Planetary gear transmission systems or components – Nonplanetary variable speed or direction transmission... – Nonplanetary transmission is friction gearing
Reexamination Certificate
2000-02-11
2001-07-10
Wright, Dirk (Department: 3681)
Planetary gear transmission systems or components
Nonplanetary variable speed or direction transmission...
Nonplanetary transmission is friction gearing
Reexamination Certificate
active
06258003
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to an infinite speed ratio, transmission device for vehicles comprising a toroidal continuously variable transmission, a fixed speed ratio transmission and a planetary gear set.
BACKGROUND OF THE INVENTION
In order to increase the range of speed ratio in a toroidal continuously variable transmission for vehicles, U.S. Pat. No. 5,935,039 and Tokkai Sho 63-219956 published by the Japanese Patent Office in 1988 disclose an infinite speed ratio transmission device using a toroidal continuously variable transmission (CVT) with double cavity, fixed speed ratio transmission and planetary gear set. In such an infinite speed ratio transmission device, an engine output is input to the CVT and fixed speed ratio transmission. The output shaft of the CVT is joined to a sun gear of the planetary gear set, and the output shaft of the fixed speed ratio transmission is joined to a planet carrier of the planetary gear set via a power circulation mode clutch. A ring gear of the planetary gear set is joined to a final output shaft of the transmission device which drives the wheels. The output shaft of the CVT is also joined to the final output shaft via a direct mode clutch.
In this device, two types of power transmission are used, i.e. a direct drive mode wherein the direct mode clutch is engaged and the power circulation mode clutch is disengaged, and a power circulation mode wherein the direct mode clutch is disengaged and the power circulation mode clutch is engaged. In the direct drive mode, the engine output is transmitted to the drive shaft via the CVT. In the power circulation mode, the rotation of the ring gear stops at a position where the rotation of the sun gear due to the output of the fixed speed ratio transmission and the rotation of the planet carrier due to the output of the CVT are balanced. This state corresponds to a neutral state where rotation torque is not transmitted to the drive shaft. In this case, the ratio of the engine speed and the rotation speed of the final output shaft becomes infinite.
With respect to the construction of the CVT, Tokkai Hei 9-317837 published by the Japanese Patent Office in 1997 discloses an upper link and lower link for displacing trunnions facing each other with opposite phase in the axial direction. The upper link is supported by a post fixed to a casing via a pin.
SUMMARY OF THE INVENTION
Some infinite speed ratio transmission devices transmit the output of the CVT to the sun gear via a pair of sprockets and a chain. However, in these devices, the upper link attached to the casing interferes with the chain when assembling the transmission device. In the double cavity CVT, one sprocket is situated between a pair of output disks, and if the upper links situated on both sides in the axial direction of the sprocket are previously attached to the casing, the chain cannot be looped around the sprocket.
It is therefore an object of this invention to facilitate the fitting of a chain to the CVT of an infinite speed ratio transmission device.
In order to achieve the above object, this invention provides an infinite speed ratio transmission device for a vehicle, comprising an input shaft, a first toroidal unit comprising a first input disk which rotates together with the input shaft, a first output disk, and two power rollers gripped between the first input disk and the first output disk, a second toroidal unit comprising a second input disk which rotates together with the input shaft, a second output disk, and two power rollers gripped between the second input disk and the second output disk, the first output disk and the second output disk being disposed coaxially and adjacent to each other, an output sprocket which is disposed between and rotates together with the first output disk and the second output disk, four trunnions which support the four power rollers of the first toroidal unit and the second toroidal unit, an upper link holding the upper end of the four trunnions, the upper link comprising a first part holding the two trunnions of the first toroidal unit, and a second part holding the two trunnions of the second toroidal unit, the first part and the second part being formed separately and fixed to each other, a fixed speed ratio transmission which transmits a rotation of the input shaft at a fixed speed ratio to an output gear, a planetary gear set comprising a sun gear joined to a sprocket, a planet carrier which rotates together with the output gear, and a ring gear which rotates according to a relative rotation of the sun gear and the planet carrier, a chain connecting the output sprocket and the sprocket, a casing housing the first toroidal unit, the second toroidal unit and the planetary gear set, a first upper link supporting member fixed to the casing which supports the first part in the casing, a second upper link supporting member fixed to the casing which supports the second part in the casing, and an intermediate wall fixed to the casing which supports the output sprocket free to rotate.
This invention also provides an assembly method of the above infinite speed ratio transmission device. The method comprises fixing the second upper link supporting member to the casing, fitting the second part to the second upper link supporting member, setting the output sprocket at a predetermined position in the casing, inserting the sprocket around which the chain has been looped and the planetary gear unit in the casing, looping the chain around the output sprocket, setting the sprocket and the planetary gear unit at a predetermined position in the casing, fixing the first upper link supporting member to the casing, fitting the first part to the first upper link supporting member, and joining the first part to the second part.
This invention also provides an assembly method comprising fixing the second upper link supporting member to the casing, fitting the second part to the second upper link supporting member, looping the chain around the output sprocket and the sprocket, fitting the intermediate wall on the output sprocket, setting the output sprocket on which the intermediate wall is fitted and the planetary gear set in which the sprocket is combined with the output sprocket via the chain, at a predetermined position in the casing, fixing the first upper link supporting member to the casing fitting the first part to the first upper link supporting member, and joining the first part to the second part.
This Invention also provides an assembly method of the infinite speed ratio transmission device in which the intermediate wall further comprise a front partition disposed between the first output disk and the output sprocket, a rear partition disposed between the second output disk and the output sprocket, and a fixing member which fixes the front partition to the rear partition. The method comprises fixing the second upper link supporting member to the casing, fitting the second part to the second upper link supporting member, setting the output sprocket at a predetermined position in the casing together with the rear partition, inserting the sprocket around which the chain has been looped and the planetary gear unit in the casing, looping the chain around the output sprocket, setting the sprocket and the planetary gear unit at a predetermined position in the casing, fixing the front partition to the rear partition by the fixing member, fixing the first upper link supporting member to the casing, fitting the first part to the first upper link supporting member, and joining the first part to the second part.
The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings.
REFERENCES:
patent: 5902208 (1999-05-01), Nakano
patent: 5935039 (1999-08-01), Sakai et al.
patent: 6155951 (2000-12-01), Kuhn et al.
patent: 6171210 (2001-01-01), Miyata et al.
patent: 63-219956 (1988-09-01), None
patent: 9-317837 (1997-12-01), None
Hirano Hiroyuki
Nakano Masaki
Foley & Lardner
Nissan Motor Co,. Ltd.
Wright Dirk
LandOfFree
Infinite speed ratio transmission device and assembly method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Infinite speed ratio transmission device and assembly method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Infinite speed ratio transmission device and assembly method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2498595