JPS5815447A - Motor - Google Patents

Abstract

PURPOSE:To improve the centering accuracy of a motor and to easily increase the rotary accuracy of a driven body by a method wherein a rotary shaft mounting a rotor and the driven body is hollowly formed and a fixed supporting shaft is inserted in the inside of the rotary shaft for supporting the shaft through a bearing. CONSTITUTION:A motor rotary shaft 7 mounting the motor rotor 12 of a rotary driving section 1 and a rotary driven body 2 is hollowly formed on at least the opposite end sections. A bearing 51 is provided in the hollow section to support the shaft with free rotation against the fixed supporting shaft 5 penetrated in the hollow section. This easily increased the centering accuracy of the motor rotary shaft 7 and easily performs assembly and adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor, and particularly to a motor that can provide highly accurate and stable rotation suitable for a rotating mirror light deflection device.

Various functions are generally required of a motor, and in particular, a motor applied to a rotating mirror light deflecting device is required to operate stably with high precision at least in a steady rotating operation state. This is because, as is well known in the art of rotating mirror light deflecting devices, when performing operations such as reading or writing information, the rotating mirror is rotated to continuously change the angle of incidence of the incident light, and the reflected light is used to obtain linear scanning. ing. Therefore, if there is eccentricity in the rotation of the rotating mirror or uneven rotation, proper linear scanning will not be obtained. In order to improve rotational accuracy in this respect, in addition to rotating the motor rotation shaft with high precision, it is necessary to precisely rotate the motor rotation shaft with a rotating mirror that is a rotationally driven object, or a rotation transmission means that applies rotational driving force to the rotating mirror. For this type of motor, it is not enough to simply configure the motor with high precision; it is desirable to assemble the motor with consideration to the mounting of the rotating driven body.

In consideration of such circumstances, a so-called outer rotor type motor has been proposed. When using an outer rotor type motor in a rotating mirror light deflection device, the shaft on which the motor stator etc. is attached (the central axis of rotation of the rotor) is fixed to a machine base, etc., and the rotating mirror is attached to the outer rotor. Install and use. Therefore, compared to using an inner rotor type motor, this has the advantage that the accuracy of the motor rotation axis can be easily achieved because the rotation center axis itself is fixed.

However, a drawback of using the above-mentioned outer rotor type motor in a rotating mirror light deflection device is that the outer diameter of the rotating mirror cannot be made much smaller because the rotating mirror is attached to the outer rotor. Furthermore, it is difficult to install the rotating mirror only after the assembly of the outer rotor has been completed, and the accuracy of the rotating mirror cannot be achieved by attaching the outer rotor via a bearing to a fixed rotating center shaft ( 3) After installation, in other words, the motor must be completely assembled, otherwise it will be meaningless. Also, because of the outer rotor structure, there were also difficulties in the heat dissipation of the motor.

In view of the above-mentioned circumstances, the present invention provides a motor having a structure that allows highly accurate and stable rotational operation and does not make the assembly and manufacturing process complicated or difficult. The basic structure of the motor of the present invention having such characteristics is as follows:
At least both ends of the motor shaft to which the rotary drive rotor and the rotary driven body are fixed are hollow, and the motor shaft is rotatably supported via a bearing by a fixed support shaft inserted into the hollow part. It is something. Furthermore, based on the above basic configuration, it is also possible to add an additional configuration to eliminate the adverse effects caused by oil mist generated from the motor bearing.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an external perspective view illustrating one embodiment of the present invention.

In FIG. 1, reference numeral 1 indicates a rotation drive unit, 2 a rotation mirror, 3 a rotation detection unit, 5 a rotation support shaft, and 6 a fixed unit such as a frame.

As will be described later, a stator or a rotor for rotationally driving a motor is provided in the rotary drive section 1 as a known means per se. The rotating mirror 2 is attached to a motor rotation shaft different from the fixed support shaft 5 so that it can be rotated by the rotation of the motor, and rotates about the rotation center determined by the fixed support shaft 5.

If the rotating mirror 2 rotates, for example, clockwise in the figure, the reflected light of the incident light P will be scanned in the direction of the arrow hole in the figure, and the number of scans per rotation of the rotating mirror 2 will depend on the number of reflective surfaces of the rotating mirror 20. It is determined. What is important here is that the settings must be strictly set so that each scan accompanying the rotational movement of the rotating mirror 2 is at the same position, that is, on the same scanning line. From this point of view, it is required that the rotating shaft of the motor that directly rotates the rotating mirror 2 has no pretension, and that the rotating mirror is properly attached and fixed to the rotating shaft. The internal structure of the motor of the present invention, which easily satisfies these requirements, is as shown in the cross-sectional view of the main part shown in FIG. 2, for example.

FIG. 2 shows a cross section of the main parts of the motor shown in FIG. 1, and the same parts as in FIG. 1 are given the same reference numerals. The fixed support shaft 5 is fixed at both ends to an applicable equipment frame or the like. A motor rotating shaft 7 is supported on the fixed support shaft 5 via a bearing such as a bearing 51 so as to be rotatable about the axial center of the fixed support shaft 5 . The motor rotating shaft 7 includes a rotating mirror 2, a motor rotor 12, and a disc-shaped encoder 31.
are each fixed by appropriate means. Further, a fixed frame 33 including a support case 11 having a motor stator 14 and a sensor 32 for reading information of the encoder 31 is fixed to the fixed support shaft 5 . Reference numeral 16 denotes a Hall sensor that performs the action of a brush in a normal brush motor, allowing non-contact rotation control.

In the motor configured as described above, power is supplied to the motor stator 14, and the motor rotor 12 is electromagnetically driven by a drive control signal from the Hall sensor 16 to rotate around the fixed support shaft 5. At the same time, the encoder 31
The rotating mirror 2 rotates integrally, and the rotating mirror 2 is used for optical scanning as described above, while the encoder 31 detects a rotation signal together with the sensor 32 to control the rotation of the motor, and sends this to the Hall sensor 16. feedback, so-called I) L T
, control (phaselock 1loop control), and stabilizes motor rotation.

It is convenient to assemble a motor having the above structure and operation as follows. That is, first, the fixed support shaft 5 is prepared, and the motor rotating shaft 7 is attached to it via the bearing 51. After confirming that the rotary shaft 7 is properly attached to the fixed support shaft 5, the rotor 12, rotary mirror 2, and encoder 31 are sequentially attached.

(7) After that, the support case 11 with the stator 14 already attached and the fixed frame 33 with the photosensor 32 attached
is fixed to the fixed support shaft 5 by an appropriate method. Since it is possible to assemble it in this way, it is possible to achieve the mounting accuracy of the rotating mirror with the rotating mirror 2 attached to the motor rotating shaft 7, and also to achieve the rotational accuracy around the fixed support shaft 5. is also possible. In some cases, in order to obtain strict accuracy by taking these into consideration, it is possible to obtain high precision by corrective cutting and corrective polishing of each reflective surface of the rotating mirror after assembling it with a fixed shaft, motor rotating shaft, and rotating mirror. . After obtaining the accuracy of the rotating mirror in this manner, all remaining parts are attached, so that assembly is easy and at the same time accuracy can be maintained reliably during assembly. Furthermore, since the motor rotor and stator can be brought into contact with the outside air, heat dissipation is also good.

Further, as shown in FIG. 2, the fixed support shaft 5 is provided with a gas passage 55(8) extending in the axial direction within the shaft. This gas flow path 55 contributes to preventing the oil mist generated in the bearing 51 from spreading +tz. For this purpose, the gas flow path 55 has two openings 5 extending outside the fixed support shaft.
5a, 551) are formed on both sides of the bearing 51. Then, as shown in FIG. 3, a suction pipe 8 is connected to the outer opening 55b of the motor rotating shaft 7, thereby suctioning. Note that the symbols used in FIG. 3 are the same as those used in FIG. 2 for the same members. According to the suction of the suction pipe 8, an air flow shown by the arrow in FIG. 3 is generated. That is, air flows into the motor rotating shaft 7 from the inflow groove between the bearing retainer 9 and the bearing b1, and then the air flows into the opening 5 of the fixed support shaft 5.
5a1 and passes through to the opening 55b. Therefore, even if the motor rotates at high speed and oil mist is generated from the bearing, it will not be spread around. The influence of this oil mist cannot be ignored, especially in rotating mirror light deflecting devices.
This is also a problem that must be solved in the seed device as shown in detail in No. 1855-142166.

As described above, in the motor of the present invention, the motor rotating shaft to which a rotary driven object such as a rotating mirror is fixed is supported by a fixed support shaft, and this fixed support shaft is connected to the rotation center axis of the motor rotating shaft. Therefore, if the motor is fixed to the applicable equipment or mount via this fixed support shaft, the rotation center axis of the motor rotation shaft itself will be used as the mounting reference part, so the rotation of the rotating driven object will be Rotation accuracy can be easily increased. Moreover, when assembling the motor, it is possible to first fix the required parts to the motor rotation shaft and then sequentially incorporate other parts, so accuracy can be achieved when attaching the rotating driven body to the Tanabata rotation shaft. This allows the most critical accuracy check to be carried out without waiting for the completion of the motor assembly process.

Further, in the motor of the present invention, a fixed support shaft can be used for removing oil mist, and no new member is particularly required for this purpose. Although only one end side is shown in FIG. 4, a fixed support shaft 100 may be provided at both ends to support the motor rotating shaft 110, thereby making it a two-shaft type. In this case, if the hollow support shaft is used as it is, oil mist suction becomes easy.

Although the motor of the present invention has been explained based on the illustrated embodiments, the present invention is not necessarily limited to these. For example, the shape of the rotating driven body, the position of attachment to the rotating shaft, It goes without saying that various modifications can be made to the embodiments of the present invention without departing from the gist of the present invention, such as changes in the magnetic configuration, changes in the rotation control system, and even the shape and number of oil mist suction openings.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of the present invention. FIG. 2 is a sectional view of a main part of the embodiment shown in FIG. 1. FIG. 3 is an enlarged view of part (11) of the main part sectional view shown in FIG. 2. FIG. 114 is a partial sectional view showing a modification of the portion shown in FIG. 3. 1...Rotation drive unit 2...Rotation driven body (rotating mirror) 3...Rotation detection unit 5...
Fixed spindle 51...! 111 reception 7...
... Motor rotation shaft 55 ... Gas flow path 55
a, 55h...Applicant Fuji Photo Equipment Co., Ltd. (12) No change in the contents of the drawings) Pruning, 3 drawings and 4 items Procedure amendment (method) 1981/ )! - Tsuki Guhi, Commissioner of the Patent Office Shima 1) Haruki Tono 1 Display of the case 1982 Patent Application No. 111675 2 Name of the invention Motor 3 - Person making the amendment Relationship with the case Patent applicant November 1988 5th day engraving of specification and drawings (no change in content) 237-1

Claims (2)

[Claims] (1) At least both ends of the motor shaft, to which the rotary drive rotor and the rotary driven body are fixed, are hollow, and the motor shaft can be freely rotated via a fixed support shaft inserted into the hollow part through a bearing. The motor that supports it. (2) At least both ends of the motor shaft to which the rotary drive rotor and the rotary driven body are fixed are hollow, and the motor shaft can be freely rotated via a fixed support shaft inserted into the hollow part through a bearing. At the same time, a gas flow path extending in the axial direction is formed within the shaft of the fixed support shaft, and openings communicating with this gas flow path and facing outside the fixed support shaft are provided on each side of the fixed support shaft. A new motor.