JPH06100442B2 - Rotational shaft wear detector for closed rotary machine - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a wear detecting device when a bearing or a rotary shaft portion (hereinafter referred to as a shaft portion) of a rotary machine that is operated in a sealed container is worn, and particularly detects a shaft wear of a closed rotary machine. The present invention relates to a rotating shaft wear detector.

[Prior art]

In a hermetic rotary machine such as a canned motor or a refrigerant compressor, the number of hermetically sealed terminals penetrating the frame of the hermetically sealed container must be minimized in order to avoid leakage of CFCs, ammonia refrigerant, etc. inside. On the other hand, in the refrigerant compressor, it is preferable to continuously grasp the wear condition of the shaft part that is most loaded, from the viewpoint of early detection of failure and efficiency of maintenance, and further, any position of the shaft part is worn. If it can be grasped whether or not there is a failure, it will lead to more efficient failure and maintenance diagnosis. For this purpose, for example, as shown in Japanese Utility Model Laid-Open No. 47754/1, it is preferable to dispose a plurality of shaft wear detection sensors around the rotary shaft in the circumferential direction at a predetermined angle unit. The number of sealed terminals corresponding to the above must be provided, and this has a problem that the leakage of CFCs, ammonia refrigerant, etc. inside will increase accordingly.

[Problems to be Solved by the Invention]

That is, when the sealed container is placed in a high pressure or high vacuum state, gas leaks from the joint portion and the penetration of the container, so minimizing such a portion is the most in terms of design and function. is necessary. Therefore, the number of sealed terminals that penetrate the container must be kept to a minimum.
On the contrary, in order to detect the wear position of the rotating shaft portion with high accuracy, the number of the electrodes is increased, and accordingly, the number of the detection signals is also increased and the number of the sealed terminals is also increased. . According to the present invention, a plurality of shaft wear detection sensors (electrodes) are arranged around the rotary shaft in the circumferential direction at a predetermined angle unit. However, the shaft portion of any electrode part is worn from the detection output taken out from one sealed terminal. It is an object of the present invention to provide a rotary shaft portion wear detecting device in a sealed rotary machine capable of easily detecting whether or not.

[Means for solving the problem]

The present invention relates to a rotary shaft wear detecting device for detecting shaft wear of a hermetically-sealed rotary machine, wherein a plurality of rotary shaft wear detectors are arranged over the entire circumference of the rotary shaft part, and are divided by a predetermined angle in the circumferential direction. An electrode, a number of impedance elements corresponding to the electrodes connected to the electrodes, respectively, and the other end of the impedance element is collectively assembled and connected, and one sealed terminal penetrating the frame of the sealed container, When the one or more electrodes come into contact with the rotating shaft due to wear of the shaft portion, the detection output extracted from the sealed terminal to be able to discriminate which position of the electrode comes into contact has a different value, The impedance constants of the impedance elements are selected respectively.

【Example】

Hereinafter, embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely examples, unless otherwise specified. Not too much. FIG. 1 is a sectional view of a refrigerating compressor integrated with a hermetic motor, and FIG. 2 is a detailed view of the shaft portion of FIG. (A) is a front view and (b) is a side view thereof. 1 is a sealed electric motor,
Reference numeral 2 is a refrigeration compressor, both of which are integrated to form a sealed structure. The rotary shaft 3 is pivotally supported by a common receiver 4. The rotating shaft 3 composed of the rotating shaft 3 and the bearing 4 is attached to the rotating shaft 3 at the position of the bearing portion of the frame 5 which is not affected by the wear of the rotating shaft portion.
In contrast, a plurality of electrodes 6n are provided so as to keep a slight gap and surround the rotary shaft with 3. This electrode has a fan shape, and in the present invention, it is made of a conductor such as four thin copper plates, molded with an insulating material such as resin, and integrally formed into a plate shape. The inner diameter of the mold plate 7 is set to be substantially equal to the diameter of the rotary shaft 3 at that portion, and the inner diameters of the plurality of metal plates 6n are machined so as to maintain the clearance within the allowable range of the shaft portion. Therefore, when the shaft portion is worn, it comes into contact with the rotary shaft 3 only. An impedance element 8n with a specific electrical weight is connected to each of the plurality of electrodes 6n,
The other ends are collectively assembled and connected to a hermetically sealed terminal 9 penetrating the frame 5 of the hermetically sealed container. 3, 4, and 5 show an electrode 6n that contacts the rotary shaft 3 only when the rotary shaft wears, an impedance element 8n with a specific electrical weight, a sealed terminal 9, and a wear detection indicator.
A wiring diagram consisting of 10 is shown. In FIG. 3, the impedance element is a real integer and is a resistor 8n. In order to give an electrical weight, in other words, the one or more electrodes are connected to the rotary shaft 3 due to wear of the shaft portion. When the contact is made, it is possible to discriminate which position of the electrode is contacted, so that the current value taken out from the sealed terminal 9 to the wear detection indicator 10 becomes a different value so that the resistance value of one resistor 8a is different. 1r, 8b is 1 / 2r, 8c is 1 / 4r, and 8d is 1 / 8r ohm, and the corresponding electrodes 6n are 6a, 6b, 6c, 6d, respectively.
If the power supply voltage applied to this is V volts and the electrode 6a contacts the rotor 3 due to wear of the shaft, the current flowing through the impedance element 8a to the sealed terminal 9 is
It becomes 1A. In this way, each of the electrodes 6n and the rotating shaft 3
If the ratio of the respective currents flowing through the terminal 9 is shown by the contact with, it becomes like a separate sheet. That is, the wear position of the shaft portion with respect to the electrode 6n can be clearly known from the current ratio shown in the attached sheet. In FIG. 4, the impedance element is a positive and negative real number, and a rectifying element is weighted by a series resistance for positive / negative discrimination, and the current is an alternating voltage. Similarly, a rectifying element may be provided outside the sealed container to discriminate between the positive and negative display portions 10. According to this circuit, the ON-OFF signal can be doubled as compared with FIG. Fig. 5 shows an example of an imaginary impedance that uses an inductance L and a capacitance C as an impedance element. It becomes a complex output and can be selected for each combination of elements from its absolute value or phase angle. The device requires a circuit for selecting Takanoden. Fig. 6 shows a case of a function impedance element in which non-linear elements are used, and each of them can be weighted. The output from the sealing element can be selected by waveform analysis or the like. Need a circuit. Alternatively, a combination of these may be used. According to the present invention, as described above, a large number of sensor outputs of ON-OFF operation in the sealed container are collectively collected and connected to the sealed terminal, and each sensor output can be obtained from a current passing through the sealed terminals. Needless to say, the sensor output other than the position detection of the shaft wear portion can be processed.

[Brief description of drawings]

FIG. 1 is a sectional view of a refrigeration compressor integrated with a hermetic motor, FIG. 2 is a detailed view of a rotary shaft portion, and (a) is a front view.
(B) is a side view, and FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are electrical connection diagrams of this embodiment, respectively. 3: Rotating shaft, 4: Bearing, 5: Frame, 6: Electrode, 7: Molded plate, 8: Impedance element, 9: Sealed terminal, 10: Wear detection indicator

Claims (1)

[Claims] 1. A rotary shaft wear detecting device for detecting shaft wear of a hermetic rotary machine, wherein the rotary shaft wear detecting device is arranged over the entire circumference of the rotary shaft part and is divided into a predetermined angle in the circumferential direction. A plurality of electrodes, a number of impedance elements corresponding to the electrodes connected to each of the electrodes, and one hermetically sealed terminal connected to the other end of the hermetically-impedance element collectively and penetrating the frame of the hermetic container. When the one or more electrodes come into contact with the rotating shaft due to wear of the shaft portion, it is possible to distinguish which position of the electrode comes into contact so that the detection output taken out from the sealed terminal has a different value. A rotary shaft wear detecting device for a hermetically sealed rotary machine, wherein the impedance constants of the impedance elements are respectively selected.