A worm drive consisting of a cone worm and a cone worm wheel.
The stagger angle of the two axes is typically 90°.
The cone worm is a cone of equal lead.
The cone worm wheel is paired with a cone worm, and its shape resembles a worm wheel of a curved bevel gear.
The cone worm is placed on one side of the cone worm (see figure).
The characteristics of the cone and worm drive are:
① The number of pairs of teeth that are in contact at the same time is large, and the degree of coincidence is large (see gear transmission), so the transmission is stable;
② The transmission ratio is large, and the single-stage transmission ratio can be 10~400 when used as a reduction device;
③ The angle between the contact line and the relative sliding speed is close to 90°.
The lubricating oil film is easily formed between the tooth surfaces, so the bearing capacity is large and the efficiency is high;
④ The 4-cone worm wheel can move axially away from the cone worm.
At this time, the minimum distance between the two axes remains unchanged, so the two are convenient to be used and can be used as a clutch.
⑤ Can use hardened steel instead of copper alloy as the worm gear material;
⑥ Can be used for speed increase transmission;
⑦ Due to the asymmetry, the bearing capacity and efficiency are different when the force is different during forward and reverse rotation.