JPS63209447A - Permanent-magnet motor - Google Patents

Abstract

PURPOSE:To reduce an unbalanced degree, by permitting the partition wall of a decelerator on the motor side, to come in close contact with the inner peripheral surface of a permanent magnet, and by pressure-transforming the permanent magnet in the diameter direction from the inner peripheral side, to form the bottom section of a thin cylinder with a bottom. CONSTITUTION:A permanent-magnet motor is provided with a thin cylinder unit 9 with a bottom having a penetration hole on the center of a bottom section, a permanent magnet 10 pressure-fixed from the inner peripheral side by the thin cylinder unit 9 with the bottom, a yoke 11 fixing the permanent magnet 10, and an armature 12 with a gear set on a projected shaft section which is inserted and projected from the penetration hole in the bottom section of the thin cylinder unit 9 with the bottom. A decelerator 8 is engaged with the gear of the armature 12 in sliding contact with each other, and output from the decelerator is transferred to a shaft 6 and to a pinion 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a permanent magnet type electric motor, and particularly to a permanent magnet type electric motor suitable for supplying an armature with a small amount of unbalance.

[Conventional technology]

In the conventional device, the partition wall of the speed reducer installed between the motor and the speed reducer has approximately the same thickness as the yoke.

Incidentally, related devices of this type include, for example, Utility Model Application Publication No. 58-70060.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the point of shortening the armature shaft length, and there is a problem in that the amount of imbalance tends to increase.

An object of the present invention is to provide an armature with a small amount of unbalance.

[Means for solving problems]

The above purpose is to make the reduction gear partition wall on the motor side closely contact the inner peripheral surface of the permanent magnet, and to press and deform it from the inner peripheral side in the radial direction to fix the permanent magnet to the inner peripheral surface of the yoke. This is achieved by constructing the bottom of a thin-walled cylinder with a bottom.

[Effect]

In order to fix the permanent magnet to the yoke, the thin-walled bottomed cylindrical body having a through hole in the center of the bottom is brought into close contact with the inner periphery of the permanent magnet and deformed under pressure in the radial direction from the inner periphery side.

As a result, the movement of the thin-walled bottomed cylinder in the circumferential direction is fixed, and because it is a cylinder, there is little deformation of the bottom, so it can be used as a bulkhead of a reduction gear, and the armature axis length can be shortened by the amount of thinning of the bulkhead. .

Shortening the shaft length is advantageous in reducing the amount of unbalance.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The permanent magnet type electric motor of the present invention includes a thin-walled bottomed cylinder 9 having a through hole in the center of the bottom, a permanent magnet 10 that is pressurized and fixed from the inner circumference side by the thin-walled bottomed cylinder 9, and the permanent magnet 10. With yoke 1 to fix.

an armature 12 provided with a gear on a protruding shaft inserted and protruded from a through hole at the bottom of the thin-walled bottomed cylindrical body 9; a reduction gear 8 slidingly engaged with the gear of the armature 12; A gear case 5 that supports the tip of the shaft 6 and clamps and fixes the speed reducer 18 between the yoke 11, and an engagement slide formed on the shaft 6 by a helical spline (not shown). a pinion 7 equipped with an overrunning clutch that moves, a shift lever 4 that pushes the pinion 7, and a shift lever 4 that moves the pinion 7;
torsion spring 3 that presses the gear case 5 to the gear case 5;
, a plunger 2 that operates to push the pinion 7 through the shift lever 4, and a magnetic switch 1 fixed to the gear case 5 that attracts the plunger 2.

When current flows through the magnetic switch 1, an electromagnetic force is generated, which attracts the plunger 2 and causes the torsion spring 3. The pinion 7 is connected to the shaft 6 via the shift lever 4.
It slides off the top and meshes with a ring gear that is directly connected to the engine (not shown).

At the same time, a large current flows through the armature 12, and the rotation of the armature 12 is reduced by the speed reducer 8. The signal is transmitted to the pinion 7 via the shaft 6 and turns a ring gear (not shown) to start the engine.

According to this embodiment, unlike a conventional starter, the partition wall on the armature 12 side of the speed reducer 8 is thin, so the axial length of the armature 12 can be shortened, which has the effect of reducing the amount of unbalance. Furthermore, since the motor length is shortened, it is also advantageous in terms of vibration resistance. Furthermore, these effects become more pronounced in a starter in which the end coil length of the armature 12 is shortened.

〔Effect of the invention〕

According to the present invention, since the reduction gear partition wall on the armature side can be made thinner, the armature shaft length can be shortened and the amount of unbalance can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view of an embodiment of the present invention. 1...Magnetic switch, 2...Plunger,
3... Torsion spring, 4... Shift lever-15.
... Gear case, 6 ... Shaft, 7 ... Pinion, 8 ... Reduction device, 9 ... Thin-walled bottomed cylinder, 10.
··permanent magnet. 11... Yoke, 12... Armature.

Claims (1)

[Claims] 1. In a permanent magnet electric motor with a built-in speed reducer, the magnet is placed in close contact with the inner peripheral surface of the permanent magnet, and is pressurized and deformed from the inner peripheral side in the radial direction to fix the permanent magnet to the inner peripheral surface of the yoke.It penetrates through the center of the bottom. The bottom of the thin-walled bottomed cylindrical body having a hole has an armature shaft provided with a gear on a protrusion inserted and protruded from the through hole, and the opposite side of the armature that is slidably engaged with the gear portion of the armature shaft is connected to the housing. A permanent magnet type electric motor characterized in that a reduction gear partition wall is closely attached to the reduction gear so as to close an open part on the armature side of the reduction gear which is sandwiched and fixed by a yoke.