and a large-diameter column portion, and the large-diameter column portion. A hollow hole is formed from the end face in the section, and the pressure detector is inserted into the stepped cylindrical hole formed in the rotary shaft or the bearing, and the axial strain is fixed in the hollow hole of the detector with a resin adhesive. A strain gauge for detection, having an inner diameter slightly larger than the outer diameter of the small-diameter cylindrical portion and an outer diameter larger than the outer diameter of the large-diameter cylindrical portion, the stepped portion formed by the both cylindrical portions having A chevron-shaped conical metal plate in which the inner diameter side tip contacts and the outer diameter side tip contacts the stepped outer diameter end of the stepped cylindrical hole of the rotating shaft or the bearing, and the large size of the detector. Inserted into the outside of the cylindrical part of the diameter, and one end surface of which is in contact with the outside diameter part of the metal plate. A fluid pressure detecting device for a bearing surface, comprising a hollow cylindrical sleeve.