JP2002199682A - Hollow motor and light wave range finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow motor superior in motor efficiency and a light wave range finder using it. SOLUTION: In the hollow motor having a rotor fixing a permanent magnet 19 magnetized in multi-poles in the circumferential direction on the rotor yoke 18 of a magnetic substance, a bearing 17 rotatably supporting the permanent magnet 19 and the rotor yoke 18, a hollow stator yoke 14 supported on a bearing housing 16 holding the bearing 17 and also serving as a motor case, and a stator 11 provided with a coil 12 fixed on the inner peripheral face of the stator yoke 14, the stator yoke 14 is formed by integral structure of silicon iron (Fe-Si). The permanent magnet 19 and the coil 12 are constituted to be wider than the bearing 17 in the axial direction, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow motor and an optical distance meter using the hollow motor.

[0002]

2. Description of the Related Art An optical distance meter emits modulated light, reflects the modulated light by a corner cube, receives the reflected modulated light, and compares the phase of the output side with the phase of the light receiving side. It is a measuring instrument for measuring distance. In this optical rangefinder,
Since the distance is measured by comparing the phase of the emission side with the phase of the light reception side, in order to improve the measurement accuracy, the emitted modulated light is required to be uniform without phase unevenness. However, the modulated light emitted from the light emitting element as the light source has more or less phase unevenness. Therefore, the phase plate is rotated by a motor in order to eliminate phase unevenness.

Usually, as means for rotating the phase plate of the optical distance meter, as shown in FIG. 4, a flange 4 having a phase plate 43 rotatably fixed to an end of a lens barrel 41 by a bearing 42 is used.
4 is supported, and the outer periphery of the flange 44 is brought into contact with a friction wheel 47 directly connected to a rotation shaft 46 of a motor 45 to rotate the phase plate 43 by friction transmission. A laser light source 48 made of a semiconductor diode is provided at a position facing the phase plate 43 in the lens barrel 41.

In addition to a method of rotating a phase plate by frictional conduction from the outside, a hollow motor used as a drive source for a camera or a robot may be used as a means for rotating the phase plate.

In this case, FIG. 5 shows a cross-sectional side view of the hollow motor. A flange 63 is provided at one end of a hollow cylindrical body 62 which is a rotating shaft supported by a pair of bearings 61a and 61b. The phase plate 6 having a disk shape is formed by the flange 63.
0 is fixed. A rotor yoke 64 is fixed between the bearings 61a and 61b on the outer periphery of the hollow cylindrical body 62 to form a rotor.

At an opposing position outside the rotor yoke 64,
A stator yoke 66 formed of a laminated steel plate between bearing housings 65, and coils 67a, 67b... 67n are wound and fixed to a surface of the stator yoke 66 facing the rotor. With these configurations, the coils 67a, 67b
.. 67n, a magnetic field is generated by the current flowing through the coils 67a, 67b... 67n, and a rotational force is generated due to the relationship of the magnetic flux with the rotor yoke 64 to rotate the phase plate 60.

[0007]

However, in the method of rotating the phase plate by friction transmission from the outside of the lens barrel with a friction wheel, it is difficult to reduce the size.

Further, when it is assumed that a hollow motor is used, it is difficult to (1) stack a silicon steel plate in response to a demand for a smaller hollow motor. (2) It is difficult to wind the stator coil on the stator. (3) If a magnetic circuit is formed by using a soft magnetic material without using a silicon steel sheet laminated on the structure of the motor, iron loss increases and motor efficiency deteriorates.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a hollow motor having good motor efficiency and a lightwave distance meter using the same.

[0010]

According to the first aspect of the present invention, there is provided a rotor in which a permanent magnet, which is magnetized to have multiple poles in the circumferential direction, is fixed to a rotor yoke made of a magnetic material, the permanent magnet and the rotor yoke. Motor having a hollow stator yoke supported by a bearing housing holding the bearing and also serving as a motor case, and a stator having a coil fixed to an inner peripheral surface of the stator yoke. Wherein the stator yoke is made of silicon iron (Fe-Si).

According to the second aspect of the present invention,
A hollow motor, wherein a pedestal for fixing the motor is formed integrally with the stator yoke.

According to the third aspect of the present invention,
The stator yoke is a hollow motor formed by sinter molding.

According to the fourth aspect of the present invention,
A hollow motor, wherein a through hole communicating with a center of the rotor yoke and a center of the bearing housing is formed.

[0014] According to the means of claim 5,
A permanent magnet is fixed to an outer peripheral portion of the rotor yoke, and the coil is arranged inside the stator yoke with an air gap around the outer periphery of the permanent magnet, and the permanent magnet and the coil are each axially displaced from the bearing. A hollow motor having a wide width.

According to the means of the invention of claim 6,
A hollow motor, wherein a recess for mounting an optical member is provided at one end of the rotor yoke.

Further, according to the means of the invention of claim 7,
A lightwave distance meter, wherein a hollow motor having a through hole of the rotor yoke as an optical path from a light source is used.

Further, according to the means of the present invention,
An optical distance meter using the above hollow motor, wherein a hollow for positioning an optical member is provided at one end of the rotor yoke.

[0018]

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

FIG. 1 is a sectional view of a hollow motor according to the present invention. This hollow motor is an inner rotor type, and a stator 11 has a cylindrical flexible printed wiring board 13 integrally provided with a plurality of coils 12a, 12b... 12n fixed to the inner peripheral surface of a cylindrical stator yoke 14. It is formed.

A wiring pattern (not shown) is formed on the flexible printed wiring board 13, and coils 12a, 12b... 12n are connected to the wiring pattern.

A motor fixing pedestal 15 is formed at one end of the stator yoke 14, and a bearing housing 16 is fixed thereto. A bearing 17 is supported by the bearing housing 16.

On the other hand, the rotor 21 has a rotor 17 in which a rotor yoke 18 is rotatably supported by bearings 17.
Is mounted with a permanent magnet 19 formed of a magnetic material magnetized in a multi-polar manner in the radial direction, and the rotation trajectory of the permanent magnet 19 faces the coils 12a, 12b... Are arranged. The permanent magnet 19 and the coils 12a, 12b...
It is formed wider. The rotor yoke 18
Has an optical component 10 fixed to one end.

When the motor is completed, the lead-out portion 13a of the flexible printed wiring board 13 extends outside the stator 11, and an AC voltage is applied to the electrode 20 of the lead-out portion to thereby rotate the rotor. 21 rotates.

The stator yoke 14 is made of silicon iron (Fe-3) having a small energy loss (iron loss) as shown in FIG.
Si (3% silicon iron) or Fe-3.5Si (3.5
% Silicon iron)).

That is, as shown in FIG.
When compared between 2,000 rpm and 2500 rpm, the value of the energy loss of pure iron, S25C, and SUS416 is 0.3 W at a rotation speed of 1000 rpm, but is 2500 W.
In pm, pure iron is about 1.5 W, and S25C is about 1.3 W. In addition, SUS4
16 is about 0.9 W. In contrast, silicon iron (F
e-3Si or Fe-3.5Si) has a rotation speed of 1
When compared between 000 rpm and 2500 rpm, the rotation speed is 0.1 W at 1000 rpm, but 2500 rpm.
At m, it increases to about 0.5 W. Therefore, it was confirmed that when the energy loss level was silicon iron (Fe-3Si or Fe-3.5Si), it was significantly lower than that of other materials.

Further, since silicon iron can be cut or sintered in terms of workability, the stator yoke 14 and the motor fixing pedestal 15 can be integrally formed. Also, after sintering, the inner peripheral surface of the stator yoke 14, which requires dimensional accuracy, and the holding surface of an optical member such as a phase plate can be finished by cutting. If it is manufactured by molding with an integral structure, it is possible to reduce the number of parts and eliminate the work of fixing them in the case of divided parts. Energy efficiency can be reduced.

Further, by arranging an optical member such as a lens in the hollow portion of the hollow motor, the driving mechanism of the optical member can be simplified, and thereby the size can be reduced.

The material of the stator yoke 14 is made of silicon iron such as Fe-3Si (3% silicon iron) or Fe-3.5Si.
(3.5% silicon iron) is used, but the present invention is not limited to this, and it is possible to configure and use the Si content by changing the Si content depending on motor characteristics and workability.

FIG. 3 is a side cross-sectional view when used in a rotating device of a phase plate of an optical distance meter. The same functional portions as those in FIG. 1 are denoted by the same reference numerals, and their description is omitted.

With the rotation axis of the rotor yoke 18 as the center,
Through holes 21 a and 22 a communicating with the rotor yoke 18 and the bearing housing 16 are provided. These through holes 21a,
22a allows the center of the motor to pass through the through hole 21 in the direction of the rotation axis.
Spaces a and 22a are formed. Bearing housing 1
On a parallel optical axis eccentric from the rotation center axis inside 6, a laser light source 2 by a semiconductor laser having this parallel axis as an optical axis.
3, a phase plate 24 fixed to the rotor yoke 18 is disposed in front of the optical axis so as to face the semiconductor laser. Therefore, the phase plate 24 also rotates with the rotation of the rotor yoke 18. The phase plate 24
Are positioned by fitting into the recesses 18b provided in the rotor yoke 18, so that they can be assembled with high accuracy in a short time.

Next, the optical distance meter will be described. In the lightwave distance meter, the light source unit emits light modulated at a predetermined modulation frequency, and the external distance measuring optical path guides the light from the light source unit to the light receiving unit via the object to be measured, and the internal distance measurement is performed. The optical path guides the light from the light source unit to the light receiving unit without passing through the object to be measured, and the arithmetic processing unit calculates the distance value obtained by the external distance measuring optical path and the distance value obtained by the internal distance measuring optical path. The distance to the object to be measured is calculated from the difference between. In the mixing apparatus, the driving means drives the phase plate, and the phase plate is configured such that the rotation center is located at a position decentered from the center of the diffraction grating. As the driving means of the phase plate, the above-described hollow motor of the present invention is used.

With these configurations, the lightwave range finder includes a semiconductor laser in the light source unit that emits light, an external distance measuring optical path that guides the light from the light source unit to the light receiving unit via the measurement object, and an internal distance measuring optical path. Guides the light from the light source unit to the light receiving unit without passing through the object to be measured, and the arithmetic processing unit calculates a difference between the distance value obtained by the external ranging optical path and the distance value obtained by the internal ranging optical path. From the difference, the distance to the measurement object is calculated.

The mixing device operates to correct uneven light emission of the semiconductor laser by, for example, rotating a phase plate by a hollow motor. In this case, since the hollow motor is used, the device can be formed small.

The hollow motor of the present invention can be used for rotating optical components in various optical devices such as a camera in addition to the optical distance meter.

[0035]

According to the present invention, it is possible to form a small-sized hollow motor with little energy loss.

Further, an optical distance meter using the hollow motor of the present invention can be small and highly accurate.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram of a hollow motor of the present invention.

FIG. 2 is a graph showing energy loss for each rotation speed of a magnetic material.

FIG. 3 is a side cross-sectional view when used in the rotation device of the phase plate of the optical distance meter according to the present invention.

FIG. 4 is a side cross-sectional view when used in a rotation device of a phase plate of a conventional lightwave distance meter.

FIG. 5 is a side cross-sectional view assuming that a hollow motor is used as a rotation device of a phase plate of the optical distance meter.

[Explanation of symbols]

11: stator, 12a, 12b to 12n: coil, 1
4 ... stator yoke, 15 ... motor fixing base, 18 ... rotor yoke, 23 ... laser light source, 24 ... phase plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) // G01C 3/06 G01C 3/06 Z (72) Inventor Tetsuya Ito Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa 33 Co., Ltd. Toshiba Production Technology Center (72) Inventor Masahiro Oishi 75-1, Hasunumacho, Itabashi-ku, Tokyo Inside Topcon Corporation (72) Inventor Masaaki Yabe 75-1, Hasunumacho, Itabashi-ku, Tokyo Stock (72) Inventor Kobe Etsuji 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Inside Topcon Co., Ltd. (72) Michio Waki 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Inside Topcon Co., Ltd. F term (reference) 2F112 AD01 BA10 CA06 DA40 5H002 AA09 AB07 AC04 AE08 5H604 AA08 BB01 BB14 BB17 CC01 CC04 CC12 DB17 DB18 PB04 PD02 PD06 QA03 QB04 QB16 5H621 AA03 BB07 GA02 GA16 HH01 JK05 5H622 CA01 CA05 CA10 PP11 PP19

Claims (8)

[Claims] A rotor in which a permanent magnet magnetized in a multi-pole circumferential direction is fixed to a rotor yoke made of magnetic material; a bearing rotatably supporting the permanent magnet and the rotor yoke;
In a hollow motor having a hollow stator yoke supported by a bearing housing holding the bearing and also serving as a motor case and a stator having a coil fixed to an inner peripheral surface of the stator yoke, the stator yoke is made of silicon iron ( A hollow motor made of Fe-Si). 2. The hollow motor according to claim 1, wherein a pedestal for fixing the motor is formed integrally with the stator yoke. 3. The stator yoke according to claim 1, wherein the stator yoke is formed by sinter molding.
2. The hollow motor according to claim 1. 4. The apparatus according to claim 1, wherein a through hole communicating with a center portion of said rotor yoke and a center portion of said bearing housing is formed.
The hollow motor according to the paragraph. 5. A permanent magnet is fixed to an outer peripheral portion of said rotor yoke, and said coil is disposed inside said stator yoke with an air gap around an outer periphery of said permanent magnet. The hollow motor according to claim 1, wherein the width of the hollow motor is larger in the direction than the bearing. 6. The hollow motor according to claim 1, wherein a recess for mounting an optical member is provided at one end of the rotor yoke. 7. The rotor according to claim 1, wherein the through hole of the rotor yoke is an optical path from a light source.
A lightwave distance meter using the hollow motor described in the paragraph. 8. A lightwave distance meter using the hollow motor according to claim 1, wherein a recess for positioning an optical member is provided at one end of the rotor yoke. .