JPS6316297Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a stator for an epidermal molded motor.

Conventionally, the stator of this type of motor has the inner peripheral surface of the stator core and the stator coil molded with a synthetic resin layer, and a bearing member that supports the rotating shaft of the rotor is press-fitted into the inner peripheral surface of the synthetic resin layer. It had a fixed structure.
Therefore, the bearing member is surrounded by a synthetic resin layer having poor thermal conductivity, resulting in poor heat dissipation and durability problems. In addition, when molding a synthetic resin layer for a mold, the cavity for molding the synthetic resin layer was formed by using two molds and putting them together. There was a problem in that it had to be well-processed, which increased production costs.

Therefore, the purpose of this invention is to improve the cooling performance of the bearing.
Further, the present invention provides a stator for an external rotor molded motor that requires only one molding die for the synthetic resin layer and that requires high-precision machining, thereby keeping manufacturing costs low.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

First, in FIG. 1 showing the overall configuration of an external rotor molded motor, reference numeral 1 denotes a stator core with grooves 2 intermittently formed on the inner circumference, and a stator coil 3 is wound around this stator core. is molded with a synthetic resin layer 4. Reference numeral 5 denotes a shaft support attached to the stator core 1, which is formed by press-forming a metal plate, and includes an annular cover portion 6 with one end open and a constriction formed in the center of the cover portion 6. The bearing case part 7 is integrally formed with a bottomed cylindrical bearing case part 7. The cover portion 6 of the shaft support 5 has an outer peripheral end surface 6.
one coil end 3a of the stator coil 3 is covered with its synthetic resin layer 4 while the bearing case part 7 is in close contact with one end surface of the stator core 1. It is press-fitted into the section. 8 is a bearing, which is fitted into the bearing case portion 7 together with the oil core 9. 10 is a rotor, and this rotor 10 has a rotor core 12 fixed to the inner circumference of a cylindrical case-shaped rotor support 11, and a rotating shaft 13 inserted through the center of the rotor support 11. One end of the rotating shaft 13 is supported by a bearing 8, and the rotor core 12 surrounds the stator core 1 with a predetermined gap. Note that a cap 7a is fitted into the bearing case portion 7.

Next, the means for forming the synthetic resin layer 4 will be described.
In FIG. 2, 14 is a fixed mold.
A movable pressing die 15 is provided corresponding to the molding die 14. The molding die 14 has a cavity 1.
4a and a gate 16 that opens at the center of the bottom of the cavity 14a, and the cavity 14a has a slightly enlarged inner diameter on the open side to form a step 17. The pressing die 15 is a simple thick plate. First, in order to attach the shaft support 5 to the stator core 1 wound with the stator coil 3, the bearing case 7 is pressed into the inner periphery of the stator core 1. In this case, the cover 6 is pressed in until its outer periphery end face 6a abuts against one end face of the stator core 1, whereby the end face 6a is in close contact with the one end face of the stator core, forming a substantially liquid-tight state therebetween. The stator core 1 with the shaft support 5 attached in this way is inserted into the cavity 14a of the forming die 14 so that the cover 6 is on the outside, and the pressing die 15 is pressed against the cover 6 to press the stator core 1.
When the molding resin is squirted from the nozzle of a molding machine (not shown) in this state, the resin is injected into the cavity 14a from the gate 16, and then collides with the bottom surface 7b of the bearing case portion 7 with great force, dispersing around it, and thereafter, while filling the cavity 14a, it flows into and fills the cover portion 6 through the slots and grooves 2 (not shown) of the stator core 1. The molding resin thus filling the cavity 14a and the cover portion 6 hardens as it cools, forming a synthetic resin layer 4 which molds the stator coil 3.
After the synthetic resin layer 4 is formed, the oil core 9, the bearing 8 and the cap 7a are mounted in the bearing case 7, completing the stator as shown in FIG.

As described above, according to this embodiment, the bearing case portion 7
is formed of metal integrally with a cover part 6 that covers one coil end 3a together with its synthetic resin layer 4, so even if the bearing 8 generates heat due to friction with the rotating shaft 13 during operation, the Heat is efficiently transmitted to the cover part 6 via the bearing case part 7 by thermal conduction, and is radiated from the cover part 6. Therefore, even if the bearing case portion 7 is surrounded by the synthetic resin layer 4, the cooling performance of the bearing 8 is very good, there is no risk of so-called seizure, and the service life is extended. in this case,
As in this embodiment, the cover part 6 is attached to the rotor support 11.
If it is located on the side, the cover portion 6 and thus the bearing 8 can be cooled more effectively by the airflow generated as the rotor support 11 rotates.
Furthermore, when molding the synthetic resin layer 4, the cover portion 6 can act as one molding cavity, so the pressing die 15 only needs to have a pressing function and must be manufactured with high precision. Only one mold 14 is required as a mold, and manufacturing costs can be kept low. Particularly in this embodiment, since it is not necessary to align the mold 14 and the press mold 15, the manufacturing cost can be further reduced. Furthermore, if the gate 16 is provided facing the bearing case part 7, the molding resin ejected from the nozzle 16 will collide with the bottom surface part 7b of the bearing case part 7, so that the molding resin will not be applied to the stator coil 3. Since no injection pressure is applied directly, damage to the insulation coating and disconnection can be prevented, and the remaining marks A of the gate 16 will be formed in the depressions of the synthetic resin layer 4, so the remaining marks A are deliberately removed. There is no need for any processing.

Next, FIG. 3 shows another embodiment, which differs from the previous embodiment in that there is a shaft protrusion in the center of the pressing mold 16 that fits into the bearing case part 7 and holds the shaft support 5. 16a is formed. In this way, the shaft support 5 can be coupled to the stator core 1 at the same time as the stator core 1 is pressed by the pressing die 16, and the ease of assembly is improved. Note that it is also possible to fix the shaft support 5 by the adhesion of the synthetic resin layer 4, so in the case shown in FIG. There is no need to press-fit and fix the cover part 6 during molding by providing a gap between the two.
The molding resin may be encouraged to flow into the interior.

As explained above, the present invention is configured such that a shaft support body integrally having a bearing case part and a cover part is made of metal, and the cover part covers one coil end of the stator coil together with its synthetic resin layer. Therefore, the bearing can be cooled well and its life can be extended, and the cover part can act as one of the molding cavities when molding the synthetic resin layer, making it possible to use molds that require high-precision machining. Therefore, it is possible to provide a stator for an external rotary molded motor, which requires only one piece and can keep mold manufacturing costs low.

[Brief description of the drawings]

Fig. 1 is a sectional view of an epidermal mold motor showing an embodiment of the present invention, Fig. 2 is a sectional view of a mold of the same embodiment, and Fig. 3 is a sectional view of another embodiment of the mold. It is. In the figure, 1 is a stator core, 3 is a stator coil, and 4 is a stator core.
5 is a synthetic resin layer, 5 is a shaft support body, 6 is a cover part, 7
is a bearing case part, 8 is a bearing, 10 is a rotor, 11
is a rotor support, 13 is a rotating shaft, 14 is a mold,
15 and 16 are press molds.

Claims (1)

[Claims for Utility Model Registration] 1. A stator core wrapped with a stator coil, a synthetic resin layer in which the stator coil is molded, and one coil end of the stator coil covered with the synthetic resin layer. A metal member integrally having a cover portion whose outer peripheral end surface is in close contact with one end surface of the stator core, and a bearing case portion formed at the center of the cover portion and fitted into the center of the stator core. What is claimed is: 1. A stator for an external rotor molded motor, comprising: a shaft support; and a bearing that is mounted on the bearing case portion and supports a rotating shaft of a rotor that rotates around the stator core. 2. According to claim 1 of the utility model registration claim, the cover portion of the shaft support is located on the side of the rotor support that connects and fixes the rotor to the rotating shaft, of both sides of the stator core. Stator of the external rotary molded motor described.