JPS61239462A - Wear detecting mechanism for motor shaft - Google Patents

Abstract

PURPOSE:To recognize a wear in an earth section of a shaft without viewing by an operator by operating a lamp or a buzzer or the like when the earth section of the shaft is worn to a level generating an abnormal oscillation of the shaft or a difficulty in contact of the shaft and the earth section of the shaft. CONSTITUTION:An earth carbon 19 is usually pressed to a slide section 30 of a shaft 29 by an operation of a leaf spring 15. Accordingly, the shaft 29 is constantly grounded to an earth 35 through the sliding section 30, an inner side carbon section 26, an inner side protrusion 22, a leaf spring base 11 and a disk base 16. By rotating the shaft 29, the sliding section 30 or the inner side carbon section 26 are worn. When an outer periphery protrusion 31 of the shaft 29 contacts an outside carbon section 28 of the earth carbon 19, a current passes through the earth 35 and a light emission diode 32 lights and a buzzer 33 rings.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a wear detection mechanism for detecting wear of a shaft grounding portion that prevents a motor from being charged with electricity.

[Technical background of the invention and its problems]

Conventionally, the shaft of a motor is provided with a shaft grounding portion at the ninth position to prevent static electricity on the shaft. Here, we will take a magnetic disk device that directly drives a disk with a spindle motor as an example, and compare the conventional shaft grounding part 't-
explain.

FIG. 1 is a diagram illustrating the configuration of a shaft grounding portion in a conventional magnetic disk device.

The spindle attached to the bottom of the disk base 1
The motor 2 has a stator 4 attached to a motor housing 3, and a rotor 6 attached to a motor housing 3. shaft 5
is attached to the motor housing 3 via a bearing 7, and a flange 8 is attached to this shaft 5, and a flange 8 is attached to the shaft 5.
A disk 9 is attached to the lunge 8. shaft 5
A sliding portion 10 formed by embedding a steel ball or the like is provided at the lowermost end of the holder, and the sliding portion 10 is in contact with earth carbon 11. The earth carbon 11 is attached to one end of a spring material 12, and the other end of the spring material 12 is fixed to the lower surface of the disc e base l with a screw.

In this rotating mechanism, when the shaft 5 rotates, the bearing 7
An insulating film made of a lubricant such as grease is formed on the surface of the hole, and the motor pace 1 and the shaft 5 are brought into a non-conducting state. On the other hand, when the disk 9 rotates, static electricity is generated due to abrasion with the air, and discharge occurs between the disk 9 and the head. This discharge causes read errors or write errors in magnetic disk drives, so the sliding part 10, earth carbon +1. A shaft grounding portion made of a spring material 12 or the like is provided.

However, the sliding portion 10 and the earth/carbon 11 inevitably wear out during the rotation of the shaft 5, causing abnormal shooting and poor contact. Therefore, when wear occurs, the shaft grounding part must be replaced, but this shaft grounding part is located at a location that is not easily visible from the outside of the magnetic disk drive, so that the operator can judge the state of wear. The problem was that it seemed feminine.

It is an object of the present invention to provide a motor shaft wear detection mechanism that allows a berator to detect kg without directly looking at it.

[Summary of the invention]

The motor shaft wear detection mechanism of the present invention includes a wear detection section that detects the degree of wear using a part other than the protrusion when a protrusion provided at one end of the shaft wears out, and this wear detection section. The device is equipped with a communication device that operates when wear is detected by the device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a partial cross-sectional view showing a configuration when a motor shaft wear detection mechanism according to an embodiment is applied to a magnetic disk device.

Wiring pattern 1 on conductive leaf spring paste 11 and base 412
One end of a leaf spring 15 constructed by adhering to the flexible substrate 14 formed at 3t is fixed to the lower surface of the disc space 16 with a screw 17. The other end of this plate spring 15 is grounded by sandwiching an insulating plate 18 on top of the plate spring plate 11.
Carbon black is provided.

Here, the leaf spring 15 viewed from below in FIG.
FIG. 3 shows the insulating plate 1st viewed from below in FIG. 1, and FIG. 4 shows the earth carboy 19 viewed from below in FIG. However, as shown in FIGS. 2 to 4, screws 17 are provided for fixing the leaf spring 15 to the pace 16. The other end of the leaf spring 15 is a hole 20 (hereinafter referred to as the first hole) provided only in the leaf spring paste 1 and a hole 21 (hereinafter referred to as the first hole) provided in the leaf spring paste 11 and the flexible substrate 15. 2) are formed. An inner protrusion 22 of the earth carbon 19, which will be described later, is formed in contact with the inner wall of the first hole 20. Further, in the second hole 21, an outer protrusion 23 of the earth carbon 19, which will be described later, is in contact with the inner wall of the flexible substrate 14 portion, and
It is formed so as not to come into contact with the inner wall of the plate spring space 16 portion.

Next, the structure of the insulating plate 18 shown in FIG. 3 will be explained. This insulating plate 18 is connected to the inner protrusion 22 of the Earth Carbon Retirement, which will be described later.
In order to prevent parts other than the outer protrusion 23 from coming into contact with the leaf spring 15, holes 24 and 25 are provided through which the inner protrusion 22 and the outer circumferential protrusion 23 of the Earth Carbon Emperor pass. Next, the structure of the earth carbon 19 shown in Fig. 4 will be explained. In the earth carbon 19, an insulating layer 27 is provided concentrically around an inner carbon portion 26 formed in a cylindrical shape, and an outer carbon portion 28 is provided surrounding this insulating layer 27. The inner carbon portion 26 is provided with an inner protrusion 2 formed so as to be in contact with the leaf spring pace 111C.
2 is provided, and the outer carbon portion 28 is provided with an outer protrusion 23 formed so as to be in contact with the wiring pattern 13. Next, returning to FIG. 1, the explanation will be continued. Above the earth carbon 19 is the shaft U of the spindle soter.
A sliding part 30, which is a protrusion formed by directly processing the shaft or embedding a copper ball or the like, is provided at the lowest end of the shaft 2, and a sliding part 30 is formed by directly processing the shaft or by embedding a copper ball or the like, and the inner carbon part 26 of the earth carbon 19 9 are placed so that they are in contact with the Also, on the outer periphery of the sliding part 30, there is an outer peripheral protrusion 31 which is a short protruding part with a shorter protrusion length than the sliding part 30. 9 is provided above the outer carbon portion 28. The protrusion length of the outer circumferential protrusion 31 is such that when the wear of the sliding part 30 reaches a level that causes abnormal vibration of the shaft 29 or poor contact between the sliding part 30 and the earth carbon 19, the outer circumferential protrusion 31 It is provided so as to be in contact with the outer carbon portion 28 of No. 19 . The bottom end of this shirt t-first
Fig. 5 shows the state seen from the bottom of the figure.

With the configuration shown in FIG. 1 described above, the shaft 29 is electrically connected to the disc pace 16 through the sliding part 30, the inner carbon part 26, the inner protrusion 22, and the leaf spring pace. In addition, the wiring pattern 13 of the flexible board 14 is as follows:
It is electrically connected to the outer protrusion 23 and the outer carbon portion 28 .

FIG. 6 is a circuit diagram of this embodiment. In the figure, [Yes] and ■ indicate that the parts shown by the same reference numerals in FIG. 1 are electrically connected.

That is, the wiring pattern 13 in FIG. 1 is connected to the cathode of the light emitting diode 32 and one end of the buzzer 33 in FIG. 6. The anode of this light emitting diode 32 is connected to one end of a step-down resistor 34, and the other end of the step-down resistor 34 is connected to a power supply of 10 Vcc.

Further, the other end of the buzzer 33 is also connected to +Vcc of the power supply. The disk e-base 16 in FIG. 1 is connected to the ground 35 in FIG.

Next, the operation of this embodiment will be explained.

The 7th carbon part of the whistle shown in Fig. 1 is always pressed against the sliding part 30 of the shaft 29 by the action of the leaf spring. Therefore, the shaft 29 includes the sliding portion 30 and the inner carbon portion 2.
6. It is always grounded to the ground 35 in FIG. 6 through the inner protrusion 22, the leaf spring plate 11, the disk, and the plate 16t. Sliding part 30 or inner carbon part 2
6 is not worn, the outer circumferential protrusion 31 of the shirt door does not come into contact with the outer carbon part 28 of the earth carbon frame.
Therefore, marks 1 and 2 in FIG. 6 are in an open state, and the electric circuit shown in FIG. 6 is not constructed. Due to the rotation of the shaft 1, the opening, the sliding part 30 or the inner carbon part 26 are worn out,
When the outer circumferential protrusion 31 of the shaft 29 comes into contact with the outer carbon part 28 of the earth/carbon 9, current flows from the power supply +Vcc in FIG. , outer protrusion 23, outer carbon 11s 2 B, outer peripheral protrusion 31° sliding part 30, inner carbon part 26, inner protrusion 22, plate honey paste 11. The disk pace 16ta flows to the ground 35 in FIG. 6, the light emitting diode 32 lights up, and the buzzer 33 sounds. The lighting of the light emitting diode and the buzzer sound indicate that the wear condition of the sliding part 30 is abnormal vibration of the shaft 29 or the sliding part 30 and the earth carbon 1.
Recognizing that the level has reached the point where contact failure etc. as described in 9 has been reached,
Replace the shaft grounding part.

In this embodiment, wear was detected using the sliding part 30, which is a protrusion, and the outer peripheral protrusion 31, which is a short protrusion.As shown in FIG.
It is also possible to detect wear by providing a carbon upper protrusion 32 on the upper surface. Further, although wear is detected by forming an Fi circuit in this embodiment, a method of detecting wear by detecting the contact pressure between the outer carbon portion 28 and the outer circumferential protrusion 31 may also be considered. Further, in this embodiment, the inner peripheral protrusion 22 of the earth carbon 19 only needs to contact the leaf spring pace 11, and the shape does not matter; the outer peripheral projection 23 of the earth carbon 19 also contacts the leaf spring paste 11. Without,
Moreover, it only needs to be in contact with the wiring pattern 13, and the shape does not matter.

〔Effect of the invention〕

According to the present invention 8AK, when the shaft grounding part is worn to a level that causes abnormal vibration of the shaft or poor contact between the shaft and the shaft grounding part, a notification device such as a lamp or a buzzer is activated. Therefore, the operator can recognize when to replace the shaft grounding part without looking directly, and can prevent abnormal shaft vibration and poor contact due to wear of the shaft grounding part.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view showing the configuration when applied to the motor shaft wear detection mechanism T-AT air disc device according to the present invention, and Fig. 2 shows the configuration of the plate shown in Fig. sg1. 3 is a diagram showing the structure of the insulating plate shown in FIG. 1,
Fig. 4 shows the structure of the earth carbon shown in Fig. 1, Fig. 5 shows the structure of the lowermost end of the shaft shown in Fig. 1, and Fig. 6 shows the motor shaft according to the present invention. FIG. 7 is a diagram showing another embodiment of the present invention, and FIG. 8 is a diagram showing the configuration of a conventional shaft grounding section. 11・・・・・・・・・Plate spring pace 12...
......Base layer 13...Wiring pattern 15...
・・・・・・・・・Leaf spring 16・・・・・・・・・・−・Disc pace 18・
......Insulating plate 19... Earth carbon 22.
......Inner protrusion 23...
......Outer protrusion 26...Inner carbon portion 27...Insulating layer 28... Outer carbon part 29
−−・−−−−・・Shaft 30 ・・・・・・
・・・・・・Sliding part 31 ・・・・・・・・・・・・
Peripheral protrusion agent Patent attorney Kensuke Norichika (and 1 other person) 2nd
Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (2)

[Claims] (1) In a motor in which a protruding part is provided at one end of a shaft that provides rotational force to the outside, and the shaft is grounded via this protruding part, when the protruding part is worn out, a part of the one end other than the protruding part 1. A wear detection mechanism for a motor shaft, comprising: a wear detection section that detects the degree of wear using the wear detection section; and a notification device that operates when wear is detected by the wear detection section. (2) The motor shaft wear detection mechanism according to claim 1, wherein a portion of the one end other than the protrusion is a short protrusion having a shorter protrusion length than the protrusion.