The ground spring is also a hydraulic door closer, except that it presses the spring with a worm gear rather than a rack and pinion.Because the worm wheel can be rotated in a positive and negative direction, the ground spring can be used for two-way open doors, while the door closer can only be used for one-way open doors.The technical key of the ground spring is the bearing seat at the lower part of the main shaft, which determines the bearing grade of the landing spring.Because the ground spring used for two-way doors carries the weight of the door, the weight of the door is crucial to the selection of the ground spring compared to the door closer.Door width and air pressure are also important in choosing the type of ground spring.
From the perspective of production, the worm wheel structure of ground spring makes the compression degree of spring smaller than that of the rack-geared door closer, and the force arm of ground spring door closing is shorter, so the mass of ground spring depends more on the structural design and machining accuracy.In addition, as the door leaf of two-way door has great force on the ground spring along the plane of the door leaf, the service life of low grade ground spring and the gap of high grade ground spring will be very large.The basic configuration of the ground spring is the celestial axis and the ground axis (or the foot).The shaft is an upper fitting that connects the door frame to the door leaf. It consists of a bolt - adjusting bolt shaft fixed to the door leaf and a shaft sleeve fixed to the door leaf.The shaft can be used for almost all wooden, steel, aluminum alloy doors and bezel-free glass doors with glass door clips.The installation precision of ground spring has great influence on its service life.Since the end of the service life of the ground spring is oil leakage, if the axial line between the shaft and the ground spring is not strictly perpendicular to the ground, the movement of the door will bring great torque to the ground spring, increase the wear between the spindle and the bearing, and finally lead to oil leakage.