Machine element or mechanism – Gearing – Interchangeably locked
Reexamination Certificate
1999-11-12
2001-09-11
Estremsky, Sherry (Department: 3681)
Machine element or mechanism
Gearing
Interchangeably locked
C074S336001
Reexamination Certificate
active
06286380
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic speed-change apparatus for automatically changing the speed of a gear transmission.
2. Description of the Related Art
There has been provided an apparatus in which a manual gear transmission mechanism is used as it is and speed-change and clutch operations are automated through a hydraulic apparatus by computer control. This apparatus, however, requires three cylinders for clutch, shift and select operations, and a number of solenoid valves for driving these cylinders as well as a hydraulic system. Due to this, the apparatus has disadvantages in complicated structure, large size and high cost.
In addition, there has been provided an apparatus in which motors are employed to the select and change speed actuators for a gear transmission, as disclosed by, for example, Japanese Patent Publication No. 61-51697. This apparatus, however, requires as many motors as select lines and a plurality of motors and solenoid valves are used. Due to this, this apparatus has disadvantages in complicated structure, large size and high cost.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above conventional disadvantages. It is, therefore, an object of the present invention to provide an automatic speed-change apparatus for a gear transmission which is simple in structure and can be manufactured at low cost.
According to the present invention, there is provided an automatic speed-change apparatus for a gear transmission, connected to a select and change speed pull-rod of the gear transmission having a constitution in which the select and change speed pull-rod is moved in an axial direction to select a line of a change speed fork provided within the gear transmission and a rotation direction of the select and change speed pull-rod cooperates with the change speed fork to complete speed change of a gear, for executing select and change speed operations of the gear transmission, wherein a select mechanism for executing the select operation and a change speed mechanism for executing the change speed operation are incorporated into the automatic speed-change apparatus; the select mechanism comprises a select shaft rotated by a select motor capable of controlling forward and backward rotation, a select sensor provided on an outer end of the select shaft and detecting an operating angle of the select shaft in rotation direction, a select lever fixed to the select shaft and a connector connecting a tip end portion of the select lever to the select shaft; the change speed mechanism comprises a change speed motor capable of controlling forward and backward rotation; a plurality of intermediate shaft gear mechanisms each having a large diameter gear, a small diameter gear and an intermediate shaft parallel to the select and change speed pull-rod; a change speed gear engaged with the intermediate shaft gear mechanism to transmit rotation and fixed to the select and change speed pull-rod; and a change speed sensor provided on an outer end of the select and change speed rod and detecting an operating angle of the select and change speed pull-rod in the rotation direction; during the select operation, when the select motor is actuated, the select shaft is deformed in the rotation direction to rock the select lever and to axially move the select and change speed pull-rod through the connector and the select shaft is adjusted by feedback control of the select sensor to thereby allow the select shaft to reach a predetermined select line; and during the change speed operation, when the change speed motor is actuated, the change speed gear is rocked through the intermediate shaft gear mechanisms and the select and change speed pull-rod is deformed in the rotation direction and adjusted by feedback control of the change speed sensor to thereby allow the select and change speed pull-rod to reach a predetermined change speed line.
Two pairs of a first intermediate shaft gear mechanism and a second intermediate shaft gear mechanism may be provided in the change speed mechanism between an output shaft of the change speed motor and the select and change speed pull-rod to thereby constitute a first reduction gear mechanism, a second reduction gear mechanism and a third reduction gear mechanism from a change speed motor side in this order and a main body of the change speed motor is provided at the gear transmission side; the shift mechanism is provided with a small diameter change speed gear fixed to the output shaft of the change shaft motor and a large diameter change speed gear engaged with the small diameter gear of the second intermediate shaft gear mechanism to transmit rotation and fixed to the select and change speed pull-rod, the first intermediate shaft gear mechanism engaged with the small diameter change speed gear to transmit rotation and having a large diameter gear provided at a gear transmission side and a small diameter gear provided at an opposite side to the gear transmission, the second intermediate shaft gear mechanism engaged with the small diameter gear of the first intermediate shaft gear mechanism and having a large diameter gear at an opposite side to the gear transmission and a small diameter gear provided at the gear transmission side; a center distance of the first reduction gear mechanism is set slightly shorter than a center distance of the second reduction gear mechanism, the center distance of the second reduction gear mechanism is set equal to a center distance of the third reduction gear mechanism, the first, second and third reduction gear mechanisms have equal gear specifications, the numbers of gear teeth of the small diameter gears of the respective reduction gear mechanisms are the same, only the number of gear teeth of the large diameter gear of the first reduction gear mechanism is set so as not to interfere with the small diameter gear of the second reduction gear mechanism.
Gear teeth surface portions, shaft portions, bearing portions of the gears and the tip end portion of the lever and a connector portion constituting the select mechanism and the change speed mechanism may be dry structure using a material or a solid lubricant to allow the select mechanism and the change speed mechanism to function without using a liquid lubricant.
Preferably, gear specifications of the intermediate gears are set such that the gears are spur gears and have modules set at 1 to 3, a pair of reduction ratios are 3 to 6, numbers of gear teeth of the small diameter gears are 10 to 20, numbers of gear teeth of the large diameter gears are 30 to 120 and that a total reduction ratio is 48 to 180.
REFERENCES:
patent: 5724856 (1998-03-01), Back
patent: 5901608 (1999-05-01), Takeyama
patent: 6003395 (1999-12-01), Rogg et al.
patent: 6151697 (1986-11-01), None
patent: 405118495 (1993-05-01), None
Imao Toshio
Takeyama Eiji
Aichi Kikai Kogyo Kabushiki Kaisha
Dennison, Scheiner Schultz & Wakeman
Estremsky Sherry
Lewis Tisha D.
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