JP2004215383A - Motor with rotation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce heat transfer from a motor to a rotation detector by an air layer formed between a motor shaft and a hollow shaft. <P>SOLUTION: This motor with the rotation detector includes the hollow shaft (12) of the rotation detector (10) connected to the motor shaft (5), a first recessed surface (51) formed on an outer periphery (5a) of the motor shaft (5), and a first threaded groove (50). Further, the motor is structured so as to have a motor shaft side air layer (100) formed out of the first recessed surface (51) or the first threaded groove (50). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor with a rotation detector, and in particular, reduces the heat transfer from the motor unit to the rotation detector by forming an air layer on the motor shaft side or an air layer on the hollow shaft side of the detector. The present invention relates to a novel improvement for achieving a higher output of a motor section.
[0002]
[Prior art]
As an example of this type of motor with a rotation detector that has been conventionally used, there is a configuration shown in FIG. 7 (for example, see Patent Document 1 as a similar configuration).
That is, what is indicated by reference numeral 1 in FIG. 7 is a motor unit such as a brushless DC motor, and a bearing 3 provided on a lid 2 of the motor unit 1 is provided with a rotor (not shown) of the motor unit 1. A supporting motor shaft 5 is rotatably provided.
[0003]
The motor shaft 3 rotatably penetrates the cover 4 and protrudes. The motor shaft 3 is provided with a rotation detector 10 including an encoder or the like.
The rotation detector 10 includes a base 11 connected and fixed to the lid 4 by a connecting means 20 such as a spring, a hollow shaft 12 rotatably provided on the base 11 via a bearing 13, The rotation position is mainly detected by the light emitting body 30 and the light receiving body 31 which are mainly constituted by the code plate 14 provided on the hollow shaft 12 and which are optical detecting means for reading the code of the code plate 14.
[0004]
The hollow shaft 12 is fitted to the motor shaft 5, and the rotation position of the motor shaft 5 of the motor unit 1 is detected by the rotation detector 10 and detected by the optical detection unit to output a signal line 40. Derived to the outside via
[0005]
[Patent Document 1]
JP-A-1-82661
[Problems to be solved by the invention]
Since the conventional motor with a rotation detector is configured as described above, the following problems exist.
That is, since the outer peripheral surface and the inner peripheral surface of the fitted motor shaft and hollow shaft are straight, the surfaces are joined to each other over the entire surface, and the heat from the motor unit is transferred to the rotation detector side. Since the rotation detector is an encoder, the adiabatic temperature is limited, and it is difficult to increase the power of the motor unit to an allowable value.
[0007]
The present invention has been made in order to solve the above problems, and in particular, by forming an air layer on the motor shaft side or an air layer on the hollow shaft side of the detector, the rotation detector from the motor unit. It is an object of the present invention to provide a rotation detector-equipped motor in which heat transfer to the motor side is reduced and high output of the motor unit is achieved.
[0008]
[Means for Solving the Problems]
A motor with a rotation detector according to the present invention is a motor with a rotation detector connected to a motor shaft rotatably projecting from a lid of a motor unit, wherein the motor is connected to the motor shaft and rotates with the rotation detector. A hollow shaft provided freely, and a first concave surface or a first screw groove formed on an outer periphery of the motor shaft, and the first concave surface or the first screw groove forms a space between the motor shaft and the hollow shaft. A motor shaft-side air layer is formed on the motor shaft, and a motor with a rotation detector connected to a motor shaft rotatably protruding from a lid of the motor unit. A hollow shaft rotatably provided on the rotation detector, and a second concave surface or a second thread groove formed on the inner periphery of the hollow shaft. Detector shaft side space between motor shaft and hollow shaft A configuration layer is formed, also, the rotation detector has a configuration composed of the encoder.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a motor with a rotation detector according to the present invention will be described with reference to the drawings. The same or equivalent parts as those in the conventional example will be described using the same reference numerals.
In FIG. 1, reference numeral 1 denotes a motor unit such as a brushless DC motor, and a shaft 3 provided on a lid 2 of the motor unit 1 supports a rotor (not shown) of the motor unit 1. The motor shaft 5 is provided rotatably.
[0010]
The motor shaft 3 rotatably penetrates the cover 4 and protrudes. The motor shaft 3 is provided with a rotation detector 10 including an encoder or the like.
The rotation detector 10 includes a base 11 connected and fixed to the lid 4 by a connecting means 20 such as a spring, a hollow shaft 12 rotatably provided on the base 11 via a bearing 13, The rotation position is mainly detected by the light emitting body 30 and the light receiving body 31 which are mainly constituted by the code plate 14 provided on the hollow shaft 12 and which are optical detecting means for reading the code of the code plate 14.
[0011]
The hollow shaft 12 is fitted to the motor shaft 5, and the rotation position of the motor shaft 5 of the motor unit 1 is detected by the rotation detector 10 and detected by the optical detection unit to output a signal line 40. Derived to the outside via
[0012]
As shown in FIG. 2, the first concave surface 51 formed on the motor shaft 5 is exposed to a small diameter over the entire periphery thereof, and a motor shaft side air space is formed between the first concave surface 51 and the inner surface 12 a of the hollow shaft 12. 100 are formed. Note that the first concave surface 51 may not be continuous in a ring shape.
[0013]
Accordingly, when the motor unit 1 is driven, heat generated on the motor unit 1 side is transmitted to the rotation detector 10 via the motor shaft 5 and the hollow shaft 12, but the motor shaft side air is The heat transfer is hindered by the layer 100, so that the conventional temperature rise on the rotation detector 10 side can be prevented.
[0014]
In the configuration shown in FIG. 3, a first screw groove 50 is formed instead of the first concave surface 51 of the motor shaft 5, and the first screw groove 50 is formed between the first screw groove 50 and the inner surface 12 a of the hollow shaft 12. The aforementioned heat transfer prevention is performed by the motor shaft side air layer 100.
[0015]
FIGS. 4 to 6 show another embodiment of the embodiment shown in FIGS. 1 to 3 described above.
1 to 3 are denoted by the same reference numerals, description thereof will be omitted, and only different portions will be described.
That is, a second annular concave surface 61 having a shape exposed to the inner periphery 12 a of the hollow shaft 12 with respect to the outer periphery 5 a of the motor shaft 5 is formed, and the detector shaft side air layer 101 is formed by the second concave surface 61. ing.
It is to be noted that the second concave surface 61 may be formed even when it is not continuous in a ring shape.
[0016]
The detector shaft side air layer 101 shown in FIG. 5 utilizes a second screw groove 60 formed on the inner periphery 12a of the hollow shaft 12 as shown in FIG. The same operation as described above can be obtained when the detector shaft side air layer 101 formed between the outer circumference 5a and the outer circumference 5a is used.
[0017]
【The invention's effect】
Since the motor with the rotation detector according to the present invention is configured as described above, the following effects can be obtained.
That is, the motor shaft-side air layer or the detector shaft-side air layer formed by a concave surface or a thread groove between the motor shaft and the hollow shaft can prevent the transfer of heat from the motor unit to the rotation detector, High output of the motor unit can be achieved.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part showing a motor with a rotation detector according to the present invention.
FIG. 2 is an enlarged sectional view of a main part of FIG.
FIG. 3 is a sectional view showing another embodiment of FIG. 2;
FIG. 4 is a sectional view showing another embodiment of FIG. 1;
FIG. 5 is an enlarged sectional view of a main part of FIG.
FIG. 6 is a sectional view showing another embodiment of FIG. 5;
FIG. 7 is a sectional view of a conventional configuration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motor part 4 Cover 5 Motor shaft 5a Outer circumference 10 Rotation detector 12 Hollow shaft 12a Inner circumference 50 First screw groove 51 First concave surface 60 Second screw groove 61 Second concave surface 100 Motor shaft side air layer 101 Detector shaft side air layer

Claims (3)

A motor with a rotation detector, wherein a rotation detector (10) is connected to a motor shaft (5) rotatably projecting from a lid (4) of the motor part (1),
A hollow shaft (12) connected to the motor shaft (5) and rotatably provided on the rotation detector (10); and a first concave surface (51) formed on the outer periphery (5a) of the motor shaft (5). ) Or a first screw groove (50), and the motor shaft side air is provided between the motor shaft (5) and the hollow shaft (12) by the first concave surface (51) or the first screw groove (50). A motor with a rotation detector, wherein a layer (100) is formed. A motor with a rotation detector, wherein a rotation detector (10) is connected to a motor shaft (5) rotatably projecting from a lid (4) of the motor part (1),
A hollow shaft (12) connected to the motor shaft (5) and rotatably provided on the rotation detector (10); and a second concave surface (12a) formed on an inner periphery (12a) of the hollow shaft (12). 61) or a second screw groove (60), and the detector shaft is provided between the motor shaft (5) and the hollow shaft (12) by the second concave surface (61) or the second screw groove (60). A motor with a rotation detector, wherein a side air layer (101) is formed. 3. A motor with a rotation detector according to claim 1, wherein the rotation detector comprises an encoder.

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