This uses 2 synchro belts, running from pulleys on each end of the motor
shaft, with overrunning clutches between each pulley and the
shaft (back to back orientation). One or other of the drive paths will be activated, dependant on the
rotational direction of the motor. One belt drives a large pulley on the output shaft directly,
the other goes to a countershaft from where a small spur gear drives a large
spur gear on the output shaft - compounding the ratio and also reversing the
direction of rotation. So, while the direction of the motor can be changed, the
output shaft will always turns in the same direction. This gives you a 2
speed gear change by flipping the motor direction. Two more overrunning
clutches on the output shaft pulley and spur gear (orientated in the same
direction, this time), completely isolate the two drive paths.
The main attraction of this design is that the gear change is done electrically
and is therefore easy to automate - based on motor speed, for instance. One of the
drawbacks is that it can't be easily used for a regen. set-up.
Development Version 1
Top gear 3.4:1 Ratio difference 2:1
5mm synchro; 1.5 Mod spur gears; 8mm synchro output.
.
shaft, with overrunning clutches between each pulley and the
shaft (back to back orientation). One or other of the drive paths will be activated, dependant on the
rotational direction of the motor. One belt drives a large pulley on the output shaft directly,
the other goes to a countershaft from where a small spur gear drives a large
spur gear on the output shaft - compounding the ratio and also reversing the
direction of rotation. So, while the direction of the motor can be changed, the
output shaft will always turns in the same direction. This gives you a 2
speed gear change by flipping the motor direction. Two more overrunning
clutches on the output shaft pulley and spur gear (orientated in the same
direction, this time), completely isolate the two drive paths.
The main attraction of this design is that the gear change is done electrically
and is therefore easy to automate - based on motor speed, for instance. One of the
drawbacks is that it can't be easily used for a regen. set-up.
Development Version 1
Top gear 3.4:1 Ratio difference 2:1
5mm synchro; 1.5 Mod spur gears; 8mm synchro output.
.