JPS5825971B2 - How to measure bearing metal temperature - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the temperature of a bearing metal sliding surface in a bearing that is operated while metal contact occurs.

In bearings that are operated while the shaft and the bearing metal are in metal contact, the temperature of the shaft and the bearing metal increases due to frictional heat at the contact point, often leading to burnout of the bearing metal.

Therefore, it is important to measure the temperature at the point of contact between the bearing metal and the shaft.

Conventionally, as shown in Figure 1, a thermocouple 3' made of chromel-alumel, iron-constantan, etc. is inserted inside the shaft 1' and the bearing metal 2 near the sliding surface to measure the temperature inside the bearing metal. The surface temperature of the bearing metal is estimated empirically.

This method estimates the temperature near the bearing surface, but does not estimate the temperature at the contact point between the bearing metal and the shaft.

Furthermore, there is an unavoidable time delay until the temperature rise due to heat generated due to contact at the contact point spreads to the temperature measurement point.

Therefore, this method has disadvantages in that the contact point temperature of the bearing sliding surface cannot be determined accurately and that there is a time delay.

In addition, in the early stages, bearing burnout often occurs locally on the bearing surface and gradually progresses to the entire bearing surface, but with conventional methods, the contact point is predicted and a thermocouple is inserted into that area. difficult to do.

Therefore, the conventional method has the disadvantage that it is difficult to detect local burnout unless a large number of thermocouples are inserted over almost the entire surface.

The present invention is a method for measuring the temperature at the contact point of the sliding surface of a bearing metal, by configuring a thermocouple that utilizes thermoelectromotive force phenomenon with the shaft as one metal and the bearing metal as the other dissimilar metal.
The purpose is to measure the contact point temperature of the metal sliding surface of a bearing.

To explain the embodiment of the present invention in detail with reference to the drawings, in FIG. 2, the shaft 1 and the bearing metal 2 are each made of different metals, and both make metal contact at a part of the sliding surface. When this occurs, the temperature rises at the contact point due to frictional heat.

At this time, the contact point between the shaft 1 and the bearing metal 2 and the lead wire 6
, 7 and zero contact 4 form a circuit equivalent to a thermocouple.

The shaft 1 is connected to the lead wire 6 via a rolling bearing or slip ring 8.

The lead wire 6 is made of the same material as the shaft 1, and the lead wire 7 is made of the same material as the bearing metal 2, or a material having the same thermoelectromotive force effect, and corresponds to a compensating lead wire of the thermocouple circuit.

When these relationships are represented in a circuit, it becomes as shown in FIG.

If there is a temperature difference between the temperature of the contact point between the shaft 1 and the bearing metal 2 and the temperature of the zero contact point, a thermoelectromotive force is generated.

By measuring this thermoelectromotive force with the mV meter 5, it is possible to know the temperature of the contact point between the shaft 1 and the bearing metal 2, that is, the contact point of the bearing metal sliding surface.

As described above, according to the present invention, the temperature at the contact point of the sliding surface of the bearing metal can be directly measured, and even if local contact occurs at any position, the temperature at that contact point can be directly measured. There is.

Needless to say, it is impossible to measure the bearing temperature if it is well lubricated with oil or other lubricant and there is no contact between the shaft and the bearing metal, but in such cases there is little need to measure the bearing temperature. Therefore, there is no problem, but if contact occurs and becomes measurable, it can be an indicator of the risk of damage to the bearing metal.

As described above, the present invention has excellent features such as being able to measure the temperature of the contact portion of the sliding surface of a bearing, helping to detect damage to the bearing at an early stage, and greatly contributing to improving the reliability of mechanical devices.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway explanatory diagram showing a conventional bearing metal temperature measurement method, Fig. 2 is a partially cutaway explanatory diagram showing an embodiment of the present invention, and Fig. 3 is a circuit diagram of Fig. 2 as an electric circuit. It is a diagram. 1...shaft, 2...bearing metal, 3...
...Thermocouple, 4...Zero contact, 5...
・mV meter, 6...Lead wire (shaft material), 7
...Lead wire (bearing metal material), 8...
...Rolling bearing or slip ring, 9...
・Lead wire (copper wire).

Claims (1)

[Claims] 1 When a sliding bearing is operated with the shaft and bearing metal in contact, the shaft is made of one metal, the bearing metal is made of the other dissimilar metal, and the friction surfaces of the mutually contacting dissimilar metals are used as thermocouple circuits. A method for measuring the temperature of a bearing metal, characterized in that the temperature of the contact point between the shaft and the bearing metal is directly measured by using a thermal contact as a thermal junction and measuring the thermoelectromotive force generated in the circuit.