SECONDARY(driven) CLUTCH OVERVIEW
This discussion is geared ONLY toward the Team Roller Secondary clutch and not the Rapid Reaction Clutch.
The Secondary (Driven) Clutch is the one that attaches to the transmission and and accepts the power that is transferred by the Primary (Drive) Clutch thru the Drive Belt.
The unit consists of a stationary or fixed sheave,and a moveable sheave. The combination of these 2 pieces work against a cam and spring within the clutch. The cam is the tool which recognizes torque changes supplied by the rear wheels. These changes are transferred thru the cam by the angle of the ramp and in then coverted to side pressure on the belt. The belt force is governed by the Primary Clutch and the Engine. As the belt moves up in the Primary Clutch, it must be forced into sheaves of the Secondary Clutch. How quick this happens is controlled by the combination of the Helix(angle) and the Spring rate in Secondary. The amount of belt grip in the Secondary is is also controlled by the same 2 elements above. The unit as it exists today is torque sensitive or torque driven, which means in simple terms, if the torque requirement is greater, you get more side pressure applied to the belt AND if the torque requirement is lessen, you get less side pressure applied to the belt. This side pressure that is being applied to the belt in any given shift range is what keeps the belt from slipping.
I’ll now try to describe shift ratio and what it means with the Secondary Clutch.
HORSEPOWER = TORQUE X SPEED
The shifting is caused by the belt being moved with the Secondary Clutch, up/down between the sheaves in that clutch.
I believe that the shift ratio’s are:
Low – 3:1
Mid – 1:1
High - .75:1
And these ratio’s DON’t take into consideration any efficiency losses, which is really outside the scope of this overview.
The only time that the Torque SHOULD be the same is in the 1:1 ratio.
At the Low ratio, the Torque is 3 times greater than the engine Torque and
At the High ratio(overdrive) the Torque at the Secondary Clutch is only ¾
of the engine Torque. What this translates to is that in Low there must be much more side pressure applied to the belt than when in High(overdrive). Ok now here is what happens.
If you fail to stay within this range, you will either end up with BELT SLIP/Belt Wear or with Inefficencies due to TOO MUCH Pressure.
This discussion is geared ONLY toward the Team Roller Secondary clutch and not the Rapid Reaction Clutch.
The Secondary (Driven) Clutch is the one that attaches to the transmission and and accepts the power that is transferred by the Primary (Drive) Clutch thru the Drive Belt.
The unit consists of a stationary or fixed sheave,and a moveable sheave. The combination of these 2 pieces work against a cam and spring within the clutch. The cam is the tool which recognizes torque changes supplied by the rear wheels. These changes are transferred thru the cam by the angle of the ramp and in then coverted to side pressure on the belt. The belt force is governed by the Primary Clutch and the Engine. As the belt moves up in the Primary Clutch, it must be forced into sheaves of the Secondary Clutch. How quick this happens is controlled by the combination of the Helix(angle) and the Spring rate in Secondary. The amount of belt grip in the Secondary is is also controlled by the same 2 elements above. The unit as it exists today is torque sensitive or torque driven, which means in simple terms, if the torque requirement is greater, you get more side pressure applied to the belt AND if the torque requirement is lessen, you get less side pressure applied to the belt. This side pressure that is being applied to the belt in any given shift range is what keeps the belt from slipping.
I’ll now try to describe shift ratio and what it means with the Secondary Clutch.
HORSEPOWER = TORQUE X SPEED
The shifting is caused by the belt being moved with the Secondary Clutch, up/down between the sheaves in that clutch.
I believe that the shift ratio’s are:
Low – 3:1
Mid – 1:1
High - .75:1
And these ratio’s DON’t take into consideration any efficiency losses, which is really outside the scope of this overview.
The only time that the Torque SHOULD be the same is in the 1:1 ratio.
At the Low ratio, the Torque is 3 times greater than the engine Torque and
At the High ratio(overdrive) the Torque at the Secondary Clutch is only ¾
of the engine Torque. What this translates to is that in Low there must be much more side pressure applied to the belt than when in High(overdrive). Ok now here is what happens.
If you fail to stay within this range, you will either end up with BELT SLIP/Belt Wear or with Inefficencies due to TOO MUCH Pressure.