28 November 2019

Advantages and disadvantages of worm gear

Worm gear drive is used to transmit power between two non-intersecting shafts, which are at right angles to each other consists of a worm and a worm wheel. The worm is a threaded screw, while the worm wheel is toothed gear. The teeth on the worm wheel envelope the threads on the worm and give the contact between mating parts. Let us have a deep insight into the benefits and drawback of the worm gear in this article. 

Advantages of worm gear : 

  • High-speed reduction: A speed reduction is as high as 100:1 can be obtained with a single pair of worm gear. 
  • The worm gear is compact with small overall dimensions, compared with equivalent spur or helical gear drives having same speed reduction. 
  • The operation is smooth and silent. 
  • Provision can be made for self-locking operation, where the motion is transmitted only from the worm to the worm wheel. This is advantageous in application like cranes and lifting devices. 
  • The worm gear has good meshing effectiveness.
  • The worm gear used for reducing speed and increasing torque. 

Disadvantages of worm gear : 

  • The efficiency is low as compared with the other types of gear drives. 
  • The worm wheel is made of phosphor bronze, which increases the cost. 
  • A considerable amount of heat is generated in worm gear drives, which is required to be dissipated by a lubricating oil to the housing walls and finally to the surroundings.
  • The power transmitting capacity is low. 
  • It is used for up to 100 kW of power transmission. 
  • Lubrication must be strictly maintained for the healthiness of worm gear.