Endless belt power transmission systems or components – Pulley with belt-receiving groove formed by drive faces on... – Load responsive
Reexamination Certificate
2001-05-04
2002-12-31
Wright, Dirk (Department: 2834)
Endless belt power transmission systems or components
Pulley with belt-receiving groove formed by drive faces on...
Load responsive
C474S028000, C074S60600R
Reexamination Certificate
active
06500083
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to automatic transmissions such as continuously variable transmissions for automotive vehicles.
2. Description of the Related Art
FIG. 4
shows a known continuously variable transmission for a motor vehicle. The known continuously variable transmission includes a stepping motor
1
having a reciprocating rod
16
, a first link
100
connected to the reciprocating rod
16
, a second link
101
connected to the first link
100
, and a transmission control valve
102
connected to the second link
101
at an intermediate part thereof. The known continuously variable transmission also includes a first pulley
103
connected to the second link
101
at an end of the second link
101
and to an engine
107
via an engine shaft
106
, a second pulley
105
connected to the first pulley
103
via a metallic belt
104
and to a wheel
109
via a driving shaft
108
, and a hydraulic servo structure for driving the transmission control valve
102
.
The hydraulic servo structure includes an oil pump
110
, an oil pan
111
, a controller
112
for controlling the transmission control valve
102
and the like so that the driving shaft
108
and the engine shaft
106
rotate at a predetermined ratio of rotational speeds between each other, and a speed sensor
113
for determining the rotation of the first pulley
103
and the second pulley
105
, respectively.
A transmission structure for controlling the ratio of rotational speeds between the driving shaft
108
and the engine shaft
106
is formed with the first pulley
103
, the second pulley
105
, and the metallic belt
104
.
In the continuously variable transmission, the rod
16
is reciprocated by the rotation of the stepping motor
1
, thereby opening and closing the transmission control valve
102
via the first and second links
100
and
101
, whereby an operating oil for the first pulley
103
is supplied and discharged through the transmission control valve
102
. The second link
101
pivots on a supporting point A.
The operating oil from the transmission control valve
102
moves a drum
103
a
of the first pulley
103
, thereby varying the ratio of the diameters between the first and second pulleys
103
and
105
on which the metallic belt
104
is mounted, and controlling the ratio of the rotational speeds of the driving shaft
108
and the engine shaft
106
.
FIG. 5
is a plan view of the stepping motor
1
shown in FIG.
4
.
FIG. 6
is a sectional view of the stepping motor
1
shown in
FIG. 5
along a line VI—VI.
FIG. 7
is a sectional view of the stepping motor
1
shown in
FIG. 6
along a line VII—VII.
FIG. 8
is a sectional view of the stepping motor
1
shown in
FIG. 6
along a line VIII—VIII.
FIG. 9
is a perspective view of a critical portion of the stepping motor
1
shown in FIG.
4
.
In the drawings, the permanent-magnet-type stepping motor
1
includes a resin casing
2
, a resin cylindrical housing
12
connected with the casing
2
, a motor body
3
housed in the casing
2
, a shaft
4
to be rotated by the motor body
3
, and a converting structure
31
for converting the rotational movement of the shaft
4
into linear movement. The cover is composed of the casing
2
and the housing
12
.
The motor body
3
includes a stator
5
fixed to the casing
2
, and a rotor
6
fixed to the shaft
4
. The stator
5
includes a coil
7
having a conductor made of a copper wire covered with an insulative film which is wound in a plurality of turns, coil terminals
8
led out from the coil
7
, connector terminals
9
connected to the coil terminals
8
, and external terminals
25
connected to the connector terminals
9
. The rotor
6
includes a bush
10
fixed to the shaft
4
, and a hollow cylindrical permanent-magnet
11
fixed to the bush
10
.
The housing
12
is fixed at a first end thereof to the casing
2
by a plurality of screws
12
A extending parallel to the shaft
4
. The casing
2
is provided with a circular mating hole
2
a
formed therein, and the housing
12
is provided with a mating member
12
a
so as to be inserted in the mating hole
2
a.
In
FIG. 7
, the mating member
12
a
is provided with three positioning-protrusions
12
b
at the outer periphery of the mating member
12
a,
the positioning protrusions
12
b
protruding in the radial directions and in contact with the inner periphery of the mating hole
2
a.
The housing
12
is provided with an annular groove
12
c
formed therein at a face in connection with the casing
2
.
The housing
12
is provided therein with a housing through-hole
12
d
communicating between the outside and the inside of the housing
12
, the housing through-hole
12
d
being provided at a side face of the housing
12
. A filter
13
for capturing contamination of oil is provided in the housing through-hole
12
d.
The shaft
4
is rotatably supported by bearings
14
and
15
. The bearing
15
affixed in the housing
15
is a rubber-seal-type bearing.
The housing
12
is provided, at a second end thereof opposite to the first end fixed to the casing
2
, with a rod
16
which reciprocates along the axis of the shaft
4
with the rotation of the shaft
4
. The rod
16
is inserted into the housing
12
at the base end of the rod
16
, and the other end of the rod
16
protrudes from the second end of the housing
12
. The rod
16
is provided therein with a through-hole
16
a
communicating between the inside of the housing
12
and the inside of the rod
16
. The housing
12
is provided at the inner face of the second end thereof with a sleeve
17
for guiding the rod
16
linearly moving, an oil seal
18
for avoiding contamination to penetrate from the outer periphery of the rod
16
, and an annular stopper
19
for restricting the linear movement of the rod
16
.
The converting structure
31
includes a threaded part
4
a
of the shaft
4
, a resin guide member
20
disposed at the base end of the rod
16
and coupled with the threaded part
4
a,
and a metallic stopper
21
for restricting the linear movement of the rod
16
at the other side of the annular stopper
19
. The guide member
20
and the stopper
21
include stopper faces
20
b
and
21
a,
respectively, perpendicular to the rotational axis of the shaft
4
. In
FIG. 8
, the guide member
20
is provided with rotation-restricting protrusions
20
a
for restricting rotation of the rod
16
formed extending in the radial directions at the outer periphery of the guide member
20
. With this arrangement, the guide member
20
is moved in the axial direction of the shaft
4
by the rotation thereof. The rod
16
is mounted with a resin member
22
to be coupled with the first link
100
at the end opposite to the base end of the rod
16
.
In the stepping motor
1
having the above-described configuration, when electrical current is applied to the coil
7
via the connectors
25
, a rotation-driving magnetic field is generated in the coil
7
, thereby rotating the rotor
6
and the shaft
4
as a unit. The shaft
4
is coupled with the guide member
20
at the threaded part
4
a
of the shaft
4
, and the rotational movement of the guide member
20
is restricted, whereby the rotational movement of the shaft
4
is converted into the linear movement of the guide member
20
and the rod
16
.
By the linear movement of the rod
16
in both directions, the transmission control valve
102
is opened and closed via the first and second links
100
and
101
, whereby the ratio of rotational speeds between the driving shaft
108
and the engine shaft
106
varies, as described above.
In the known continuously variable transmission, the stepping motor
1
is dipped in oil containing sulfur and organic sulfur compounds. Therefore, sulfur and the like transmit through an insulative film of a conductor included in the coil
7
, and a sulfur compound is produced so as to be disposed between a copper wire and the insulative film by the chemical reaction between the copper wire and the sulfur, whereby the adhesion between
Hasegawa Shiro
Hashimoto Naoya
Miyaoku Teruo
Ohta Hirohisa
Ozawa Hiromasa
Mitsubishi Denki & Kabushiki Kaisha
Sughrue & Mion, PLLC
Wright Dirk
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