JPH04117918U - Bearing-embedded composite sensor - Google Patents

Abstract

(57) [Summary] [Purpose] Simultaneously detects the metal contact conduction status and temperature rise status between the bearing and the rotating shaft, and eliminates the need for insulation on the back of the bearing and the installation of a slip ring on the rotating shaft side. [Structure] A hollow cylindrical sensor body 5a is embedded in the bearing 2, and a (+) electrode 6 and a (-) electrode 7 for contact conduction are inserted into the hollow of the sensor body 5a with their tips connected to the bearing 2. A temperature sensor 10 is embedded in the (-) electrode 7 flush with the sliding friction surface.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a bearing-embedded composite sensor suitable for performance detection sensors of oil-lubricated plain bearings. Regarding sir.

0002

[Conventional technology]

Conventionally, in order to prevent burnout of oil-lubricated plain bearings, as shown in the electrical circuit diagram in Figure 4, In addition, contact continuity measurement using an applied voltage method has been carried out. That is, in FIG. 01 is a rotating shaft, 02 is a fixed bearing, and both surfaces are formed by oil lubrication. It is separated by an oil film and operates without abnormality, and this formed oil film Due to accidents such as alignment, overspeed, overload, and lack of oil, oil film thickness may increase. When the temperature decreases and further breaks, the rotating shaft 01 and the bearing 02 come into direct metal contact, resulting in abnormal temperatures. This will lead to a rise in temperature, which in turn will cause serious problems such as burnout.

[0003] Therefore, an insulating coating 03 is applied to the back surface of the bearing 02 to insulate it from the mechanical equipment, and the bearing 02 serves as a (+) electrode, while a slip ring 04 is provided on the rotating shaft 01 (-). A circuit centered around these two electrodes is composed of resistors R ₁ , R ₂ , R _r and a voltage E ₀ supplied to the circuit. Then, when the oil film resistance R _r between the rotating shaft 01 and the bearing 02 changes, that is, metal contact occurs, a voltage drop occurs during this time and is detected as a contact continuity signal output E _AB . By evaluating this output E _AB , the bearing Performance can be evaluated.

0004 However, such means have the following problems. (1) To configure bearing 02 as a (+) electrode, completely separate the bearing from the mechanical device. It is necessary to insulate the bearing, and insulation tends to increase the temperature of the bearing. This will lead to a decline in bearing performance. (2) In order to configure the rotating shaft 01 side as a (-) electrode, it is necessary to input and output voltage signals. Therefore, the installation of slip ring 04 is an essential condition. This slip ring 04 increases the cost due to the circuit configuration and also requires regular maintenance. For example, in a turbine shaft system, a grounding device is originally used as a grounding device. It has a lip ring, so there is the inconvenience of having to install a double slip ring. be.

[0005]

[Problem that the idea aims to solve]

This invention was proposed in view of these circumstances, and is designed to evaluate bearing performance. It is possible to simultaneously detect the metal contact continuity status and temperature rise status of the bearing. Embedded bearing eliminates the need for insulation and installation of a slip ring on the rotating shaft side The purpose is to provide a composite sensor.

[0006]

[Means to solve the problem]

To this end, the present invention uses a hollow sensor body buried within the bearing and the sensor - A pair of (+) and (-) electrodes insulatively embedded in the hollow of the main body, and the above-mentioned It is characterized by comprising a temperature sensor embedded in the hollow of the sensor body.

[0007]

[Effect]

In the bearing-embedded composite sensor of the present invention, both electric currents to which several volts of DC voltage are applied The space between the electrodes is completely insulated by the insulating material, and the rotating shaft is on the friction surface of both electrodes. When the electrodes are separated by an oil film and are operating, the resistance of the oil film is infinite, so the distance between the two electrodes is No short-circuit phenomenon occurs in this case. However changes in operating conditions e.g. misalignment , If an accident such as overspeed, overload, or lack of oil occurs, the space between the rotating shaft and the bearing will The thickness of the oil film that is formed decreases, and at the same time metal contact between the rotating shaft and the bearing surface occurs, both electrodes Metal contact of the rotating shaft occurs, and the electric circuit is short-circuited through the rotating shaft, causing both electrodes to contact each other. The DC voltage applied between them causes a voltage drop. Bearings due to this voltage drop situation Performance during operation can be evaluated. Additionally, a temperature sensor detects the temperature between the rotating shaft and the bearing. fever can be detected at the same time.

[0008]

【Example】 One embodiment of the bearing-embedded composite sensor of the present invention will be explained with reference to the drawings. Figure 2 is a vertical cross-sectional view of the bearing-embedded composite sensor of the present invention embedded in a bearing. FIG. 3, a view taken along II-II, is an electrical circuit diagram of the contact conduction circuit of the present sensor.

[0009] In Figures 1 and 2, a composite sensor is embedded in a bearing 2 installed opposite to a rotating shaft 1. The sensor body 5a of the sensor 5 is made of a material that has properties equivalent to or similar to the bearing metal material. It is machined into a hollow cylindrical shape. There is a contact conduction in the hollow part of this sensor body 5a. (+) electrode 6 and (-) electrode 7 have their tips flush with the sliding friction surface of bearing 2. and is insulated with an insulating material 8 such as heat-resistant epoxy resin. is fixed. Lead wires 9 for voltage input/output signals are connected from these electrodes 6 and 7. The electrical circuit shown in FIG. 3 is constructed. Furthermore, inside the (-) electrode 7 A temperature sensor 10 such as alumel/chromel thermocouple is buried, and the output is shown in the figure. It is directly connected to the recorder. Note that both electrodes 6 and 7 are axially connected like the sensor body 5a. It is made of a material that has the same or similar properties as the receiving metal material.

[0010] In this way, the rotating shaft 1 is inserted onto the sliding friction surface of the bearing 2 in which the composite sensor 5 is embedded through an oil film of lubricating oil, and rotates. That is, during normal operation, the rotating shaft 1 and the bearing 2 are completely separated and do not come into contact with each other due to the oil film, and therefore both electrodes 6 and 7 of the composite sensor 5 rotate without coming into contact with each other. However, if the oil film decreases due to accidents such as misalignment, overspeed, overload, or lack of oil, and direct metal contact occurs between the rotating shaft 1 and the bearing 2, the same will occur between the electrodes 6, 7 and the rotating shaft 1. contact occurs, resulting in a short circuit between A, B, and C. As a result, the voltage applied in the circuit instantly drops, giving a warning that the rotating shaft 1 and the bearing 2 have come into metal contact. The situation of voltage drop due to this metal contact is extracted as an output from E _AB shown in FIG. 3 and inputted to a recorder (not shown) to evaluate bearing performance. Further, the amount of heat generated between the rotating shaft 1 and the bearing 2 is detected by a recorder (not shown) to which a temperature sensor 10 is connected.

[0011] Thus, according to such a device, the sensor body 5a buried directly in the bearing 2 can be A (+) electrode 6 and a (-) electrode 7 insulated by an insulating material 8 are embedded therein. By embedding the temperature sensor 10 in the (-) electrode 7, the bearing performance is evaluated. The metal contact situation and temperature rise situation, which are important physical quantities, can be detected simultaneously. In addition, the disadvantages of conventional methods are the insulation on the back of the bearing and the slip ring installed on the rotating shaft side. This makes it possible to eliminate the need for bearings, which in turn improves bearing performance and reduces equipment costs. can.

0012

[Effect of the idea]

In short, according to the present invention, the hollow sensor body buried in the bearing and the sensor a pair of (+) and (-) electrodes insulatively embedded in the hollow of the sensor body; By including a temperature sensor embedded in the hollow of the sensor body, the shaft Can simultaneously detect metal contact conduction status and temperature rise status to evaluate receiving performance In addition, it eliminates the need for insulation on the back of the bearing and the installation of a slip ring on the rotating shaft side. This invention is extremely useful industrially because it provides a bearing-embedded composite sensor that can It is.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the bearing-embedded composite sensor of the present invention embedded in a bearing.

FIG. 2 is a view taken along II-II in FIG. 1;

FIG. 3 is an electrical circuit diagram of the contact conduction circuit of the present sensor.

FIG. 4 is an electrical circuit diagram of a conventional contact continuity measuring means.

[Explanation of symbols]

1 Rotating axis 2 Bearing 5 Composite sensor 5a Sensor body 6 (+) electrode 7 (-) electrode 8 Insulating material 9 Lead wire 10 temperature sensor

Claims (1)

[Scope of utility model registration request] Claim 1: A hollow sensor body embedded in a bearing, and a sensor body insulatively embedded in the hollow of the sensor body.
A bearing-embedded composite sensor comprising a pair of (+) and (-) electrodes and a temperature sensor embedded in the hollow of the sensor body.