JPH1189157A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which prevents a foreign body from being sucked from an intake port and which prevents the damage of an armature, a field coil or the like. SOLUTION: When a cooling fan 2 is turned on, the open air is taken into from an intake port 7 so as to be passed inside a housing 3, it is discharged to the outside from an evacuation port 8, and the inside of the housing 3 is then cooled. The intake port 7 and the evacuation port 8 are arranged, so as to be separated from a part on the grounding side of the housing 3. The housing 3 is composed of an inner housing 4 and an outer housing 5 which is arranged on the outer side of the inner housing 4 by keeping an interval, so as to form a ventilation passage 6 between the inner housing 4 and itself. The entrance side of the ventilation passage 6 is connected to the intake port 7, and its exit side is connected to the evacuation port 8 via a space part 4b inside the inner housing 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric motor used as a power source for various electric tools.

[0002]

2. Description of the Related Art Generally, an electric motor includes a housing and a power unit including a plurality of members housed therein. A conventional motor will be described below with reference to FIG. As shown in FIG. 3, the conventional electric motor B includes a housing 17 and a power unit P housed in the housing 17.

The power unit P includes an armature 1, a cooling fan 2 attached to a front portion of a shaft 1a thereof, a field coil 9 and a field core 1 arranged around the armature 1.
0, a commutator 11 provided at the rear of the shaft 1 a of the armature 1, and a brush 12 attached to a housing 17 so as to contact the commutator 11.
The shaft 1a of the armature 1 is rotatably supported by a housing 17 via bearings 13 and 14.

A plurality of intake ports 18 are formed in a lower portion of the housing 17, that is, a ground-side portion, and an exhaust port 19 is formed in an upper portion of the housing 17 at a position on the outer peripheral side of the cooling fan 2. I have.

When the armature 1 is rotated by energizing the commutator 11 and exciting the field around the armature 1, the cooling fan 2 is rotated together with the rotation. By the rotation of the cooling fan 2,
The air in the housing 17 is discharged to the outside from the exhaust port 19, and as a result, the inside of the housing 17 becomes a negative pressure. Therefore, outside air is taken in from the intake port 18, the outside air passes through the inside of the housing 17 as cooling air, cools the inside thereof, that is, the field coil 9 and the like, and is then discharged to the outside through the exhaust port 19. The above-described electric motor B is hereinafter referred to as “motor of prior art 1”.

A motor having the same basic configuration as the motor of the prior art 1, but having an intake port and an exhaust port arranged in opposite positions, that is, an exhaust port at a lower portion of the housing, that is, a ground side portion. On the other hand, a motor having an intake port formed at an upper portion thereof outside the cooling fan (hereinafter, referred to as “motor of prior art 2”) has also been proposed.

[0007]

However, when the motor of the prior art 1 is operated with the lower portion of the housing 17 grounded or close to this, dust, gravels, debris, etc. come from the air inlet 18. Foreign matter may be sucked in and damage the armature 1, the field coil 9 and the like. In particular, while improving the cooling efficiency by improving the shape and material of the cooling fan 2, the suction force from the intake port 18 is significantly increased, and as a result, foreign substances generated by cutting, grinding, crushing, and the like are further reduced. Attraction becomes easy, and damage to the armature 1, the magnetic field coil 9, and the like due to this is regarded as a problem.

Further, in the electric motor of the prior art 2, since the intake port is formed in the upper part of the housing, foreign substances such as dust, gravel, and debris on the ground are hardly directly sucked through the intake port. However, the foreign matter is scattered by an exhaust flow from an exhaust port formed at a lower portion of the housing, so that the foreign material flies, and the foreign material so fluttered is sucked from an intake port formed at an upper portion of the housing. As in the case of the electric motor, the armature, the magnetic field coil and the like may be damaged.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric motor capable of preventing foreign matters such as dust, gravel, and debris from being sucked from an intake port, thereby preventing damage to an armature, a magnetic field coil, and the like. It is in.

[0010]

In order to achieve the above object, according to the present invention, there is provided a housing (3) accommodating an armature (1) and a cooling fan (2) attached to a shaft (1a) thereof. ), An intake port (7) and an exhaust port (8) are respectively formed, and by the rotation of the cooling fan (2), outside air is taken in from the intake port (7), and this is used as cooling air to form the housing (3). In the electric motor that passes through the inside of the housing and discharges the outside through the exhaust port (8), thereby cooling the inside of the housing (3), the intake port (7) and the exhaust port (8) are connected to the housing ( 3)
The housing (3) is disposed apart from the ground-side portion of the inner housing (4), and the inner (4) is formed so that a ventilation path (6) is formed between the inner housing (4) and the inner housing (4). An outer housing (5) arranged at an interval outside the housing (4), and an inlet of the ventilation path (6) is connected to the intake port (7); The exit side of ()) is via a space (4b) in the inner housing (4),
It is characterized in that it is connected to the exhaust port (8).

According to a second aspect of the present invention, in the electric motor of the first aspect, the intake port (7) and the exhaust port (8) are respectively disposed in a portion of the housing (3) opposite to a ground-side portion. It is characterized by being.

According to a third aspect of the present invention, in the electric motor according to the first or second aspect, the exhaust direction of the cooling air from the exhaust port (8) is opposite to the ground-side portion of the housing (3). It is characterized by being directed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric motor according to an embodiment of the present invention will be described below with reference to FIGS. FIG.
1 is a sectional view showing an electric motor according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II of FIG.

The electric motor of the present invention is used as a power source for various electric tools such as a hammer drill and a concrete hammer, and includes a housing 3 and a power unit P including a plurality of members housed therein. It is configured.

The housing 3 includes an inner housing 4
And an outer housing 5 arranged at an interval outside the outer housing 5. That is, the inner housing 4
Is composed of a cylindrical inner housing 4 having a capacity capable of accommodating the power unit P, and a cylindrical outer housing 5 having a capacity slightly larger than the inner housing 4.
The inner housing 4 is formed in the outer housing 5 so as to form the ventilation path 6 between the inner housing 4 and the outer housing 5.
Is stored. The lower end of the outer housing 5 is used as a ground side portion.

The space between the inner housing 4 and the outer housing 5 is held by a plurality of spacers 15 and 16. As shown in FIG. 2, these spacers have a cylindrical shape for maintaining a constant vertical distance of the inner housing 4 with respect to the outer housing 5.
It comprises four spacers 15 and four quadrangular prism-shaped spacers 16 for keeping the horizontal distance of the inner housing 4 to the outer housing 5 constant. These spacers 15 and 16 are not limited to such a form, and may be any as long as they can maintain the space between the inner housing 4 and the outer housing 5.
The form and number are arbitrary.

The bottom wall of the inner housing 4 has a ventilation passage 6 between the inner housing 4 and the outer housing 5.
Are formed into a plurality of introduction holes 4a for connecting the inner space 4 to the space 4b of the inner housing 4. On the other hand, a cooling fan storage part 4c is formed on the upper part of the inner housing 4, and the cooling fan storage part 4c is connected to an exhaust port 8 communicating with the outside. The exhaust port 8 is configured such that the exhaust direction of the cooling air therefrom is directed obliquely upward so as to cross the intake port 7.

The position of the upper edge of the outer housing 5 is
The position of the lower edge of the above-mentioned exhaust port 8 of the inner housing 4 coincides with the position in the vertical direction, and the upper edge of the outer housing 5 and the exhaust port 8 of the inner housing 4
An intake port 7 is formed between the lower end and the lower edge. Therefore, the intake port 7 and the exhaust port 8 are respectively arranged away from the lower end portion of the outer housing 5, that is, away from the ground side, and the inlet side of the ventilation passage 6 between the inner housing 4 and the outer housing 5 is connected to the intake port. 7, and the outlet side of the ventilation path 6 is connected to an exhaust port 8 via a space 4 b in the inner housing 4.

The power unit P is, like the electric motor B of the prior art 1, provided with an armature 1 and a cooling fan 2 attached to a front portion of a shaft 1a thereof and arranged in a cooling fan housing 4c of the inner housing 4. , A field coil 9 and a field core 10 arranged around the armature 1,
And a brush 12 attached to a housing 17 so as to contact the commutator 11. The shaft 1a of the armature 1 is rotatably supported by the inner housing 4 via bearings 13 and 14.

Next, the operation of the electric motor A according to the above-described embodiment of the present invention will be described below. The armature 1 rotates at a high speed by energizing the commutator 11 and exciting the field around the armature 1, and a drill, hammer, etc. (not shown) attached to the shaft 1a cuts, grinds, etc. Crush, etc.

With the rotation of the armature 1 described above, the cooling fan 2 rotates, and the rotation causes the air in the inner housing 4 to be discharged from the exhaust port 8 to the outside. The space 4b is at a negative pressure.

On the other hand, the space 4 in the inner housing 4
b is the introduction hole 4a of the inner housing 4 and the ventilation passage 6
Through the air inlet 7. Therefore, when the cooling fan 2 rotates as described above, outside air is taken in from the intake port 7, and this outside air passes through the inner housing 4 as cooling air and cools the inside thereof, that is, the field coil 9 and the like. Next, the air is discharged from the exhaust port 8 to the outside.

In the motor A of the present invention, the intake port 7 and the exhaust port 8 are connected to the outer housing 5 as described above.
Since the lower end of the outer housing 5 is disposed apart from the ground-side portion, that is, the intake and exhaust are performed at positions away from the ground-side portion of the outer housing 5,
In addition to preventing the suction of foreign matter such as dust, gravel, and debris from the intake port 7 as in the motor of the prior art 1, the foreign matter due to the exhaust flow from the exhaust port 8 as in the motor of the prior art 2 can be prevented. Can be prevented from scattering.
In addition, the exhaust port 8 is directed obliquely upward, and the exhaust port is configured to flow in this direction, that is, to prevent suction of foreign matter from the intake port 7. Even if foreign matter floats in the vicinity of 7, there is no suction of these. Therefore, even if dust and the like near the processing portion are blown off by using the exhaust flow from the exhaust port 8 and the processing is performed while reliably grasping the black line, the dust and the like are not sucked from the intake port 7.

In the motor A according to the above-described embodiment of the present invention, the exhaust port 8 has been described as being directed obliquely upward, but the exhaust direction of the cooling air from the exhaust port 8 The same effect can be obtained by arranging the exhaust gas to flow in the horizontal direction as long as the exhaust gas is directed transversely.

Further, in the electric motor A according to the above-described embodiment of the present invention, the opening area of the intake port 7 has been described as being constant, but a means for adjusting the opening area of the intake port 7 is provided. It is also possible to provide. Such an opening area adjusting means is constituted by, for example, a slide cover provided in the intake port 7. If such a slide cover is provided in the intake port 7, the opening area of the intake port 7 can be adjusted by sliding the slide cover in accordance with chips generated during processing, that is, pebbles, gravel, wood chips, and the like. .

[0026]

According to the first aspect of the present invention, an intake port and an exhaust port are respectively formed in a housing accommodating a cooling fan mounted on an armature and a shaft thereof, and the rotation of the cooling fan causes the intake air to be generated. In an electric motor that takes in outside air from a port and passes it through the housing as cooling air and discharges it from the exhaust port to the outside, thereby cooling the inside of the housing, the intake port and the exhaust port are The inner housing and the inner housing are spaced apart from each other so as to form a ventilation path between the inner housing and the inner housing. An outer housing, an inlet side of the ventilation path is connected to the intake port, and an outlet side of the ventilation path is a front side. Since it is connected to the exhaust port via a space in the inner housing, it prevents suction of foreign matter such as dust, gravel, and debris from the intake port, and prevents damage to the armature, the magnetic field coil, and the like. And an electric motor capable of performing the operation.

According to the second aspect of the present invention, since the intake port and the exhaust port are respectively disposed on the opposite side of the housing from the ground side, the suction of foreign matter from the intake port is effective. In addition, it is possible to effectively prevent foreign matter from being scattered by the exhaust flow from the exhaust port.

According to the third aspect of the present invention, since the exhaust direction of the cooling air from the exhaust port is directed to cross the intake port, dust,
Even if gravels and debris are floating, they will not be sucked.Thus, the debris near the processing part will be blown off using the exhaust flow from the exhaust port, and processing will be performed while reliably grasping the black line. Even if it is performed, suction of dust and the like from the intake port can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electric motor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a cross-sectional view showing an electric motor of Prior Art 1.

[Explanation of symbols]

 1: Armature 1a: Shaft 2: Cooling fan 3: Housing 4: Inner housing 5: Outer housing 6: Ventilation path 7: Inlet 8: Exhaust

Claims (3)

[Claims] An intake port and an exhaust port are respectively formed in a housing accommodating a cooling fan attached to an armature and a shaft thereof, and outside air is taken in from the intake port by rotation of the cooling fan to cool it. An electric motor that passes through the inside of the housing as wind, discharges the outside from the exhaust port, and thereby cools the inside of the housing, wherein the intake port and the exhaust port are arranged separately from a ground-side portion of the housing. Wherein the housing comprises: an inner housing; and an outer housing disposed at an interval outside the inner housing so as to form a ventilation path between the inner housing and the inner housing. The entrance of the passage is connected to the intake port, and the exit of the ventilation passage is connected to the air inside the inner housing. An electric motor connected to the exhaust port via a gap. 2. The electric motor according to claim 1, wherein the intake port and the exhaust port are respectively arranged in a portion of the housing opposite to a ground-side portion. 3. The exhaust direction of the cooling air from the exhaust port is:
The electric motor according to claim 1, wherein the electric motor is directed to cross the intake port.