Worm gear and worm
Worm gear worm mechanism is commonly used to transfer the movement and power between the two staggered axis.Worm gear and worm in the middle of the plane is equivalent to gear and rack, worm and screw shape is similar.
Modulus m, pressure Angle, worm diameter coefficient q, lead Angle, worm head number, worm gear number, tooth height coefficient (take 1) and top clearance coefficient (take 0.2).Among them, modulus m and pressure Angle refer to the modulus and pressure Angle of worm shaft surface, that is, the modulus and pressure Angle of turbine end face, and both are standard values.The diameter coefficient q is the ratio of the diameter of the dividing circle of the worm to its modulus m.
Worm gear and worm roughly these series: 1, WH series worm gear and worm reducer: WHT/WHX/WHS/WHC2, the CW series worm gear and worm reducer: CWU/CWS/CWO3, WP series worm gear and worm reducer: WPA/WPS/WPW/WPE WPZ/WPD4, TP series enveloping worm gear and worm reducer: TPU/TPS/TPA/TPG5, PW type planar quadratic enveloping torus worm reducer in addition, according to different shape of the worm, the worm drive can be divided into cylindrical worm drive, ring surface worm drive and cone worm drive.
Features of the mechanism
1. Large transmission ratio can be obtained, which is more compact than the staggered helical gear mechanism.2. There is a linear contact between the meshing tooth surfaces of two wheels, and its carrying capacity is much higher than that of the staggered helical gear mechanism.3. Worm drive is equivalent to spiral drive, which is multi-tooth meshing transmission, so the transmission is smooth and the noise is small.4. Self-locking.When the lead Angle of worm is less than the equivalent friction Angle between meshing gear teeth, the mechanism has self-locking, can achieve reverse self-locking, that is, only the worm drive worm gear, but not by the worm drive worm gear.Such as in the lifting machinery used in the self-locking worm mechanism, its reverse self-locking can play a safety role.5. Low transmission efficiency and serious wear.Worm gear meshing transmission, the relative sliding speed between meshing gear teeth is large, so the friction loss is large, low efficiency.On the other hand, the relative sliding speed means that the tooth surface is severely worn and heated. In order to dissipate heat and reduce wear, expensive materials with good anti-friction and anti-wear properties and good lubrication devices are often used, so the cost is relatively high.6. Large axial force of worm.
Worm gear and worm mechanism is often used for two shaft staggered, transmission ratio, transmission power is not large or intermittent work occasions