JPH05300679A - Structure for fixing rotor for motor - Google Patents

Abstract

PURPOSE:To surely retain the magnet fixed to an output shaft even if the temperature under use circumstance becomes high, and the rotor of a motor gets to high temperature, concerning the structure of fixing the rotor for a motor used in high-temperature circumstance. CONSTITUTION:In the structure of fixing a rotor for a motor, wherein the rotor 1 is constituted by bonding and fixing a magnet 4 to the output shaft of a motor used in high-temperature circumstance, flanges, calking projections 11, or calking parts are provided on the periphery of the output shaft in the positions on both sides of the magnet 4, and the magnet 4 is caught and fixed by these flanges, the calking projections 11, or the calking parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor fixing structure for a motor used in a high temperature environment.

[0002]

2. Description of the Related Art Conventionally, as a motor used in a high temperature environment, for example, an exhaust gas recirculation device (EGR: Ex) of an automobile.
Haust Gas Recirculation device). The EGR device is provided with a bypass pipe between the intake manifold and the exhaust manifold, and a part of exhaust gas is recirculated to the intake side through the bypass pipe. At this time, an on-off valve that opens or closes the bypass line is provided, and this on-off valve is connected to the output shaft of the stepping motor.

Therefore, when the stepping motor is drive-controlled by the control device, the opening / closing valve adjusts the opening amount of the bypass passage, and the amount of exhaust gas returned from the exhaust manifold to the intake manifold is adjusted.

Further, as shown in FIG. 8, the rotor 31 constituting the stepping motor comprises a rotor core 32 and a magnet 33. The rotor core 32 has an output shaft (not shown) that controls the rotation of the on-off valve inserted therein. A multi-pole magnet 33 is arranged on the outer peripheral surface of the rotor core 32. The magnet 33 is fixed by an adhesive 35 in a state of contacting a flange 34 formed on the rotor core 32.

Therefore, when an exciting coil (not shown) of the stepping motor is excited, the magnetic force causes the magnet 33 and the rotor core 32 to rotate and the on-off valve connected to the output shaft to rotate. Therefore, the opening amount of the bypass passage is adjusted.

Further, the stepping motor is cooled by a water cooling device so that the temperature does not become higher than necessary.
Therefore, the temperature of the rotor 31 is suppressed to about 120 ° C.

[0007]

However, since the structure becomes complicated by providing the water cooling device, cooling by air has recently been considered. In this case, the temperature of the rotor rises to about 170 ° C. as compared with the water cooling device, and the adhesive 35 that fixes the magnet 33 to the rotor core 32 may peel off. for that reason,
There is a problem that the magnet 33 may come off from the rotor core 32, or the magnet 33 may idle and the opening degree of the on-off valve connected to the output shaft may not be accurately controlled.

The present invention has been made to solve the above problems, and its purpose is to fix a magnet to an output shaft even if the temperature of a motor in a use environment becomes high and the rotor of a motor becomes high in temperature. It is an object of the present invention to provide a rotor fixing structure for a motor capable of reliably holding the motor.

[0009]

In order to solve the above problems, the present invention has a rotor fixing structure for a motor in which a magnet is bonded and fixed to an output shaft of the motor used in a high temperature environment to form a rotor. In the above, the gist is to provide a holding means on the outer peripheral surface of the output shaft at both sides of the magnet, and to hold and fix the magnet by the holding means.

[0010]

The magnet is sandwiched and fixed in the axial direction of the output shaft by the sandwiching means on the outer peripheral surface of the output shaft at both positions where the magnet is adhered and fixed. Therefore, even if the rotor is heated to a high temperature due to the use of the motor in a high temperature environment and the adhesive is peeled off, the magnet can be reliably fixed to the output shaft by the clamping and fixing of the clamping means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a stepping motor of an EGR device for a vehicle will be described below with reference to FIGS.

As shown in FIG. 4, a rotor 1 which constitutes a stepping motor includes an output shaft 2, a rotor core 3 formed on the outer peripheral surface of the output shaft 2 and made of aluminum.
It is composed of a magnet 4 arranged on the outer peripheral surface of the rotor core 3.

A through hole 5 is formed in the rotor core 3 to form a cylindrical shape, and a guide claw 6 is integrally formed at the center of the inner peripheral surface of the through hole 5. A guide groove (not shown) formed in a spiral shape is formed on the outer peripheral surface of the output shaft 2. When the output shaft 2 is rotated while the guide groove and the guide claw 6 in the rotor core 3 are engaged with each other, the output shaft 2 is guided along the guide claw 6 with respect to the through hole 5 of the rotor core 3. Can be penetrated. And
The rotor core 3 is supported and fixed to the output shaft 2 by the engaging relationship between the guide claw 6 and an engaging recess (not shown) formed in a part of the guide groove of the output shaft 2.
An open / close valve for adjusting the opening amount of the bypass passage is provided at one end of the output shaft 2.

As shown in FIGS. 2 and 4, the rotor core 3
A large-diameter portion 7 is formed at the center of the outer peripheral surface, and a flange 8 as a holding means is integrally formed on the outer peripheral surface of the base end of the large-diameter portion 7. The magnet 4 having a cylindrical shape is bonded and fixed to the outer peripheral surface of the large-diameter portion 7 of the rotor core 3 with an adhesive 9. The base end surface of the magnet 4 is in contact with the flange 8 of the rotor core 3, and the magnet 4 is positioned and fixed to the large diameter portion 7.

The outer peripheral surface of the magnet 4 is magnetized so that N poles and S poles are alternately multi-pole. Further, as shown in FIG. 3, a plurality of engaging recesses 10 (four in this embodiment) are formed on the inner peripheral surface side of the tip end surface of the magnet 4. As shown in FIGS. 1 and 4, the rotor core 3
The tip portion of the large-diameter portion 7 is crimped in the axial direction thereof, and the crimping projections 11 as clamping means formed by the crimping are engaged with the plurality of engaging recesses 10 of the magnet 4, respectively. Therefore, the magnet 4 adhered and fixed to the large diameter portion 7 with the adhesive 9 is sandwiched in the axial direction of the rotor core 3 by the flange 8 and the caulking projection 11.

Further, when a coil (not shown) provided on the inner peripheral surface of the main body case of the stepping motor is excited, the multi-poles of the magnet 4 are attracted or repelled by the magnetic force generated in the coil, so that the rotor core 3 and the output shaft 2 are attracted. To rotate. Therefore, the open / close valve (not shown) of the output shaft 2 rotates, and the opening degree of the bypass passage is adjusted.

Therefore, the rotor 1 constructed as described above
When the stepping motor using is used in the EGR device, the rotor 1 of the stepping motor is used in a high temperature environment. At this time, even if the adhesive 9 for adhesively fixing the magnet 4 and the rotor core 3 is peeled off, the magnet 4 is sandwiched by the caulking projection 11 and the flange 8 formed on the large diameter portion 7 by caulking. Therefore, it is possible to reliably prevent the magnet 4 from spinning around or coming off from the rotor core 3. As a result, it is possible to accurately control the opening degree of the opening / closing valve that adjusts the opening degree of the bypass passage connected to the output shaft 2.

Further, since the caulking projection 11 formed on the large-diameter portion 7 by caulking engages with the engaging concave portion 10 of the magnet 4, the adhesive 9 may peel off at high temperature, so that the magnet 4 is attached to the rotor core 3. It is possible to reliably prevent the vehicle from spinning around and trying to slip out.

Further, as long as the adhesive 9 does not peel off at high temperature,
The magnet 4 can be reliably fixed to the rotor core 3 by the adhesive force of the adhesive 9 and the clamping force between the caulking projection 11 and the flange 8.

In this embodiment, the magnet 4 is adhered and fixed to the rotor core 3, and the caulking projection 11 and the flange 8 sandwich and fix the magnet 4, but after the magnet 4 is directly adhered and fixed to the output shaft 2. , Caulking protrusion 11
It is also possible to sandwich and fix the magnet 4 by sandwiching it with the flange 8.

In this embodiment, the magnet 4 is provided with a plurality of engaging recesses 10, but the number can be changed as required. Further, the structure for sandwiching the magnet 4 with respect to the rotor core 3 can be made as follows.

As shown in FIG. 5, both ends of the large-diameter portion 7 of the rotor core 3 are crimped to form caulking projections 11 which are engaged with the engaging recesses 10, and are formed at both ends of the large-diameter portion 7. The magnet 4 is clamped and fixed by the caulking protrusion 11.

As shown in FIG. 6, with the washer 12 disposed on the base end surface of the magnet 4, the caulking portion 13 is formed by caulking the tip of the large diameter portion 7. And
The magnet 4 is clamped and fixed by the caulking portion 13 formed through the washer 12 and the flange 8.

As shown in FIG. 7, by caulking the entire base end of the large-diameter portion 7 of the rotor core 3, a caulking projection 11 that engages with the engaging recess 10 of the magnet 4 is formed, and caulking is performed. The part 13 is formed on the entire circumference, and the magnet 4 is clamped and fixed by the caulking projection 11 and the caulking part 13 and the flange 8.

Further, in this embodiment, the EGR for a vehicle is used.
Although it was embodied in the stepping motor used in the device,
In addition to this, if the environment to be used is at a high temperature, the motor having the rotor fastening structure can be used reliably. For example, embodying a motor for rotating a heating roller of a heat fixing device that fixes toner on copy paper of a copying machine.

[0026]

As described in detail above, according to the present invention, the temperature of the motor in the operating environment becomes high, and even if the rotor of the motor becomes high in temperature, the magnet can be securely fixed to the output shaft. There is an excellent effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a rotor fastening structure of a stepping motor according to the present invention.

FIG. 2 is a perspective view showing the shape of a rotor core.

FIG. 3 is a perspective view showing the shape of a magnet.

FIG. 4 is a sectional view of a rotor.

FIG. 5 is a sectional view showing another example of the present invention.

FIG. 6 is a sectional view showing another example of the present invention.

FIG. 7 is a cross-sectional view showing another example of the present invention.

FIG. 8 is a sectional view showing a conventional rotor core.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Output shaft, 4 ... Magnet, 8 ... Flange as a clamping means, 11 ... Caulking projection part as a clamping means, 13 ... Caulking part as a clamping means

Claims (1)

[Claims] 1. A rotor fixing structure for a motor, wherein a magnet is adhered and fixed to the output shaft of the motor used in a high temperature environment to form a rotor, wherein the outer peripheral surface of the output shaft is located on both sides of the magnet. A rotor fastening structure for a motor, characterized in that a holding means is provided and the magnet is held and fixed by the holding means.