JP7090569B2 - Rotating electric machine and dump truck equipped with this - Google Patents

Description

The present invention relates to a rotary electric machine having an electrolytic corrosion countermeasure on the rotary shaft, and a dump truck provided with the rotary electric machine.

Generally, when the inverter is operated by a generator, if the carrier frequency of the inverter is set high, a voltage (shaft voltage) generated by high frequency induction is applied to the rotating shaft of the generator, and a bearing (bearing) supporting the rotating shaft is applied. ), The potential difference between the inner ring and the outer ring becomes large, and a phenomenon occurs in which a current flows through the bearing.

When a current flows through the bearing, corrosion called electrolytic corrosion occurs on both the inner and outer raceways of the bearing and the rolling surface of the rolling element of the bearing, which causes a problem that the durability of the bearing deteriorates.

Therefore, in Patent Document 1, as a countermeasure against electrolytic corrosion of the bearing of the rotary electric machine, in order to "obtain an earth brush for the rotary electric machine having a structure that is not complicated and is easy to manufacture and can surely reduce the shaft current", it is conductive. Sex fibers are formed at a plurality of locations on the annular sheet metal member, and the textiles are brought into contact with the rotating shaft to suppress electrolytic corrosion.

Japanese Unexamined Patent Publication No. 2018-78704

However, Patent Document 1 does not consider that the rotary electric machine is used in a polluted environment, and does not study a coping method when mud or dust adheres to the rotary shaft of the rotary electric machine.

For example, the generator used in a dump truck is used in a polluted environment where mud and dust can adhere, and the earth brush of Patent Document 1 stabilizes the earth effect due to the adhered mud and dust. There is a problem that it cannot be obtained.

Therefore, an object of the present invention is to provide a rotary electric machine capable of obtaining a stable grounding effect even in a polluted environment.

In order to solve the above problems, the rotary electric machine of the present invention is provided with a ground structure in contact with the rotary shaft, and the ground structure includes a mounting member having a pair of fixing portions and rotation of the rotary shaft. The cleaning device has a cleaning device installed in a fixed portion on the upstream side in the direction and an earth device installed in a fixed portion on the downstream side in the rotation direction of the rotating shaft, and the cleaning device has a rectangular cross section. The grounding device is installed so that the longitudinal direction of the rectangular cross section substantially coincides with the axial direction of the rotating shaft, while having a broom-shaped brush installed so that the longitudinal direction of the rotating shaft substantially coincides with the axial direction of the rotating shaft. The cleaning device and the grounding device have the broom-shaped conductive fibers, and the region of the outer peripheral surface of the rotating shaft that the tip of the broom-shaped brush passes through while contacting the rotating shaft. It was assumed that the inside was installed so that the tip portions of the broom-shaped conductive fibers passed through while in contact with each other.

According to the rotary electric machine of the present invention, a stable grounding effect can be obtained even in a polluted environment.

It is a perspective view which shows the earth structure of the rotary electric machine of Example 1. FIG. It is a perspective view which shows the earth structure of the rotary electric machine of Example 2. FIG. It is a perspective view which shows the earth structure of the rotary electric machine of Example 3. FIG. It is a perspective view which shows the earth structure of the rotary electric machine of Example 4. FIG. It is a schematic diagram of a dump truck equipped with a generator.

Hereinafter, the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings.

The rotary electric machine according to the first embodiment of the present invention and the dump truck provided with the rotary electric machine will be described with reference to FIGS. 1 and 5.

FIG. 5 is a schematic view of the dump truck 100 provided with the rotary electric machine of this embodiment. In the following, the generator 10 will be illustrated as an example of the rotary electric machine, but the rotary electric machine may be an electric machine (motor).

The dump truck 100 is a truck capable of unloading a load 100b such as earth and sand at a time by inclining the loading platform 100a so that the front side is high and the rear side is low, and is equipped with a generator 10, an engine 20, a hydraulic pump 30, and the like. ing. Then, the rotating shafts of the generator 10 and the engine 20 and the rotating shafts of the generator 10 and the hydraulic pump 30 are connected so that the driving force generated by the engine 20 can be transmitted to the generator 10 and the hydraulic pump 30. .. With this configuration, the driving force of the engine 20 can be converted into electric power by the generator 10 and also converted into electric power for lifting the loading platform 100a by the hydraulic pump 30.

In this embodiment, the rotating shaft 10a protruding from the generator 10 toward the hydraulic pump 30 is provided with a ground structure 1 as a measure against electrolytic corrosion. The rotating shaft 10a is exposed for reasons such as improving maintainability, and mud and dust flying up from the ground adhere to the rotating shaft 10a in a polluted environment such as a construction site where the dump truck 100 is used. Sometimes. Therefore, the ground structure 1 of the present embodiment is configured to cope with the adhesion of mud and dust.

FIG. 1 is a perspective view showing the ground structure 1 of this embodiment. The rotary shaft 10a shown here is supported by a bearing (not shown), and the ground structure 1 is mainly composed of a cleaning device 2, a ground device 3, and a mounting member 4. Of these, the attachment member 4 is a metal plate or the like fixed to the housing of the generator 10, and a pair of fixing portions 4a are attached to the base portion perpendicular to the rotating shaft 10a by welding or the like. Further, the cleaning device 2 uses the fixing portion 4a and the sandwiching plate 2b on the upstream side with respect to the rotation direction of the rotation shaft 10a so that the longitudinal direction of the rectangular cross section of the broom-shaped brush 2a coincides with the axial direction of the rotation shaft 10a. The grounding device 3 sandwiches and holds the broom-shaped conductive fiber 3a by the fixing portion 4a and the sandwich plate 3b on the downstream side with respect to the rotation direction of the rotation shaft 10a. It is sandwiched and held so as to coincide with the axial direction of.

Further, the broom-shaped brush 2a and the broom-shaped conductive fiber 3a are arranged in the radial direction so as to be substantially radial when viewed from the central axis of the rotating shaft 10a, and their tip portions are arranged on the outer periphery of the rotating shaft 10a. It is pressed against the surface and bent. Due to this bending, the contact area between the broom-shaped brush 2a or the broom-shaped conductive fiber 3a and the rotating shaft 10a is larger than that when the tip of the broom-shaped brush 2a or the broom-shaped conductive fiber 3a is simply brought into contact with the rotating shaft 10a. It's getting bigger.

Further, since both the cleaning device 2 and the grounding device 3 are mounted on the same surface perpendicular to the rotating shaft 10a, the rotating shaft that the tip of the broom-shaped brush 2a passes through while rotating when the rotating shaft 10a rotates. The tip of the broom-like conductive fiber 3a passes through the region of the outer peripheral surface of 10a while contacting.

It is preferable that the cleaning device 2 and the grounding device 3 are installed relatively close to each other so that the circumferential installation interval is about 30 ° to 90 °. Further, in FIG. 1, the number of installations of the ground structure 1 is one, but a plurality of earth structures may be installed.

The ground structure 1 having the configuration described above has the following effects.

That is, in the ground structure 1 of the present embodiment, both the broom-shaped brush 2a of the cleaning device 2 and the broom-shaped conductive fiber 3a of the grounding device 3 are arranged so that the longitudinal direction of the rectangular cross section coincides with the axial direction of the rotation axis 10a. Since the contact area with the rotating shaft 10a is increased by pressing both tips against the rotating shaft 10a and bending it, the cleaning ability by the cleaning device 2 and the grounding by the grounding device 3 are performed. Both abilities can be improved.

Further, when the rotating shaft 10a is rotated, the broom-shaped brush 2a of the cleaning device 2 arranged on the upstream side passes through the outer peripheral surface region of the rotating shaft 10a while cleaning mud and dust, and the grounding device is arranged on the downstream side. Since the broom-shaped conductive fiber 3a of 3 follows, the possibility of mud or dust intervening between the grounding device 3 and the rotating shaft 10a is low even in a polluted environment where the dump truck 100 is used. The grounding performance of the ground structure 1 as a whole can be stabilized, and electrolytic corrosion of the bearing supporting the rotating shaft 10a can be suppressed.

Further, since the ground structure 1 of the present embodiment is a simple structure with few components, it is easy to additionally install it in a generator to which the ground structure 1 is not applied at the time of manufacture. In addition, both the broom-shaped brush 2a and the broom-shaped conductive fiber 3a can adjust the installation position of the rotating shaft 10a in the radial direction, so that the broom-shaped brush 2a and the broom-shaped conductive fiber 3a can be installed even if the contact area decreases due to wear or the like due to operation. By readjusting the positions, the pressed state of the cleaning device 2 and the grounding device 3 can be appropriately maintained, so that the replacement cycle of the cleaning device 2 and the grounding device 3 can be lengthened.

In the above, the generator 10 in which the cleaning device 2 is arranged on the upstream side and the grounding device 3 is arranged on the downstream side is exemplified, but the broom-shaped brush 2a of the cleaning device 2 on the upstream side is used as a broom-shaped conductive fiber 3a. May be replaced with. As a result, the cleaning device 2 on the upstream side can also be provided with the grounding function, so that a more reliable grounding structure 1 can be realized.

Next, Example 2 of the present invention will be described with reference to FIG. It should be noted that the common points with the first embodiment are omitted.

FIG. 2 is a perspective view showing the ground structure 1 of the second embodiment. In the first embodiment, the cleaning device 2 and the grounding device 3 are brought into contact with the outer peripheral surface of the rotating shaft 10a having a uniform diameter, but in the present embodiment, the diameter is larger at the shaft end of the rotating shaft 10a. A flange portion 10b having a width narrower than that of the broom-shaped brush 2a is formed, and the cleaning device 2 and the grounding device 3 are brought into contact with the outer peripheral surface of the flange portion 10b.

In the configuration of the first embodiment, even if the cleaning device 2 removes mud and dust outside the passing area of the cleaning device 2, a part of the mud and dust remains on the outer peripheral surface of the rotating shaft 10a, so that the mud once removed is removed. Etc. may reattach to the passing area of the grounding device 3 or the like.

On the other hand, in the configuration of the present embodiment, the mud and dust adhering to the outer peripheral surface of the flange portion 10b are removed to the outside of the outer peripheral surface by the cleaning device 2, so that the mud and the like once removed are removed by the grounding device 3. Since the possibility of reattaching to the passing region such as the above is greatly suppressed, it is possible to realize a more reliable earth structure 1 as compared with the configuration of the first embodiment.

The flange portion 10b may be integrally formed with the rotary shaft 10a, but if the flange portion 10b is a separate part, the flange portion 10b deteriorates over time due to wear due to contact with the cleaning device 2 and the grounding device 3. Even in this case, it is possible to replace only the flange portion 10b while leaving the rotating shaft 10a, which is generally difficult to replace, so that maintainability can be improved.

Next, Example 3 of the present invention will be described with reference to FIG. It should be noted that the common points with the above embodiments are omitted.

FIG. 3 is a perspective view showing the ground structure 1 of the third embodiment. In the first and second embodiments, the cleaning device 2 and the grounding device 3 are brought into contact with only the outer peripheral surface of the rotating shaft 10a and the flange portion 10b, but in this embodiment, the broom-shaped brush 2a and the broom-shaped conductive fiber 3a are brought into contact with each other. By further widening the width of the broom or narrowing the width of the flange portion 10b, a part of the cleaning device 2 and the grounding device 3 is brought into contact with the rotating shaft 10a or the shaft end portion of the flange portion 10b. With this configuration, in this embodiment, the contact area between the cleaning device 2 and the grounding device 3 and the rotating shaft 10a is further expanded, so that a higher dust removing effect and a grounding effect can be realized.

Example 4 of the present invention will be described with reference to FIG. It should be noted that the common points with the above embodiments are omitted.

FIG. 4 is a perspective view showing the ground structure 1 of the fifth embodiment. In Examples 1 to 3, the length of the broom-shaped brush 2a of the cleaning device 2 and the length of the broom-shaped conductive fiber 3a of the grounding device 3 are substantially the same, but in this embodiment, the length of the broom-shaped conductive fiber 3a is substantially the same. The length of fiber 3a has been significantly extended.

With this configuration, in the configuration of this embodiment, the contact area between the grounding device 3 and the rotary shaft 10a can be significantly expanded, so that not only a higher grounding effect can be realized, but also observations are made in the configurations of Examples 1 to 3. The wear state of the contact surface of the grounding device 3 which was difficult can be easily observed by lifting the broom-shaped conductive fiber 3a.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace other configurations with respect to the configurations of each embodiment.

1 ... Earth structure,
2 ... Cleaning device,
2a ... Broom-shaped brush,
2b ... sandwich plate,
3 ... Grounding device,
3a ... Broom-like conductive fibers,
3b ... sandwich plate,
4 ... Mounting member,
4a ... Fixed part,
100 ... Dump truck,
100a ... Loading platform,
100b ... cargo,
10 ... Rotating electric machine,
10a ... rotation axis,
10b ... Flange part,
20 ... engine,
30 ... Hydraulic pump

Claims (7)

It is a rotating electric machine with a grounding structure that comes into contact with the rotating shaft.
The ground structure includes a mounting member having a pair of fixing portions, a cleaning device installed in the fixing portion on the upstream side with respect to the rotation direction of the rotation shaft, and a cleaning device on the downstream side with respect to the rotation direction of the rotation shaft. It has a grounding device installed in the fixed part,
The cleaning device has a broom-shaped brush installed so that the longitudinal direction of the rectangular cross section substantially coincides with the axial direction of the rotation axis.
The grounding device has broom-like conductive fibers installed so that the longitudinal direction of the rectangular cross section substantially coincides with the axial direction of the rotation axis.
In the cleaning device and the grounding device, the tip of the broom-shaped conductive fiber passes through the region of the outer peripheral surface of the rotating shaft through which the tip of the broom-shaped brush passes while contacting the tip of the broom-shaped brush when the rotating shaft rotates. A rotary electric machine characterized by being installed so that it passes through while in contact with each other. The broom-shaped conductive fiber and the tip of the broom-shaped brush are pressed against the rotating shaft and bent.
The rotary electric machine according to claim 1, wherein the installation position of the broom-shaped conductive fiber and the broom-shaped brush with respect to the axial direction is adjustable. The rotary electric machine according to claim 2, wherein the broom-shaped brush of the cleaning device is replaced with the broom-shaped conductive fiber. A flange portion is formed at the shaft end portion of the rotating shaft, and the flange portion is formed.
The rotary electric machine according to claim 2, wherein the broom-shaped conductive fiber and the broom-shaped brush are brought into contact with the flange portion. The rotary electric machine according to claim 2, wherein the shaft end portion of the rotary shaft, the broom-shaped conductive fiber, and the tip portion of the broom-shaped brush are brought into contact with each other. The rotary electric machine according to claim 2, wherein the length of the broom-shaped conductive fiber is made longer than the length of the broom-shaped brush. A dump truck equipped with the rotary electric machine according to any one of claims 1 to 6.

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