JPH0315138B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small and lightweight thrust load measuring device for accurately measuring the thrust load acting on a bearing.

[Prior Art] For example, when an excessive thrust load is applied to a bearing portion of a rotating machine such as an aircraft engine, a gas turbine, or an axial flow compressor, not only the bearing is damaged but also the entire machine is affected. For this reason,
Accidents can be prevented and safety can be improved by measuring this thrust load and taking measures according to the value to bring the bearing to its original normal load state.

Therefore, various devices for measuring thrust loads have been studied.

[Problems to be solved by the invention] However, since the area around the bearing is generally located in a narrow area and the atmosphere is immersed in high temperature oil, it is considered difficult to install a thrust load measuring device in this area. Moreover, a mechanism for detecting thrust load and a device equipped with the mechanism may be large in size, making it difficult to put them into practical use. Conventionally, operations were performed without a thrust load measuring device, disassembled after operation, and inspections of the degree of damage to bearings, etc. were determined based on guesswork and experience. It was a sloppy operation, which was the biggest safety defect.

In view of the above-mentioned circumstances, the present invention has been made with the object of making it possible to quickly and accurately measure the thrust load acting on a bearing by installing a small and lightweight thrust load measuring device around the bearing. be.

[Means for Solving the Problems] The present invention provides bearing support members on both sides of a flange fixed to the outer periphery of a rotatably fitted bearing outer race. Unit cells equipped with strain gauges and whose tops abut against the side surfaces of the flange are arranged at approximately equal intervals in the direction, and a preload is applied to one of the bearing support members and the unit cells arranged on both sides of the flange. The bearing flange and the bearing support portions provided on both sides of the flange are fastened together using bolts that also serve as a rotation stopper.

[Operation] Thrust load is transmitted from the shaft through the bearing and the flange of the bearing outer race to the preloaded unit cell, detected by a strain gauge attached to the unit cell, and taken out to the outside. The tangential force caused by this is supported by the bolts connecting the bearing support member and the flange.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 6 show an embodiment of the present invention, in which an inner race 3 of a bearing 2 is fitted onto a rotatable shaft 1 so as to be able to rotate integrally with the shaft 1, and the inner race 3 is fitted around the outer periphery of the inner race 3. An outer race 5 is fitted through balls 4, and a flange 6 is fixed to the outer periphery of the outer race 5. The inner race 3 is also tightened with a tightening nut 7 and fixed to the shaft 1.

On both sides of the flange 6 of the bearing 2, there is an annular bearing support member 8 and a hollow cylindrical side plate 9a on the flange 6 side.
A bearing support member 9 is provided, and the facing parts on the outer peripheral sides of the bearing support members 8 and 9 are fitted into each other in a nested manner, and the side plates 9a of the bearing support members 8 and 9 are connected to the flange 6. A slight gap G is maintained between the surfaces facing each other, and the side plates 9a of the bearing support member 8, flange 6, and bearing support member 9 are arranged at approximately equal intervals in the circumferential direction. It is fastened by a bolt 10 which also serves as a lock.

Unit cells 1 for thrust load measurement are installed in recesses provided at approximately equal intervals in the circumferential direction of the bearing support member 8.
1 is arranged, the top of the unit cell 11 is in contact with one side of the flange 6, and unit cells 12 for thrust load measurement are arranged in recesses provided at approximately equal intervals in the circumferential direction of the bearing support member 9. 1
1, the top of the unit cell 12 is in contact with the other side of the flange 6, and an initial tightening member 13 is provided on the opposite side of the flange 6 of the recess into which the unit cell 12 is fitted. By pushing the initial tightening member 13 with a tightening bolt 14 screwed into the side plate 9a, a preload can be applied to the unit cells 11, 12 via the protrusion 13a.

Since the unit cells 11 and 12 described above have the same structure, the details of the unit cell 11 will be explained below with reference to FIGS. 5 and 6. On the anti-spherical side of the unit cell body 15,
A protrusion 16 is provided so that the thrust load F acting from the flange 6 can be transmitted to the bearing support member 8,
A recess 17 is provided on the upper and lower surfaces of the unit cell body 15, and a strain gauge 18 for detecting shear strain is attached to the bottom and ceiling of the recess 17.
is filled with a heat-resistant and oil-resistant resin, and the unit cell body 15 is covered with stainless steel foil to protect the strain gauge 18 from heat and oil. In addition, a protrusion 1 of the unit cell 11 is provided on the center side of the shaft 1 in the portion of the bearing support member 8 into which the unit cell 11 is inserted.
Notches 19 for taking out lead wires, etc. are provided at approximately the same intervals as the spaces between the protrusions 16 and 16, and heat-resistant resin is filled between the protrusions 16 and 16 for protection, except for the space for taking out the lead wires. ing.

The thrust load is shaft 1 → bearing 2 → flange 6 →
Unit cell 11 or 12 → bearing support members 8, 9
Or it is transmitted through the path 9, 8, and in the process the load -
The signal is converted into an electrical signal by unit cells 11 and 12 having electrical conversion capability, and is recorded and displayed.
When detecting the thrust load acting on the bearing 2, unit cells 11 and 12 are installed in the rotating machine whose thrust load is to be measured as shown in FIG.
is set, and the bolt 14 is rotated to apply the required preload to the unit cells 11 and 12. By applying this preload, when the thrust load is F, for the same reason as stated in the specification of Japanese Patent Application No. 60-6603, the thrust load F/ which increases the initial tightening force is applied to the unit cell 11 side. 2 is detected, and on the other hand, on the unit cell 12 side, a thrust load F/2 which reduces the initial tightening force is detected.

The thrust load F/2 that increases this initial tightening force is In the following explanation, it is expressed as F/2 and the initial tightening force is reduced. The thrust load F/2 to be applied is -F/2 in the following explanation. represent.

Since the strain gauge on the unit cell 11 side is compressed by the thrust load F/2, the contraction of this strain gauge is set as ε ₁ /2, and the strain gauge on the unit cell 12 side is extended due to the thrust load -F/2, so this strain gauge When the elongation of is -ε ₁ /2, the output of the strain gauge in unit cell 11 is ε 1 '=ε 1 /2 + ε _H , taking into account the influence of thermal output, that is, thermal strain ε H, and the output of the strain gauge in unit cell 12 is ε ₁ '=ε ₁ /2+ε _H. The output of the strain gauge is -ε ₁ '=-ε ₁ /2+ε _H.

Here, the output ε ₁ ' of the strain gauge of the unit cell 11 increases by ε ₁ ' compared to the output when the initial tightening force is applied, and the output -ε 1 ' of the strain gauge of the unit cell 12 increases by ε ₁ ' compared to the output when the initial tightening force is applied. This means that the output is reduced by ε ₁ ' from the output when a tightening force is applied. Therefore, the signals of ε ₁ ′ and −ε ₁ ′ are
As in the case of No. 6603, the signal is sent to the differential amplifier through the signal conditioner, but since the differential amplifier has the function of adding electrical signals of different polarities and canceling electrical signals of the same polarity, the difference is The output ε of the dynamic amplification is ε=ε ₁ /2+ε _H +ε ₁ /2−ε _H =ε ₁ .

The output ε thus obtained is sent to a load digital display, an analog recorder, a magnetic recorder, a computer, etc. in the post-processing section, and is subjected to predetermined processing.

The bolt 10 supports the tangential force due to the twisting torque caused by one rotation of the shaft.

It should be noted that the present invention is not limited to the above-described embodiments, and that unit cells of various shapes can be used, and that various other changes can be made without departing from the gist of the present invention. Of course.

[Effects of the Invention] According to the bearing thrust load measuring device of the present invention, the thrust load can be measured by immersion in high-temperature oil, vibration,
Even repeated forces such as sudden loads and sudden releases are quickly and reliably transmitted to the unit cell, allowing for highly accurate load detection. The entire device is smaller and lighter.〈〉〈〉 The bearing can be brought into a normal state at the assembly stage so that no abnormal load is applied to it, improving the safety of the device. This reduces the burden on other mechanical parts, and stabilizes the area around the bearing, making it possible to detect other abnormalities at an early stage. Because they are compatible, they are easy to manufacture, and because the entire device can be treated as one unit, it is easy to inspect faulty parts and replace load conversion parts. It can have excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the first embodiment of the bearing thrust load measuring device of the present invention, and FIG. 2 is a diagram showing the − of FIG. 1.
3 is a view in the negative direction of FIG. 1, FIG. 4 is a view in the positive direction of FIG. 2, and FIG. 5 is a unit cell used in the bearing thrust load measuring device of the present invention. FIG. 6 is a partially cutaway plan view of FIG. 5. In the figure, 1 is a shaft, 2 is a bearing, 6 is a flange, 7 is a tightening nut, 8, 9 are bearing support members, 10 is a bolt, 11, 12 are unit cells, 13 is an initial tightening member, 14 is a tightening bolt, 15 indicates the unit cell body, and 18 indicates a strain gauge.

Claims (1)

[Claims] 1 Bearing support members are arranged on both sides of a flange fixed to the outer periphery of the bearing outer race that is rotatably fitted, and each bearing support member is equipped with strain gauges at approximately equal intervals in the circumferential direction. A unit cell is disposed in contact with the side surface of the flange, an initial tightening member is attached to one of the bearing support members to give a preload to the unit cell disposed on both sides of the flange, and the bearing flange and the flange are connected to each other. A thrust load measuring device for a bearing, characterized in that the bearing support portions provided on both sides are fastened with a bolt that also serves as a rotation stopper.