JPH023384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sealed liquid type electric motor equipped with a journal spiral group bearing mechanism as a bearing mechanism.

[Conventional technology]

Conventionally, this type of sealed liquid type electric motor has been constructed as shown in FIGS. 2 to 4. This will be explained based on the figure. In the figure, what is indicated by the reference numeral 1 is a motor casing having a frame body 2, inner flanges 3 and 4, and brackets 5 and 6. The frame body 2 of this motor casing 1 is formed into a cylindrical shape. Both inner flanges 3 and 4 are connected to the frame body 2.
, and is liquid-tightly welded to the inner circumferential surface of the frame 2. One of the brackets 5 and 6 closes the opening of the inner flange 3 and is attached to the outer end surface of the inner flange 3. Cylindrical portions 7 and 8 opening in the axial direction are integrally provided on both the inner and outer end surfaces of the bracket 5. Both of these cylindrical parts 7 and 8 have
A communication hole 9 is provided that opens to the outer circumferential surface of the inner cylindrical portion 7 and the inner circumferential surface of the outer cylindrical portion 8 . The other bracket 6 has an insertion hole 6a that opens in the axial direction, closes the opening of the inner flange 4, and is attached to the outer end surface of the inner flange 4. This bracket 6 includes a cylindrical portion 10 that communicates with the insertion hole 6a, and a cylindrical portion 10 that communicates with the insertion hole 6a.
A communication hole 11 that opens on the inner and outer circumferential surfaces of 0 is provided. Note that a pump device (not shown) is attached to the outer end of the bracket 6. Also,
The bracket 5 is provided with a hole (not shown) for liquid injection. 12 is a stator having a stator core 13 and a fixed winding 14. This stator 1
The second fixed core 13 is fitted onto the inner peripheral surface of the frame 2, and the fixed winding 14 is wound around the stator core 13. 15 is a rotor having a rotor 16 corresponding to the stator core 13. 17 is a rotor shaft having a spiral shaft portion 17a at one end and spiral shaft portions 17b and 17c at the other end. The rotor shaft 17 is made of a high-hardness material such as stainless steel, and is inserted into the rotor core 16 and rotatably supported by a bearing body, which will be described later. An impeller (not shown) is attached to the insertion end of the rotor shaft 17. The spiral shaft portion 17a is formed with a left-handed twist by photo-etching, and the spiral shaft portions 17b and 17c are formed with a left-hand twist in opposite directions by photo-etching. Further, the rotor shaft 17 may be made into a shaft body having a predetermined hardness by hardening a part of the outer peripheral surface (the outer peripheral surface including the spiral shaft portions 17a to 17c). 18 is a bearing body 19, a liquid 20,
This is a first journal spiral group bearing mechanism having the spiral shaft portion 17a. The bearing body 19 of the journal spiral group bearing mechanism 18 is formed of a bottomed cylindrical body made of a low hardness material such as a copper alloy, and is fitted onto the inner peripheral surface of the cylindrical portion 7. The liquid 20 is made of fresh water containing antifreeze, for example, used to cool the spiral shaft portion 17a and the bearing body 19,
It is stored in the motor casing 1. 2
1 includes a bearing body 22, the spiral shaft portion 17b,
17c and the liquid 20. The bearing body 22 of this journal spiral group bearing mechanism 21 is formed of a cylindrical body made of the same material as the material of the bearing body 19, and the cylindrical portion 10
It is fitted onto the inner circumferential surface of. In addition, this bearing body 2
2 and the bearing body 19 may be formed of a fixed lubricant. The liquid 20 is applied to the bearing body 22.
It is also used for cooling the spiral shaft portions 117b and 17c. Reference numeral 23 denotes a shaft sealing member made of an oil seal, which is fitted into the opening of the insertion hole 6a. A bellows 24 automatically adjusts the pressure of the liquid 20, and is fitted onto the inner peripheral surface of the cylindrical portion 8. Note that symbols D and L in the figure indicate the outer diameter and length of the front spiral shaft portions 17a to 17c, respectively, and L/D is set to be 0.8 to 1.5.

In a liquid-sealed motor configured in this way, a switch (not shown) for operating the motor is turned on.
In this state, the rotor core 16, rotor shaft 17, and impeller (not shown) rotate in the direction shown by arrow A in FIGS. 3 and 4, and the pump device (not shown) is driven. In this case, the thrust load of the rotor shaft 17 is supported by the first bearing mechanism 18, and the radial load thereof is supported by the first bearing mechanism 18 and the second bearing mechanism 21. Further, the liquid 20 is indicated by arrow B in FIGS. 3 and 4.
As shown by C and E, between the spiral shaft portion 17a and the bearing body 19 and between the spiral shaft portions 17b, 17
c and the bearing body 20 to form a lubricating film.

Incidentally, the liquid 20 used in this type of sealed liquid type electric motor has a function of cooling the inside of the electric motor and a function of lubricating the bearing mechanisms 18 and 21.

[Problem to be solved by the invention]

However, in the conventional sealed liquid type electric motor, since the bearing bodies 19 and 22 are fitted into the cylindrical parts 7 and 8, respectively, the rotor shaft 17 and the bearing bodies 19 and 2
If the machining accuracy or assembly accuracy of No. 2 is lower than the set accuracy, the rotor shaft 17 may be
It was not possible to rotate it on the same axis as 2. That is, this is because both journal spiral group bearing mechanisms 18 and 21 are not provided with a self-aligning function. As a result, an unbalanced load acts on the rotor shaft 17 and the bearing bodies 19, 22, making the rotor shaft 17 and the bearing bodies 19, 22 more likely to be damaged, resulting in a problem that the life of the electric motor is shortened.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a liquid-sealed electric motor that can prevent damage to the rotor shaft and bearing body, and thereby extend the life of the motor. .

[Means to solve the problem]

The liquid-sealed electric motor according to the present invention includes a cylindrical portion into which the bottom of the bearing body fits loosely on the inner end surface of the bracket, a rotation preventing member on the inner bottom surface of the cylindrical portion, and a tip end of the rotation preventing member loosely fitting. A recessed portion for fitting is provided on the outer bottom surface of the bearing body, and a buffer member is interposed between the inner bottom surface of the cylindrical portion and the outer bottom surface of the bearing body, through which the rotation preventing member is inserted.

[Effect]

In the present invention, even if the machining accuracy and assembly accuracy of the rotor shaft and bearing body are lower than the set accuracy,
During driving, the rotor shaft rotates on the same axis as the bearing body due to the rocking of the bearing body.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a cross-sectional view showing a sealed liquid type electric motor according to the present invention. In this figure, the same members as in FIGS. 2 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, what is indicated by the reference numeral 31 is a bearing body 32, a buffer member 33, and a rotation prevention member 34.
, the liquid 20, and the spiral shaft portion 17a.
1 is a first journal spiral group bearing mechanism having a first journal spiral group bearing mechanism; Bearing body 32 of this bearing mechanism 31
The space 32a, the opening 32b, and the recess 32
c, and the entire body is formed of a bottomed cylindrical body made of a low hardness material such as a copper alloy. The bottom of this bearing body 32 is connected to the bracket 5.
It is loosely fitted into the cylindrical portion 7 of. The buffer member 3
3 is formed into a circular flat plate shape, and the cylindrical portion 7
is interposed between the inner bottom surface of the bearing body 32 and the outer bottom surface of the bearing body 32. The rotation prevention member 34 is made up of a plurality of pins and prevents the bearing body 32 from rotating. This anti-rotation member 34 is provided on the inner bottom surface of the cylindrical portion 7, and is provided on the inner bottom surface of the cylindrical portion 7.
and is loosely fitted into the recess 32c. 35 is a bottomed hole for attaching the rotation prevention member 34. The liquid 20 is enclosed within the space 32a. Note that the second journal spiral group bearing mechanism (not shown) is
It is constructed in the same manner as the conventional bearing mechanism 21. That is, the second journal spiral group bearing mechanism includes the bearing body 22 and the spiral shaft portion 1.
7b, 17c, and the liquid 20.

In the liquid-sealed electric motor configured in this way, even if the machining accuracy or assembly accuracy of the rotor shaft 17 and the bearing body 32 is lower than the set accuracy, the rotor shaft can be fixed by the swing of the bearing body 32 during driving. 17 rotates on the same axis as the bearing body 32.

Therefore, in this embodiment, since a balanced load acts on the rotor shaft 17 and the bearing body 32 during driving, the rotor shaft 17 and the bearing body 3
2 damage can be prevented.

〔Effect of the invention〕

As explained above, according to the present invention, a cylindrical portion into which the bottom of the bearing body loosely fits is provided on the inner end surface of the bracket, a rotation preventing member is provided on the inner bottom surface of this cylindrical portion,
A recess into which the tip of the rotation prevention member loosely fits is provided on the outer bottom surface of the bearing body, and a buffer member through which the rotation prevention member is inserted is interposed between the inner bottom surface of the cylindrical portion and the outer bottom surface of the bearing body. Even if the machining accuracy or assembly accuracy of the rotor shaft and bearing body is lower than the set accuracy, the rotor shaft will rotate on the same axis as the bearing body due to the rocking of the bearing body. Therefore, during driving, a balanced load acts on the rotor shaft and the bearing body, and damage to the rotor shaft and the bearing body can be prevented, so that the life of the electric motor can be extended.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of a sealed liquid type electric motor according to the present invention, FIG. 2 is a sectional view showing the entire conventional sealed liquid type electric motor, and FIGS. 3 and 4 are bearings shown in FIG. 1. FIG. 3 is an enlarged cross-sectional view of the mechanism. 1...Motor casing, 5...Bracket,
7...Cylindrical part, 17...Rotor shaft, 17a...Spiral shaft part, 20...Liquid, 32...Bearing body,
32a...Space, 32b...Opening, 32c...
... recess, 33 ... buffer member, 34 ... rotation prevention member.

Claims (1)

[Claims] 1 A liquid-sealed electric motor having a motor casing 1, a bearing body 32, a rotor shaft 17, and a liquid 20, the motor casing 1 having a bracket 5 at an end, and the bearing body 32 is formed of a cylindrical body with a bottom, the rotor shaft 17 has a spiral shaft portion 17a, and the liquid 20 is used for cooling the bearing body 32 and the spiral shaft portion 17a. The bearing body 32 is attached to the bracket 5, the rotor shaft 17 is supported within the bearing body 32, and the liquid 20 is stored within the motor casing 1. , a cylindrical portion 7 into which the bottom of the bearing body 32 fits loosely is provided on the inner end surface of the bracket 5, a rotation preventing member 34 is provided on the inner bottom surface of this cylindrical portion 7, and the rotation preventing member 34 is provided on the inner bottom surface of the cylindrical portion 7.
The recess 32c into which the tip of the bearing body 32 is loosely fitted
The anti-rotation member 34 is provided between the inner bottom surface of the cylindrical portion 7 and the outer bottom surface of the bearing body 32.
A liquid-sealed electric motor characterized in that a buffer member 33 is inserted through the buffer member 33.