JPH07298551A - Vehicle alternator - Google Patents

Abstract

PURPOSE:To increase freedom in the axial direction of a pulley by employing a washer faced nut and providing an unthreaded part having diameter larger than that of a rotary shaft and depth comparable to that of a spring washer at the inner diametral part of the washer faced nut. CONSTITUTION:A nut 13 for tightening a pulley 2 is formed of a washer face 13a and a unthreaded part 13. The unthreaded part 13b has inner diameter phi1 larger than the outer diameter phi2 of a rotary shaft 1 so that the rotary shaft 1 does not interfere with the unthreaded part with the range of axial depth L3 of the unthreaded part 13b. Consequently, the position of the pulley can be set freely in the range of the axial depth L3 and the depth L4 between the end face of the nut 13 and the forward end of the thread.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator in which similar pulleys can be integrated by expanding the degree of freedom of axial position of the pulleys.

[0002]

2. Description of the Related Art In the prior art, as a method for fixing a pulley, as disclosed in Japanese Patent Laid-Open No. 60-5750, a pulley formed by forming a screw portion at one end of a rotating shaft and arranging the screw on the rotating shaft. And, the pipe-shaped spacer for setting the axial position of the pulley was tightened and fixed with the nut via the spring washer.

The position of the pulley has been adapted to various engine mounting requirements by changing the axial length of the spacer.

In the manufacturing process, since the rotary shaft is inserted into the rotor core from the screw portion and press-fitted, the screw diameter is smaller than the diameter of the rotary shaft, and there is no boundary between the screw portion and the non-screw portion. There is a step.

[0005]

In the prior art described above, when the end face of the spring washer interferes with the stepped surface of the threaded portion and the non-threaded portion of the rotating shaft due to the displacement of the spring washer, the pulley cannot be tightened. The position of the end face needs to be more convex than the step face.

On the other hand, the screw length becomes long when it is dimensioned so as to cover the axial positions of all pulleys, and it is uneconomical, so it is necessary to make it a common dimension. Therefore, some pulleys such as small-volume products may be dedicated even if they have the same effective diameter, and the types of pulleys are increasing.

An object of the present invention is to provide an alternator for a vehicle, which expands the degree of freedom of the axial position of the pulley without changing the screw length of the rotary shaft and integrates similar pulleys to improve the productivity. To do.

[0008]

In order to achieve the above object, in the present invention, a spring washer is abolished, a nut with a washer is used, and the inner diameter of the washer is larger than the diameter of the rotating shaft and the thickness of the spring washer is large. By providing a non-threaded portion having a considerable depth to allow the rotary shaft to escape, it is possible to set the end surface of the pulley on the nut side with seat to a concave position from the stepped surface of the rotary shaft.

[0009]

According to the present invention, the non-threaded portion of the inner diameter portion of the seated nut acts as a relief for the rotary shaft.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a vertical cross-sectional view showing a vehicle AC generator according to this embodiment.

The rotary shaft 1 comprises a pulley 2, spacers 3, 4,
The rotor cores 5, 6 pass through the rotor coil assembly 7 and the slip ring assembly 8 and are knurled into the rotor cores 5, 6. The rotary shaft 1 is supported by front brackets 11 and rear brackets 12 via bearings 9 and 10.

A screw portion 1a is formed at one end of the rotary shaft 1, and a pulley 2 is fastened and fixed by a nut 13.

The pulley 2 is driven by the engine via a belt (not shown). The position of the pulley is the flange 11a of the front bracket 11 attached to the engine.
Is controlled by the distance L1 from the
By changing No. 2, it is possible to meet various engine mounting requirements.

A stator core 15 around which a stator coil 14 is wound is arranged at a position facing the outer diameters of the rotor cores 5 and 6, and is sandwiched between a front bracket 11 and a rear bracket 12.

The rear bracket 12 contains a rectifier 16, a brush holder 17, and a voltage regulator 18.

FIG. 2 shows an enlarged view of part A of FIG.

The nut 13 for fastening and fixing the pulley 2 is formed by a seat 13a and a non-threaded portion 13b. Non-threaded part 1
The inner diameter φ1 of 3b is larger than the outer diameter φ2 of the rotary shaft 1 so as not to interfere with the non-threaded portion of the rotary shaft 1 within the axial depth L3 of the non-threaded portion 13b. Therefore, the position of the pulley can be freely set within the range of L3 + distance L4 between the end surface of the nut 13 and the tip of the screw.

[0019]

According to the present invention, productivity can be improved because similar pulleys can be integrated.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a vehicle AC generator according to an embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 1a ... Screw part of rotating shaft, 2 ... Pulley, 5,
6 ... Rotor core, 9, 10 ... Bearing, 13 ... Nut, 13
a ... nut seat, 13b ... non-threaded part of nut.

Claims (2)

[Claims] 1. A rotary shaft having a threaded portion at one end, a pulley driven by a vehicle engine via a belt and arranged on the rotary shaft, and a pulley positioning spacer that is integral with or separate from the pulley. A bearing that supports the shaft,
An automotive alternator having a pair of rotor cores and a nut with a seat for fastening and fixing the pulley, wherein a non-screw part is provided on an inner diameter portion of the nut. 2. A vehicle alternator according to claim 1, wherein the diameter of the non-threaded portion of the nut is larger than the outer diameter of the rotating shaft.