JPH06253492A - Motor and apparatus built in motor - Google Patents

Abstract

PURPOSE:To provide a motor that is substantially free of vibration and an office automation apparatus capable of providing printed images of high quality. CONSTITUTION:Concerning to a motor composed by fitting a rotor to a shaft 3 supported by bearings in a freely rotatable state, a holding member 11 touching a bearing is fitted to a rotor inserting part 10 bent in the direction of a ball bearing 2a along the above-mentioned shaft 3. This motor is used as a component to assemble the paper feed device of an office automation apparatus such as a copying machine, etc., for example. Accordingly, it become possible to reduce the dislocation of the vertically of a rotor yoke to the shaft to be generated by using the motor. Besides, it becomes possible to prevent the big dislocation of the verticality, since the positioning of the rotor yoke can be performed only by the holding member without the aid of a retaining ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a motor for driving a paper feeding device of an apparatus and the OA apparatus, and particularly to a mounting structure of a rotor yoke of the motor.

[0002]

2. Description of the Related Art As a conventional motor of this type, a brushless motor having a longitudinal sectional view shown in FIG. 10 will be described. The motor body has a housing (1) which is an OA for a copying machine or the like.
It has a structure that is fixed by screwing it to a chassis that is a mounting bracket when it is attached to equipment.

Ball bearings (2a) and (2b) are mounted as bearings on the inner surface of the opening of a housing (1) having a cylindrical opening as shown in FIG.
A shaft (3) is rotatably supported on the ball bearings (2a) (2b). Of these ball bearings (2a) (2b), the ball bearing (2a) located on the side opposite to the output side of the shaft (3) is restricted by the retaining ring (17) fitted to the shaft (3). ing.

Around the housing (1), stator cores (5), around which coils (4) are wound, are spaced apart, and the stator cores (5) are fixed to the housing by caulking. A step portion (6) is provided at a portion of the housing (1) coupled to the shaft (3), and the printed circuit board (7) is brought into contact with the step portion (6).
Are placed. The printed circuit board (7) is screwed and fixed to the spacer (8) provided on the housing (1).

A rotor yoke (9) is inserted and fixed at the end of the shaft (3) in the opposite output direction so as to be perpendicular to the shaft (3). And this insertion part (1
0) has a structure in which a part of the center of the rotor yoke (9) is bent in the direction of the ball bearing (2a) by forming a diaphragm and extends along the shaft (3). The difference in diameter between the shaft (3) and the insertion portion (10), so-called interference fit, is about 9 to 28 (μm).

A magnet (12) is provided on the rotor yoke (9) at a position facing the coil (4), and a frequency generating magnet (on the printed circuit board (7) side of the magnet (12) is provided. 13) is integrally provided to form a rotor. A frequency power generation pattern (not shown) is formed in a portion of the printed circuit board (7) facing the frequency power generation magnet (13), and the voltage generated in the frequency power generation pattern by the rotation of the motor is also the same as the printed voltage. The mechanism is applied to the detection signal processing circuit formed on the substrate (7) to control the rotation speed of the motor.

[0007]

Since the rotor yoke (9) of the motor according to the prior art described above is formed by bending, there is an advantage that the manufacturing is very simple and the cost is low. Further, since the stator core (5) is fixed to the housing (1) by screwing or caulking, the size of the radial gap between the housing (1) and the stator core (5), which serves as an adhesive portion when an adhesive is used, is reduced. There is an advantage that it does not need to be taken into consideration, and the number of parts can be reduced without the need for parts such as spacers as in the conventional case.

However, the conventional motor has the following drawbacks. In other words, even if the interference fit of the insertion part (6) is set to an appropriate value, the insertion part (6) itself is easily bent, so that the fixing strength of the shaft (3) is low and the shaft (3) is attached to the shaft (3) when the motor is used. The verticality of the rotor yoke (9) sometimes went wrong. Further, the position of the ball bearing (2a) with respect to the shaft (3) is regulated by the retaining ring (17), but the dimensions of the retaining ring and / or the fitting groove of the retaining ring are slightly deviated, and the ball bearing (2a).
If the contact between the ring and the retaining ring (17) is not good, smooth rotation of the rotor may be hindered.

When such a motor is driven, a large vibration occurs, and when used by being incorporated in a paper feeding device of an OA device such as a copying machine, the vibration is also transmitted to the paper feeding device, that is, a printed image, that is, a copied image. Disturbances could occur.

In view of this, in the present invention, the motor is improved in the mounting structure of the shaft and the rotor yoke so that the motor has very little vibration. Further, when the motor is incorporated in the paper feeding device, the disturbance of the printed image is less likely to occur. The purpose is to provide an embedded device.

[0011]

In order to achieve the above object, a motor according to claim 1 of the present invention is a motor in which a rotor is mounted on a shaft rotatably supported by a bearing. The insertion portion is formed by bending in the direction of the bearing and along the shaft,
A holding member that comes into contact with the bearing is attached to the insertion portion.

The motor according to the second aspect is a motor in which a rotor is mounted on a shaft rotatably supported by a bearing, and a rotor yoke constituting the rotor is bent in the direction of the bearing by bending. An insertion portion is formed along the shaft by a length that is 2 to 3 times the thickness of the rotor yoke, and the insertion portion has a length equal to at least the portion of the insertion portion that extends along the shaft. A holding member having a width is attached.

According to a third aspect of the present invention, in a motor in which a rotor is mounted on a shaft rotatably supported by bearings, a rotor yoke forming the rotor is bent in the direction of the bearing by bending. An insert portion is formed that extends along the shaft by a length that is 2 to 3 times the thickness of the rotor yoke.
A holding member having a width equal to a length of at least a portion of the insertion portion extending along the shaft is attached to the insertion portion, the holding member being in contact with the bearing.

According to a fourth aspect of the present invention, there is provided a motor built-in device,
The motor according to claim 1 or 3 is incorporated in a paper feeding device.

[0015]

In the motor of the present invention, the holding member is fitted and mounted in the insertion portion of the rotor where the shaft is inserted, so that the fixing strength between the shaft and the rotor is improved. The generated vertical deviation between the shaft and the rotor can be reduced, and the retaining member is brought into contact with the bearing to regulate the position of the bearing, so that the retaining ring is not required and the rotor can be smoothly rotated. .

Further, when the rotor yoke is formed by bending such as drawing, the portion of the insertion portion bent in the direction of the bearing is formed on the shaft by a length of 2 to 3 times the thickness of the rotor yoke. By extending along the line, the fixing strength between the shaft and the rotor can be improved, and the deviation of the verticality can be further reduced.

Due to the above, it is possible to provide a motor with extremely small vibration, and further, when the motor is incorporated in the paper feeding device of the motor built-in device, the disturbance of the printed image can be extremely reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view of a motor according to the first embodiment of the present invention. The motor is, for example, a brushless motor used as a drive motor for a paper feeding device of a motor-incorporated device such as a copying machine. This motor is of a type that is mounted on a motor built-in device via a chassis made of a metal member, and has a structure in which the housing (1) is screwed and fixed to the chassis.

As shown in FIG. 1, ball bearings (2a) and (2b) are mounted as bearings on the inner surface of the opening of a housing (1) having a cylindrical opening. The ball bearing (2a) A shaft (3) is rotatably supported on (2b). Here, the ball bearings (2a) and (2b) may be a slide bearing or the like in addition to the ball bearing, and different bearings may be used on the output side and the counter output side.

Around the housing (1), the stator cores (5) of the coils (4) are spaced apart, and the stator cores (5) are fixed to the housing (1) by caulking. Note that this fixing may be screwed or the like. A step portion (6) is provided at a portion of the housing (1) coupled to the shaft (3), and a printed circuit board (7) is arranged in contact with the step portion (6).
The printed circuit board is fixed by caulking to a spacer (8) provided on the chassis.

A rotor yoke (9) is inserted and fixed at a predetermined position at the end of the shaft (3) in the opposite output direction.
At this time, the shaft (3) is connected to the rotor yoke (9).
Inserted vertically with respect to. The rotor yoke (9) is made of a zinc steel plate or the like, and as shown in FIG. 2, a part of the center of the rotor yoke (9) is bent toward the ball bearing (2a) by bending such as drawing. The structure extends along the shaft (3). Further, the insertion portion (10) of the rotor yoke (9)
A holding member (11) is fitted and attached to the rotor yoke (9) by inserting the shaft (3) in the direction of the arrow.
Is fixed. Further, the ball bearing (2a) is also positioned by bringing the holding member (11) into contact with the ball bearing (2a). Since the holding member (11) contacts the rotor yoke (9) made of a conductive material, it is a non-magnetic material such as brass or aluminum in consideration of the occurrence of eddy current loss depending on the positional relationship with the coil (4). It is preferable. Also, these shafts (3)
The interference fit between the rotor yoke (9) and the rotor yoke (9) and the holding member (11) is about 9 to 28 (μ), respectively.
m) and about 5 to 20 (μm).

A magnet (11) is provided on the rotor yoke (9) at a position facing the coil (4), and a frequency power generation magnet (on the printed circuit board (7) side of the magnet (12) is provided. 13) is integrally provided to form a rotor. A frequency power generation pattern (not shown) is formed on a portion of the printed circuit board (7) facing the frequency power generation magnet (13).

Next, the function and effect of this embodiment will be described. In the insertion portion (10) of the rotor yoke (9) into which the shaft (3) is inserted, the holding member (11) is fitted and mounted in the insertion portion (10).
The bending of the insertion part (10) due to the press-fitting of the shaft (3) can be absorbed by the holding member (11). As a result, the fixing strength of the shaft (3) in the insertion portion (10) of the rotor yoke (9) can be improved, and the deviation of the perpendicularity of the rotor yoke (9) with respect to the shaft (3) generated by the use of the motor can be prevented. It can be reduced. Furthermore, since the retaining member (11) is brought into contact with the ball bearing (2a) to regulate the position of the ball bearing (2a), a retaining ring is not required, so that the rotor can be smoothly rotated. There is.

Therefore, the motor having these characteristics has very little vibration, and when this motor is incorporated in the paper feeding device of the motor built-in device, smooth paper feeding can be realized and the disturbance of the printed image is extremely reduced. can do. Here, the motor built-in device is not limited to the copying machine described in the first embodiment, but any device having a paper feeding device such as a printer or a facsimile can be applied. Needless to say, even if the motor is incorporated into a drive unit other than the paper feeding device and used, various advantages resulting from the reduction in vibration can be obtained.

A case in which the holding member (11) having a large diameter which is almost equal to the diameter of the rotor yoke (9) is used will be described with reference to FIG. The holding member (11) is positioned by making some play between the outer edge portion and the rotor yoke (9) and fitting it into the insertion portion (10). According to such a holding member (11), the shaft (3)
The bending of the insertion portion (10) due to the insertion of the shaft can be further absorbed, and the fixing strength of the shaft (3) at the insertion portion (10) of the rotor yoke (9) can be further improved. Further, if the holding member (11) is made of a material such as aluminum which is relatively soft and can be easily shaved off, the outer periphery of the holding member (11) is eliminated to balance the rotor. This also has the synergistic effect that the uneven rotation of the motor can be further reduced.

Regarding the motors described in the above embodiments, the materials of the rotor yoke (9) and the holding member (11), the shaft (3) and the rotor yoke (9), and the rotor yoke (9) and the holding member (11). The size of the interference fit is not limited to the values in the first embodiment. Further, the rotor yoke (9) and the holding member (11) may be in a loose state when the shaft (3) is not inserted.

The insertion portion (1) of the rotor yoke (11)
0) is not limited to the one manufactured by bending, but for improving the fixing strength of the shaft (3) in the insertion part (10) even if it is formed by a method such as shaving. It is effective to use a holding member for the.

Further, the shape of the holding member (11) also has a high degree of freedom, and the insertion portion (1) of the rotor yoke (9) is
0) can be fitted and installed, and the end of the insertion part (1) 0 on the ball bearing (2a) side does not protrude in the state where it is installed in the insertion part (10), and the holding member (11) directly contacts the ball bearing. Anything can be used as long as it comes into contact with (2a).

By the way, when the rotor yoke is manufactured by drawing, as shown in FIG. 4, the insertion portion (10) has a tapered portion extending along the shaft (3).
A gap may be formed between the holding member (11) and the insertion portion (10). This relates to the length of the insertion portion (10) in the direction of the ball bearing (2a) with respect to the thickness of the rotor yoke (9). In such a case, when the shaft (3) is inserted into the rotor yoke (9), the insertion portion (1
The spread of 0) may not be transmitted to the holding member (11), that is, the fixing strength of the shaft (3) may be impaired and the perpendicularity of the shaft (3) and the rotor yoke (9) may be lost.

In such a case, as shown in FIG. 5, the rotor yoke (9) has a structure in which the insertion portion (10) is formed by bending a part of the center of the rotor yoke (9) toward the ball bearing (2a). The shape is such that it extends along the shaft (3) by a length of 2 to 3 times the thickness. A holding member (11) having the same length as that of the portion extending along the shaft (3) is attached to the insertion portion (10), and the position of the ball bearing (2a) is restricted by the retaining ring (17). Is done by.

Insert portion (10) of this rotor yoke (9)
Has a constant thickness over the entire length extending along the shaft (3), and as described above, the fixing strength between the shaft (3) and the rotor is not impaired at all, so that the vertical deviation is more It can be further reduced.

Further, the length of the insertion portion (10) in the direction of the ball bearing (2a) is regulated, and the holding member (11) is fitted and attached to the insertion portion (10) to mount the ball bearing (2a). By contacting the position of the bearing) to regulate the position of the bearing, the vertical deviation can be extremely reduced, the rotor can be smoothly rotated, and a motor with less vibration can be obtained.

Although the first to third embodiments of the present invention have been described above, the present invention can be applied to various motors as long as the shaft is inserted into and fixed to the rotor. Another structure of the housing will be described below.

FIG. 6 is a longitudinal sectional view of a motor in which a printed circuit board fixing member (14) and a stator core fixing member (15) are integrally formed in a housing (1), and a plan view of a chassis thereof is shown in FIG. Show. This motor fixes the printed circuit board (7) to the printed circuit board fixing member (14) and the stator core (5) to the stator core fixing member (15) by, for example, caulking. Then, a ball bearing (2a) is fixed to the housing (1), and a shaft (3) to which a rotor is fixed is supported by the ball bearing (2a) as in the above embodiment. According to this motor, the number of parts can be reduced and the motor can be formed by bending, so that the cost can be reduced.

FIG. 8 shows a motor in which the housing (1) is formed by bending, and a printed board (7) and a stator core positioning spacer (16) are sandwiched between the stator core (5) and the housing (1). The structure is fixed by. Since this motor has a relatively wide space between the printed circuit board (7) and the chassis, the printed circuit board (7) can be configured with circuits on both sides, and the printed circuit board (7) has a circuit. The structure is particularly effective for saving area.

Further, as a structure when the printed board (7) is large, as shown in FIG. 9, the housing (1) is used.
Can be reinforced by extending the printed circuit board (7) to a position away from the shaft (3) and fixing at the end portions of the printed circuit board (7) to reinforce the flexible printed circuit board (7). Then, in this case, it is fixed together with the heat sink (18) of the transistor which tends to be relatively large, or the housing (1) and the heat sink (18) are integrally formed and fixed to the printed circuit board (7). For example, it is possible to save parts and downsize the device.

[0038]

As described above, according to the present invention,
By fitting and mounting the holding member in the insertion portion of the rotor with the shaft inserted therein, the vertical deviation of the rotor yoke with respect to the shaft that occurs with the use of the motor can be reduced, and the holding member can be used as a bearing. The rotor can be smoothly rotated by bringing them into contact with each other to regulate the position of the bearing.

Further, when the rotor yoke is formed by bending, by restricting the length of the portion of the insertion portion that is bent in the direction of the bearing, the vertical deviation can be further reduced.

By these, it is possible to provide a motor with extremely little vibration, and further, it is possible to provide an OA device in which the disturbance of the printed image is extremely small when the motor is incorporated in the paper feeding device.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an assembly view of essential parts of a first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of the essential parts of the first and second embodiments.

FIG. 5 is a longitudinal sectional view showing a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a plan view showing a chassis of a motor according to a fourth embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing a fifth embodiment of the present invention.

FIG. 9 is a vertical sectional view showing a sixth embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view showing a conventional motor.

[Explanation of symbols]

2a ... Ball bearing, 3 ... Shaft,
10 ... insertion part, 11 ... holding member

Claims (4)

[Claims] 1. A motor in which a rotor is mounted on a shaft rotatably supported by a bearing, wherein the rotor is bent in the direction of the bearing and an insertion portion is formed along the shaft. Is equipped with a holding member that comes into contact with the bearing. 2. In a motor in which a rotor is mounted on a shaft rotatably supported by a bearing, a rotor yoke forming the rotor is bent in the direction of the bearing by a bending process and has a thickness of 2 to 3 of the rotor yoke. The insertion portion is formed along the shaft by double the length, and a holding member having a width at least equal to the length of the portion of the insertion portion extended along the shaft is attached to the insertion portion. The motor is characterized by. 3. A motor in which a rotor is mounted on a shaft rotatably supported by a bearing, and a rotor yoke constituting the rotor is bent in the direction of the bearing by a bending process, and has a thickness of 2 to 3 of the rotor yoke. A double-length insert is formed along the shaft, the insert having a width at least equal to the length of the insert extending along the shaft. A motor having a holding member that is in contact with the bearing. 4. A motor-incorporated device in which the motor according to claim 1 or 3 is incorporated in a paper feeding device.