Växellås

Växellås is a locking mechanism used in gear systems to prevent unwanted movement of gears or to immobilize a machine. The term is used in Swedish to describe devices and features that lock a gear selector or a gear train in a fixed position, helping to increase safety and security or to facilitate servicing.

In motor vehicles, växellås commonly refers to shift interlocks and parking locks. Modern automatic transmissions often include electronic or hydraulic interlocks that prevent shifting out of parking or into certain gears unless the brake pedal is pressed. This reduces the risk of accidental gear engagement. There are also locking devices used to immobilize the transmission during maintenance or in some anti-theft configurations, which can require a key, a code, or a specific procedure to unlock.

Outside road vehicles, växellås is used in industrial gearboxes and machinery to hold a gear in a fixed position during maintenance, transport, or to prevent shaft rotation when the machine is stopped. Such locking mechanisms can be mechanical, such as pawls or detents, or electromechanical, using solenoids or electronic controls. They are selected to be strong enough to withstand expected forces and to fail safe in power or control-system outages.

Security-oriented växellås devices are also marketed to deter theft by locking the gear lever, particularly on motorcycles and some cars. These systems vary in design but share the common purpose of preventing unintended or unauthorized gear movement.

Maintenance generally involves checking for wear, lubrication of moving parts, and testing the interlock or lockout function to ensure reliable operation.