JPS61266044A - Light deflecting motor - Google Patents

Abstract

PURPOSE:To facilitate the manufacture and to reduce the cost of a light deflecting motor for performing a pneumatic bearing by shortening the axial length of a stationary shaft and a rotor housing. CONSTITUTION:A hollow stationary shaft 2 formed with an air groove is stood on the outer periphery of a motor base 1, and a stator coil 6 is arranged on the inner periphery. A rotor housing 7 is engaged with the outer periphery of the shaft 2, a rotor magnet 8 is engaged with the housing to oppose to the coil 6, and a light deflecting mirror 10 is engaged with the outer periphery of the housing 7. Thus, since the mirror, the magnet and the coil are arranged in parallel with substantially perpendicularly to the axial direction, the axial length of the stationary shaft and the rotor housing can be shortened. As a result since the length of the region accurately formed can be reduced, the manufacture can be facilitated, and the cost can be reduced.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an optical deflection motor that performs air bearing by forming a dynamic pressure air flow between a rotor housing equipped with an optical deflection mirror and a fixed shaft. .

[Technical background of the invention and its problems]

Conventionally, in a motor for light deflection, a fixed shaft is installed upright on the motor base, an air groove for forming a dynamic pressure air flow is formed on the outer circumferential surface of the fixed shaft, and a rotor magnet and a radar light deflecting motor are further formed on the outer circumferential surface. A cylindrical rotating shaft having a light deflection mirror arranged in the axial direction is rotatably fitted to the outer circumferential surface of the fixed shaft, so that when the rotating shaft is rotated, there is no interference between the fixed shaft and the rotating shaft. A structure is provided in which a dynamic pressure air flow is formed to perform a so-called air bearing.

By the way, when forming a dynamic pressure air flow, high machining accuracy is normally required for the outer circumferential surface of the fixed shaft and the inner circumferential surface of the rotating shaft, but in the above conventional method, the rotor magnet and the optical deflection mirror When the rotary shaft is rounded and arranged in the axial direction of the rotating shaft, as the rotating shaft becomes longer in the axial direction, the fixed shaft must also become longer.In particular, the outer circumferential surface of the fixed shaft and the inner circumferential surface of the rotating shaft are Since extremely small gap dimensions and high roundness are required, as well as high parallelism in the axial direction, sufficient consideration must be given to perform such high precision machining on long areas. It is necessary to pay for this method, which generally requires a lot of time and effort to manufacture, resulting in high costs.

[Purpose of the invention]

Therefore, an object of the present invention is to provide an optical deflection motor that can shorten the fixed shaft in the axial direction, which has an air groove for forming a dynamic pressure air flow, thereby reducing the length area for high-precision machining. is to provide.

[Summary of the invention]

The present invention forms a fixed shaft having an air groove on its outer peripheral surface in a hollow shape, and arranges a stator coil in the hollow part of this fixed shaft,
A rotor housing is rotatably fitted to the outer peripheral surface of the fixed shaft, a rotor magnet is disposed in the rotor housing so as to face the stator coil via the peripheral wall of the fixed shaft, and an optical deflection mirror is provided. It is characterized in that it is arranged around the outer periphery of the rotor magnet, so that the optical deflection mirror, the rotor magnet, and the stator coil are arranged in parallel in a direction substantially perpendicular to the axial direction. .

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIG. Reference numeral 1 denotes a motor base, on which a fixed shaft 2 is erected, and the fixed shaft 2 is formed in a hollow shape, for example, a cylindrical shape. A ring zone-shaped 2fi groove 3 is formed on the outer peripheral surface of the fixed shaft 2. The coil 4 is a pin, and is screwed to the motor base 1 inside the fixed shaft 2.A stator yoke 5 is disposed on the coil I pin 4, and a stator coil 6 is attached to the coil I pin 4. The stator coil 6 is wound around the fixed shaft 2, so that the stator coil 6 is arranged on the inner peripheral surface of the fixed shaft 2. A seven-piece rotor housing is rotatably fitted to the outer peripheral surface of the fixed shaft 2, and a rotor magnet 8 is fitted to the rotor housing 7 so as to face the stator coil 6 through the peripheral wall of the fixed shaft 2. A stator yoke 9 is fitted around the outer periphery of the rotor magnet 8. Furthermore, a light deflection mirror 10 is fitted onto the outer circumferential surface of the rotor housing 7, so that the light deflection mirror 10 is disposed around the outer periphery of the rotor magnet 8. On the other hand, reference numeral 11 denotes a drive control circuit board, on which a well-known position detection element and a power transistor (both not shown) are arranged, and the drive control circuit board 1 includes: The coil is inserted through the pin 12 so that it is located above the fixed shaft 2? It is arranged on pin 4.

Further, in the motor base 1, the rotor housing 7
A thinly wound thrust load air #$13 is formed on the upper surface portion opposite to the lower end surface.

Now, in the above configuration, when the rotor housing 7 is rotated, a dynamic pressure air flow is formed between the outer peripheral surface of the fixed shaft 2 and the inner peripheral surface of the rotor housing 7 by the air #II3, and the rotor housing 7 is rotated. It is supported in a non-contact manner in the radial direction with respect to the fixed shaft 2, and the thrust load air groove 1311' of the motor base 1! : Okay, a dynamic pressure air flow is also formed between the upper surface of the motor base 1 and the lower end surface of the rotor housing 7, and the rotor housing 7 is supported in the thrust direction with respect to the motor base 1 in a non-contact state. . In this case, air flows from the lower end side of the rotor housing 7 as shown by the arrow between the lower end surface of the rotor housing 7 and the upper surface of the motor base 1, and then flows between the outer peripheral surface of the fixed shaft 2 and the rotor housing 7.
It passes between the inner peripheral surface and flows out from the upper end of the fixed shaft 2. In this case, the drive control circuit board 11 located near the air outflow side of the fixed shaft 2 is cooled by the airflow.

According to this embodiment, the rotor housing 7 is rotatably fitted to the fixed shaft 2 having the air groove 3 on the outer peripheral surface, and the rotor magnet 8 is disposed in the rotor housing 1, and the rotor magnet 8 is disposed on the rotor housing 1. The structure is such that 10 ft of optical deflection mirrors are arranged around the periphery and both are arranged side by side in a direction substantially orthogonal to the axial direction, which is different from the conventional structure in which the rotor magnet and the optical deflection mirror are arranged in the axial direction. On the contrary, the rotor housing 7 does not need to be made axially long, and therefore the fixed shaft 2 also does not need to be made axially long. Therefore, the axial length of the fixed shaft 2 and the rotor housing 7 can be shortened, and as a result, ,
The machining area for obtaining a dynamic pressure air flow for radial loads can be shortened in the axial direction, making manufacturing easier, contributing to lower costs, and reducing the overall size. By shortening the machining area, fixed axis 2
The parallelism in the axial direction between the outer circumferential surface of the rotor housing 7 and the inner circumferential surface of the rotor housing 7 can be achieved with high accuracy, and rotation accuracy can also be improved.

Moreover, according to this embodiment, the fixed shaft 2 is formed into a cylindrical shape,
A stator coil 6 is disposed on the inner peripheral surface of the fixed shaft 2, and the stator coil 6 and rotor magnet 8 are connected to the fixed shaft 2.
The stator coil 6
Since the stator coil 6 and the rotor magnet 8 are positioned in a direction substantially perpendicular to the axial direction together with the optical deflection mirror IQ and the rotor magnet 8, the fixed axis is The length in the axial direction of the shaft 2 can be further shortened, and the above-mentioned simplification of manufacture, reduction in cost, and improvement in rotational accuracy are further achieved. Further, according to this embodiment, since the load in the thrust direction is received by the air bearing action of the thrust load air groove 13, the rotation accuracy is further improved.

In the above embodiment, the thrust load air groove 13 was formed on the motor base 1 side, but the thrust load air groove 13
may be formed on the rotor housing 7 side; in short, it may be formed on one of the two vertically opposing surfaces of the motor base 1 and the rotor housing 7.

Next, FIG. 2 shows a second embodiment of the present invention, in which the load in the thrust direction is carried by magnets 24. attached to the upper surface of the motor base 1 and the lower end of the rotor housing 7, respectively. This is different from the first embodiment in that it is received by a repulsion force of 15. According to the second embodiment, in addition to achieving substantially the same effects as the first embodiment, the rotor housing 7
There is an advantage that the rotor housing 7 can be kept in a non-contact state with the motor base 1 even when the rotor housing 7 is stopped.

Further, FIG. 3 shows a third embodiment of the present invention, and the third embodiment differs from the first embodiment in the following points. That is, the rotor housing 16 has a cylindrical shape with a closed top surface, and a support #F7 is provided vertically at the center of the top wall. On the other hand, a thrust receiver seat 19 is formed in the center of the motor base 18, and the thrust receiver has a thrust receiver with a spiral oil groove (not shown) formed on the upper surface. A receiver 20 is fitted. And this thrust receiver 20
A steel ball 21 is buried in the center of the thrust receiver 20, but a portion thereof protrudes from the upper surface of the thrust receiver 20. The lower end of the support shaft 17 of the rotor housing 16 is supported by the steel ball 21 of the thrust bearing 20 in a point contact state. In this configuration, when the rotor housing 16 is rotated, a strong dynamic pressure film is formed on the upper surface of the thrust receiver 20 by lubricating oil such as grease. , which has the advantage of being able to handle large thrust loads.

In each of the above embodiments, the air groove 3 is formed in a Herring zone shape, but the shape is not limited to this, and in each of the above embodiments, the air groove 3 is formed in a Herring zone shape.
Although the fixed shaft 2 and the fixed shaft 2 are separately formed, they may be integrally molded.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications within the scope of the invention.

〔Effect of the invention〕

As is clear from the above description, the present invention has a configuration in which the optical deflection mirror, the rotor magnet, and the king of the stator coils are arranged in parallel in a direction substantially perpendicular to the axial direction. The length in the axial direction can be shortened, and the machining area for obtaining dynamic pressure airflow can therefore be shortened in the axial direction, making manufacturing easier and reducing costs. It is possible to achieve excellent effects such as downsizing of the entire K and improvement of rotational accuracy.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing the first embodiment of the present invention.
2 and 3 are views corresponding to FIG. 1 showing a second embodiment and a third embodiment of the present invention, respectively. In the figure, 1 is a motor base, 2 is a fixed shaft, 3 is an air groove, 6 is a stator coil, 7 is a rotor housing, 8 is a rotor magnet, 10 is a light deflection mirror, 1 is a drive control circuit board, 13 is an air groove for thrust load, 14 and 15 are magnets, 16 is a rotor housing, 18 is a motor base,
20 is a thrust receiver. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (2)

[Claims] (1) A hollow fixed shaft that stands upright on the motor base and has an air groove for forming a dynamic pressure air flow on its outer circumferential surface, a stator coil that is disposed in the hollow part of this fixed shaft, and a rotor housing having a rotor magnet rotatably fitted on the outer circumferential surface thereof and disposed so as to face the stator coil through the circumferential wall of the fixed shaft, and an optical deflection mirror disposed around the outer periphery of the rotor magnet; A light deflection motor comprising: (2) The optical deflection motor according to claim 1, wherein a drive control circuit board is disposed near the air outflow side of the fixed shaft.