JPH0759289A - Canned motor - Google Patents

Abstract

PURPOSE:To improve sealing property between a can and a housing by providing a male thread part and a female thread part at one and the other part out of a cylindrical can and a housing for separating and breaking a stator side space part and a rotor side space part. CONSTITUTION:A female thread part 38 of a can 25 is clamped by screwing a male thread part 34 of a housing 27 and then is sealed by a screw part 44 between the water-tight-shaped female thread part 38 and the male thread part 34. In the thread part 44, a state where adhesion force is applied to the thread surface can be maintained and the thread part 44 is less subjected to the influence of deterioration due to pressure difference or temperature change or chemical reaction as compared with the case of sealing by an O ring 43 only, thus improving the sealing property between the can 25 and the housing 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canned motor having a cylindrical can between a stator and a rotor.

[0002]

2. Description of the Related Art A conventional structure of a canned motor of this type is shown in FIGS. First, referring to FIG. 3, the motor case 1
Has a stepped cylindrical shape in which the upper end side is closed, and the flange portion 1a at the lower end opening side is fixed to the outer surface of the housing 2 with the screw 3
It is attached and fixed by. A stator core 4 is press-fitted and fixed to an inner peripheral portion of the motor case 1, and a stator coil 5 is wound around a slot of the stator core 4. The stator core 4 and the stator coil 5 constitute a stator 6.

On the other hand, the rotor 7 includes a rotating shaft 9 rotatably supported by the motor case 1 and the housing 2 via bearings 8a and 8b, and a rotor yoke fitted to the outer peripheral portion of the rotating shaft 9. 10 and a rotor magnet 11 provided on the outer peripheral portion of the rotor yoke 10. The lower end of the rotary shaft 9 in FIG. 3 penetrates the housing 2 and is inserted into the load space 12 in the housing 2. There is.

A cylindrical can 13 is provided between the stator 6 and the rotor 7 to surround the rotor 7. Between the lower outer peripheral surface of the can 13 and the inner peripheral surface of the recess 2a provided in the housing 2, and the can 1
Between the upper outer peripheral surface of 3 and the inner peripheral surface of the motor case 1,
O-rings 14, 14 made of rubber are respectively interposed, and in the motor case 1, the cans 13 and O
As shown in FIG. 4, the rings 14 and 14 separate and block the stator-side space 15 and the rotor-side space 16.

The stator coil 5 has a lead wire 17
Is connected, and the lead wire 17 is connected to the motor case 1
Is penetrated through the hole 1b and connected to the external control circuit 18. The stator-side space 15 and the surrounding space 19 are in communication with each other through the gap between the outer surface of the housing 2 and the motor case 1 and the hole 1b of the motor case 1, and the load space 12 is provided. And rotor side space 16
, And are communicated with each other through the gap of the lower bearing 8b.

In the canned motor having such a structure, the rotor 7 can be directly connected to the load space 12 even when the factor causing damage to the stator 6, particularly the charging portion of the stator coil 5 is on the load space 12 side.

[0007]

However, in the conventional structure described above, since the O-ring 14 seals, the pressure difference between the stator-side space 15 and the rotor-side space 16 is large. The O-ring 14
The elastic forces of the can lose pressure and leak between them. Further, when there is a chemical atmosphere on the side of the load space 12, the O-ring 14 is deteriorated by a chemical reaction and the sealing property is deteriorated. Furthermore, as the ambient temperature changes,
The sealability of the O-ring 14 may vary due to the difference in thermal expansion coefficient between the O-ring 14 and the metal can 13, the housing 2, the motor case 1 and the like that are in contact with the O-ring 14.

Therefore, an object of the present invention is to provide a canned motor which can improve the sealing performance between the can and the housing.

[0009]

According to the present invention, a cylindrical can for separating and isolating a stator side space portion and a rotor side space portion is provided between a stator and a rotor rotatably provided with respect to the stator. In the canned motor in which the can is attached to the housing, one of the can and the housing is provided with a male screw portion, and the other is provided with a female screw portion that is screwed into the male screw portion, and the male screw portion and the female screw portion are combined. The can is attached to the housing by screwing.

In the above structure, it is preferable to apply a sealing material between the male screw portion and the female screw portion. Further, between the can and the housing, an O-ring is provided in the vicinity of a screwing portion between the male screw portion and the female screw portion, and a sealed space portion is provided between the screwing portion and the O ring. Is preferred. Further, it is preferable to position the can with respect to the housing by a screw member.

[0011]

According to the above means, the can is attached to the housing by screwing the male screw portion and the female screw portion, and the can is sealed by the screwing portion of the male screw portion and the female screw portion. The threaded portion is less susceptible to pressure difference, temperature change, or deterioration due to chemical reaction, as compared with the case where only the O-ring is used for sealing, and the sealing property can be maintained.

When a sealing material is applied between the male screw portion and the female screw portion, the sealing material can seal a minute gap between the male screw portion and the female screw portion, so that the sealing performance can be further improved. When the O-ring is provided in the vicinity of the screwed portion and the sealed space is provided between the screwed portion and the O-ring, the screwed portion, the sealing material, and the O-ring are used. It has a triple sealing structure, and the sealing performance can be further improved.

Further, by positioning the can with respect to the housing with a screw member, it is possible to reliably prevent loosening of the screwed portion between the can and the housing.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to FIGS.
Will be described with reference to. First, in FIG. 1 showing the overall configuration, a motor case 21 is formed into a cylindrical shape with its upper end side closed by press-molding a galvanized steel sheet. A stator core 22 formed by laminating a large number of press-molded silicon steel plates is press-fitted and fixed to an inner peripheral portion of the motor case 21, and a stator coil 23 insulated by polyurethane is inserted into a slot of the stator core 22. It is wrapped. The stator core 22 and the stator coil 23 form a stator 24.

A rotor 26 is rotatably disposed inside the stator 24 via a can 25. here,
The rotor 26 includes a rotating shaft 29 made of a stainless material rotatably supported by a can 25 and a housing 27 via bearings 28a and 28b formed of ball bearings, and a magnetic stainless material fitted to the rotating shaft 29 and made of a magnetic stainless material. The rotor yoke 30 and a ferrite rotor magnet 31 attached to the rotor yoke 30 by adhesion are provided. The lower end of the rotary shaft 29 in FIG.
7 is inserted into the load space 32 in the housing 27.

Here, the housing 27 is formed by cutting a stainless steel material, and a cylindrical portion 33 is integrally provided so as to surround the rotating shaft 29, and the outer peripheral portion of the cylindrical portion 33 is formed. 2, a male screw portion 34 is provided as shown in FIG. The cylindrical portion 3 is provided on the upper surface of the housing 27.
An annular groove 35 is formed around 3, and a plurality of screw holes 36 (only one is shown in FIGS. 1 and 2) are formed.

The can 25 is formed by cutting a stainless material, has a substantially cylindrical shape with its upper end closed, and is arranged in a state of surrounding the rotor 26 in the motor case 21. It is set up. This can 2
A collar portion 37 that projects laterally is integrally provided on the lower portion of 5, and an internal thread portion 38 is provided on the inner peripheral portion of the collar portion 37. The can 25 is attached to the housing 27 by screwing the female screw portion 38 of the can 25 into the male screw portion 34 of the housing 27.
9 and the rotor side space 40 are separated and cut off. In this case, the male screw portion 34 and the female screw portion 38 have a watertight screw shape. Further, these male screw portion 34 and female screw portion 38
A sealing material 41 made of an epoxy adhesive for applying a caulking effect is applied between and.

An annular recess 42 is formed on the lower surface of the flange 37, and an O-ring 43 made of Viton rubber is interposed between the recess 42 and the annular groove 35 on the housing 27 side. Then, a sealed space portion 45 is formed between the O-ring 43 and the screwing portion 44 of the male screw portion 34 and the female screw portion 38.

Further, a plurality of screw holes 46 and a plurality of screw insertion holes 47 are formed in the flange portion 37 (one is shown in FIG. 1). Of these, screw holes 4
6, a case fixing screw 48, which is passed through the collar portion 21a of the motor case 21, is screwed into the case 6, and the case fixing screw 48
Thus, the motor case 21 is attached and fixed to the can 25. Further, the screw insertion hole 47 is formed in a circular arc shape extending in the circumferential direction, and in a state where the male screw portion 34 and the female screw portion 38 are tightened, a can fixing screw 49 as a screw member inserted through the screw insertion hole 47 is inserted. The can 25 is fixed to the housing 27 by being screwed into the screw hole 36 of the housing 27.

Here, the can 2 for the housing 27
5 is attached as follows. First, O-ring 4
3 is placed in the annular groove 35 of the housing 27, and the sealing material 41 is applied to the surface of the male screw portion 34. Thereafter, the female screw portion 38 of the can 25 is screwed into the male screw portion 34, and the lower surface of the collar portion 37 abuts against the upper surface of the housing 27 and is tightened until it stops. Then, the can fixing screw 49 is screwed into the screw hole 36 of the housing 27 through the screw insertion hole 47 of the flange portion 37, and the tightening is completed.

A vinyl-insulated lead wire 50 is connected to the stator coil 23, and the lead wire 50 penetrates a hole 51 formed in the upper portion of the motor case 21 to provide an external control circuit 52. It is connected to the. The stator-side space portion 39 and the surrounding space 53 are in communication with each other through the gap between the motor case 21 and the collar portion 37 of the can 25 and the hole portion 51 of the motor case 21. The space 32 and the rotor-side space 40 are in communication with each other through the gap of the lower bearing 28b.

In the above-described structure, the control circuit 52 controls the stator coil 23 to switch on and off, whereby the rotor 26 and the rotor magnet 31 generate a rotational force by the magnetic field generated by the stator 24 and the magnetic field generated by the rotor magnet 31.
Rotates, and its rotational force is output via the rotary shaft 29 to act as a motor.

According to the above-described embodiment, the female screw portion 38 of the can 25 is screwed into the male screw portion 34 of the housing 27 and tightened, and the watertight screw-shaped female screw portion 38 and the male screw portion 34 are screwed together. Since the sealing is performed by means of, the threaded portion 44 maintains a state in which the screw surface has an adhesive force applied thereto, and can maintain a high sealing property as compared with the case of sealing only by the O-ring. . In particular, since both the female screw portion 38 and the male screw portion 34 are made of metal, they are unlikely to be affected by the pressure difference in the surroundings, the temperature change, or the deterioration due to the chemical reaction, and the sealing property can be maintained.

Further, in this case, since the sealing material 41 is applied between the female screw portion 38 and the male screw portion 34, and the sealing material 41 seals even a minute gap between them,
The sealability can be further improved. Furthermore, since the O-ring 43 is provided in the vicinity of the screwing portion 44, the screwing portion 44, the sealing material 41, and the O-ring 43 form a triple seal structure, and the sealing performance can be further improved. Therefore, even if one sealing property deteriorates and a leak occurs, the leak is caused by the sealed space portion 45 between the screwing portion 44 and the O-ring 43.
Therefore, the sealing property can be remarkably improved as compared with the conventional structure.

Further, since the can 25 is fixed to the housing 27 by the can fixing screw 49 to prevent rotation, the can 27 is fixed by the can fixing screw 49.
The can 25 can be reliably positioned with respect to the can 2
The loosening of the screwing portion 44 between the housing 5 and the housing 27 can be reliably prevented.

In the above embodiment, the housing 2
7 is provided with an external thread portion 34 on the outer peripheral portion of the tubular portion 33,
Although the internal thread portion 38 is provided on the inner peripheral portion of the can 25, conversely, the internal thread portion is provided on the inner peripheral portion of the cylindrical portion 33 of the housing 27, and the female screw portion is formed on the outer peripheral portion of the can 25. It is also possible to adopt a configuration in which a male screw portion to be screwed is provided.

[0027]

According to the canned motor of the first aspect, the can is attached to the housing by screwing the male screw portion and the female screw portion, and the can is sealed by the screwing portion of the male screw portion and the female screw portion. Therefore, the threaded part is
Compared to the case of sealing with only O-ring, it is less susceptible to pressure difference, temperature change, or deterioration due to chemical reaction,
It is possible to improve the sealing property.

According to the canned motor of the second aspect, by applying the sealing material between the male screw portion and the female screw portion, a minute gap between the male screw portion and the female screw portion can be sealed by the seal material. The sealability can be further improved.

According to the canned motor of the third aspect, the O-ring is provided in the vicinity of the screwed portion between the male screw portion and the female screw portion, and the sealed space portion is provided between the screwed portion and the O ring. By doing so, a double or triple sealing structure is formed by the screwed portion and the O-ring or the sealing material, and the sealing performance can be further improved.

According to the canned motor of the fourth aspect, by positioning the can with respect to the housing with the screw member, it is possible to reliably prevent loosening of the threaded portion between the can and the housing.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical side view of a main part.

FIG. 3 is a view corresponding to FIG. 1 showing a conventional configuration.

FIG. 4 is a view corresponding to FIG.

[Explanation of symbols]

21 is a motor case, 24 is a stator, 25 is a can,
26 is a rotor, 27 is a housing, 34 is a male screw part, 3
8 is a female screw part, 39 is a stator side space part, 40 is a rotor side space part, 41 is a seal material, 43 is an O ring, 44 is a screw part, 45 is a sealed space part, 49 is a can fixing screw (screw member). Is.

Claims (4)

[Claims] 1. A cylindrical can is provided between a stator and a rotor rotatably provided with respect to the stator so as to separate and separate the stator-side space from the rotor-side space, and the can is attached to a housing. In the canned motor, one of the can and the housing is provided with a male screw portion, and the other is provided with a female screw portion that is screwed to the male screw portion, and the can is attached to the housing by screwing the male screw portion and the female screw portion. A canned motor characterized by that. 2. The canned motor according to claim 1, wherein a sealing material is applied between the male screw portion and the female screw portion. 3. An O-ring is provided between the can and the housing in the vicinity of a screwing portion between the male screw portion and the female screw portion, and a sealed space portion is provided between the screwing portion and the O ring. The canned motor according to claim 1 or 2, characterized in that: 4. The canned motor according to claim 1, 2 or 3, wherein the can is positioned with respect to the housing by a screw member.