Electromagnetic automatic transmission locks
Electromagnetic interlocks are used in automatic transmissions to improve efficiency and fuel economy. They provide a mechanical connection between the input and output shafts when needed to improve shifting characteristics.
Operating principle
An electromagnetic blocker is a solenoid that creates a magnetic field when an electric current is applied to it. The magnetic field attracts and holds the reinforcement, blocking the rotation of the secondary shaft relative to the primary.
Automatic transmission lock elements
* Solenoid – creates a magnetic field that holds the armature.
* The armature is a metal core that is attracted to the solenoid and blocks the output shaft.
* Spring – returns the valve to the unlocked position when the solenoid is de-energized.
Functions of blockers in automatic transmission
Electromagnetic blockers perform the following functions in automatic transmissions:
* Anti-slip – When the input and output shafts are mechanically connected, locking prevents the clutch from slipping, resulting in increased efficiency and increased torque.
* Fuel Economy – Locking allows torque to be transferred directly from the engine to the transmission, reducing power loss and improving fuel economy.
*Improved shift feel – By synchronizing the rotation of the shafts during gear changes, locking provides smoother, faster gear changes.
* Increased automatic transmission service life – by reducing clutch slip and stress on transmission components, locking increases automatic transmission service life.
Restrictions
Although electromagnetic jammers bring many benefits, they also have certain limitations:
* Speed restrictions – lockup cannot be engaged at all engine speeds.
* Increased noise and vibration – blocking can create additional noise and vibration at low engine speeds.
* Increased cost – adding electromagnetic blockers to an automatic transmission increases the cost of the transmission.
Despite these limitations, electromagnetic interlocks are widely used in modern automatic transmissions because they provide significant improvements in efficiency and fuel economy.