JP2002127048A - Motor-driven tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong a service life of a motor-driven tool by preventing suction of dust from a suction port of a cooling air during using of the motor-driven tool, and sticking to the a surface of a commutator and a bearing. SOLUTION: This motor-driven tool 1 comprises: the cooling fan 8 held by an armature 7; the suction port 13 formed in a switch case 37; an exhaust port 14 formed between a frame 5 and a gear case 40; an approximately cylindrical first guard 1 arranged so as to cover an outer periphery of the commutator 9 and the bearing 11; and an approximately dish-like second guard 3 held by the armature 7 so as to cover the bearing 12 at an output shaft side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling and dustproof structure for a power tool.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a cross-sectional structure of a conventional electric power tool.

[0003] The motor 31 used in the electric tool 30 is
Single-phase commutator motors (also known as series motors) are used. The armature 32 of the motor 31 rotates at a high speed of 20,000 to 30,000 rotations, and obtains a power and a rotation speed suitable for the purpose by decelerating with gears.
Further, since the power tool requires a small size and high output as a function, the motor 31 is provided with a cooling fan 33. Further, a suction port 38 is provided in the frame 36 or the switch case 37 in order to circulate the cooling air 34 by rotating the cooling fan 33 to enhance the cooling effect, and an exhaust port is provided between the frame 36 and the gear case 40. 3
9 are provided.

[0004]

When working with a power tool, especially a disk grinder, dust is always generated during the work, and the dust is sucked from the suction port during use and accumulates in the inside, which adversely affects the motor. Has been exerted. The dust adheres to the surface of the commutator and bearings, thereby significantly shortening the life of the power tool.

[0005]

Means for Solving the Problems A frame which is a handle which is an outer shell, a stator which is mounted on an inner peripheral portion of the frame, and both ends or end portions are held by bearings, and a commutator is provided on the non-load side. , An electric tool comprising a speed reduction mechanism for reducing the rotation of the armature, and a tool held on the output shaft of the speed reduction mechanism, wherein the cooling held on the load side of the armature is provided. A fan, a suction port formed in a frame portion or a switch case portion, an exhaust port formed between the frame and the gear case, and an outer peripheral portion of the commutator and a bearing arranged so as to cover a bearing in the vicinity thereof. The problem is solved by comprising a cylindrical first guard and a substantially dish-shaped second guard held on the armature shaft so as to cover the bearing on the output shaft side.

[0006]

When the switch is turned on, the armature rotates, and the cooling fan press-fitted into the armature of the armature is turned. Due to the rotation of the fan, air in the power tool is discharged from the air outlet, and at the same time, cooling air flows in from the air inlet. At this time, the commutator and the bearing near the commutator are arranged so that the outer periphery of the bearing is covered by the first guard, so that the commutator and the bearing held near the commutator are protected from dust and the like.

Further, since the substantially dish-shaped second guard is provided to cover the bearing at the bearing portion on the exhaust port side, the bearing is protected from dust and the like, and the life of the power tool can be extended.

[0008]

FIG. 1 shows an electric power tool according to an embodiment of the present invention, FIG. 2 shows an embodiment of a first guard, and FIG.
FIG. 4 shows another embodiment of the first guard, and FIG. 4 shows one embodiment of the second guard.

In FIG. 1, a stator 6, an armature 7, a cooling fan 8, and a bearing 1 are arranged in a frame 5.
Reference numerals 1, 12 and the like are the same as those used in the conventional electric power tool, and a description thereof will be omitted.

The present invention covers the commutator 9 and the bearing 11 in the vicinity of the commutator 9 with the first guard 2 having a substantially cylindrical shape as shown in FIG.
Since the dust passes between the guard 2 and the frame 5 and goes to the cooling fan 8 side, dust does not go to the commutator 9 and the bearing 11. Although the first guard 2 in FIG. 2 is pressed into and held on the outer peripheral portion of the ball housing, a guard 10 having a shape as shown in FIG. 3 may be used.

The bearing 12 in the vicinity of the cooling fan 8 is covered with the substantially dish-shaped second guard 3 so that the cooling air 4
Does not directly hit the bearing 12, and the bearing 12 can be protected from dust.

As described above, the structure in which the first guards 2, 10 and the second guard 3 are provided makes the flow of the wind in the electric power tool 1 smooth, and removes most of the dust entering from the suction port 13. The electric power can be discharged from the air outlet 14 to the outside, and the life of the power tool 1 can be extended.

[0013]

According to the structure of the present invention, the dust entering inside can be discharged without accumulating, so that the life of the power tool, especially the life of the commutator and the bearing can be extended.

[Brief description of the drawings]

FIG. 1 is a power tool according to an embodiment of the present invention.

FIG. 2 shows an embodiment of a first guard.

FIG. 3 shows another embodiment of the first guard.

FIG. 4 shows an embodiment of a second guard.

FIG. 5 is a conventional power tool.

[Explanation of symbols]

 1, 30 Power tool 2, 10 First guard 3 Second guard 4, 34 Cooling air 5, 36 Frame 6 Stator 7, 32 Amateur 8, 33 Cooling fan 9 Commutator 11, 12 Bearing 13, 38 Suction port 14, 39 Outlet 31 Motor 37 Switch case 40 Gear case

Claims (1)

[Claims] 1. A frame which is a handle which is an outer shell, a stator mounted on an inner peripheral portion of the frame, and both ends or near end portions are held by bearings, and a commutator is provided on the non-load side. An amateur, a power reduction tool configured to reduce the rotation of the amateur, and a power tool including a tool held on an output shaft of the speed reduction mechanism, a cooling fan held on a load side of the amateur, A suction port formed in a frame portion or a switch case portion, an air discharge port formed between the frame and the gear case, and a substantially cylindrical second portion disposed to cover an outer peripheral portion of the commutator and a bearing in the vicinity thereof. An electric tool comprising: a guard; and a substantially dish-shaped second guard held on the armature shaft so as to cover a bearing on an output shaft side.