JPS63140895A - Fan for motor - Google Patents

Abstract

PURPOSE:To improve the efficiency of a motor by providing blade sections on a boss section fitted to a rotor shaft via a deformation section made of a shape memory alloy deformed by the wind temperature. CONSTITUTION:A deformation section 4 using a shape memory alloy deformed as the temperature is decreased is provided on a boss section 3 fitted to the rotor shaft 2 of a motor M. Blade sections 5 decreasing the wind quantity via the deformation of the deformation section 4 as the temperature of the wind from the motor M is decreased are provided. The blade sections 5 are warped in the direction opposite to the rotating direction of a fan 1 in the atmosphere corresponding to the temperature requiring to decrease the wind quantity. Accordingly, the electric power of the motor to send the wind is decreased, thus the efficiency of the motor can be improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention changes the amount of air blown according to the amount of heat generated by an electric motor,
The present invention relates to a fan for an electric motor that can reduce power consumption of the electric motor by reducing mechanical loss of the electric motor.

[Conventional technology]

In electric motors, when converting electrical energy into rotational energy, iron loss due to the field of the electric motor, eddy currents generated in the steel bones of the rotor, and loss in the rotor and stator! ! Energy loss such as copper loss occurs, and this loss turns into heat and increases the temperature of the motor itself. In order to suppress the heat generation of such an electric motor, a fan is attached to the rotor shaft (it is formed so that the heat inside the electric motor is discharged and cooled).

[Problem that the invention seeks to solve]

However, in this fan, the air flow rate is set based on the maximum heat generation amount of the electric motor, and conventionally, as shown in Fig. 9, the blade body of fan a and the boss C were formed as one piece. , the structure was such that the UR clause of the air volume could not be determined. Therefore, in winter, even when the temperature of the electric motor itself is low, such as immediately after startup, the fan a blows the same amount of air as when it is hot.

In particular, in the case of a high-speed motor with a high output rotation speed, the energy loss due to the air blowing is large.Furthermore, if the motor is a DC motor that uses a storage battery as a power source, battery consumption will be accelerated and the number of charging cycles will increase. There is a problem in that the operating rate of the device is reduced.

In order to solve one part of the above problems, the fan is connected to the rotor shaft via a clutch, and a shape memory alloy is used for the actuation spring of the clutch, so that the clutch disengages as the temperature of the electric motor decreases. There is also a fan, but this only turns the fan on and off, and cannot adjust the air volume to increase or decrease the fan, so for example, if the fan stops, the electric motor may temporarily rise in temperature, etc. The points have not yet been completely resolved. Therefore, in order to reduce changes in the temperature of the electric motor, it was expected that the air volume could be adjusted in accordance with changes in temperature.

The present invention is based on providing a deformable part in the blade part using a shape memory alloy that deforms as the temperature decreases, so that the amount of air blown from the electric motor can be reduced as the temperature of the air decreases, increasing the efficiency of the electric motor. The aim is to provide a fan for electric motors that can save energy.

[Means for solving problems]

Hereinafter, an embodiment of the means of the present invention that can achieve the above-mentioned objects and meet the requirements will be described with reference to the drawings.

In FIGS. 1 to 5, a fan 1 for an electric motor (hereinafter referred to as fan 1) is a rotor of an electric motor M! The boss part 3 attached to the Ih2 has a deformable part 4 made of a shape memory alloy that deforms as the temperature decreases, and the deformation of the deformable part 4 causes the electric iM
A blade section 5 is provided to reduce the amount of air blown by lowering the temperature of the air.

In this embodiment, the electric motor M is formed as a DC motor, and a hydraulic pump P is connected to the output shaft 11 of the electric motor M.

The hydraulic pump P rotates in a fixed direction at a predetermined number of revolutions, and its load increases and decreases over a relatively large range. Therefore, the load fluctuation of the electric motor M also becomes large.

The electric motor M has a cylindrical stator 1 inside a cylindrical case 12.
Bearings 1 are provided at the centers of a front cover 14 and a rear cover 15, respectively, which are attached to both sides of the case 12.
The rotor shaft 2 is pivotally supported by 4a and 15a,
This DC motor has a well-known structure in which a cylindrical rotor 16 is fitted onto the rotor shaft 2, and a gap g is present between the inner circumferential surface of the stator 13 and the outer circumferential surface of the rotor 16. The rotor shaft 2 has its front end inserted through the front cover 14, and its core end is connected to the input shaft of the hydraulic pump P via a coupling 19. Further, a brush 20 communicating with the roller 16 is attached to the rear part of the rotor shaft 2.

A front vent 21 and a rear vent 22 are provided in each side wall of the front cover 14 and rear cover 15, respectively, to ventilate the inside and outside of the electric motor M.

The fan 1 of the present invention is installed between the rotor 16 of the rotor shaft 2 and the bearing sand 14a of the front cover 14.

In this embodiment, the fan 1 has a cylindrical boss portion 3 fixed to the rotor shaft 2 using a key or the like as shown in FIG.
and a plurality of wing portions 5 radially extending from the outer periphery of the boss portion 3 in the radial direction.

The wing portion 5 has a retaining piece 27 extending on both sides of the base piece 26 at the lower end of a thin plate-shaped base piece 26, and the engaging piece 27 has a T-shaped portion extending in the axial direction of the circumferential surface of the boss portion 3. By fitting the retaining piece 27 into the groove 29, its blade surface is attached to the boss portion 3 with the front and rear surfaces of the base piece 26 facing in the rotational direction of the rotor shaft 2. Note that the engagement piece may be attached to the wing portion 5, or the engagement piece may be attached to the boss portion 3 using fixing means such as bolting or welding.

Therefore, the fan 1 is rotated by the drive of the electric motor M,
Due to its rotation, it enters the stator 13 from the rear vent 22.
The air passing through the gap g between the rotor 16 and the rotor 16 is sucked up and discharged outside the machine from the front vent 21.

Shape memory alloy is a well-known alloy that has the property of returning to the shape before deformation when heated to a higher temperature than the temperature at which it was deformed, and the wing portion 5 has good workability. A NiTi-based alloy with a two-way memory having O and toughness can be suitably used, and a Cu-based alloy can also be used.

The wing portion 5 is formed in advance into a flat plate shape as shown by the solid line in FIG. 2 using the shape memory alloy, and then formed in an atmosphere at a temperature corresponding to the temperature at which the air flow rate should be reduced as shown by the two-dot chain line in FIG. 2. As shown in FIG.

Therefore, in this embodiment, almost the entire wing section 5 forms the deformed section 4, and due to the deformation of the wing section 5, the outer diameter of the fan 1 changes from Dl at high temperature to D2 at low temperature as shown in FIG. Change.

In addition, the relationship between the air supply amount Q of the fan 1 and the outer diameter DO of the fan 1 is proximally Q −K Do3n (1−(Db/Do) when viscous resistance of air and eddy current loss are ignored. ”) −
--= (1) Q: Air supply amount (n?/Hr) DO: Outside diameter of fan (n) Db: Boss diameter of fan (m) n: Rotation speed of rotor shaft (r, p+i) The formula is known.

Here, n is the rotation speed of the electric motor M and is a constant, and Db
Since is a unique dimension, from equation (1), Q '-k D o' −−−−−−−−−−−=
−・・−−−−−−−(21 relationships are derived.

K: constant In this way, the amount of air blown Q is approximately proportional to the cube of the outer diameter Do of the fan 1, and the most effective way to adjust the amount of air blown is to change the outer diameter Do.

In this manner, the blade portion 5 deforms as the temperature of the air from the electric motor M decreases to below the temperature, thereby reducing the amount of air blown.

Note that even when the electric motor M rotates in the reverse direction, that is, in the direction in which the blade portion 5 is warped, the outer diameter DO of the fan 1 decreases as in the case of forward rotation, although there is some power loss due to the generation of vortices. This reduces the amount of air blown.

As the electric motor M is driven, the fan 1 attached to the rotor shaft 2 rotates, and this rotation ventilates the electric motor M, so that the wind passing through the inside of the electric motor M absorbs heat generated by iron loss and W4 loss. The electric motor M is cooled by discharging the air from the rear vent 22 to the outside of the machine. Note that when the electric motor M is at full load or in the summer, the wind from the electric motor M is high temperature, the blade portion 5 stands up as shown in FIG. 4, and the outer diameter D1 of the fan 1 becomes maximum. The fan 1 blows air with its full capacity to cool the electric motor M. In addition, when the load on the electric motor M decreases, or when a large amount of heat is radiated from the surface of the electric motor M in winter, etc., the air from the electric motor M is at a low temperature, so the blade portion 5 curls. The temperature drops below the temperature during processing and warps as shown in FIG. Therefore, the outer diameter D2 of the fan 1 becomes smaller than that when the fan 1 is in the upright position, and the amount of air blown by the fan 1 decreases, and the power consumption of the electric motor M also decreases as the amount of air blown decreases.

〔Example〕

FIG. 6 shows another embodiment of the present invention. In this embodiment, the boss portion 3
A plurality of projecting pieces 31 are provided radially protruding from the outer periphery, and a plate-shaped connecting piece 33 made of a shape memory alloy is connected to the lower end of a rectangular base plate 32 made of 3g of metal such as an aluminum plate. 5 is formed. The lower part of the connecting piece 33 fits into the groove at the upper end of the protruding piece 31, and the two are fixed together by rivets or the like. Therefore, by subjecting the connecting piece 33 to the process of memorizing its shape as described above, the connecting piece 33 forms the deformed portion 4 of the wing portion 5. In this example, as the temperature decreases, the substrate 32 of the blade section 5 tilts around the deformed section 4 as a rotation center, and this inclination reduces the outer diameter of the fan 1 and reduces the amount of air blown.

FIG. 7 shows another embodiment. In this embodiment, a through hole is formed in the ear piece 36 at the lower end of the wing portion 5 in the axial direction of the d-evening shaft 2, and a hole is provided protruding from the outer periphery of the rotor shaft 3. The wing section 5 is rotatably attached to the boss section 3 using a pin 39 that is inserted through the hole of the protruding piece 37, while a shape memory alloy is used between the wing section 5 and the boss section 3, A tear spring 4 that biases the portion 5 in the rotational direction
0 is set. Note that a stopper 41 is attached to the lower end of the wing portion 5 to restrict rotation of the wing portion 5 by coming into contact with the boss portion.

Therefore, the tear spring 40 forms the deformed portion 4 of the wing portion 5, and the tear spring 40 tilts the wing portion 5 as the temperature of the wind decreases, thereby reducing the amount of air blown.

FIG. 8 shows another embodiment in which the amount of air blown can be reduced by changing the inclination of the blade 5 with respect to the rotation direction. In this example, the blade 5 is attached to the boss 3 in the rotation direction of the blade 5. β1 for
The wing portion 5 is entirely formed using a shape memory alloy, and the shoulder portion 5 itself forms the deformable portion 4.

Therefore, by making the blade portion 5 memorize the shape so that it can collapse to the above-mentioned inclination angle β2 degrees at low temperatures, the inclination angle becomes smaller as the temperature of the wind decreases, and the amount of air blown can be reduced.

As described above, the present invention can be modified in various ways, and in addition to the shape memory alloy that memorizes the shape in two directions, an omnidirectional shape memory alloy that memorizes the deformation temperature at both high and low temperatures is adopted. By the way, send m! # can also be changed to multiple stages.

〔Effect of the invention〕

As mentioned above, the fan for an electric motor of the present invention has a deformable part using a shape memory alloy in the boss part 3 attached to the rotor shaft,
Since the blade part 5 is provided to reduce the blowing layer by lowering the temperature of the air from the electric motor by deforming the deforming part, the power for blowing air at low temperatures of the electric motor is reduced, thereby increasing the efficiency of the morph and saving energy. In addition, compared to a fan that simply turns on and off, it is equipped with a clutch that uses a conventional shape memory alloy, which eliminates the need for the fan to stop at low temperatures, reducing the temperature range of the motor and extending the life of the motor. At the same time, the structure becomes easier. Furthermore, when the electric motor obtains electric power from a storage battery, excellent effects such as reduced consumption of the storage battery and the ability to extend the charging cycle can be achieved.

Note that the electric motor may be one for alternating current as well as one for direct current, and may also be used as an electric motor that rotates in two directions, forward and reverse.Furthermore, if a fan is provided, the fan of the present invention may be of an open type or other type. It can be used in various types of electric motors such as , closed type, etc.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention together with an example of use, Fig. 2 is a front view showing the above-mentioned embodiment, Fig. 3 is a partially sectional side view thereof, and Fig. 4.5 is its operation. Diagram showing 6th
8 are perspective views showing other embodiments, and FIG. 9 is a front view showing the prior art. 2-rotor shaft, 3-boss part, 4-deformed part 4.5-
Wing section, M-... electric motor. Patent applicant: Agent of Nippon Yusoki Co., Ltd.
Patent Attorney Tadashi Naemura No. 6a, Figure 3, Figure 211, Figure 4, Figure 5, Figure 8, Figure 7r! l:I

Claims (1)

[Claims] (1) The boss attached to the rotor shaft of the electric motor has a deformable part using a shape memory alloy that deforms as the temperature of the air from the electric motor decreases, and the temperature of the air from the electric motor decreases due to the deformation of the deformable part. A fan for electric motors that has blades that reduce the amount of air blown.