JPH1066292A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproof motor wherein a liquidtightness at a through hole section for passing through a bolt for tightening a case and an end cover can be obtained easily. SOLUTION: A bolt insertion hole 4c is formed in a bottom wall section 4b of an end cover 4 for closing an end of a case 1 of a motor. A bolt 7 which has passed through the bolt insertion hole 4c is driven into a screw hole 3a formed in an end wall 3 of the case to join the case 1 and the end cover 4. In an inner section at one end of the bolt insertion hole 4c, a tapered O-ring storing section 4c2 whose inner diameter gets larger toward an opening at one end of the bolt insertion hole 4c is formed and an O-ring 21 is stored in the O-ring storing section. A flat washer 20 is located between a head 7a of the through bolt 7 and an opening of the O-ring storing section 4c2 to press the O-ring 21. Owing to the existence of the O-ring 21, a liquidtightness of the through hole for the through bolt 7 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof electric motor.

[0002]

2. Description of the Related Art In a motor of a waterproof type which is used underwater or in an environment where water drops are present, a fitting portion between a yoke and a cover constituting a housing of the motor and a portion where an output shaft penetrates the cover. Since there is a possibility that water may enter from a portion through which the cover and the yoke and the cover mutually penetrate through the cover, it is necessary to make these portions a liquid-tight structure.

FIG. 5 shows an example of the structure of a conventional waterproof motor of this type (a DC motor in this example). In the figure, reference numeral 1 denotes a case having a cylindrical yoke portion 2 and an end wall 3 provided to close one end of the yoke portion in the axial direction, and 4 denotes the other end of the yoke portion 2 of the case. An end cover having a peripheral wall portion 4a having a fitting portion fitted at one open end thereof and a bottom wall portion 4b closing the other end of the peripheral wall portion. One end of the yoke portion 2 of the case and the end wall 3 are fitted via a packing 5, and the packing 5 ensures liquid-tightness of the fitted portion. Further, the other end of the yoke portion 2 of the case and one end of the peripheral wall portion 4a of the end cover are fitted via a packing 6, and the packing 6 makes the fitting portion liquid-tight.

[0004] The yoke portion 2 of the case, the end wall 3 and the end cover 4 are inserted into bolt insertion holes 4c provided in the bottom wall 4b of the end cover to form screws formed in the end wall 3 of the case. They are fastened to each other by through bolts 7 screwed into the holes 3a.

[0005] Reference numeral 8 denotes a fixed field fixed to the inner periphery of the yoke portion 2 of the case. Reference numeral 9 denotes a rotating shaft rotatably supported by bearings 10 and 11 arranged along the central axis of the case 1 and held by the bottom wall 4b of the end cover and the end wall 3 of the case, respectively. A rotor 14 formed by winding an armature coil 13 around an armature iron core 12,
Is connected to the commutator 15. The brush 16 held on the end cover 4 is brought into contact with the commutator 15. One end of the rotating shaft 9 passes through a rotating shaft through hole 3c provided in the end wall 3 of the case and is led out to the outside. One end of the led rotating shaft 9 serves as an output shaft 9a of the electric motor. I have. A waterproof seal 17 is provided between the inner periphery of the rotating shaft through-hole 3c and the rotating shaft 9, and the waterproof seal ensures liquid tightness between the inner periphery of the rotating shaft through-hole 3c and the rotating shaft 9. Have been.

Water enters the motor through a gap between the inner periphery of a bolt insertion hole 4c provided in the bottom wall 4b of the end cover 4 and a through bolt 7 inserted in the bolt insertion hole. The adhesive 18 is applied so as to cover the head 7a of the through bolt 7 and the outer surface of the bottom wall of the end cover around the head.

[0007]

In the above-described conventional electric motor, the adhesive 18 is applied to the head 7a of the through bolt 7 and the peripheral portion of the head, so that the bolt insertion hole in the bottom wall of the end cover is provided. And the through-bolt inserted into the bolt insertion hole is liquid-tight. Therefore, in this electric motor, it is necessary to perform an adhesive application step at the time of assembly, which increases the number of assembling steps, and furthermore, in this adhesive application step, management of the application amount of the adhesive and control of the application range Since complicated management such as management is required, it is inevitable that the assembly work of the electric motor becomes complicated. In addition, when an adhesive is used to achieve liquid tightness in the bolt penetration portion, it takes a long time until the applied adhesive dries, and thus there has been a problem that the efficiency of the assembling operation is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the efficiency of assembling work by liquid-tightening a penetrating portion of a through-bolt without applying an adhesive to the head of the through-bolt or a peripheral portion thereof. It is an object of the present invention to provide a waterproof electric motor.

[0009]

In order to solve the above problems, according to the present invention, one end of the bolt insertion hole is provided at an inner peripheral portion of one end of the bolt insertion hole provided in the bottom wall of the end cover. A divergent O-ring accommodating portion whose inner diameter gradually increases toward the opening is formed, and the O-ring is accommodated in the O-ring accommodating portion. Then, the flat washer fitted to the through bolt is brought into contact with the head of the through bolt and the opening at one end of the bolt insertion hole, and an O-ring is inserted between the flat washer and the O-ring accommodating portion of the bolt insertion hole. The ring is housed in a compressed state.

[0010] With this configuration, the gap between the through bolt and the inner periphery of the bolt insertion hole is closed by the O-ring housed in a compressed state in the O-ring housing, and the gap is liquid-tight. Can be achieved. With the above configuration, the through-bolt in which the flat washer and the O-ring are fitted is passed through the bolt insertion hole, and the through-bolt is simply screwed into the screw hole formed in the end wall of the case. Since the liquid-tightness of the through portion can be achieved, the efficiency of the assembling operation of the electric motor can be improved.

[0011]

FIG. 1 shows an example of the configuration of a DC motor to which the present invention is applied. In FIG. 1, the upper half and a part of the lower half are sectioned to show the inside of the motor. Shows the structure. In FIG. 1, parts that are the same as the corresponding parts in FIG. 5 are given the same reference numerals as in FIG.

In FIG. 1, reference numeral 1 denotes an electric motor case, which is a cylindrical yoke portion 2 made of a magnetic material, and a non-magnetic material such as an aluminum alloy, which is made of a non-magnetic material. And an end wall 3 provided so as to close one end of the end wall. In the illustrated example, the yoke part 2 and the end wall 3 are formed separately, and the end wall 3 is fitted to one end of the yoke part 2 via the packing 5. The packing 5 is provided between a step 2a formed on the inner periphery of one end in the axial direction of the yoke portion 2 of the case and a step 3b of a fitting portion of the end wall 3 fitted with one end of the yoke portion. The casing 5 is compressed and housed in the packing housing, and the packing 5 ensures liquid tightness of a fitting portion between one end of the yoke portion 2 of the case and the end wall 3.

Reference numeral 4 denotes an end cover made of a non-magnetic material such as an aluminum alloy. The end cover 4 has a packing 6 at one end thereof at the other open end of the yoke portion 2 of the case 1 in the axial direction.
And a bottom wall portion 4b that closes the other end of the peripheral wall portion 4a. The packing 6 includes a step portion 2b formed on the inner periphery of the other end of the yoke portion 2 of the case, and a step portion 4d of a fitting portion of the peripheral wall portion 4a of the end cover fitted with the other end of the yoke portion 2. Is compressed and housed in a packing housing portion formed between them, and the packing 6 ensures liquid tightness of a fitting portion between the other end of the yoke portion 2 of the case and the peripheral wall portion 4a of the end cover. I have.

The yoke portion 2 of the case, the end wall 3 and the end cover 4 are connected to screw holes 3a formed in the end wall 3 of the case through bolt insertion holes 4c provided in the bottom wall 4b of the end cover. They are fastened to each other by threaded through bolts 7.

Reference numeral 8 denotes a fixed field fixed to the inner periphery of the yoke portion 2 of the case. The illustrated fixed field is made of a permanent magnet radially magnetized such that different magnetic poles are alternately arranged in the circumferential direction. Instead of a fixed field using a permanent magnet, a fixed field consisting of a field coil wound around a field coil may be used.

Reference numeral 9 denotes a rotating shaft arranged along the center axis of the case 1. The rotating shaft is a bearing holding portion 4e formed at the center of the bottom wall 4b of the end cover 4 and the end wall 3 of the case. Are rotatably supported by bearings 10 and 11 respectively held by bearing holding portions 3d formed at the center of the. At a substantially central portion in the axial direction of the rotating shaft 9, a rotor 14 formed by winding an armature coil 13 around an armature iron core 12 is attached.

A commutator 15 connected to the armature coil 13 is fixed at a position near one end of the rotating shaft 9, and a brush 16 held on the end cover 4 is brought into contact with the outer peripheral surface of the commutator. ing.

The other end of the rotating shaft 9 is led out through a rotating shaft through hole 3c formed in the center of the end wall 3 of the case, and is passed through the end wall 3 and led to the outside. Is an output shaft 9a of the electric motor. Rotary shaft through hole 3
A waterproof seal 17 is provided between the inner periphery of the shaft c and the portion of the rotating shaft 9 that penetrates the rotating shaft through-hole, and the waterproof seal ensures liquid-tightness of the through portion of the rotating shaft. ing.

As shown in FIG. 2A, two bolt insertion holes 4c provided in the bottom wall 4b of the end cover are provided at symmetrical positions in the radial direction. Each bolt insertion hole 4c
As shown in FIG. 2B, a right circular hole 4c1 extending straight in the axial direction with a constant inner diameter, and one end of the bolt insertion hole (the outer surface of the bottom wall 4b of the end cover). The O-ring accommodating portion 4c2 is formed so as to gradually increase in inner diameter toward the opening (a).

As shown in FIG. 3, the through bolt 7 inserted into the bolt insertion hole 4c has a head 7a at one end and an end of the case corresponding to the bolt insertion hole 4c at the other end. It has a screw portion 7b that is screwed into a screw hole 3a provided in the wall 3. The through bolt 7 is provided with a spring washer 19, a flat washer 20, and an O-ring 21 made of an elastic material such as rubber fitted in a portion adjacent to the head 7a.
c, and the screw portion 7b at the other end of the through bolt is screwed into the screw hole 3a provided in the end wall of the case.

In a state where the screw portion 7b of the through bolt 7 is screwed into the screw hole 3a and the yoke portion 2 of the case is fastened to the end wall 3 and the end cover 4, as shown in FIG. 20 is in contact with the periphery of the opening at one end of the bolt insertion hole 4c, and the O-ring 21 is accommodated in a compressed state between the flat washer and the O-ring accommodation portion 4c2 of the bolt insertion hole. The ring ensures liquid tightness between the through bolt 7 and the inner periphery of the bolt insertion hole 4c.

As described above, according to the present invention, the flat washer 20 is provided.
By simply screwing a through bolt fitted with the O-ring 21 into the screw hole 3a through the bolt insertion hole 4c,
Can be made liquid-tight. Therefore, there is no need to control the amount and range of application of the adhesive, and there is no need to wait for the adhesive to harden, so that the assembling work of the electric motor can be simplified.

In the above example, the yoke portion 2 and the end wall 3 of the case 1 are formed separately and the yoke portion and the end wall are fastened via the packing 5.
The present invention can also be applied to a case where the and the end wall 3 are integrally formed of a magnetic material.

In the above description, a DC motor is taken as an example. However, it goes without saying that the present invention can be applied to an AC motor.

[0025]

As described above, according to the present invention, the flared O-ring accommodating portion is formed in the bolt insertion hole provided in the bottom wall portion of the end cover, and the flat washer fitted to the through bolt is provided. The O-ring is accommodated in a compressed state between the O-ring and the O-ring accommodating portion, so that the through-hole of the through-bolt is made liquid-tight. As compared with the conventional electric motor in which the through portion of the through bolt is made liquid-tight by applying, the efficiency of the assembling work can be improved, and there is an advantage that the electric motor having the waterproof structure can be provided at a low cost.

[Brief description of the drawings]

FIG. 1 is a structural view showing the structure of an electric motor according to the present invention, in which an upper half and a part of a lower half are sectioned.

2A is a front view of an end cover used in the electric motor of FIG. 1, and FIG. 2B is an enlarged cross-sectional view of a main part of FIG.

FIG. 3 is a side view showing a state in which a flat washer and an O-ring are fitted to through bolts used in the electric motor of FIG. 1;

FIG. 4 is an enlarged sectional view showing a main part of the electric motor of FIG. 1;

FIG. 5 is a structural diagram showing a cross section of a structure of a conventional example, in which an upper half portion and a part of a lower half portion are shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Yoke part 3 End wall 3a Screw hole 3c Rotating shaft through-hole 4 End cover 4a Peripheral wall 4b Bottom wall 4c Bolt insertion hole 4c2 O-ring receiving part 5, 6 Packing 7 Through bolt 8 Fixed field 9 Rotating shaft 10, 11 Bearing 14 Rotor 17 Waterproof seal 20 Flat washer 21 O-ring

Claims (1)

[Claims] 1. A case having a cylindrical yoke portion and an end wall provided so as to close one end in the axial direction of the yoke portion, and a yoke portion of the case having an open end at the other end thereof. An end cover having a peripheral wall portion having a fitted portion at one end and a bottom wall portion closing the other end of the peripheral wall portion, and a fixed field fixed to an inner periphery of a yoke portion of the case. A rotating shaft arranged along a central axis of the case and rotatably supported by bearings respectively held on a bottom wall of the end cover and an end wall of the case; and a rotating shaft arranged in the case. A rotor attached to a shaft, a bolt insertion hole provided in a bottom wall portion of the end cover with one end opened outside the case and the other end opened inside the case, and the bolt insertion hole Corresponding to the end of the case An electric motor comprising: a screw hole formed in a wall; and a through bolt screwed into a corresponding screw hole through the bolt insertion hole, wherein the end cover is fastened to a case by the through bolt. A divergent O-ring accommodating portion whose inner diameter gradually increases toward an opening on one end side of the bolt insertion hole is formed in an inner peripheral portion on one end side of the bolt insertion hole provided in the wall portion. The flat washer fitted to the bolt is disposed between the head of the through bolt and the bolt insertion hole, and the flat washer is brought into contact with the periphery of the opening on the one end side of the bolt insertion hole, An O-ring is accommodated in a compressed state between the flat washer and the O-ring accommodating portion of the bolt insertion hole, and the O-ring allows liquid tightness between the through bolt and an inner periphery of the bolt insertion hole. Is being planned Electric motor and said.