The stator wheel is only unlocked during what phase?

The stator wheel is only unlocked during what phase?

• A. Coupling
• B. Lock-up
• C. Torque multiplication
• D. Cool-down

Answer: (A)

The stator wheel in a torque converter functions as a fluid redirection device and uses a one-way clutch. When the engine drives the pump faster than the turbine, the clutch locks the stator to the housing so the stator cannot spin, and the hydraulic flow is redirected back toward the pump. This creates torque multiplication, giving the drivetrain more torque at low speeds. As the turbine speeds up and the speed difference between pump and turbine decreases, the one-way clutch allows the stator to rotate freely again. This unlocking happens as the system moves toward direct drive, which is described as the coupling phase. In this phase the need for torque multiplication eases and smoother engagement is achieved by allowing the stator to spin rather than resist motion. During the lock-up phase, a separate mechanism briefly locks the torque converter to provide a direct connection, bypassing the need for the stator’s redirection, so unlocking is not the focus there. Cool-down simply refers to the engine and system winding down, not to the stator unlocking behavior. Thus, the stator is only unlocked during coupling.

The stator wheel in a torque converter functions as a fluid redirection device and uses a one-way clutch. When the engine drives the pump faster than the turbine, the clutch locks the stator to the housing so the stator cannot spin, and the hydraulic flow is redirected back toward the pump. This creates torque multiplication, giving the drivetrain more torque at low speeds.

As the turbine speeds up and the speed difference between pump and turbine decreases, the one-way clutch allows the stator to rotate freely again. This unlocking happens as the system moves toward direct drive, which is described as the coupling phase. In this phase the need for torque multiplication eases and smoother engagement is achieved by allowing the stator to spin rather than resist motion.

During the lock-up phase, a separate mechanism briefly locks the torque converter to provide a direct connection, bypassing the need for the stator’s redirection, so unlocking is not the focus there. Cool-down simply refers to the engine and system winding down, not to the stator unlocking behavior. Thus, the stator is only unlocked during coupling.