This Agilent Varian OEM TriScroll 300 motor coupling is used to transfer power to the scroll pump module. In fact, the electric motor and pump module both bolt to the transition frame where the pump and module shafts are joined together using a coupling and spider. The scroll module coupling is built in combination with the cooling fan. These Agilent Varian TriScroll 300 dry scroll vacuum pump motor couplings are keyed for the motor shaft with side set screw.