JP4199343B2 - Electric motor and permanent magnet rotary synchronous motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric motor configured by housing a stator and a rotor in a motor case, and a permanent magnet rotary synchronous motor.
[0002]
[Prior art]
2. Description of the Related Art An induction motor that supplies power to a drive device such as a pump uses a structure in which a stator and a rotor are arranged in a motor case having a split structure. Specifically, as shown in FIGS. 4A and 4B, a cylindrical body portion b and end walls c and d for closing the opening end of the body portion b are fastened to the motor case a of the induction motor. For example, a structure constituted by fastening with a long bolt e is employed, and a stator f is installed on the inner surface of the body portion b, and the rotor g is accommodated in the stator f.
[0003]
Such an induction motor employs a bearing portion i that rotatably supports a motor shaft h extending in the axial direction from the rotor g in the motor case a. Specifically, as shown in FIGS. 4 (a) and 4 (b), an annular recess j for housing a bearing is formed on the inner surface side of each end wall g, and when the motor is assembled, In addition, a structure has been used in which a bearing k press-fitted into the shaft portions on both ends of the motor shaft h is removably inserted to support the motor shaft h rotatably.
[0004]
[Problems to be solved by the invention]
The induction motor may be required to replace the bearing k that supports the motor shaft h at the time of maintenance / inspection performed at a site where a driving device such as a pump is installed, and further repair.
[0005]
However, in the case of an electric motor in which the bearing k is arranged in the motor case a, the bearing k can be replaced only after the entire motor shaft h is taken out of the motor case a.
[0006]
Specifically, the replacement operation of the bearing k is performed by removing the bolt e as shown in FIG. 5, uncoupling the body b and the end walls c and d, and removing one end wall d from the body b. After removing the motor shaft h from which the bearing k is press-fitted at both ends, together with the rotor g, the bearing is pressed into the motor shaft h by using an extraction jig such as a pulley removal tool (not shown). k is extracted and a new bearing (not shown) is mounted instead.
[0007]
In other words, the replacement of the bearing k cannot be performed unless the entire electric motor is disassembled.
[0008]
For this reason, a considerably troublesome work is forced to replace the bearing k. Moreover, at the time of this replacement, the entire inside of the motor case a is opened, and the rotor g is moved or placed on the floor surface, so that foreign matters are mixed in the motor case a, There is a risk of damaging the surface of the rotor g.
[0009]
In particular, a permanent-magnet rotary synchronous motor using a permanent magnet (not shown) for the rotor g (a rotor core composed of permanent magnets) disassembles the motor and places the rotor g on the floor for the next operation. If it is placed on a surface, etc., foreign matter such as iron powder will adhere to the surface of the rotor g due to magnetic force, making it difficult to reassemble the motor after replacement. Therefore, the bearing k cannot be replaced locally, and the motor must be installed in a specialized factory. It was forced to replace the bearing k at the same factory.
[0010]
The present invention has been made paying attention to the above circumstances, and a first object of the present invention is to provide an electric motor that can be easily replaced without introducing foreign substances and damaging the rotor.
[0011]
Similarly, in addition to the first object, the second object is to provide a permanent magnet rotary synchronous motor that allows a bearing to be exchanged locally, not a specialized factory.
[0012]
[Means for Solving the Problems]
In order to achieve the first object, an electric motor according to claim 1 includes a cylindrical body, two end walls each having a through-hole and closing both open ends of the body, and A motor case having a fastener that fastens the body and the two end walls, a stator installed on the inner surface of the body, a rotor disposed in the stator, and an axially extending direction from the rotor In addition, both ends of each through-hole pass through each of the through-holes, and a motor shaft having a stepped portion on the outside of each of the through-holes. The motor shaft is rotatably supported and installed on each of the two end walls. comprising a bearing portion, wherein the respective bearing unit is fitted inserted into the stepped portion, and a sleeve outer diameter of the end portion is formed to have a larger diameter than the inner diameter of the through hole facing the end wall, the sleeve It is removably press-fitted into the A bearing for rotatably supporting the motor shaft, and fitted to detachably the bearing therein and a bearing receiving member detachably attached to an outer surface of said end wall, said end wall, this The portion of the outer surface of the end wall that faces the side surface of the bearing from the outer periphery of the bearing has a recess that is separated from the bearing .
[0013]
As a result, the bearing replacement operation is performed by removing the bearing housing from the outer surface of the end wall of the motor case, representing the bearing press-fitted into the motor shaft portion outside the motor case, and removing the bearing from the jig (pulley removal tool). Etc.) is used to pull out from the motor shaft and replace with a new bearing.
[0014]
Therefore, the bearing can be easily replaced without disassembling the motor case. In addition, the replacement work is performed in a state in which the foreign matter is difficult to enter the motor case and the rotor is housed in the motor case, so that it is possible to prevent the foreign matter from being mixed inside the motor or damage to the rotor.
[0015]
In order to achieve the second object, a permanent magnet rotary synchronous motor according to claim 2 is provided with a cylindrical body and two ends each having a through hole and closing both open ends of the body. A motor case having a wall and a fastener that fastens the body portion and the two end walls; a stator installed on an inner surface of the body portion; and a rotor disposed in the stator and having a permanent magnet. The motor shaft extends in the axial direction from the rotor, and both ends of the rotor shaft pass through the through holes. The motor shaft has step portions on the outer sides of the through holes, and the motor shaft is rotatably supported. Bearing portions respectively installed on two end walls, and each of the bearing portions is fitted into the stepped portion, and the outer diameter of the end portion facing the end wall is larger than the inner diameter of the through hole. Formed with sleeve This is removably press-fitted into the sleeve, a bearing for rotatably supporting the motor shaft, a bearing housing body detachably attached to an outer surface of said end wall removably fitted insert the bearing in the interior The end wall has a concave portion in which the portion of the outer surface of the end wall facing the side surface of the bearing from the outer periphery of the bearing is separated from the bearing .
[0016]
Thus, as in the first aspect, the bearing replacement operation is performed by removing the bearing housing from the outer surface of the end wall of the motor case, representing the bearing press-fitted into the motor shaft portion outside the motor case, and extracting the bearing. Using a jig (pulley puller, etc.), pulling it out from the motor shaft and replacing it with a new bearing.
[0017]
That is, since the replacement of the bearing is performed while the rotor is housed in the motor case, foreign matter such as iron powder is not attached to the magnetized rotor.
[0018]
Therefore, the bearings can be easily replaced on the site where the electric motor is installed without depending on a specialized factory.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the first embodiment shown in FIG. 1 and FIG.
[0020]
FIG. 1 shows the structure of the front side and the side of an electric motor to which the present invention is applied, for example, an induction motor. In FIG. 1, 1 is a motor case.
[0021]
The motor case 1 is configured by fastening, for example, a cylindrical body 2 and end walls 3 and 4 that close the opening end of the body 2 with a fastener, for example, a long bolt 5. Among these, a stator 6 is installed on the inner surface of the body portion 2, and a rotor 7 is accommodated in the stator 6. A motor shaft 8 extends from both ends of the rotor 7 along the axial direction and penetrates the end walls 3 and 4. Reference numerals 3a and 4a denote through holes formed in the end walls 3 and 4, respectively. Then, both end sides of the motor shaft 8 are rotatably supported by bearing portions 9 formed on the outer surface side of the end walls 3 and 4 which are essential parts of the present invention.
[0022]
These bearing portions 9 have the same structure. Among them, the structure of the bearing portion 5 on the end wall 4 side will be described. Reference numeral 10 denotes a sleeve 11 on the outer peripheral surface of the motor shaft protruding from the outer surface of the end wall 4. For example, it is a ball-type bearing that is press-fitted through. The sleeve 11 is fitted into the outer peripheral surface of the step portion 8a formed in the shaft portion immediately after the end wall 4, and the bearing 10 is detachably disposed at a position close to the outer surface of the end wall.
[0023]
A bearing box 15 (corresponding to a bearing housing) is attached to the outer surface of the end wall 4 so as to surround the bearing 10 from the periphery.
[0024]
As shown in FIG. 2, a disk-shaped cover body 17 having a circular recess 16 formed at the center of the inner surface is used for the bearing box 15. And the recessed part 16 has fitted the bearing 10 so that insertion or removal is possible. A through-hole 18 for penetrating the shaft is formed in the central portion of the recess 16, and a shaft portion penetrating the sleeve 11 projects out of the cover body 16 from the through-hole 18. A flange 20 is formed on the entire outer periphery of the cover body 16 so as to overlap the mounting seat 19 formed on the outer surface of the end wall 4. The flange 20 is fastened to the end wall 4 by bolts 21 screwed into the end wall 4 from the flange 17, and the cover body 17 containing the bearing 10 therein, that is, the bearing box 15 is connected to the outer surface of the end wall 4. Removably attached to. Further, a recess 22 for inserting a jig tip is formed on the outer surface portion of the end wall 4 which is a portion facing the side surface of the bearing 10 from the outer periphery of the bearing 10, and the bearing box 15 is removed from the outer surface of the end wall. The bearing 10 comes out of the bearing box 15, and the bearing 10 can be pulled out of the motor shaft 8 by a pulley unloading tool (unloading jig) (not shown), that is, the posture in which the pulley removing tool can be easily set. So that it appears outside.
[0025]
In addition, about the bearing part 9 by the side of the end wall 3, the same code | symbol is attached | subjected to the same part as the bearing part 9 by the side of the end wall 4, and the description is abbreviate | omitted.
[0026]
Therefore, in the induction motor configured as described above, it is assumed that the bearing 10 on the side of the end wall 4 is now required to be replaced locally.
[0027]
At this time, as shown in FIG. 2, the bolt 21 is removed, and the bearing housing 15 is removed from the outer surface of the end wall 4.
[0028]
Then, the bearing 10 press-fitted into the motor shaft 8 appears outside the motor case 1. At this time, the rear surface side of the bearing 10 appears outside the end wall 4 in a posture away from the outer surface of the end wall 5 by the recess 22 formed on the outer surface of the end wall. That is, the bearing 10 press-fitted into the motor shaft 8 appears outside while maintaining a posture in which a pulley puller (not shown) can be easily set.
[0029]
Thereafter, a pulley removing tool (not shown) is set on the bearing 10, and the bearing 10 is pulled out from the motor shaft 1 by the operation using the pulley removing tool. Then, after mounting a new bearing (not shown) instead, the bearing box 15 is assembled again to the outer surface of the end wall 4 with the bolt 21 to complete the replacement of the bearing 10. The operation is the same when the bearing 10 on the end wall 3 side is replaced.
[0030]
Therefore, the bearing 10 can be easily replaced without disassembling the motor case 1. In addition, the replacement operation of the bearing 10 is performed in a state in which foreign matter is unlikely to enter the motor case 1, that is, in a state where the inside of the motor case is not opened and the rotor 7 is housed in the motor case 1. It is possible to eliminate foreign matters from being mixed inside and the rotor 7 being inadvertently damaged.
[0031]
FIG. 3 shows a second embodiment of the present invention.
[0032]
In the present embodiment, the present invention is applied not to an induction motor but to a permanent magnet rotary synchronous motor employing a rotor having a permanent magnet.
[0033]
That is, the permanent magnet rotary synchronous motor of this embodiment is a rotary synchronous motor using a rotor 7 having a permanent magnet 25 on the outer peripheral portion as shown in FIG. And the same bearing part 9 as 1st Embodiment is employ | adopted for this electric motor, and the both ends of the motor shaft 1 are supported so that rotation outside the motor case 1 is possible.
[0034]
That is, even in the permanent magnet rotary synchronous motor, as in the first embodiment, the replacement work of the bearing 10 that supports the motor shaft 8 is performed by removing the bearing box 15 from the outer surface of the end wall 4 and press-fitting into the motor shaft 8. The bearing 9 is represented outside the motor case, and a pulley removal tool (not shown) is used to pull out the bearing 10 from the motor shaft 8, and a new bearing (not shown) is assembled instead.
[0035]
Thereby, the replacement of the bearing 10 can be performed while the rotor 7 is housed in the motor case 1, and foreign matter such as iron powder does not adhere to the magnetic rotor 7 during the replacement operation.
[0036]
As a result, the replacement work of the bearing 10 can be easily performed on the site of the permanent magnet rotary synchronous motor bearing 9 without relying on a specialized factory.
[0037]
In FIG. 3, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0038]
【The invention's effect】
As described above, according to the first aspect of the present invention, the bearing supporting the motor shaft can be easily replaced without disassembling the motor case. In addition, the bearing can be replaced in a state in which foreign matter does not easily enter the motor case and the rotor is contained in the motor case, so that foreign matter is not mixed into the motor and the rotor is not damaged.
[0039]
According to the second aspect of the present invention, in addition to the above effect, foreign matter such as iron powder adheres to the magnetized rotor by utilizing the fact that the replacement operation of the bearing proceeds while the rotor is housed. The bearings can be replaced without doing so.
[0040]
Therefore, the bearings that support the motor shaft can be exchanged locally without relying on a specialized factory.
[Brief description of the drawings]
FIG. 1 is a view for explaining the structure of an induction motor according to a first embodiment of the present invention.
FIG. 2 is an exploded front view, partly in cross section, for explaining an operation of replacing a bearing in the same electric motor.
FIG. 3 is a partially sectioned front view for explaining a permanent magnet rotary synchronous motor according to a second embodiment of the present invention.
FIG. 4 is a view for explaining a bearing structure in a conventional induction motor.
FIG. 5 is an exploded front view, partly in section, for explaining the operation of replacing the bearing in the same motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Motor case 3, 4 ... End wall 6 ... Stator 7 ... Rotor 8 ... Motor shaft 9 ... Bearing part 10 ... Bearing 15 ... Bearing box (bearing container)
21 ... bolt 22 ... concave 25 ... permanent magnet.

Claims (2)

A cylindrical case, a motor case that closes both open ends of the case and has two end walls each having a through-hole, and a fastener that fastens the case and the two end walls; ,
A stator installed on the inner surface of the body,
A rotor disposed in the stator;
A motor shaft extending from the rotor in the axial direction, both ends of which penetrate each through hole, and have stepped portions on the outside of each through hole,
The motor shaft is rotatably supported, and includes bearing portions respectively installed on the two end walls.
Wherein the bearings, the fitted in the step portion, and a sleeve outer diameter of the end portion is formed to have a larger diameter than the inner diameter of the through hole facing the end wall, is removably press-fitted into the sleeve A bearing that rotatably supports the motor shaft, and a bearing housing that is removably inserted into the inner wall of the bearing and is detachably attached to the outer surface of the end wall .
The electric motor according to claim 1, wherein the end wall has a concave portion in which an outer surface of the end wall is opposed to the side surface of the bearing from an outer periphery of the bearing . A cylindrical case, a motor case that closes both open ends of the case and has two end walls each having a through-hole, and a fastener that fastens the case and the two end walls; ,
A stator installed on the inner surface of the body,
A rotor disposed in the stator and having a permanent magnet;
A motor shaft extending from the rotor in the axial direction, both ends of which penetrate each through hole, and have stepped portions on the outside of each through hole,
The motor shaft is rotatably supported, and includes bearing portions respectively installed on the two end walls.
Each of the bearing portions is fitted into the stepped portion, and a sleeve in which an outer diameter of an end facing the end wall is larger than an inner diameter of the through-hole, and a press-fit insertion into the sleeve are removably inserted. the has a bearing for rotatably supporting the motor shaft, inside and removably fitted inserted a bearing receptacle which is detachably attached to an outer surface of the end wall of the bearing,
The permanent magnet rotary synchronous motor characterized in that the end wall has a concave portion in which the outer surface of the end wall faces the side surface of the bearing from the outer periphery of the bearing .

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