U.S. patent application number 11/474958 was filed with the patent office on 2006-11-02 for motor.
This patent application is currently assigned to MITSUBISHI DENKI KABUSHIKI KAISHA. Invention is credited to Youichi Fujita, Kenta Hatano, Tomokuni Kato, Sotsuo Miyoshi.
Application Number | 20060244323 11/474958 |
Document ID | / |
Family ID | 34055927 |
Filed Date | 2006-11-02 |
United States Patent
Application |
20060244323 |
Kind Code |
A1 |
Hatano; Kenta ; et
al. |
November 2, 2006 |
Motor
Abstract
A sliding hole is formed so that a screw portion can pass
therethrough. Also, a seal member is provided at a portion, through
which the screw portion placed in the sliding hole can pass and in
which a sliding portion does not slide.
Inventors: |
Hatano; Kenta; (Tokyo,
JP) ; Fujita; Youichi; (Tokyo, JP) ; Miyoshi;
Sotsuo; (Tokyo, JP) ; Kato; Tomokuni; (Tokyo,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
MITSUBISHI DENKI KABUSHIKI
KAISHA
|
Family ID: |
34055927 |
Appl. No.: |
11/474958 |
Filed: |
June 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10893317 |
Jul 19, 2004 |
|
|
|
11474958 |
Jun 27, 2006 |
|
|
|
Current U.S.
Class: |
310/80 |
Current CPC
Class: |
H02K 5/1732 20130101;
H02K 5/10 20130101; H02K 7/06 20130101; F16K 31/04 20130101; H02K
7/003 20130101; H02K 5/225 20130101 |
Class at
Publication: |
310/080 |
International
Class: |
H02K 7/06 20060101
H02K007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2003 |
JP |
P.2003-199218 |
Claims
1. A motor comprising: a stator provided with a coil to be supplied
with electric current; a resin rotor adapted to rotate in said
stator and provided with a magnet; an output shaft having a screw
portion to be screwed into a threaded hole provided in said rotor;
a regulating portion for axially moving said output shaft by
regulating rotation of said output shaft and for sliding and
holding said output shaft; a sliding portion, provided in said
output shaft and adapted to slide in a sliding hole provided in
said regulating portion; and a metallic stopper, provided in said
rotor and adapted to abut against said output shaft, for axially
regulating said output shaft.
2. The motor according to claim 1, wherein said stopper axially
abuts against said output shaft.
3. The motor according to claim 1, wherein said stopper is
insert-molded into and fixed to said rotor.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional of U.S. application Ser.
No. 10/893,317 filed Jul. 19, 2004; the above-noted application
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a current-driven
motor, and more particularly to a motor for performing a
rotational-to-linear motion conversion on rotation of a rotor
provided in a motor to cause an output shaft of the motor to
perform a linear motion.
[0004] 2. Description of the Related Art
[0005] A related motor is configured so that a portion, through a
screw portion of a sliding shaft is passed, is provided in a
sliding hole of a regulating portion, which regulates rotation of
an output shaft and that slides the output shaft, and opened to the
outside of the motor.
[0006] Also, a stopper provided in a part of a resin rotor is made
to abut against the output shaft so as to stop an axial movement of
the output shaft.
[0007] Also, a spring holder for supporting a spring, which pushes
the output shaft in the direction of a rotor, has a necessary
minimum size for supporting the spring in such a way as not to
hinder the movement of the output shaft.
[0008] Moreover, a coil wire is supported by caulking a part of
each of terminals and also fixed to the terminals by being welded
thereto.
[0009] [Patent Document 1]
[0010] JP-A-7-55012
[0011] [Patent Document 2]
[0012] JP-A-7-274472
[0013] [Patent Document 3]
[0014] JP-A-6-141502
[0015] Because the related motor is configured so that a portion,
through a screw portion of a sliding shaft is passed, is provided
in a sliding hole of a regulating portion, which regulates rotation
of an output shaft and that slides the output shaft, and opened to
the outside of the motor, foreign substances, moisture, gas and so
on enter the inside of the motor and bring about performance
deterioration thereof.
[0016] Also, because the stopper provided in a part of a resin
rotor is made to abut against the output shaft so as to stop an
axial movement of the output shaft, the rotor is broken by an
impact force exerted thereon. Such a broken part becomes a foreign
matter and brings about performance deterioration of the motor.
[0017] Also, because the spring holder for supporting a spring,
which pushes the output shaft in the direction of a rotor, has a
necessary minimum size for supporting the spring in such a way as
not to hinder the movement of the output shaft, foreign substances,
moisture, gas and so on enter the inside of the motor through
surrounding areas of the spring holder and bring about performance
deterioration thereof.
[0018] Moreover, although the coil wire is supported by caulking a
part of each of terminals and also fixed to the terminals by being
welded thereto, when the coil wire is hung on the terminals, hung
parts thereof are liable to be flawed. Thus, the coil wire becomes
easy to be broken. Also, when plural coil wires are caulked
together to the terminal, the areas of parts of the coil wires,
which are brought into contact with the terminal, become small.
Consequently, defects of welding are caused.
SUMMARY OF THE INVENTION
[0019] The invention is accomplished to solve the aforementioned
problems. Accordingly, an object of the invention is to obtain a
motor enabled to prevent foreign substances, moisture, gas and so
on from entering the inside of the motor even when a portion,
through a screw portion of a sliding shaft is passed, is provided
in a sliding hole of a regulating portion, which regulates rotation
of an output shaft and that slides the output shaft.
[0020] Another object of the invention is to provide a motor
enabled to obtain a rotor from being broken by an impact force
exerted thereon when an output shaft abuts against the rotor.
[0021] Another object of the invention is to obtain a motor enabled
to prevent foreign substances, moisture, gas and so on from going
thereinto through surrounding areas of a spring holder thereof.
[0022] Another object of the invention is to obtain a motor enabled
to prevent flaws from being caused in a part of a coil wire when
the part of the coil wire is hung on a terminal, and also enabled
to bring plural coil wires into sufficient contact with a terminal
when the plural coil wires are caulked together to the
terminal.
[0023] According to an aspect of the invention, there is provided a
motor that comprises a stator provided with a coil to be supplied
with electric current, a rotor adapted to rotate in the stator and
provided with a magnet, an output shaft having a screw portion to
be screwed into a threaded hole provided in the rotor, a regulating
portion for axially moving the output shaft by regulating rotation
of the output shaft and for sliding and holding the output shaft,
and a sliding portion, provided in the output shaft and adapted to
slide in a sliding hole provided in the regulating portion. The
sliding hole is formed in such a way as to permit a screw portion
to pass therethrough. A seal member is provided at a portion,
through which the screw portion placed in the sliding hole is
permitted to pass and in which the sliding portion does not
slide.
[0024] According to another aspect of the invention, there is
provided a motor that comprises a stator provided with a coil to be
supplied with electric current, a rotor adapted to rotate in the
stator and provided with a magnet, an output shaft having a screw
portion to be screwed into a threaded hole provided in the rotor, a
regulating portion for axially moving the output shaft by
regulating rotation of the output shaft and for sliding and holding
the output shaft, and a sliding portion, provided in the output
shaft and adapted to slide in a sliding hole provided in the
regulating portion. The sliding portion is larger in cross-section
than the screw portion.
[0025] According to another aspect of the invention, there is
provided a motor that comprises a stator provided with a coil to be
supplied with electric current, a rotor adapted to rotate in the
stator and provided with a magnet, an output shaft having a screw
portion to be screwed into a threaded hole provided in the rotor, a
regulating portion for axially moving the output shaft by
regulating rotation of the output shaft and for sliding and holding
the output shaft, a sliding portion, provided in the output shaft
and adapted to slide in a sliding hole provided in the regulating
portion, a pushing member for pushing the output shaft in a
direction of the rotor, a plate, fixed to the output shaft, for
supporting the pushing member, and an accommodating member in which
the plate and the output shaft are displaceably accommodated. An
extension portion extended from a support portion of the plate,
which supports the pushing member, toward a direction of an inner
surface of the accommodating member is provided in the plate.
[0026] According to another aspect of the invention, there is
provided a motor that comprises a stator provided with a coil to be
supplied with electric current, a resin rotor adapted to rotate in
the stator and provided with a magnet, an output shaft having a
screw portion to be screwed into a threaded hole provided in the
rotor, a regulating portion for axially moving the output shaft by
regulating rotation of the output shaft and for sliding and holding
the output shaft, a sliding portion, provided in the output shaft
and adapted to slide in a sliding hole provided in the regulating
portion, and a metallic stopper, provided in the rotor and adapted
to abut against the output shaft, for axially regulating the output
shaft.
[0027] According to another aspect of the invention, there is
provided a motor that comprises a stator provided with a coil to be
supplied with electric current, a rotor adapted to rotate in the
stator and provided with a magnet, an output shaft having a screw
portion to be screwed into a threaded hole provided in the rotor, a
regulating portion for axially moving the output shaft by
regulating rotation of the output shaft and for sliding and holding
the output shaft, and a sliding portion, provided in the output
shaft and adapted to slide in a sliding hole provided in the
regulating portion, a terminal provided in the stator. A coil wire
of a coil is fixed to the terminal. This motor also comprises a
concave hook portion provided in the terminal. The coil wire is
wound around the hook portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and other objects and advantages of this invention
will become more fully apparent from the following detailed
description taken with the accompanying drawings in which:
[0029] FIG. 1 is an axially sectional view illustrating an electric
motor that is a first embodiment of the invention;
[0030] FIG. 2 is an enlarged view illustrating a portion indicated
by a dot-dash line .alpha. in FIG. 1;
[0031] FIG. 3A is a perspective view illustrating a boss 2 and an
output shaft 3 of a comparative example so as to explain the first
embodiment. FIG. 3B is a top view illustrating the output shaft 3
shown in FIG. 3A;
[0032] FIG. 4 is a perspective view illustrating members used for
shaft seal;
[0033] FIG. 5 is an axially sectional view illustrating an electric
motor that is a second embodiment of the invention;
[0034] FIG. 6A is a perspective view illustrating a boss 2 and an
output shaft 3 of the third embodiment. FIG. 6B is a top view
illustrating the output shaft 3 shown in FIG. 6A;
[0035] FIG. 7 is a perspective view illustrating the shape of a
plate 9 provided with slip-off preventing parts;
[0036] FIG. 8 is an explanatory view illustrating a rotor, an
output shaft, and a plate shown in FIG. 1;
[0037] FIG. 9 is an explanatory view illustrating a rotor, an
output shaft, and a plate;
[0038] FIG. 10 is aside view illustrating a motor terminal portion
of a sixth embodiment of the invention;
[0039] FIG. 11 is a view illustrating a comparative example so as
to explain a coil wire fixing portion;
[0040] FIG. 12 is a top view illustrating the motor terminal
portion;
[0041] FIG. 13 is a perspective view illustrating the motor
terminal portion;
[0042] FIG. 14 is an explanatory view illustrating a shape of a
surface of a hook portion;
[0043] FIG. 15 is an explanatory view illustrating another shape of
the surface of the hook portion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0044] Hereinafter, a first embodiment of the invention is
described.
[0045] FIG. 1 is an axially sectional view illustrating a DC
(direct current) electric motor according to the first embodiment
of the invention.
[0046] In the motor shown in this figure, a rotor 1 uses a PPS
resin. A threaded hole portion 1a is provided in a central shaft
portion thereof. A rotation-stop sliding portion 2a (a regulating
portion) is formed into a shape having a flat face.
[0047] Reference numeral 3 designates an output shaft. Reference
numeral 3a denotes an output shaft sliding portion. Reference
numeral 3b designates a screw disposed at the side opposite to the
output end of the output shaft 3. This screw 3b meshes with and is
inserted into the threaded hole portion 1a provided in the rotor 1.
The output shaft sliding portion 3a provided in the output shaft 3
penetrates through the rotation-stop sliding portion 2a provided in
the boss 2 and is formed into a shape having a flat face engaging
with the rotation-stop sliding portion 2a.
[0048] When the rotor 1 is rotate-driven, torque thereof is
transmitted to the output shaft 3 through the threaded hole portion
1a and the screw 3b. However, the engagement between the output
sliding portion 3a and the rotation-stop sliding portion 2a
prevents rotation of the output shaft 3. Thus, the torque of the
rotor 1 is converted to an axial linear motion force owing to the
presence of the screw portion 3b and the rotation-stop sliding
portion 2a, which engage with each other in the rotor 1. That is,
the screw portion 3b and the rotation-stop sliding portion 2a
constitute a rotational-to-linear motion conversion mechanism.
[0049] FIG. 3A is a perspective view illustrating a boss 2 and an
output shaft 3 of a comparative example so as to explain the first
embodiment. FIG. 3B is a top view illustrating the output shaft 3
shown in FIG. 3A. As shown in FIGS. 3A and 3B, usually, the screw
portion 3b is larger than the output shaft sliding portion 3a.
Thus, a hole 2b, which is larger than the output shaft sliding
portion 3a, is opened to the boss 2 so as to pass the screw portion
3b, which is provided in the output shaft 3, through the boss 2
when the output shaft 3 is assembled to the motor.
[0050] As shown in FIG. 1, in this embodiment, the hole 2b is
covered with a seal 4 so as to block up the hole 2b. Then, the seal
4 is held by a plate 5, which is fixed to the boss 2 by being
press-fitted thereto.
[0051] FIG. 2 is an enlarged view illustrating a portion indicated
by a dot-dash line .alpha. in FIG. 1. FIG. 4 is a perspective view
illustrating members used for shaft seal.
[0052] The hole 2b, which is larger than the output shaft sliding
portion, is formed in the boss 2 and covered with a deformable (or
flexible) seal portion 4a of the seal 4. At that time, the
positioning of the seal 4 is performed by fitting and assembling
convex portions 2c of the boss 2 to a positioning portion 4b of the
seal 4. Then, the positioning portion 4b is covered with the plate
5. A claw portion 5a is press-fitted into a plate holding hole 2d
of the boss 2, so that the plate 5 is fixed thereto. At that time,
the dimensions of the seal 4a are set so that the seal 4a does not
slide together with the sliding portion 3a of the output shaft 3.
Thus, similarly to a case that the seal 2 is not attached thereto,
no sliding resistance is provided to the sliding portion 3a.
Incidentally, as a result of blocking up the hole 2b with the seal
portion 4a formed of a deformable material, such as rubber, when
the screw 3b is inserted, the screw 3b can be inserted in such a
way as to push the seal portion 4a aside. Thus, the insertion of
the screw 3b can easily be performed. The process of assembling the
output shaft 3 to the rotor can easily be performed without being
changed. Incidentally, during a normal operation other that the
assembling of the output shaft 3 thereto, the screw 3b does not
pass through the seal 4. Consequently, the screw 3b does not affect
an operation of the motor.
Second Embodiment
[0053] FIG. 5 is an axially sectional view illustrating an electric
motor that is a second embodiment of the invention.
[0054] As shown in FIG. 5, a spring holder 6 attached to an output
shaft 3 is shaped in such a manner as to be slightly smaller in
inside diameter than a counterpart housing 7. Thus, airtightness
can be ensured. In short, it is sufficient to provide an extension
portion 6c in such a manner as to be extended outwardly from a
portion 6b of the spring holder 6, which holds a spring. It is
preferable for preventing the ingress of foreign substances that
the gap between the extension portion 6c and the housing 7 is set
to be as small as possible. Incidentally, a breathing hole 6a may
be provided in a plate 6 in a case where the size of the hole 6a is
set in consideration of airtightness. The provision of the
breathing hole 6a therein results in the fact that obstruction to
upward-downward motions of the plate 6 due to the difference in
pressure between the top and the bottom of the plate 6 becomes hard
to occur.
Third Embodiment
[0055] FIG. 6A is a perspective view illustrating a boss 2 and an
output shaft 3 of the third embodiment. FIG. 6B is a top view
illustrating the output shaft 3 shown in FIG. 6A.
[0056] As shown in FIGS. 6A and 6B, a screw portion 3b is formed in
such a way as to be larger than an output shaft sliding portion 3a.
This eliminates the necessity for a hole 2b dug for passing the
screw portion 3b, which is provided in the output shaft 3, through
the boss 2. Thus, the output shaft sliding portion 3a can slide a
rotation-stop sliding portion 2a in a state in which airtightness
is ensured.
[0057] The first to third embodiments have the following
features.
[0058] A component for blocking up a gap opened so as to pass the
screw portion, which is provided in the output shaft, at the
assembling of the output shaft, which performs a linear motion, to
the motor is attached to the motor. Thus, foreign substances,
moisture, gases and so forth can be prevented from entering the
inside of the motor. Consequently, the reliability of the motor is
enhanced. Also, the dimensions of the component for blocking up the
gap are set so that the component does not slide together with the
output shaft. Thus, the motor can ensure performance, which is
equal to that in a case in which the motor is not provided with the
component for blocking up the gap.
[0059] Also, a rubber material is used as the material of the
component for blocking up the gap. Consequently, when the output
shaft is assembled to the motor, the rubber can be pushed aside by
the output shaft screw portion. Thus, workability is enhanced by
postponing the process of assembling the output shaft to the
motor.
[0060] Also, the plate attached to the output shaft is shaped in
such a manner as to be slightly smaller than a counterpart
actuator. Thus, foreign matters, moisture, gasses and so on can be
prevented from being entering the motor from the actuator.
[0061] Also, the sliding portion of the output shaft is formed in
such a way as to be larger than the output shaft screw portion.
Thus, a gap to be opened for passing the screw provided in the
output shaft is not formed. Consequently, foreign substances,
moisture, gasses and so on can be prevented from being entering the
inside of the motor.
Fourth Embodiment
[0062] A fourth embodiment of the invention is further described by
using FIG. 1.
[0063] Reference numeral 8 designates a permanent magnet. Reference
numeral 9 denotes a plate. Reference numeral 10 designates each of
bearings respectively provided on the top and the bottom of the
rotor 1. Permanent magnets 8 divided into plural pole-pairs are
disposed on the outer peripheral surface of the rotor 1. The
bearings 10 are inserted to both end sides of a set of the
permanent magnets 8. The rotor 1 uses a PPS resin. A threaded hole
portion 1a is provided in a central shaft portion thereof. The
permanent magnets 8, each of which is constituted by a ferrite
magnet, and a plate 9, which serves as a stopper for the rotor 1,
are integrally insert-formed on the outer peripheral surface of the
rotor 1.
[0064] A commutator 5 is inserted and assembled to one of side
surfaces of the rotor 1. One of the commutator 5 and the rotor 1 is
partly or entirely plastic-deformed or heat-deformed (in this
embodiment, at a caulking portion 1b) to thereby fix both of the
commutator 5 and the rotor 1.
[0065] Reference numeral 15 designates a stator. Reference numeral
11 denotes a core. Reference numeral 12 designates a coil.
Reference numeral 13 denotes a housing. Reference numeral 14
designates a motor terminal. The stator 15 is constituted by
winding a three-phase coil around the core 11. The core 11 is
disposed so that stator-side magnetic poles are formed outside the
permanent magnets 8 of the rotor 1 by providing a predetermined gap
therebetween. The housing 13 holds and fixes the stator 15. Also,
the housing 13 encloses and supports the rotor 1 at a central
portion thereof through the bearing 10.
[0066] Reference numeral 2 designates a boss. Reference character
2a denotes a rotation-stop sliding portion. Reference numeral 21
designates a preload spring. The boss 2 is assembled to one of
sides of the housing 13. The preload spring 21 is disposed between
the boss 2 and the bearing 10 that movably supports the rotor 1,
and prevents axial displacement and wobbling of the rotor 1 by
applying a predetermined pushing force to the rotor 1. The
rotation-stop sliding portion 2a provided in the boss 2 is formed
in such a way as to have a shape including a flat face. The boss 2
is assembled to and seals the housing 13, which accommodates the
stator 15, in such a manner as to be able to maintain airtightness.
The boss 2 is fixed thereto by screwing, heat-caulking or the
like.
[0067] Reference numeral 3 designates an output shaft. Reference
character 3a denotes an output shaft sliding portion. Reference
character 3b designates a screw portion. Reference character 3c
denotes an output shaft stopper. The screw portion 3b disposed at a
counter-output side (that is, at a side opposite to a direction in
which the output shaft 3 projects) of the output shaft 3 is
inserted into the threaded hole portion 1a, which is provided in
the rotor 1, in such a way as to mesh therewith. The output shaft
sliding portion 3a provided in the output shaft 3 penetrates
through the rotation-stop sliding portion 2a provided in the boss
2, and is shaped in such a way as to have a flat face that abuts
against the rotation-stop sliding portion 2a.
[0068] Reference numeral 40 designates a position sensor formed in
such a way as to be integral with a motor external terminal 43.
Reference numeral 41 denotes a brush connected to the motor
external terminal 43. Reference numeral 42 designates a brush
connected to the motor terminal 14. The motor external terminal 43,
which is formed in such a manner as to be integral with the
position sensor 40, and the brush 41 are electrically connected to
each other. The motor terminal 14 and the brush 42 are electrically
connected to each other. The brushes 41 and 42 are electrically
connected to the commutator 5 and form connection patterns, which
are needed for driving the motor, on the commutator 5.
[0069] Therefore, energization is mechanically switched by the
commutator 5 to the coil 12 thereby to rotation-drive the rotor 1.
Torque of the rotor 1 is transmitted to the output shaft 3.
Incidentally, rotation of the output shaft 3 is hindered by
abutment between the output sliding portion 3a and the
rotation-stop sliding portion 2a. Thus, the torque of the rotor 1
is converted to an axial linear motion force by the screw portion
3b and the rotation-stop sliding portion 2a, which engage with each
other in the rotor 1.
[0070] The output shaft 3 is driven in this manner. When the output
shaft 3 is retracted, the output shaft stopper 3c abuts against the
stopper 9 of the rotor 1. Thus, the rotor can resist collision
impact.
[0071] FIG. 7 is a perspective view illustrating the shape of the
plate 9 provided with slip-off preventing parts.
[0072] The rotor 1 is formed of a PPS resin and holds the plate 9
by insert-forming using the resin. Thus, the plate 9 is shaped, as
illustrated in FIG. 7, so that the resin engages with a claw 3a,
and that a holding strength in a slip-off direction is enhanced.
Incidentally, in this embodiment, a leading end portion of the claw
3a is laterally projected. However, as long as the resin engages
with the plate, each of the claws 3a may take any shape. The
holding strength can be enhanced by increasing an amount of the
resin engaged with the plate.
[0073] FIG. 8 is an explanatory view illustrating the rotor, the
output shaft, and the plate shown in FIG. 1.
[0074] As shown in FIG. 8, the plate 9, which is provided in the
rotor 1 and serves as a stopper, is disposed in such a way as to
abut against the output shaft in the direction in which a linear
motion thereof is performed. The plate 9 is shaped so that an
abutting surface, on which the plate 9 abuts against the output
shaft 3, is a flat face.
Fifth Embodiment
[0075] FIG. 9 is an explanatory view illustrating a rotor, an
output shaft, and a plate. As shown in this figure, the plate 9,
which is provided in the rotor 1 and serves as a stopper, is
disposed in such a way as to abut against the output shaft 3 in the
direction of rotation. The plate 9 is shaped so that an abutting
surface, on which the plate 9 abuts against the output shaft 3, is
a flat face.
[0076] The plate 9 is attached to an end surface 1d in a rotating
direction of the stopper 1c, which is provided in the rotor 1 and
shaped in such a way as to form a slope like a semi-circular ring,
by insert-molding or the like.
[0077] As the rotor 1 rotates, the plate 9 rotates and abuts
against the output shaft stopper 3c of the output shaft 1 thereby
to stop the output shaft 1.
[0078] Incidentally, in a case where the number of threads of the
screw of the rotor differs from that of stopper surfaces, there are
plural positions, at which the output shaft 1 may be stopped, in a
structure shown in FIG. 9. However, in the case of the structure
shown in FIG. 8, for any number of threads, there is only one
position at which the output shaft may be stopped. Thus, an initial
position (that is, a position at which the output shaft 1 is made
to abut against the stopper) of the output shaft 1 is uniquely
determined. This facilitates initialization of the position of the
output shaft 1 to the initial position.
[0079] The forth and fifth embodiments of the invention have the
following features.
[0080] When a rotor of a DC motor is manufactured by resin-molding,
a metallic plate is insert-formed in the rotor as a stopper. Thus,
endurance of the rotor against the impact of a collision thereof
with the output shaft can be considerably enhanced.
[0081] Also, slip-off preventing parts are provided in the metallic
plate. This strikingly enhances a plate holding strength.
[0082] Consequently, the invention can prevent the resin from being
damaged and sticking by the collision thereof with the output
shaft.
[0083] Also, the stopper is disposed in the direction of a linear
motion instead of being disposed in the direction of rotation.
Moreover, the stopper is shaped in such a way as to have a flat
face. Thus, for any number of threads of the screw portion of the
output shaft, the position, at which the output shaft is assembled,
is uniquely determined. Thus, there is no necessity for replacing
the output shaft, so that the workability is enhanced.
[0084] For example, in the case of the related art, in which the
stopper of the rotor is disposed in the direction of rotation
thereof and where the number of stopper surfaces differs from that
of threads of the screw portion, there may be different positions,
at which the output shaft is assembled thereto. Thus, the related
motor needs reassembling of the output shaft thereto or equipment
of an output shaft.
Sixth Embodiment
[0085] FIG. 10 is a side view illustrating a motor terminal portion
of this sixth embodiment of the invention. FIG. 11 is a view
illustrating a comparative example so as to explain a coil wire
fixing portion. FIG. 12 is a top view illustrating the motor
terminal portion. FIG. 13 is a perspective view illustrating the
motor terminal portion. FIGS. 14 and 15 are explanatory views
illustrating shapes of a surface of a hook portion.
[0086] In these figures, reference numeral 14 designates a motor
terminal. Reference numeral 51 denotes a coil wire. Reference
numeral 11 designates a bobbin. The motor terminal 14 is
press-fitted into a hole formed in the bobbin 11 (alternatively,
insert-formed when the bobbin 11 is mold-formed) and fixed
thereto.
[0087] As shown in FIG. 10, a stopper 52a for preventing
displacement of a coil is provided in a coil wire fixing portion 52
of the motor terminal 14. The stopper 52a is adapted in such a
manner as not to be displaced to the side of a fusing portion 52c
and affect fusing after the coil wire 51 is engaged with a hook
portion 52b. Incidentally, the stoppers 52a are provided on both
sides of the hook portion 52a, which is formed into a concave
shape.
[0088] Incidentally, after the coil wire 51 is hooked on the hook
portion 52b, the coil wire fixing portion 52 is bent. Thus, the
coil wire 51 is caught in the coil wire fixing portion 52. Then,
fusing (resistance welding or the like) is performed on the fusing
portion 52c. Consequently, the coil wire 51 is physically and
electrically connected to the coil wire fixing portion 52.
[0089] When the coil wires 51 are wound around the motor terminal
hook portion 52b, the two coil wires 51 may be caught therein in an
overlaid manner (thus, the hook portion 52b is bend as indicated by
dashed lines .beta. in FIG. 11). This may affect fusing in the
subsequent process (that is, a fusing failure may occur, and there
is possibility of occurrence of a contact failure of the coil wires
51). Thus, as illustrated in FIG. 12, an initial bending width of
the coil wire fixing portion 52 is set to be less than the
thickness of the coil wire 51. Consequently, the coil wire fixing
portion is set so that the two coil wires 51 are not overlaid.
[0090] As illustrated in FIG. 13, a tapered shape 52d is formed so
that a nozzle of an automatic winding machine for introducing (or
engaging) the coil wire 51 is easily moved when the coil wire 51 is
engaged with the motor terminal 14.
[0091] When the coil wire 51 is wound around the hook portion 52b
of the motor terminal 14 as shown in FIG. 13, preferably, the
tapered shape 52d is formed by performing R-chamfering
(Rounded-shape chamfering) 52e as shown in FIG. 5 for preventing
the coil from being flawed. This is implemented by performing press
working through the use of a jig having an R-surface.
[0092] Although the press working may be performed on this hook
portion 52d by a planar jig as shown in FIG. 14, a material is
moved by the press working at that time. Thus, this method has
problems that a burr 52f is formed, and that the coil wire 51 is
flawed. Therefore, a method of performing R-chamfering 52e, as
illustrated in FIG. 15, is preferable.
[0093] This sixth embodiment also has the following features.
[0094] A stopper portion is provided so as to prevent displacement
of the coil wire and ingress thereof into the fusing portion when
the coil wire is connected to the motor terminal hook portion by
performing fusing thereon after the coil wire is engaged with the
hook portion (that is, after coil terminal processing). Thus, the
connection therebetween is achieved by performing stable fusing
without displacement of the coil wire and ingress thereof into the
fusing portion. Consequently, a coil wire can be prevented from
being displaced and causing a fusing failure.
[0095] When the coil terminal processing is performed on the coil
wire at the motor terminal, a corner part of the fusing portion is
formed into the tapered shape so as to facilitate the movement of
the nozzle for introducing the coil wire. Thus, stable coil
terminal processing is achieved. Also, a coil-terminal-processing
time can be reduced. When the coil wire is wound around the hook
portion as the coil terminal processing, a time taken to move the
nozzle for introducing the coil wire can be decreased. Also, the
nozzle can be prevented from being into contact with the hook
portion and causing a failure of the terminal processing.
[0096] In a case where two coil wires are caught in a motor
terminal hook portion when the coil wires are wound therearound, a
fusing failure is liable to occur in the subsequent process. Thus,
in consideration of a wire diameter of a coil wire, the hook
portion is formed into a shape, which contains only one coil wire.
Consequently, stable coil terminal processing is achieved. Also,
when the coil wire is wound around the hook portion as the coil
terminal processing, two coil wires are prevented from being caught
therein in an overlaid manner and affecting the fusing.
[0097] The corner part of the motor terminal hook portion is
chamfered so as to prevent the coil wire from being flawed when a
coil wire is wound around the motor terminal hook portion. However,
the motor terminal is manufactured in a press working process, so
that the chamfering is performed thereon usually by pressing a
chamfering face thereagainst through the use of a die. Then, the
pressed material is displaced, so that a burr is produced. The
R-chamfering is performed thereon so as to restrain a burr from
being produced. Thus, a burr is restrained from being produced when
a motor terminal is manufactured. Consequently, quality and
workability can be enhanced. Also, a burr can be prevented from
being produced and affecting the quality and the workability.
[0098] The motor according to the invention has the seal member
provided at a portion, through which the screw portion placed in
the sliding hole can pass and in which the sliding portion does not
slide. Thus, foreign substances or the like can be prevented from
entering the motor from the sliding hole.
[0099] Also, the sliding portion is larger in cross-section than
the screw portion. Thus, foreign substances or the like can be
prevented from entering the motor from the sliding hole.
[0100] Also, the extension portion extended from the support
portion of the plate, which supports the pushing member, toward the
direction of the inner surface of the accommodating member is
provided in the plate. Thus, foreign substances or the like can be
prevented from entering the motor through the surrounding areas of
the plate.
[0101] Also, the motor according to the invention has the metallic
stopper, which is provided in the rotor and which abuts against the
output shaft and axially regulates the output shaft. Thus, even
when the rotor is broken and such a broken part becomes a foreign
matter, the foreign matter can be prevented from entering the
motor.
[0102] Also, the concave hook portion, around which the coil wires
are wounded, is provided in the terminal of the motor according to
the invention. Thus, the coil wires can be prevented from being
flawed when caulked to the terminal.
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