Gear with at least two gearing stages, a linear actuator including such a gear and a table leg including such a linear actuator

Abstract

Gear, preferably for actuators of the type, where an electric motor () through the gear drives an activation element, such as a pivotal arm or a longitudinally movable element, and where the gear has at least two gearing stages. The first stage is constituted by a worm drive with a worm—() and the subsequent gearing stage is constituted by a crown and bevel wheel (). The crown wheel faces towards the worm drive and has a power take-off () in extension of or in all essentials in extension of the worm () or parallel thereto. The bevel wheel () is with its axis of rotation arranged perpendicular in relation to the axis of rotation of the worm (), and the worm wheel () is in drive connection with the bevel wheel () through a gear train (). Thus a relatively compact transmission with a high gearing is achieved, and by having worm wheels, toothed gearing and bevel and crown wheels of plastic the transmission is in addition silent. A good tooth mesh between bevel wheel and crown wheel is particularly important. The gear may be used in a linear actuator which again may be used in a height adjustable table leg.