JPH0226210Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an expansion absorption device for a water-sealed submersible motor using a conical coil spring.

A water ring submersible motor is filled with a sealed liquid, and as the motor generates heat during operation, the filled liquid and a small amount of gas contained therein are heated and expand. In order to absorb this expansion, the internal and external pressures of the motor are separated by, for example, a diaphragm, the amount of compression is increased, and the diaphragm is expanded using a conical coil spring in order to maintain the shape of the diaphragm and increase its lateral rigidity. A submersible motor equipped with such an expansion absorbing device spring will be explained with reference to the drawings. FIG. 1 is a longitudinal sectional view of a conventional example. A stator 2 is fixed in a cylindrical sheet metal frame 1, and ring-shaped upper frame side plates 3 and lower frame side plates 4 are press-fitted and fixed on both sides.
An upper bracket 6 is fitted into the upper frame side plate 3 via a sealing ring 5, and an upper radial metal 7 is fitted into the upper bracket 6 via a detent pin (not shown). A lower bracket 9 is fitted into the lower frame side plate 4 via a sealing ring 8, and a bolt 19 is inserted into the lower frame side plate 4.
A lower radial metal 10 is fitted into the lower bracket 9 via a detent pin (not shown). A motor shaft 12 has a rotor 11 press-fitted into the upper radial metal 7 and the lower radial metal 10 via the stator 2 and the stator can 27 with a slight gap from the stator can.
is slipping into. A balance ring 13 is press-fitted onto the motor shaft 12 and is used to adjust dynamic balance.

The lower end of the motor shaft 12 is press-fitted to a rotating disk at the upper end of a self-aligning thrust bearing 14 via a key 15. The self-aligning thrust bearing 14 supports the leveling disk 14a on the hemispherical surface at the upper end of the adjusting screw 16, and the swingable sliding member carried by the leveling disk 14a moves around the rotation circle of the end of the motor shaft 12. A shaft joint at the end of the motor shaft 12 (not shown), a shaft joint at the end of the motor shaft 12, which slides on the plate directly or via a thrust carbon plate, and is thrust by the operation of a pump connected to the underwater motor.
1 and the weight of the motor shaft 12 and the like as loads. The adjustment screw 16 adjusts the position of the motor shaft 12 and is screwed into the thrust housing 17 and fixed by a lock nut 18.
The thrust housing 17 is screwed into the lower bracket 9 with a female thread at its end using a sealant and fixed, and is prevented from rotating with a dowel pin 20. Upper bracket 6
A shaft sealing device such as an oil seal 21 is fitted into the
The motor shaft 12 is sealed. oil seal 21
Next, a cylindrical seal cover 22 with an L-shaped cross section is installed.
is press-fitted into the upper bracket 6, and the seal cover 2
A sand slinger 23 press-fitted onto the motor shaft 12 is in contact with the outer periphery of the seal cover 22 at a small distance, and also acts as a drainer due to centrifugal force. The coil 24 of the stator 2 is connected to a three-core flat cable connector 25, and the three-core flat cable connector 25 passes through a circular hole provided in the axial direction of the upper frame side plate 3 to ensure watertightness with a sealing means, and the cable 26 It is connected to and receives three-phase AC power from the outside. Both sides of a cylindrical stator can 27 made of sheet metal are welded to the upper frame side plate 3 and the lower frame side plate 4 so as to be in contact with the inner circumference of the stator 2 . The hexagonal hole plug 28 is screwed into the sealed water inlet 29 of the upper bracket 6, which is disposed obliquely upward so as to be located at the highest position in the motor interior space.

A diaphragm 30 is provided at the bottom of the thrust housing 17 as an expansion/contraction member that partitions the inside and outside of the motor.
A holding plate 32 having a hole 31 is press-fitted into a cylindrical hole at the lower end of the thrust housing 17 so as to press the outer flange portion of the diaphragm 30, and the diaphragm 30 is fixed to the thrust housing 17 in a watertight manner. Holding plate 32 and diaphragm 3
A conical coil spring 34 is inserted in a compressed state between the spring receiving plates 33 that are in contact with the bottom surface of the spring. The diaphragm 30, the conical coil spring 34, and the presser plate 32 constitute an expansion absorbing device that absorbs the internal pressure of the motor.

In the above, the presser plate 32 is a conical coil spring 3
It also serves as a spring receiving member on which the small end of the spring 4 is seated.
In the above, the motor frame constituted by the frame 1, the upper bracket 6, and the thrust housing 17 is filled with a sealed liquid. The diaphragm 30 is balanced by adjusting the difference between the inside and outside pressures at the installation position of the underwater motor. That is, since there is a small amount of air or other hydrogen gas in the underwater motor, the diaphragm 30 is slightly deformed by the external pressure.

When the motor is energized and the motor shaft 12 rotates, the volume of the enclosed water expands due to heat generated by stirring the water, resistance heat caused by electric current, frictional heat of sliding parts, etc., and the pressure of the enclosed liquid increases. When the pressure rises, the conical coil spring 34 is compressed via the diaphragm 30, and the reaction force of the conical coil spring 34 in this state plus the external pressure balances the internal pressure of the underwater motor. Therefore, the performance of the conical coil spring 34 determines the pressure of the sealed liquid.

Figure 4 shows the spring characteristic curve, with the horizontal axis representing the spring load and the vertical axis representing the spring deflection.
As shown in Figure 2, the deflection characteristics of the conventional constant pitch conical coil spring are such that the spring constant is small in areas where the load is small, but as the load increases to a certain extent, the spring constant quickly becomes stiff. That is, once the internally sealed liquid and gas expand beyond a certain level, the internal pressure of the motor increases rapidly.

When the pressure of the sealed liquid inside the submersible motor increases, (1) the oil seal 21 becomes easily damaged or damaged;
(2) The stator can 27 is deformed or damaged. (3) Large pressure is applied to the diaphragm 30, causing abnormal deformation and even damage. Problems such as this may occur.

It is an object of the present invention to provide a water ring submersible motor equipped with a conical coil spring that can solve the above-mentioned conventional problems and reduce the increase in pressure of the sealed liquid due to temperature rise.

The present invention includes a flexible expansion and contraction member that is installed in an opening that communicates with a water-sealed space of a motor frame and that partitions the inside and outside of the motor to seal the motor; The motor is equipped with an expansion absorbing device having a spring bearing member arranged as a motor frame and attached to the motor frame, and a contracted coil spring between the spring bearing member and the expansion/contraction member, the inside of which is sealed with a sealed liquid. In the water ring submersible motor, the coil spring is a conical coil spring with a large end seated on the expansion/contraction member and a small end seated on the spring receiving member, and the conical coil spring is on the large end side. This is a water-filled submersible motor characterized by having non-equally distributed pitches that gradually become smaller toward the smaller end.

Embodiments of the present invention will be described below with reference to the drawings in comparison with a conventional example. FIG. 2 is a longitudinal sectional view of a conventional conical coil spring, FIG. 3 is a longitudinal sectional view of a conical coil spring of the present invention, and FIG. 4 is a diagram showing spring characteristics. In Figures 2 and 3, the bottom coil diameter is
D ₁ , the upper coil diameter is D ₂ , the spring wire diameter is d, the spring height is H, and the winding wire is n. However, the coil spacings h ₁ , h ₂ , h ₃ , h ₄ in Fig. 2 are equal pitches, that is, h ₁ = h ₂ =
h ₃ = h ₄ . To simplify the explanation, each turn of the coil is approximately assumed to be a cylindrical coil spring, and the deflection of the spring for each turn is δ=8D ³ W/d ⁴ G (D: coil diameter, W: load on the spring, d: wire diameter, G: shear modulus of elasticity), so if the coil diameter D is large, the deflection of the spring will increase in proportion to the cube of the coil diameter D for wires with the same diameter, so the coil spacing h ₁ , h ₂ , If h ₃ and h ₄ are equal, the load increases and the deflection increases and even if h ₁ becomes zero, the upper coil with less deflection will have less deflection, and h ₂ , h ₃ , h ₄ will be It doesn't become zero. However, when the load increases, then h ₂ =0. Thus, as the load increases, the upper spring acts with less deflection against the increased load, and as the load applied to the spring increases, the increase in deflection decreases, resulting in the characteristics shown by the dotted line a in FIG.

However, the spring shown in Fig. 3 of the present invention has h' ₁ >h' ₂ >h' ₃
> h′ ₄ , and even if the load applied to the spring increases, the deflection of each coil of the spring becomes h′ ₁ , h′ ₂ ,
If h' ₃ and h' ₄ are not exceeded, even if the load applied to the spring increases, the amount of deformation of the spring relative to the load, that is, the deflection rate of the reciprocal of the spring constant of that part will not change. In other words, in the rigid part where the coil diameter is small, the pitch is made small and the number of turns is increased, and in the part where the coil diameter is large, the pitch is made large and the number of turns is made small, making each part of the full conical coil spring closer to that of a cylindrical coil spring. Due to this, the deflection rate becomes the same as the initial value, and a spring characteristic curve close to a straight line as shown in line b in FIG. 4 is shown. Therefore, in the conventional example using a conical coil spring 34 as shown in Fig. 2, even if the sealed water expands and the pressure increases, the conical coil spring 34 hardly bends beyond a certain level, and the sealed water pressure increases rapidly. However, the increased pressure is applied to the diaphragm 30, stator cann 27, and oil seal 21, causing the above-mentioned trouble. However, when using the conical coil spring 34 of the present invention as shown in FIG. As the pressure rises, the conical coil spring 34 flexes, and the corresponding increase in load is small and balances the enclosed water pressure. In other words, the sealed water pressure does not increase much and no trouble occurs. If you use a cylindrical coil spring with a coil diameter of D ₁ in Figures 2 and 3, the line C in Figure 4
Although the water pressure can be further reduced as shown in the figure, the amount of expansion and absorption will be reduced because the length of the spring will become longer when it is in close contact.

As mentioned above, the present invention includes a flexible expansion/contraction member provided in the opening leading to the water-sealed space of the motor frame to partition the inside and outside of the motor and seal the motor; a spring bearing member disposed opposite to the member and attached to the motor frame;
In a water-sealed submersible motor, which is provided with an expansion absorbing device having a contracted coil spring between the spring bearing member and the expansion/contraction member, and in which a liquid is sealed inside, the coil spring has a large end that is connected to the A conical coil spring that is seated on an expansion/contraction member and whose small end is seated on a spring receiving member, the conical coil spring having a non-uniform pitch in which the pitch gradually becomes smaller from the large end toward the small end. Since the water ring type underwater motor is characterized by having Since the sealed liquid pressure can be kept lower than when using a water-sealed submersible motor, components that are vulnerable to pressure inside the submersible motor, such as the diaphragm, stator can, oil seal, etc., will not be deformed or damaged, and the life of the water-sealed submersible motor will be extended. I was able to do it.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the underwater motor, FIG. 2 is a vertical cross-sectional view of a conventional conical coil spring, FIG. 3 is a vertical cross-sectional view of a conical coil spring according to an embodiment of the present invention, and FIG.
The figure is a diagram showing the characteristics of a conical coil spring. 1...Frame, 1,6,17...Motor frame,
2... Stator, 3... Upper frame side plate, 4...
Lower frame side plate, 5...Sealing ring, 6...Upper bracket, 7...Upper radial metal, 8...Sealing ring, 9...Lower bracket, 10...Lower radial metal, 11...Rotor, 12... ...Motor shaft, 13...Balance ring, 14...Thrust bearing, 14a...Leveling disk, 15...
Key, 16...Adjust Screw, 17...
Thrust housing, 18... Lock nut, 1
9... Bolt, 20... Knock pin, 21... Oil seal, 22... Seal cover, 23... Sandslinger, 24... Coil, 25... Three-core flat cable connector, 26... Cable, 27
...Stator canister, 28...Plug, 29...
Inlet, 30...diaphragm, 31...hole, 3
2... Holding plate, 33... Spring receiving plate, 34...
...Conical coil spring.

Claims (1)

[Scope of utility model registration request] A flexible expansion/contraction member 30 is provided at the opening communicating with the water-sealed space of the motor frames 1, 6, 17, and partitions the inside and outside of the motor to seal the motor. A spring bearing member 32 disposed opposite to the contraction member 30 and attached to the motor frame 17, and the spring bearing member 32 and the expansion and contraction member 3.
In a water-sealed submersible motor, which is equipped with an expansion/absorption device having a coil spring 34 contracted between 0 and 34, the large end of the coil spring 34 is connected to the expansion/contraction member 30. A conical coil spring 34 is seated, and its small end is seated on the spring receiving member 32.
A water seal submersible motor characterized in that the conical coil spring 34 has non-uniform pitches in which the pitches gradually become smaller from the large end toward the small end.