JPH023383B2 - - 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 opening 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 has the insertion hole 6
A cylindrical portion 10 that communicates with a, and a communication hole 11 that opens on the inner and outer circumferential surfaces of this cylindrical portion 10 are provided. Note that a pump device (not shown) is attached to the outer end of the bracket 6. Further, the bracket 5 is provided with a hole (not shown) for injecting liquid. 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 highly hard material such as stainless steel, and is inserted and fitted into the rotor core 16, and is 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. In addition,
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 used for cooling the spiral shaft portion 17a and the bearing body 19, and is made of fresh water containing antifreeze, for example, and is stored in the motor casing 1. 21 is a bearing body 22 and the spiral shaft portion 1
7b, 17c, and the liquid 20.
This journal spiral group bearing mechanism 21
The bearing body 22 is formed of a cylindrical body made of the same material as the material of the bearing body 19, and is fitted onto the inner peripheral surface of the cylindrical portion 10. Note that this bearing body 22 and the bearing body 19 may be formed of a fixed lubricant. The liquid 20 is
It is used for cooling the spiral shaft portions 17b, 17c and the bearing body 22. Reference numeral 23 denotes a shaft sealing member made of an oil seal, which is fitted into the outer opening of the insertion hole 6a. 24 is a bellows that automatically adjusts the pressure of the liquid 20, and the cylindrical portion 8
It is fitted onto the inner circumferential surface of. Note that symbols D and L in the figure indicate the outer diameter and length of the 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.

[Problems to be Solved by the Invention] However, in conventional liquid-sealed electric motors, not only the bearing portion of the rotor shaft 17 but also other portions are immersed in the liquid 20.
When a high viscosity liquid is used as zero, the load capacity of the bearing mechanisms 18 and 21 can be increased.
There was a problem in that the stirring loss of the liquid 20 due to the rotation of the rotor shaft 17 became significantly large, and the efficiency of the electric motor decreased. In addition, the increased stirring loss causes a problem in that the cooling ability of the liquid 20 decreases, the number of maintenance operations increases, and the operating rate of the motor decreases. On the other hand, liquid 20
If a low viscosity liquid is used as liquid 2,
Although the stirring loss relative to zero is reduced, the load capacity of the bearing mechanisms 18 and 21 is reduced, resulting in a disadvantage that the reliability of the motor is reduced.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a sealed liquid type electric motor that can increase the efficiency and operating rate of the electric motor and also improve the reliability of the electric motor.

[Means to solve the problem]

In the sealed liquid type electric motor according to the present invention, the space of the bearing body is formed by a sealed space, the spiral shaft portion faces the sealed space, and a lubricant having a viscosity higher than that of the liquid is contained. It is sealed.

[Effect]

In the present invention, the spiral shaft portion of the rotor shaft is immersed in the lubricant, and the rotor shaft outside the space is immersed in the liquid.

〔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 the main parts of a liquid-sealed 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 explanations are omitted. . This figure shows a first journal spiral group bearing mechanism that supports one end of the rotor shaft among the two journal spiral group bearing mechanisms. In the figure, reference numeral 31 indicates a bearing body 32.
This is a first journal spiral group bearing mechanism having a lubricant 33, a shaft sealing member 34, and a spiral shaft portion to be described later. This bearing mechanism 31
The bearing body 32 has two spaces 32a and 32b with different diameters, and both spaces 32.
Large diameter space (lubricant reservoir) between a and 32b
A stepped inner flange 35 protruding from the inner peripheral surface of 32a.
The entire body is formed of a bottomed cylindrical body made of a low hardness material such as a copper alloy. This bearing body 32 is fitted into the cylindrical portion 7 of the bracket 5. The shaft sealing member 34 is an oil seal that uses the spaces 32a and 32b as hermetically sealed spaces.
5a. The lubricant 33 is made of, for example, mineral oil having a viscosity higher than that of the liquid 20, and is enclosed in the spaces 32a and 32b. 36 is a rotor shaft having a spiral shaft portion 36a and a smooth portion 36b. This rotor shaft 36 is formed in the same manner as the rotor shaft 17, one end is supported by the bearing body 32, and is inserted through the shaft sealing member 34. Moreover, the tip surface of this rotor shaft 36 and the bearing body 32
A predetermined gap is formed between the bottom surface and the bottom surface. The spiral shaft portion 36a and the smooth portion 36b each face the space portions 32b, 32a through a predetermined gap from the inner peripheral surface of the bearing body 32. A second journalled group bearing mechanism (not shown) that supports the other end of the rotor shaft 36 is constructed in substantially the same manner as the journalled spiral group bearing mechanism 31.
That is, the second shearling spiral group bearing mechanism includes a spiral shaft portion of the rotor shaft 36,
It has a cylindrical bearing body that supports this spiral shaft portion, a lubricant having a higher viscosity than the viscosity of the liquid 20, and a shaft sealing member that seals the space of the bearing body.

In the liquid-sealed electric motor configured in this manner, the spiral shaft portion 36a and the smooth portion 36b of the rotor shaft 36 are immersed in the lubricant 33.

Therefore, in this embodiment, when the pump device (not shown) is driven by turning on the switch (not shown) for operating the electric motor, the load capacity of the journal spiral group bearing mechanism 31 is increased. be able to.

Further, in this embodiment, the space portions 32a, 3
Since the rotor shaft 36 outside 2b is immersed in the liquid 20, stirring loss to the liquid 20 due to rotation of the rotor shaft 36 can be reduced.

Furthermore, in this embodiment, not only the journal spiral group bearing mechanism 31 but also the bearing body 3
Since the lubricant 33 in the lubricant 2 can be cooled by the liquid 20, the lubricating ability of the lubricant 33 can be maintained.

Although the present embodiment shows an example in which the bearing body 32 is formed into a cylindrical shape with a bottom, the present invention is not limited to this. be effective. In this case, one side opening of the bearing body is closed by the bracket 5.

Further, in this embodiment, a case is shown in which mineral oil is used as the lubricant 33, but the present invention is a lubricant having a viscosity higher than that of the liquid 20,
Other lubricants may be used as long as they increase the load capacity of the bearing mechanism to the required load capacity compared to when the liquid 20 is used.

Furthermore, in the present invention, since the load capacity of the bearing mechanism for selecting the viscosity of the lubricant 33 can be changed as appropriate, the bearing mechanism can be made smaller, lighter, and lower in cost.

〔Effect of the invention〕

As explained above, according to the present invention, the space of the bearing body is formed by a closed space, the spiral shaft of the rotor shaft is exposed to this closed space, and the viscosity is higher than that of the liquid. Since the lubricant is sealed inside, the spiral shaft portion of the rotor shaft is immersed in the lubricant. Therefore, since the load capacity of the bearing body can be increased during driving, reliability as an electric motor can be improved. In addition, since the rotor shaft outside the space is immersed in the liquid, it is possible to reduce stirring loss to the liquid due to rotation of the rotor shaft.
It can also increase the efficiency of electric motors. Furthermore, since not only the bearing body but also the lubricant in the space can be cooled with liquid, the lubrication ability of the lubricant can be maintained, and the operating rate of the motor can be increased by reducing the frequency of maintenance. There is also the advantage that it can be done.

[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, 20...Liquid, 32 Bearing body, 32
a, 32b...Space, 33...Lubricant, 35
...Inner flange, 36...Rotor shaft, 36a...
Spiral shaft.

Claims (1)

[Claims] 1. A liquid-sealed electric motor having a motor casing 1, a bearing body 32, a rotor shaft 36, and a liquid 20, wherein the motor casing 1 has a bracket 5 at an end. The bearing body 32 has spaces 32a, 32b and an opening, and the rotor shaft 36 has a spiral shaft part 36a.
The liquid 20 is used to cool the bearing body 32 and the spiral shaft portion 36a, the bearing body 32 is attached to the bracket 5, and the rotor shaft 36 is It is supported by the bearing body 32 and the liquid 20
is stored in the motor casing 1,
The spaces 32a and 32b are formed by closed spaces, and the spiral shaft portion 3 is inserted into the closed spaces.
6a, and a lubricant 33 having a viscosity higher than that of the liquid 20 is sealed inside. 2. The spaces 32a and 32b are formed by the bearing body 32, the rotor shaft 36, and the shaft sealing member 34. Of these, the shaft sealing member 34 is formed between the inner circumferential surface of the opening of the bearing body 32 and the outer circumference of the rotor shaft 36. A sealed liquid type electric motor according to claim 1, which is interposed between a surface and a surface. 3 The space 32a is a lubricant reservoir, and the space 32a is a lubricant reservoir.
2a is a sealed liquid type electric motor according to claim 1, wherein 2a is formed around a smooth circumferential portion 36b of a rotor shaft 36. 4. The liquid sealed electric motor according to claim 1, wherein the liquid 20 is fresh water and the lubricant 33 is mineral oil.