JP3141065B2 - Explosion-proof molded motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof mold motor capable of flowing exhaust gas into a rotating space so that combustible gas does not stay in the rotating space in which the rotor rotates.

[0002]

2. Description of the Related Art In a motor used in a device used in a flammable gas atmosphere, such as a painting robot, when the flammable gas stays in the motor, that is, in a rotating space in which the rotor rotates, the motor is used. Flammable gases may explode due to heat or sparks that may be generated inside the motor. Therefore, for this type of application, a structure for supplying an exhaust gas not containing a combustible gas into the rotating space and discharging the exhaust gas from the rotating space is provided so that the combustible gas does not stay in the rotating space. An explosion-proof type motor is used. Specifically, in an explosion-proof motor, a ventilation hole for air supply and a ventilation hole for exhaust are provided in brackets arranged on both sides of the stator, and exhaust gas is supplied from the ventilation hole for air supply to the rotating space. The exhaust gas is exhausted from the exhaust vent. Recently, a molded motor in which a core and a winding of a stator are molded with insulating resin has been used for the purpose of increasing mechanical strength of the stator and reducing mechanical vibration noise generated from the stator.

[0003]

When the explosion-proof motor is a molded motor, it is necessary to form a ventilation hole in the bracket avoiding the molded portion. Therefore inevitably bracket problem occurs that is large in size.

An object of the present invention is to provide an explosion-proof molded motor that can be molded without increasing the size of a bracket that forms a ventilation hole.

Another object of the present invention is to provide an explosion-proof mold motor that can be molded using a bracket having a plurality of recesses in order to reduce the weight and without increasing the size of the bracket that forms the ventilation holes. Is to provide.

Another object of the present invention is to provide a compact explosion-proof molded motor.

Another object of the present invention is to provide a compact explosion-proof mold motor in which a mold section can be easily formed.

[0008]

SUMMARY OF THE INVENTION An explosion-proof molded motor to be improved by the present invention has a stator having a core wound with windings, and first and second bearings disposed on both sides of the stator and having respective bearings. And a second bracket;
A rotor rotatably supported by bearings and rotating inside the stator. And the first
In a state where the bracket and the stator are combined, the periphery of the stator is filled with an insulating resin to form a mold part for molding the core and the winding. Where the stator is
This includes both those with and without a housing on the outer periphery of the core. For a stator with a housing, the first and second brackets are attached to the housing, and for a stator without a housing, the first and second brackets are attached to the core. Then, in forming the mold portion, a middle mold for forming a mold portion is inserted into the stator with the first bracket attached to the stator. The middle mold has a structure in which a space for forming a molded portion can be created around the core and the winding of the stator by the first bracket, the stator, and the middle mold. After the space for forming the mold portion is filled with the insulating resin and cured, the middle mold is taken out. The second bracket is attached to the stator when assembling the rotor.

The first bracket has at least one of a ventilation hole for supplying exhaust gas to the rotating space of the rotor and a ventilation hole for discharging exhaust gas from the rotating space. In consideration of the exhaust efficiency, one of the ventilation hole for supplying the exhaust gas to the rotation space of the rotor and the ventilation hole for discharging the exhaust gas from the rotation space is formed in the first bracket, and the other ventilation hole is formed. Preferably, a hole is formed in the second bracket. The ventilation hole formed in the second bracket does not hinder the formation of the mold portion, and can be basically formed at an arbitrary position. It is needless to say that an encoder or the like for detecting the rotation of the rotor may be arranged on the second bracket side.

In such an explosion-proof molded motor, in the present invention, at least one ventilation hole extends in the radial direction of the shaft inside the first bracket, and the outer opening is formed on the outer peripheral surface of the first bracket. An opening is formed in the first bracket so that the inner opening is opened toward the rotating space. More specifically, the inside opening of the ventilation hole is opened toward the rotating space at a position where the formation of the mold portion is not hindered. In other words, the ventilation hole extends in the radial direction of the shaft through the inside of the first bracket so that the inner opening is opened toward the rotating space at a position that does not hinder the formation of the mold portion. The case where the ventilation holes extend in the radial direction includes both the case where all the ventilation holes extend in the radial direction and the case where most of the ventilation holes extend in the radial direction. When all the ventilation holes are extended in the radial direction, the inner opening opens radially inward. When most of the ventilation holes extend in the radial direction, the inner opening is opened in the axial direction.

When the ventilation hole is formed so as to extend in the radial direction inside the first bracket in this manner, the inside opening of the ventilation hole can be basically formed at a position not facing the stator, and the ventilation hole can be formed. Does not hinder the formation of the mold portion. Therefore, the mold part can be easily formed. If the ventilation hole is formed so as to penetrate the first bracket in the axial direction of the shaft, the mold portion is formed so as not to block the ventilation hole unless the outer diameter of the rotor is considerably larger than the outer diameter of the bearing. It is very difficult to form. On the other hand, when the ventilation holes are formed so as to extend in the radial direction inside the first bracket as in the present invention, even if the outer diameter of the rotor is not much larger than the outer diameter of the bearings, the inside of the ventilation holes is The opening can be opened in the rotating space at a position that does not hinder the formation of the mold portion.

[0012] The first bracket may be constructed from a casting. In this case, at least a part of at least one of the ventilation holes is preferably formed as a cast-out hole (a hole formed at the time of casting).

In the first bracket, it is necessary to secure a space for forming a ventilation hole extending in the radial direction. However, in order to reduce the weight of the motor (in order to partially reduce the thickness of the bracket), it is preferable to form a plurality of recesses at intervals in the circumferential direction on at least one side in the axial direction of the shaft. This has been done conventionally. Generally, such a concave portion is formed on both side surfaces in the axial direction. When applying the present invention to such a structure,
If the portion forming the ventilation hole is formed to be particularly thick, the weight of the bracket increases accordingly. Therefore, in such a case, the ventilation hole is formed so as to extend in the radial direction in the rib formed between the two adjacent concave portions. In this case, since the ventilation holes are formed by using the thickness of the existing ribs, the weight of the bracket can be reduced, and the dimension of the bracket in the axial direction can be prevented from increasing.

In order to make the axial dimension and the radial dimension of the molded motor more compact, it is necessary to reduce the outer diameter of the rotor and the thickness of the bracket, that is, the axial dimension. In such a case, if the ventilation holes formed in the first bracket are formed radially outside the bearing, the axial dimension of the bracket can be further reduced. However, in this case, the ventilation hole has a radially extending portion that has an outer opening at one end and extends in the radial direction, and an axially extending one end communicates with the other end of the radially extending portion and has an inner end at the other end. And an axially extending portion having an opening. With this configuration, the ventilation holes can be arranged radially outside the bearing, and the inner opening of the ventilation holes can be opened toward the rotation space of the rotor.

When the radial dimension of the rotor is further reduced,
When arranging the ventilation holes on the radial outside of the bearing, when forming the axially extending portion of the ventilation holes with cast holes,
The axially extending portion of the ventilation hole has to be formed in such a state that the inner opening partly faces the forming space of the mold portion. This is because it is difficult to form the cast hole at an arbitrary angle. In such a case, an inflow prevention plate for preventing the insulating resin forming the mold portion from flowing into the axially extending portion is fitted into the inner opening of the axially extending portion of the ventilation hole. This inflow prevention plate does not completely close the inner opening. By employing such a structure in which the inflow prevention plate is provided, it is easy to form the axially extending portion of the ventilation hole with a cast-out hole, thereby preventing an increase in the manufacturing cost of the bracket.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a half sectional view of an example of an embodiment in which the present invention is applied to an explosion-proof mold motor having an AC servomotor as a basic structure. FIG. 1 shows only the upper half of the cross section of the motor. In this figure, 1 is a shaft, 2 is a rotor core fixed to the shaft 1, and 3 is a rotor magnetic pole composed of a plurality of permanent magnets fixed to the outer periphery of the rotor core. The rotor 4 is constituted by these 1 to 3 members. Reference numeral 5 denotes a stator in which a winding 8 is wound on a bobbin 7 fitted to a stator-side core 6. A cylindrical housing 9 is fitted around the outer periphery of the core 6. In this example, a core 6 in which a plurality of divided cores divided for each magnetic pole are combined in an annular shape is used.
A bobbin 7 is fitted to each divided core, and a winding 8 is wound for each divided core. The housing 9 clamps the plurality of split cores to the outside.

First and second brackets 10 and 11 made of an aluminum casting are attached to both sides of the housing 9 of the stator 5. Bearings 12 and 13 for rotatably supporting the shaft 1 of the rotor 4 are fixed to these brackets 10 and 11. In order to fix the bearings 12 and 13, iron-made annular bearing mounting bushes 10 a and 11 a are insert-molded on the first and second brackets 10 and 11.
14 is a bearing mounting bush 10a and a bearing 1
2 is a bearing pressing member that abuts against the axial end face and prevents the bearing 12 from moving outward in the axial direction. Reference numeral 15 denotes an oil seal, and reference numeral 16 denotes an annular spring member. Reference numeral 17 denotes a molding portion for molding the core 6 and the winding 8 formed by filling the periphery of the stator with an insulating resin and curing the stator 6 in a state where the first bracket 10 and the stator 5 are combined. This insulating resin is a thermosetting insulating resin containing a reinforcing material having heat resistance and low thermal expansion.

In the first bracket 10, the thickness (dimension in the axial direction of the shaft) of the main body portion 10b radially outside the bearing mounting bush 10a is increased. In particular, in the example of FIG. 1, the main body portion 10 b protrudes (or protrudes) inward in the axial direction (toward the stator 5) to form a protruding portion 10 c. On the outer side in the axial direction of the main body 10b, three recesses 10d are formed so as to surround the bearing mounting bush 10a at predetermined intervals in the circumferential direction as shown in FIG. FIG.
FIG. 3 is a half side view of the first bracket 10. These recesses 10d are formed for the purpose of reducing the weight of the bracket 10 and for the purpose of a chuck fitting portion for gripping the bracket 10 with a chuck during machining. Three ribs 10e for reinforcement are formed between two adjacent concave portions 10d. Similarly, three concave portions 10f are formed on the axially inner side surface of the bracket 10 (so that the concave portions on both side surfaces face each other) symmetrically with the three concave portions 10d, and two adjacent concave portions 10f. Rib 10 between
e is formed.

A ventilation hole 18 extending linearly in the radial direction of the shaft 1 is formed inside one rib 10e formed on the side of the bulging portion 10c. This ventilation hole 18
Is for supplying exhaust gas to the rotation space S of the rotor 4. The outer opening 18a of the ventilation hole 18
Are open on the outer peripheral surface of the bracket 10, and the inner opening 18b is open on the inner end surface of the rib 10e formed in the bulging portion 10c of the bracket 10. From another viewpoint, the inner opening 18b of the ventilation hole 18 opens toward the rotating space S at a position where the formation of the mold portion 17 is not hindered. In the outside opening 18a of the ventilation hole 18,
A flexible tube for supplying exhaust gas is inserted. Note that the insulating resin forming the mold portion 17 is filled on the side surface on the inner side in the axial direction of the bracket 10 in a state of being in close contact therewith.

When forming the mold portion 17, first, the first bracket 10 is attached to the stator 5. Then, with the first bracket 10 down, the stator 5
Then, a cylindrical middle mold for forming a molded part is inserted into the stator 5 through the opening. This medium size is the first bracket 1
0, the stator 5 and the medium size, the core 6 of the stator 5
And a structure for forming a space for forming a molded portion around the winding 8. A release agent is applied to the outer peripheral surface of the middle mold. In this state, an insulating resin is filled into the space for forming the mold portion and cured. The end face of the mold portion 17 on the second bracket 11 side may be molded using an appropriate mold member, or in particular, by controlling the amount of the insulating resin to be filled without using the mold member or the like, and merely curing It may be molded. After the insulating resin is cured, the middle mold is taken out. Second bracket 1
1 is attached to the housing 9 when assembling the rotor 4.

On the side wall of the main body portion 11b of the second bracket 11 near the bearing mounting bush 11a, there is formed a ventilation hole 19 which penetrates in the axial direction and discharges exhaust gas from the rotating space S. Second bracket 11
Is attached to the housing 9 of the stator 5 after the mold portion 17 is formed, so that there is basically no problem where the ventilation holes are formed. In this example, in order to smoothly discharge the exhaust gas from the rotating space S,
A ventilation hole 19 is formed at a position not substantially facing the mold portion 17.

For coupling the first and second brackets 10 and 11 and the stator 5, a plurality of bolt insertion holes are formed in alignment with these members, and long bolts are inserted into these bolt insertion holes. Insert from the side [Fig.
Only the head of the bolt 20 is shown], and the male screw at the tip of the bolt 20 is screwed into the female screw provided inside the bolt insertion hole formed in the second bracket 11. Then, the three members are tightened. In the case having a large housing, both the first bracket and the second bracket are fastened to the housing.

In the above embodiment, the ventilation hole 18 formed in the bracket 10 is opened toward the shaft 1, so that the dimension of the bracket 10 in the axial direction is inevitably increased. FIG. 3 is a half sectional view of an embodiment in which the axial dimension of the bracket 10 is reduced to further reduce the overall axial dimension of the motor. In FIG.
The same members as those in the above embodiment shown in FIGS. 1 and 2 include:
The same reference numerals as in FIGS. 1 and 2 denote the same parts, and a description thereof will be omitted. In this example, the shape of the first bracket 10 ′ and the shape of the ventilation holes 18 ′ are different from those in the examples of FIGS. The first bracket 10 'is different from the bracket 10 shown in FIG.
The thickness dimension (dimension in the axial direction of the shaft) of the main body portion 10'b on the radially outer side is not large. That is,
Maximum thickness of main body 10'b (maximum axial dimension)
Is almost the same as the thickness dimension (axial dimension) of the portion where the bearing mounting bush 10'a is provided. Therefore, only one annular concave portion 10'f is formed continuously on the axially inner side surface of the bracket 10 ', and the rib 10e does not protrude from the inner side surface.

The ventilation hole 18 'is formed radially outside the bearing 12 or the bush 10'a supported by the bracket 10'. The ventilation hole 18 'is composed of a radially extending portion 18'A and an axially extending portion 18'B. The radially extending portion 18'A is
The rib 10′e formed on the outside in the axial direction of ′ linearly extends in the radial direction and has an outer opening 18′a at one end. The axial extension 18′B extends in the axial direction, and has one end communicating with the other end of the radial extension 18′A and an inner opening 18′b at the other end. The radially extending portion 18'A of the ventilation hole 18 'is a hole formed by machining, while the axially extending portion 18'B is a cast hole formed at the time of casting. Therefore, the shape of the axially extending portion 18'B is such that the casting is easy and the inner opening 18'b is directed toward the shaft 1 so as not to hinder the formation of the mold portion 17 as much as possible. . In this example, the radial dimension of the rotor 4 is small, and the bearing mounting bush 10'a and the rotor-side magnetic pole 3 are located at substantially the same position. Therefore, the axially extending portion 1 of the ventilation hole 18 '
When 8'B is formed by a cast hole, the axially extending portion 18'B must be formed in such a state that the inner opening 18'b partially faces the space where the mold portion 17 is formed. . Therefore, in this example, the inflow resin that forms the mold portion 17 in the inner opening 18 ′ b of the axially extending portion 18 ′ B of the ventilation hole 18 ′ prevents the insulating resin from flowing into the axially extending portion 18 ′ B. The prevention plate 21 is fitted. That is, the concave portion 22 for fitting a part of the inflow prevention plate 21 is formed in the inner opening 18'b. In this example, in order to facilitate fixing of the inflow prevention plate 21, the concave portion 22 is formed in an annular shape concentric with the bush 10'a. Therefore, the inflow prevention plate 21 is also formed in an annular shape so as to fit into the annular concave portion 22.

In this example, the mold portion 17 is formed with the inflow prevention plate 21 fitted in the concave portion 22. Therefore, the insulating resin does not enter the inside of the axially extending portion 18'B. As shown in FIG. 3, the inflow prevention plate 21 does not completely block the inner opening 18'b.
If a structure in which such an inflow prevention plate 21 is provided is adopted,
It becomes easy to form the axially extending portion 18'B of the ventilation hole 18 by a cast-out hole.

In the above-described embodiment, the ventilation holes for supplying the exhaust gas are formed in the first bracket, and the ventilation holes for discharging the exhaust gas are formed in the second bracket. Both air supply and exhaust holes may be formed. Further, in the above embodiment, each bracket is formed with one ventilation hole, but it goes without saying that two or more ventilation holes for air supply and exhaust may be formed.

[0027]

According to the present invention, when the ventilation holes are formed so as to extend in the radial direction inside the first bracket, even if the outer diameter of the rotor is not much larger than the outer diameter of the bearing, the inside of the ventilation holes can be reduced. The opening can be opened in the rotating space at a position that does not hinder the formation of the mold portion. Therefore, there is an advantage that the explosion-proof mold motor can be molded without increasing the size of the bracket forming the ventilation hole.

When the ventilation hole is formed so as to extend in the radial direction in the rib formed between the two adjacent concave portions, the ventilation hole is formed by using the existing thickness of the rib. Therefore, the size of the bracket in the axial direction can be prevented from increasing.

Furthermore, a radially extending portion having a ventilation hole and having an outer opening at one end and extending in the radial direction, an axially extending one end communicating with the other end of the radially extending portion and an inner opening at the other end. When it is configured with the axially extending portion having, even if the outer diameter of the rotor is reduced and the thickness of the bracket is reduced,
It is possible to form a molded part, and a smaller explosion-proof molded motor can be obtained.

[Brief description of the drawings]

FIG. 1 is a half sectional view of an example of an embodiment in which the present invention is applied to an explosion-proof molded motor having an AC servomotor as a basic structure.

FIG. 2 is a half side view of the bracket 10 of FIG.

FIG. 3 is a half sectional view of an example of another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 shaft 4 rotor 5 stator 6 core 8 winding 9 housing 10 first bracket 11 second bracket 12, 13 bearing 10d, 10'd, 10f, 10'f recess 10e, 10'e rib 18, 18 ', 19 ventilation hole 18a, 18'a outer opening 18b, 18'b inner opening 18'A radial extension 18'B axial extension 21 inflow prevention plate

Continuation of front page (72) Inventor Takataka Shimomura 1-5-15-1 Kita-Otsuka, Toshima-ku, Tokyo Sanyo Electric Co., Ltd. (56) References JP-A-63-99739 (JP, A) JP-A-2 -55551 (JP, A) Fully open 1987-68436 (JP, U) Fully open 60-108162 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 5/136 H02K 5/08

Claims (7)

(57) [Claims] 1. A stator having a core wound with windings, first and second brackets disposed on both sides of the stator and having bearings mounted thereon, respectively, and a shaft rotatably supported by the bearings. And a rotor that rotates inside the stator, and a mold that molds the core and the winding by filling an insulating resin around the stator in a state where the first bracket and the stator are combined. A portion is formed, and the first bracket is formed with at least one of a ventilation hole for supplying exhaust gas to a rotation space of the rotor and a ventilation hole for discharging the exhaust gas from the rotation space. An explosion-proof molded motor, wherein the at least one ventilation hole extends inside the first bracket in a radial direction of the shaft, and An outer opening is formed on the outer peripheral surface of the first bracket, and an inner opening is formed so as to open toward the rotating space at a position that does not hinder the formation of the mold portion. Explosion-proof molded motor. 2. A plurality of recesses are formed in at least one side surface of the first bracket in the axial direction of the shaft at intervals in a circumferential direction to reduce the weight of the bracket. The explosion-proof molded motor according to claim 1, wherein the at least one ventilation hole is formed so as to extend in a radial direction in a rib formed between two adjacent concave portions. 3. The at least one ventilation hole is provided in the first
A radially extending portion extending in the radial direction with the outer opening at one end, the radially extending portion having the outer opening at one end, and the axial direction. The explosion-proof molded motor according to claim 2, further comprising an axially extending portion having one end communicating with the other end of the radially extending portion and having the inside opening at the other end. 4. The first bracket is made of a cast product, the axially extending portion is a cast hole, and the inner opening of the axially extending portion of the at least one ventilation hole is provided with the mold. The explosion-proof molded motor according to claim 3, wherein an inflow prevention plate that prevents the insulating resin forming the portion from flowing into the axially extending portion is fitted. 5. A stator having a core wound with windings, first and second brackets disposed on both sides of the stator and having bearings mounted thereon, respectively, and a shaft rotatably supported by the bearings. And a rotor that rotates inside the stator, and a mold that molds the core and the winding by filling an insulating resin around the stator in a state where the first bracket and the stator are combined. The first bracket is formed with one of a ventilation hole for supplying exhaust gas to the rotating space of the rotor and a ventilation hole for discharging the exhaust gas from the rotating space. The other of the ventilation holes for supplying the exhaust gas to the rotation space of the rotor and the ventilation holes for discharging the exhaust gas from the rotation space is provided on the second bracket. An explosion-proof molded motor, wherein the one ventilation hole has an outer opening opening at an outer peripheral surface of the first bracket and an inner opening at a position where it does not hinder the formation of a molded portion. An explosion-proof molded motor characterized in that the interior of the first bracket extends in the radial direction of the shaft so as to open toward a rotating space. 6. A stator having a core wound with windings, first and second brackets disposed on both sides of the stator and having bearings mounted thereon, respectively, and a shaft rotatably supported by the bearings. And a rotor that rotates inside the stator. The first and second brackets are made of a cast product in which a bearing mounting bush is insert-molded, and the first bracket and the stator are combined. In this state, the periphery of the stator is filled with an insulating resin to form a mold part for molding the core and the winding, and a ventilation hole for supplying exhaust gas to a rotation space of the rotor in the first bracket; and One of the ventilation holes for discharging the exhaust gas from the rotation space is formed, and the rotation space of the rotor is provided in the second bracket. An explosion-proof mold motor in which a ventilation hole for supplying exhaust gas and another ventilation hole for discharging the exhaust gas from the rotating space are formed, wherein the one ventilation hole is the first ventilation hole. An outer opening that extends in the radial direction and one end of which is open on the outer peripheral surface of the first bracket. A radially extending portion that constitutes a portion, and an axially extending portion that extends in the axial direction of the shaft and has one end communicating with the other end of the radially extending portion and an inside opening that opens at the other end toward the rotating space. The one ventilation hole is a cast-out hole at least in the axially extending portion, and the mold portion is formed in the inner opening of the axially extending portion of the one ventilation hole. It said insulating resin inflow prevention plate for preventing the flow into said axially oriented portion, explosion-proof molded motor which is fitted so as not to close the inner opening that. 7. The first bracket has a plurality of recesses formed on both side surfaces in the axial direction of the shaft at intervals in a circumferential direction to reduce the weight of the bracket. 7. The explosion-proof molded motor according to claim 1, wherein one of the ventilation holes is formed so as to extend in the radial direction in a rib formed between two adjacent concave portions.