JPH0528928Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of Industrial Application The present invention relates to a sealing device for a cable outlet, and more particularly to a sealing device for preventing water from entering from a cable outlet of a rotating machine.

〓Summary of the invention〓 The present invention provides a grommet that is attached to the cable outlet formed in the casing of a rotating machine, forms a tapered part on this grommet, and presses the tapered part of the casing with a holding plate. The grommet is crimped into the tapered hole, thereby crimping the inner peripheral surface of the through hole of the grommet to the cable and creating a seal.It is waterproof without using a waterproof boot-like cap or fastener. This is what I decided to do.

<Prior Art> A conventional DC motor is, for example, as shown in FIG. 4, and is equipped with a power cable 3 for passing current through a rotor coil 2 wound around a rotor core 1. When such a motor is used underwater or under the sea, it is necessary to provide a sealing device to prevent water from entering the motor from the outlet of the power cable 3. Therefore, as shown in FIGS. 5 and 6, a ground 4 and a grommet 5 have been used.

〓Problems to be solved by the invention〓 However, according to such a conventional seal structure, there is a problem that the cable 3
There is a drawback that water or seawater 8 can enter between the cap and the cap, so as shown in FIG. I was trying to do this. Therefore, in such a conventional motor, the number of parts required for sealing the outlet portion of the cable 3 increases, and the sealing structure becomes complicated.

The present invention was developed in view of the above problems, and the object thereof is to provide a sealing device that reliably seals the outlet of a cable of a rotating machine with a simple structure. It is.

〓Means for solving the problem〓 The present invention is a device for preventing water from entering through the outlet of the cable 24 of a rotating machine. 27, and a tapered portion 28 is formed on the outer circumferential surface of one end of the grommet 27 in the axial direction, and a circumferential groove 35 having a small diameter is formed on the outer circumferential surface of the grommet 27 adjacent to the tapered portion 28.
is formed, and the grommet 27 is pressed toward one end in the axial direction by the holding plate 30 in which the center hole 36 is fitted into this circumferential groove, and the tapered portion 28 is crimped into the tapered hole 26 of the casing 12. The inner peripheral surface of the through hole 33 of the grommet 27 is crimped to the cable 24, and a protrusion 29 is formed on the other end in the axial direction adjacent to the circumferential groove 35 of the grommet 27. A sealing device for a cable outlet, characterized in that a portion 29 passes through a holding plate 30, and the cable 24 is drawn out through the through hole 33 passing through the protrusion 29. It is.

Effect: The cable 24 is led out through the through hole 33 of the grommet 27 fitted in the tapered hole 26 formed in the casing 12. Moreover, the taper portion 2 of the grommet 27 is held by the presser plate 30 fitted in the circumferential groove 35 of the grommet 27.
8 is a tapered hole 2 formed in the casing 12
At the same time, the inner peripheral surface of the through hole 33 of the grommet 27 comes to be crimped to the cable 24. Even when the cable 24 is swung, the cable 24 is followed by the deformation of the protrusion 29 that protrudes above the holding plate 30, and the cable 24 is
The adhesion between the grommet 27 and the grommet 27 is not impaired.

〓Example〓 The present invention will be described below with reference to an illustrated example.
FIG. 2 shows a DC motor equipped with a sealing device according to an embodiment of the present invention, and this DC motor is equipped with a cylindrical casing 10 that also serves as a yoke. Openings formed at the front and rear ends of the casing 10 are sealed by a front bracket 11 and a rear bracket 12, respectively. A stator core 13 is installed inside the casing 10, and
A stator coil 14 is wound around this stator core 13 .

A rotating shaft 15 is disposed inside the casing 10 so as to pass through the center of the casing 10, and is rotatably supported by the front bracket 11 and the rear bracket 12 via ball bearings 16 and 17. A rotor yoke 18 is fixed to the rotating shaft 15, and a rotor coil 19 is wound around the yoke 18. A brush 20 and a commutator 21 are connected to this coil 19.
A current is passed through the shaft, and rotational force is thereby extracted. Note that the brush 20 is supported by an insulating substrate 22 via a brush holder 23.

The above rotor coil 19 and stator coil 1
Power cable 24 for supplying current to 4
As shown in FIGS. 3 and 1, the rear bracket 12 is led out through an exit through hole 25. As shown in an enlarged view in FIG. 1, this through hole 25 is provided with a tapered hole 26, into which a rubber grommet 27 is fitted. The grommet 27 has a tapered portion 28 and is fitted into the tapered hole 26. Furthermore, a presser plate 30 is attached to the protrusion 29 that protrudes above the grommet 27, and the presser plate 30 is attached to the grommet 27 via an insulating sheet 31.
is pushed downward in Fig. 1. A screw 32 is used to fix the presser plate 30 to the rear bracket 12.

In the above configuration, when the stator coil 14 wound around the stator core 13 provided on the inner peripheral surface of the casing 10 is energized, the stator core 13 is magnetized. On the other hand, a brush 20 and a commutator 2 are connected to the rotor coil 19.
Current will be supplied via 1. The rotor coil 19 through which current flows receives a rotational force due to the magnetic field generated by the stator, and this rotational force is extracted through the rotating shaft 15, thereby operating the motor.

Next, the operation of the seal structure of this motor will be explained. As shown in FIG. This causes the retaining plate 30 to push the grommet 27 downward in FIG. Therefore, the tapered portion 28 of this grommet 27 is connected to the tapered hole 2 of the rear bracket 12.
6 will be crimped. This seals the outer peripheral side of the grommet 27. Further, since the tapered portion 28 of the grommet 27 is pushed by the tapered hole 26, the grommet 27 is subjected to a force that causes it to contract toward the center in the radial direction.
Also, the part of the circumferential groove 35 of the grommet 27 is
It will be tightened by 0. Therefore, the radius of the through hole 33 of the grommet 27 is subjected to a force that reduces the radius, and the inner peripheral surface of the through hole 33 is pressed against the power cable 24. Therefore, the portion between the inner peripheral surface of the through hole 33 of the grommet 27 and the power cable 24 is completely sealed.

Note that the cable 24 is inserted into the through hole 3 of the grommet 27.
3, the grommet 27 is deformed in advance so that the center hole 36 of the holding plate 30 is fitted into the circumferential groove 35 of the grommet 27. And in this state, grommet 2
The cable 24 is inserted into the through hole 33 in such a manner that the through hole 33 of No. 7 is pushed wider, and the holding plate 30 is fixed to the case 12 with screws 32. Therefore, ease of assembly is improved.

Therefore, according to such a seal structure, by using the grommet 27, the grommet 2
Sealing can be achieved by simply pressing 7 with the presser plate 30. Therefore, the number of parts for the seal is significantly reduced, the structure of the seal is simplified, and assembly work is facilitated. Furthermore, it becomes possible to reduce the cost of seals. Note that the insulating sheet 31 is attached to the presser plate 30 and the rear bracket 1.
It is used for insulation between the two. That is, when the rear bracket 12 made of aluminum and the presser plate 30 made of stainless steel come into direct contact, an electromotive force is generated due to the Seebeck effect, and this electromotive force causes an electrolytic corrosion phenomenon. In order to prevent this, an insulating sheet 31 is used.

= Effect of the invention = As described above, according to the invention, the grommet 27
A tapered portion 28 formed on the outer circumferential surface of one end in the axial direction of the grommet 27 is pressed into the tapered hole 26 of the casing 12 by a presser plate 30 whose center hole 36 is fitted into the circumferential groove 35 of the grommet 27. As a result,
This improves the adhesion between the grommet 27 and the tapered hole 26 of the casing 12, and this portion is completely sealed.

Further, this grommet 27 has a protrusion 29 formed on the other end side in the axial direction adjacent to the circumferential groove 35,
The protrusion 29 passes through the holding plate 30, and the cable 24 is passed through the through hole 33 passing through the protrusion 29.
is being brought out. Therefore, even if the cable 24 is shaken due to vibration or the like, the protrusion 29
protrudes beyond the presser plate 30, the degree of freedom is increased and the adhesion between the cable 24 and the grommet 27 is not impaired, and the through hole 3 of the grommet 27 is
It becomes difficult for water to enter the gap between 3 and the cable 24.

Further, according to the present invention, a circumferential groove 35 having a small diameter is formed on the outer circumferential surface of the grommet 27 adjacent to the tapered portion 28, and the presser foot is inserted into the circumferential groove 35 through which the center hole 36 passes. The grommet 27 is pressed toward one end in the axial direction by the plate 30. According to such a configuration, the presser plate 30 can be fitted into the grommet 27 in advance and the cable 24 can then be inserted therethrough, thereby improving the ease of assembly.

Further, even if the protrusion 29 is deformed due to vibration and water enters between the through hole 33 of the protrusion 29 and the cable 24, the circumferential groove 35 in which the presser plate 30 is fitted on the outer circumferential side
At a position corresponding to , the grommet 27 is constricted toward the center, thereby making it difficult for water to penetrate beyond this portion and into the interior through the through hole 33 of the grommet 27. Furthermore, when the deformation of the protrusion 29 returns, the structure is such that water is discharged to the outside. This makes it possible to provide a cable outlet sealing device that can achieve a more complete seal.

[Brief explanation of the drawing]

Fig. 1 is an enlarged vertical cross-sectional view showing a cable outlet sealing device according to an embodiment of the present invention, Fig. 2 is a partially cutaway front view of the motor, and Fig. 3 is a side view of the rear bracket side. , FIG. 4 is a partially cutaway front view of a conventional motor, and FIG. 5 is a longitudinal cross-sectional view showing the seal structure of the cable outlet of this motor.
FIG. 6 is a cross-sectional view of the same. The names of the main parts in the drawings are as follows. 12... Rear bracket, 24... Power cable, 25... Penetration hole, 26... Taper hole, 27... Grommet, 28... Taper part, 2
9... Projection, 30... Holding plate, 31... Insulating sheet, 32... Screw, 33... Through hole, 35... Circumferential groove, 36... Center hole.

Claims (1)

[Claims for Utility Model Registration] A device for preventing water from entering from an outlet of a cable 24 of a rotating machine, which includes a grommet 27 attached to an outlet 25 of a cable 24 formed in a casing 12, A tapered portion 28 is formed on the outer peripheral surface of one end in the axial direction of the grommet 27, and a circumferential groove 35 having a small diameter is formed on the outer peripheral surface of the grommet 27 adjacent to the tapered portion 28.
is formed, and the grommet 27 is pressed toward one end in the axial direction by the holding plate 30 in which the center hole 36 is fitted into this circumferential groove, and the tapered portion 28 is crimped into the tapered hole 26 of the casing 12. The inner peripheral surface of the through hole 33 of the grommet 27 is crimped to the cable 24, and a protrusion 29 is formed on the other end in the axial direction adjacent to the circumferential groove 35 of the grommet 27. A sealing device for a cable outlet, characterized in that a portion 29 passes through a holding plate 30, and the cable 24 is drawn out through the through hole 33 passing through the protrusion 29.