Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
2001-03-29
2002-09-17
Nguyen, Tran (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S099000
Reexamination Certificate
active
06452296
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a motor device applicable to a system such as a vehicle power window apparatus in which a transmission mechanism is employed for transmitting rotational driving force.
2. Description of Related Art
Conventionally, as shown in
FIG. 6
, in a motor device of a vehicle power window apparatus for opening and closing a side window glass of a vehicle door, rotational driving force of a motor
50
is transmitted through a motor output shaft with a worm (not shown) to a worm wheel
51
. The driving force transmitted to the worm wheel
51
is further transmitted via a rubber damper
52
to an output plate
53
and an output shaft
54
.
The worm wheel
51
, the output plate
53
and the output shaft
54
are arranged to rotate in a same center axis. As shown in
FIG. 7
, the worm wheel
51
is housed in a wheel accommodating recess
55
a
of a gear housing
55
and is rotatably held by a bearing portion
56
protruding out of a bottom of the recess
55
a
. The rubber damper
52
is housed in a damper accommodating ring shaped recess
51
a
opened upward in the worm wheel
51
. The output shaft
54
is rotatably held in a shaft receiving hole
56
a provided in the bearing portion
56
and supports the output plate
53
arranged at an opening axial end of the damper accommodating recess
51
a
. Each of engaging portions
51
b
of the worm wheel
51
is engaged via each of damper portions
52
a
of the rubber damper
52
with each of engaging projections
53
a
of the output plate
53
so that the rotational driving force is transmitted from the worm wheel
51
to the output plate
53
.
The output plate
53
is formed by press stamping a metal sheet. The output plate
53
is provided in a center thereof with a shaft receiving hole
53
b
formed by stamping. As shown in
FIG. 8
, a shaft inserting portion
54
a
of the output shaft
54
is fitted to the shaft receiving hole
53
a
. The engaging projections
53
a
are formed by bending downward outer circumferential parts of the output plate
53
so as to form notches or holes adjacent thereto.
When the motor
50
rotates to drive the side window glass upwardly and, then, the side window glass comes in contact with a window frame so that the upward movement of the side window glass is suddenly restricted, a rotation of the output plate
53
is restricted. The restriction of the output plate
53
causes a restriction of rotation of the worm wheel via the rubber damper
52
. The rubber damper
52
absorbs reaction force suddenly acting against the worm wheel
51
or the motor
50
so that a shock to the motor
50
is eased.
The conventional motor device has a drawback that fitting of the output plate
53
to the output shaft
54
is likely to loose as a clearance therebetween is formed circumferentially during an actual use. The rotational driving reaction force causes to deform the shaft receiving hole
53
b
of the output plate
53
so that that the clearance is circumferentially formed. That is, a construction of the shaft receiving hole
53
b
of the output shaft
53
does not have sufficient strength to endure large force applied from the shaft inserting portion
54
a
of the output shaft
54
to the shaft receiving hole
53
b
at a time during which the shock is absorbed.
To cope with this problem, it may be contemplated to employ the output plate
53
whose material sheet thickness is thicker or whose material strength is stronger so that the shaft receiving hole
53
b
is unlikely to deform. However, press stamping a metal sheet having thicker thickness or stronger strength is more difficult, resulting in shortening a lifetime of pressing equipment and reducing dimensional accuracy of the output plate or increasing material cost.
SUMMARY OF THE INVENTION
An object of the invention is to provide a transmission mechanism having an output plate and an output shaft for transmitting rotational driving force from the output plate to the output shaft in which fitting of the output shaft to the output plate is unlikely to loose during an actual use.
It is another object of the invention to provide a motor device having the transmission mechanism thereof.
To achieve the above object, a transmission mechanism for transmitting rotational driving force has a driven member rotating upon receiving the rotational driving force, an output plate having a flat surface and engaged with the driven member to rotate together therewith, and an output shaft.
The output plate is integrally provided in a center thereof with a linking portion axially extending by a length longer than thickness of the flat surface. The linking portion has a shaft receiving hole with a plurality of engaging surfaces extending axially for receiving circumferentially the rotational driving force. The output shaft is provided at an axial end thereof with a shaft inserting portion fitted to the shaft receiving hole so that the output shaft penetrates the driven member and is connected to the output plate so as to rotate together therewith in a state that an axial length of the shaft inserting portion in contact with each of the engaging surfaces is longer than the thickness of the flat surface.
In a case of a motor device having the transmission mechanism, the motor device is composed of a motor, a gear housing fixed to the motor and provided in a center thereof with a bearing, a wheel housed in the gear housing and driven to rotate around the bearing by the motor, a damper housed in the recess to rotate together with the wheel, an output plate having a flat surface and engaged with the damper to rotate via the damper together with the wheel, and an output shaft rotatably held in the bearing.
The wheel is provided on a surface thereof perpendicular to a center axis of the bearing with a recess. The output plate is integrally provided in a center thereof with a linking portion axially extending by a length longer than thickness of the flat surface. The linking portion has a shaft receiving hole with a plurality of engaging surfaces extending axially for receiving circumferential force. The output shaft is provided at an axial end thereof with a shaft inserting portion fitted to the shaft receiving hole so that the output shaft penetrates the wheel and the damper and is connected to the output plate so as to rotate together therewith in a state that an axial length of the shaft inserting portion in contact with each of the engaging surfaces is longer than the thickness of the flat surface. With the motor device mentioned above, the wheel and the damper correspond to the driven mechanism of the transmission mechanism.
According to the transmission mechanism or the motor device mentioned above, reaction force from the output shaft is applied to axially extending wide areas of the engagement surfaces so that stresses are not concentrated to a limited area thereof. Accordingly, the linking portion scarcely deforms so that the fitting of the output shaft to the output plate is unlikely to loose during an actual use, even if the output plate is formed by press stamping a metal sheet whose sheet thickness and material strength are similar to the conventional metal sheet.
It is preferable that the linking portion is formed in shape of a composite pipe having inside and outside walls which are folded down each other. The outside wall extends to protrude out of the flat surface toward the driven member and the inside wall, which is formed in cylindrical shape, extends perpendicularly to the flat surface in a direction opposite to the driven member through an inside of the outside wall.
Preferably, the inside wall extends up to a position exceeding a surface of the flat surface on an opposite side to the driven member so that both axial ends of the inner wall are positioned on opposite sides of the flat surface.
Accordingly, structural strength of the linking portion is sufficiently reinforced, axial length of the transmission mechanism is effectively limited.
Further, it is preferable that the output plate is
Kato Manabu
Torii Katsuhiko
Yamamoto Hiroaki
Asmo Co. Ltd.
Law Offices of David G. Posz
Nguyen Tran
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