JP2001327113A - Fin structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fin structure of a motor which enables silent operation by preventing resonance of a fan and improvement of heat exchanger effectiveness by turbulent flow thermal conduction. SOLUTION: In this fin structure of a motor, fins 6 for radiation are arranged at intervals in the longitudinal or transversal direction on an outside surface. Ribs 10 for generating turbulent flow are formed between the fins 6, and rigidity is increased. Thereby resonance due to the action of a vibromotive force of a rotating shaft is prevented, and generation of vibration and noise is suppressed. Cooling performance is improved by turbulent flow thermal conduction due to turbulence of air caused by the ribs 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipating fin structure for a motor which prevents fin resonance and has a high heat exchange rate.

[0002]

2. Description of the Related Art In a motor, an engine of an internal combustion engine, or the like, fins are formed on the surface of the main body for promoting heat radiation from the main body and cooling the air. FIG. 5 shows a longitudinal sectional view of a motor having a conventional fin structure.

In FIG. 5, a rotor 102 having a rotating shaft 101 integrally fixed thereto and a first bearing 1 supporting the rotating shaft 101 are shown.
03 and the second bearing 104 are arranged, and a stator 105 for rotating the rotor 102 by magnetic action is arranged around the rotor 102. Further, the stator 105 is press-fitted into a motor casing 107 having heat dissipating fins 106 formed vertically and in parallel, and the motor casing 107 is a bearing housing 1 into which the second bearing 104 is press-fitted.
08 is integrally provided. The first bearing 103 is press-fitted into a motor cover 109 integrally connected to a motor casing 107. There is no obstacle between the fins 106, and the fins 106 are configured so as not to block the air flow between the fins 106.

[0004]

In the heat radiation cooling by the fins 106, it is necessary to make the fins 106 thin and long to increase the surface area in order to increase the heat radiation amount and increase the cooling performance. However, in the case of such a thin and long fin 106, the fin 106 may resonate due to the action of the vibrating force due to the rotation of the rotor 102. When such resonance of the fins 106 occurs, large vibrations and loud noises are caused, and a quiet operation cannot be performed, resulting in a decrease in the strength of the members.

Further, since the fins 106 have a uniform and smooth surface, air flows in a laminar flow along the surfaces of the fins 106. For this reason, the heat transfer rate becomes laminar heat transfer with a low heat transfer rate, and there is an upper limit to the cooling effect by heat radiation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor fin structure capable of preventing fin resonance and performing a quiet operation and increasing a heat exchange rate by turbulent heat transfer.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a fin structure for a motor in which radiating fins are arranged vertically or horizontally at intervals on an outer surface of a motor. The ribs are formed.

In such a configuration, the height of the rib can be set to １ ／ to の of the height of the radiation fin.

According to the present invention, there is provided a motor fin structure capable of preventing fin resonance, performing quiet operation, and increasing the heat exchange rate by turbulent heat transfer.

[0010]

The invention according to claim 1 is a fin structure in a motor in which fins for radiating heat are arranged on the outer surface of the motor at intervals vertically or horizontally, and a turbulent flow is provided between the fins. A fin structure in a motor characterized by forming ribs for the purpose of improving the rigidity of the radiating fins by the ribs, preventing vibration and noise of the radiating fins due to the vibrating force caused by the rotation of the rotating shaft, Since the turbulent flow is formed by the ribs, the turbulent heat transfer has the effect of improving the heat transfer coefficient.

According to a second aspect of the present invention, in the fin structure of the motor according to the first aspect, the height of the rib is set to １ ／ to の of the height of the radiating fin. Yes, it has the effect of being able to optimize both the suppression of vibration and noise and the improvement of the heat transfer coefficient.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a front view of a motor having a fin structure of the present invention, and FIG. 1B is a longitudinal sectional view of a motor having a fin structure of the present invention.

In FIG. 1, bearings 3 and bearings 4 are fixed to a bearing housing 8 and a motor cover 9 of a motor frame 7, respectively, and the rotating shaft 1 is supported by these bearings 3 and bearings 4. A rotor 2 is integrally fixed to the rotating shaft 1, and a stator 5 is fixed around the rotor 2. By energizing the coils of the stator 5,
Rotor 2 rotates by the action of magnetic attraction and repulsion,
The rotating shaft 1 integrally fixed to the rotor 2 rotates.

The surface of the motor frame 7 is shown in FIG.
As shown in FIG. 5, fins 6 arranged at regular intervals are formed so as to run in the vertical direction. Then, ribs 10 are formed between adjacent fins 6 to connect the fins 6 to each other.

Next, an example of a heat radiation experiment and a vibration experiment is shown in FIG.
This will be described using FIGS.

FIG. 2 is a graph showing the relationship between the rib height and the heat transfer coefficient in the embodiment of the present invention. FIG. 3 (a) shows the turbulent heat when the ribs indicating the air flow between the fins are provided. FIG. 4B is a diagram showing heat transfer, FIG. 4B is a diagram showing laminar flow heat transfer when there is no rib indicating air flow between fins, and FIG. 4 is a relationship between rib height and vibration amplitude in the embodiment of the present invention. FIG.

First, in the heat radiation experiment, the outside air temperature was 25 ° C., the surface temperature of the motor frame 7 was 90 ° C.
That is, a temperature difference of 65 ° C. was given, and forced convection was generated at a wind speed of 3 m / s. A few hours later, assuming that the heat transfer coefficient at the time of reaching the temperature equilibrium state is h, the heat release amount is Q, the temperature difference is ΔT, and the surface area of the fin portion is S, the heat transfer coefficient h is given by the following equation (1). Can be

H = Q ÷ (S × ΔT)-Equation (1) At this time, the height H of the rib 10 and the fin 6
The ratio of the height D to the height D is A = H / D, an experiment was conducted using this variable, and a graph showing the relationship between the variable A and the heat transfer coefficient h obtained as a result is shown in FIG.

As can be seen from the experimental results, A = 1 /
In the case of 2, the heat transfer coefficient h is the highest, and decreases above that. Where A = 1/2 or more, air stays near the ribs 10 and conversely, the effective area of the fins 6 is reduced, so that the heat transfer coefficient is worse than that without the ribs of A = 0. I have. As a result, when the value of A is in the range of 1/8 to 1/2, the air flow transitions from laminar flow to turbulent flow as shown in FIG. It can be said that there is. That is, in FIG. 3A, since the ribs 10 are arranged between the fins 6, the air flowing upward from below is in a turbulent state with the ribs 10 acting as baffles. on the other hand,
In the case where there is no rib 10 as shown in FIG. 3B, the air flowing upward from the bottom is in a laminar state between the fins 6. Therefore, the provision of the ribs 10 enables turbulent heat transfer between the fins 6 and the surface of the motor frame 7, so that the heat transfer efficiency can be improved as compared with the case where the ribs 10 are not provided.

FIG. 4 shows the result of measuring the amplitude of the vibration of the fin 6 by changing the variable A in the vibration experiment. As shown in the figure, the amplitude decreases from the vicinity where A exceeds 1/4 to the amplitude allowable value or less, and the amplitude decreases as A increases.

From the above experimental results on the heat transfer coefficient and the vibration, the range of the value of A with which the heat radiation efficiency is good and the vibration can be effectively prevented is A = 1/4 to 1/2.

As described above, by providing several ribs 10 intersecting with the fins 6 and making the height of the ribs １ ／ to 倍 times the height of the fins 6, It is possible to prevent the generation of large vibrations and loud noises due to the vibrating force caused by the rotation unevenness. Also, as described with reference to FIG.
The turbulent flow is formed by the ribs 10 during the turbulent flow, and heat transfer in the turbulent flow region is mainly performed to improve the heat transfer coefficient, and as a result, the heat exchange efficiency is improved.

[0024]

According to the present invention, since the ribs are provided between the radiating fins, the rigidity of the fins can be increased, and the generation of fin vibration and noise can be suppressed. In addition, since the air flow flowing between the fins can be made turbulent by the ribs, the air flow flowing between the fins promotes turbulent heat transfer regardless of natural convection or forced convection, thereby improving heat exchange efficiency. Cooling performance can be improved.

[Brief description of the drawings]

FIG. 1 (a) is a front view of a motor having a fin structure of the present invention. FIG. 1 (b) is a longitudinal sectional view of a motor having a fin structure of the present invention.

FIG. 2 is a graph showing a relationship between a rib height and a heat transfer coefficient according to the embodiment of the present invention.

FIG. 3 (a) is a diagram showing turbulent heat transfer when ribs indicating air flow between fins are provided. (B) Laminar flow heat transfer without ribs indicating air flow between fins. Figure showing

FIG. 4 is a graph showing a relationship between rib height and vibration amplitude in the embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a motor having a conventional fin structure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotating shaft 2 rotor 3 bearing 4 bearing 5 stator 6 fin 7 motor frame 8 bearing housing 9 motor cover 10 rib 101 rotating shaft 102 rotor 103 first bearing 104 second bearing 105 stator 106 fin 107 motor casing 108 bearing housing 109 Motor cover

Claims (2)

[Claims] 1. A fin structure for a motor in which radiating fins are arranged vertically or horizontally at intervals on an outer surface of a motor, wherein fins for turbulence are formed between the fins. Fin structure in the motor. 2. The fin structure for a motor according to claim 1, wherein the height of the rib is set to ４ to の of the height of the radiation fin.