JP5402833B2 - Waterproof motor - Google Patents

Description

  The present invention relates to a waterproof motor used in an environment with water, for example, to a structure of a waterproof cover suitable for a direct drive motor for positioning an index table or the like by rotating it by a predetermined angle.

  Conventionally, direct drive motors with the characteristics of high torque and high resolution can directly drive the index table, and are used for applications that require high-precision positioning without backlash despite being high-speed operation. ing.

  By the way, when the index table is used for conveyance of a process such as polishing or cleaning of a semiconductor wafer, a liquid such as water adheres to the semiconductor wafer, and the adhering liquid falls to the upper surface of the direct drive motor. May accumulate. If liquid enters the direct drive motor, the inside of the motor may be corroded and cause a failure, and the number of maintenance operations may increase, leading to a decrease in cost performance and productivity. In order to prevent the liquid from entering, a method of covering the entire motor with a waterproof metal or rubber cover, or a method of sealing a gap such as a mating surface of the motor case with a liquid gasket is employed. However, the above-described method has a problem that the maintainability of the motor is poor, and further, the method of sealing with a liquid gasket does not provide complete waterproofness.

  As a prior art for improving this portion, Patent Document 1 discloses a geared motor that prevents foreign matter and water from entering by covering a non-waterproof motor with a waterproof rubber. . Patent Document 1 describes a geared motor in which a rubber cover is covered so as to cover the entire outer casing of the motor case and a part of the outer casing of the gear case, and the mating surface of the case and the rubber cover is sealed with a liquid gasket. Has been.

Japanese Patent Laid-Open No. 10-032951

  However, in this prior art, the rubber cover does not completely cover the entire motor, and there is a mating surface between the case and the rubber cover, and this mating surface is sealed with a liquid gasket. Therefore, the motor is not completely sealed, and there is a problem that it is necessary to provide a drain hole in the bottom of the motor and the rubber cover in order to allow moisture to enter from the gap between the external wiring and the liquid gasket.

  The present invention covers the entire motor with a metal waterproof cover assembled with an oil seal and dust seal, and the rotating part is completely sealed by a shaft with a sealing surface. The purpose is to add.

In order to solve the above problems, the waterproof motor of the present invention is configured to be freely rotatable via a bearing facing the stator, a motor housing disposed on the base, a stator disposed on the housing, and the stator. In a waterproof motor comprising a supported rotor, an output shaft fixed to the rotor, and a waterproof cover that covers an outer surface of the motor, the outer peripheral portion of the umbrella portion formed on the output shaft is directed toward the waterproof cover side. A peripheral wall formed in the above manner, a dust seal and an oil seal attached to the waterproof cover and abutting against the inner surface of the umbrella, and a shaft attached to a seal housing disposed on the base and extending from the output shaft And an oil seal that comes into contact with.
In addition, a packing is provided between a connector spacer attached to the outer peripheral surface of the waterproof cover and the waterproof cover, the packing is made of a thin elastic body, and a series of convex portions are formed on both surfaces of the thin plate. It is characterized by that.
Furthermore, an O-ring is interposed between the connector spacer attached to the outer peripheral surface of the waterproof cover and the waterproof cover.

  According to the present invention, there is an effect that the non-waterproof motor can be waterproofed by the structure in which the entire motor is covered with the waterproof cover in which the oil seal and the dust seal are assembled and completely sealed.

It is sectional drawing of the waterproof motor in this embodiment. It is a top view of the waterproof motor in FIG. It is explanatory drawing of the packing in FIG.

  FIG. 1 is a cross-sectional view of a waterproof motor 1 in the present embodiment. FIG. 2 is a top view of the waterproof motor 1 in FIG. The waterproof motor 1 has a cylindrical motor stator 3 fixedly attached to an outer peripheral edge of a bottom plate of a housing 2 having a substantially cylindrical shape with a through hole in an axial center. The motor stator 3 includes an electromagnet having a plurality of magnetic poles that are formed in a rake shape and that have a plurality of teeth arranged at equal intervals in the circumferential direction. A motor rotor 4 having iron core teeth (not shown) is coaxially disposed inside the motor stator 3. The teeth of the iron core are formed so as to protrude uniformly on the outside of the motor rotor 4 at a pitch different from that of the magnetic pole teeth of the electromagnet of the motor stator 3, and the direct drive motor has a structure in which both tooth rows face each other with a slight gap therebetween. Is configured.

  The motor rotor 4 is integrally attached to the inner surface of the disk-shaped umbrella portion 7 of the output shaft 6 formed in an umbrella shape having a T-shaped cross section. The output shaft 6 is rotatably supported by the housing 2 via a cross roller bearing 5 fitted to the inner periphery of the motor rotor 4. The output shaft 6 is connected to a positioning device such as an index table. use. The outer ring of the cross roller bearing 5 is fitted and fixed to the inner circumferential step portion of the motor rotor 4, while the inner ring of the cross roller bearing 5 is fitted and fixed to the middle step of the deformed step portion of the housing 2.

  In the inner space of the output shaft 6 above the cross roller bearing 5, a resolver 9, which is a high-resolution rotation detector, is incorporated in order to position the motor rotor 4 and thus the output shaft 6 with high accuracy. Then, the reluctance between the rotor and the stator of the resolver 9 changes with the rotation of the motor rotor 4, and the change is digitized by a resolver control circuit of a drive unit (not shown) and used as a position signal to output the rotation angle of the motor rotor 4 and output. The rotational position of the shaft 6 is detected.

  In the waterproof motor 1 of the present embodiment having the above-described configuration, the housing 2 is fixed to the upper surface of the base 30 that is the bottom plate of the waterproof motor 1, and the prevention cover 20 that covers the outer peripheral surface of the waterproof motor 1 on the upper surface of the base 30. Is installed. The outer peripheral surface of the waterproof cover 20 is an inclined surface, and is provided with a gradient that allows water to flow easily. Further, an O-ring that comes into contact with the base 30 is housed on the joint surface of the waterproof cover 20 with the base 30 to ensure waterproofness. The opening 21 on the opposite side to the joint surface of the waterproof cover 20 with the base 30 is covered with the disc-shaped umbrella portion 7 of the output shaft 6, and the peripheral edge from the peripheral portion of the disc-shaped umbrella portion 7 toward the waterproof cover 20. The wall 14 is erected, and the peripheral wall 14 covers the outer periphery of the opening 21 of the waterproof cover 20, thereby preventing water from entering the waterproof cover 20. Further, the dust seal 11 is fitted on the outer periphery of the opening 21 of the waterproof cover 20, and the lip of the dust seal 11 abuts against the inner surface of the disc-shaped umbrella portion 7 to prevent dust from entering the waterproof cover 20. The oil seal 12 is fitted into the inner periphery of the opening 21 of the waterproof cover 20, and the lip of the oil seal 12 abuts on the outer surface of the cylindrical portion formed on the inner surface of the disc-shaped umbrella portion 7. To prevent water from entering.

  On the other hand, a seal housing 10 into which the oil seal 13 is fitted is attached to the central opening of the base 30 via an O-ring. A hollow cylindrical shaft 8 extending from the output shaft 6 reaches the base 30 through the shaft center through hole of the housing 2, and the lip of the oil seal 13 fitted in the seal housing 10 contacts the outer peripheral surface of the shaft 8. In contact therewith, dust and liquid are prevented from entering the waterproof motor 1.

  Further, a waterproof connector 23 is provided on the outer peripheral portion of the waterproof cover 20 for supplying power to the motor stator 3 and receiving a signal from the resolver 9. The packing 24 is applied to the peripheral edge of the wiring opening provided on the outer periphery of the waterproof cover 20, the connector spacer 22 is pressed from the outside of the packing 24, and the connector spacer 22 is fixed to the outer periphery of the waterproof cover 20 with bolts. A waterproof connector 23 connected to an external connector is further attached to the connector spacer 22. As shown in FIG. 3 a, the packing 24 is a rectangular thin plate made of rubber, and an opening for passing wiring is formed in the center. In addition, bolt holes 26 through which bolts are inserted are formed at the four corners of the packing 24. Then, as shown in FIG. 3b, a series of convex portions 25 projecting from both sides of the backing 24 are formed on the peripheral portion of the central opening and the peripheral portion of the bolt hole 26, and the convex portion 25 is deformed. The waterproof function is exhibited by the close contact.

As described above, in the waterproof motor 1 of the present embodiment, the entire motor is covered with the waterproof cover 20 made of metal and assembled with the oil seal 12 and the dust seal 11, and the sealing on the bottom surface is the seal housing 10 assembled with the oil seal 13. The rotating part has a structure in which the whole motor is completely sealed by a shaft 8 having a hollow hole having a sealing surface.
Furthermore, since the outer peripheral surface of the waterproof cover 20 is provided with a gradient that facilitates the flow of water and the shaft 8 having a hollow hole functions as a drainage groove, water does not collect on the outer surface of the motor. Can be avoided.

As the structure of the external wiring portion, an O-ring can be installed between the connector spacer 22 having the fall-off O-ring groove and the waterproof cover 20. Maintenance is easy because the O-ring does not fall off due to the locking O-ring groove.
Since the direct drive motor is often installed with the output shaft 6 facing upward, the base 30 should be replaced with a surface plate that allows the housing 2, the waterproof cover 20, and the seal housing 10 to be installed. Can do. In this case, the surface plate needs to be provided with screw holes and spigot holes in the same manner as the base 30.

  The direct drive motor of the present invention can be suitably applied to uses such as machine parts.

DESCRIPTION OF SYMBOLS 1 Waterproof motor 2 Housing 3 Motor stator 4 Motor rotor 5 Bearing 6 Output shaft 7 Disk-shaped umbrella part 8 Shaft 9 Resolver 10 Seal housing 11 Dust seal 12, 13 Oil seal 14 Perimeter wall 20 Waterproof cover 21 Opening 22 Connector spacer 23 Waterproof connector 24 Packing 25 Convex 26 Bolt hole 30 Base

Claims (3)

  A motor housing disposed on the base; a stator disposed on the housing; a rotor opposed to the stator and rotatably supported via a bearing; an output shaft fixed to the rotor; A waterproof motor comprising a waterproof cover that covers an outer surface of the motor, a peripheral wall formed from an outer peripheral portion of an umbrella portion formed on the output shaft toward the waterproof cover side, and attached to the waterproof cover; A waterproofing system comprising: a dust seal and an oil seal that contact the inner surface of the umbrella; and an oil seal that is attached to a seal housing disposed on the base and contacts a shaft extending from the output shaft. motor.   A packing provided between a connector spacer attached to the outer peripheral surface of the waterproof cover and the waterproof cover, the packing is made of a thin elastic body, and a series of convex portions are formed on both surfaces of the thin plate. The waterproof motor according to claim 1.   The waterproof motor according to claim 1, wherein an O-ring is interposed between a connector spacer attached to the outer peripheral surface of the waterproof cover and the waterproof cover.

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