JPH0321855B2 - - 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 includes a flange fixed to the outer periphery of a rotatably fitted bearing outer race, which is housed in a cylindrical bearing support member, and a side plate of the bearing support member in which the flange is fixed to the outer periphery of the bearing outer race. Unit cells each having a strain gauge and having a top abutting one side of the flange are disposed at approximately equal intervals between the bearing support member and the bearing outer race,
An annular unit cell holder which can be tightened by a tightening nut screwed onto the inner periphery of the bearing support member is fitted, and strain gauges are provided at approximately equal intervals in the circumferential direction of the unit cell holder, and the top is connected to the flange and other parts. A unit cell is disposed in contact with the side surface, and a rotation preventing member is interposed between the bearing support member side plate and the bearing flange.

[Operation] Thrust load is transmitted from the shaft to the unit cell via the bearing and the flange of the bearing outer race.
It is measured by a strain gauge and taken out to the outside, and the rotation in the direction of rotation of the shaft is prevented by a rotation preventing member.

[Examples] Examples of the present invention will be described below with reference to the accompanying 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. Also inner lace 3
is tightened by a tightening nut 7 and fixed to the shaft 1.

The flange 6 of the bearing 2 is fitted into a hollow cylindrical bearing support member 8, and a small gap G is maintained between the annular side plate 8a at one end of the bearing support member 8 and the side of the flange 6. Unit cells 9 for thrust load measurement are arranged in recesses provided at approximately equal intervals in the circumferential direction of the side plate 8a, and the top of the unit cells 9 is brought into contact with one side of the flange 6. , 9, one end of the rotation stopper pin 10 is fitted into a hole provided in the flange 6,
Rotation of the shaft 1 prevents the flange 6 from twisting around.

An annular unit cell holder 11 is disposed on the side opposite to the plate 8a of the flange 6 so as to be located between the inner periphery of the bearing support member 8 and the outer periphery of the outer race 5 of the bearing 2. A small gap G is maintained between the unit cell holder 11, and unit cells 12 for thrust load measurement are arranged in recesses provided at approximately equal intervals in the circumferential direction of the unit cell holder 11. Tightening nut 1 screwed onto the inner periphery of support member 8
3 is tightened so that the top of the unit cell 12 comes into contact with the other side surface of the flange 6.

Since the unit cells 9 and 12 described above have the same structure, the details of the unit cell 9 will be explained below with reference to FIGS. 5 and 6. A protrusion 15 is provided on the anti-spherical side of the unit cell main body 14 so that the thrust load F acting from the flange 6 can be transmitted to the side plate 8a.A recess 16 is provided on the upper and lower surfaces of the unit cell main body 14. Strain gauges 17 for detecting shear strain are attached to the bottom and ceiling surfaces, and heat-resistant,
The unit cell body 14 is filled with oil-resistant shaft fat and covered with stainless steel foil, and the strain gauge 17
are designed to be protected from heat and oil. Further, on the center side of the shaft 1 of the unit cell 9 insertion part of the side plate 8a, a notch 18 for taking out lead wires etc. is provided at approximately the same interval as the interval between the protrusions 15 of the unit cell 9. is filled with heat-resistant resin for protection except for the lead wire extraction space.

The thrust load is shaft 1 → bearing 2 → flange 6 →
The signal is transmitted along the path from the unit cell 9 or 12 to the bearing support member 8, and in the process is converted into an electrical signal by the unit cell 9 or 12, which has a load-to-electricity conversion capability, and is recorded and displayed. When detecting the thrust load acting on the bearing 2, set the unit cells 9 and 12 on the rotating machine whose thrust load is to be measured as shown in FIG. Apply the required initial tightening force to 9 and 12. By applying this initial tightening force, when the thrust load is F, for the same reason as stated in the specification of Japanese Patent Application No. 60-6603, the unit cell 9 side has a thrust force that increases the initial tightening force. The load is detected at F/2, and on the other hand, on the unit cell 12 side, a thrust load that reduces the initial tightening force is detected at F/2. The thrust load F/2 that increases this initial tightening force is expressed as F/2 in the following explanation, and the thrust load F/2 that decreases the initial tightening force is expressed as -F/2 in the following explanation.

Since the strain gauge on the unit cell 9 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 _{If the} elongation _of
H , and the output of the strain gauge in the unit cell 12 is -ε ₁ '=-ε ₁ /2+ε _H. Here, the output ε ₁ ' of the strain gauge of the unit cell 9 increases by ε ₁ ' than the output when the initial tightening force is applied, and the output of the strain gauge of the unit cell 12 -
ε ₁ ' means that the output is reduced by ε ₁ ' from the output when the initial tightening force is applied. The ε ₁ ′ and −ε ₁ ′ signals are sent to the differential amplifier through the signal conditioner as in the case of Japanese Patent Application No. 60-6603, but the differential amplifier receives electrical signals of different polarities. Since the differential amplifier has a function of adding up electric signals of the same polarity and canceling out electrical signals of the same polarity, the output ε of the differential amplifier becomes 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.

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

[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 transmitted quickly and reliably to the unit cell, allowing for highly accurate load detection. () The unit cell is fitted into the bearing support member and the bearing support member. Since the unit cell holder is attached to a unit cell holder, the entire device is small and lightweight. () Prevents damage to the bearing, reduces the burden on other mechanical parts, and stabilizes the area around the bearing, making it possible to detect other abnormalities early. () Load conversion with strain gauges attached The parts and materials can be used repeatedly and are interchangeable, resulting in good manufacturability. Various excellent effects can be achieved, such as easy replacement.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the bearing thrust load measuring device of the present invention, FIG. 2 is a view taken in the - direction arrow of FIG. 1, and FIG. 3 is a view taken in the - direction arrow of FIG. 1.
Fig. 4 is a view taken in the - direction of Fig. 3, Fig. 5 is a detailed view of a unit cell used in the bearing thrust load measuring device of the present invention, and Fig. 6 is a partially cutaway plan view of Fig. 5. be. In the figure, 1 is a shaft, 2 is a bearing, 6 is a flange, 7 is a tightening nut, 8 is a bearing support member, 9 is a unit cell, 10 is a rotation stopper pin, 11 is a unit cell holder, 12 is a unit cell, and 13 is a tightening nut. , 14 is a unit cell body, and 17 is a strain gauge.

Claims (1)

[Claims] 1. A flange fixed to the outer periphery of a rotatably fitted bearing outer race is housed in a cylindrical bearing support member, and strain gauges are provided on the side plate of the bearing support member at approximately equal intervals in the circumferential direction, and the top is A unit cell is disposed in contact with one side of the flange, and an annular unit cell holder is fitted between the bearing support member and the bearing outer race to be tightened by a tightening nut screwed onto the inner circumference of the bearing support member. unit cells each having a strain gauge and whose top abuts the other side of the flange are disposed at approximately equal intervals in the circumferential direction of the unit cell holder, and a rotation prevention member is provided between the bearing support member side plate and the bearing flange. A thrust load measuring device for a bearing, characterized in that a bearing thrust load measuring device is provided.