I finally understand the working principle of the worm gear this time!

Release Time：

2024-11-28

The worm gear transmission is composed of a worm gear and a worm wheel, with the worm gear being the active component. Worm gears, like threads, can be divided into right-handed and left-handed worm gear transmissions, known as right-handed worm gears and left-handed worm gears, respectively. A worm with only one spiral line on it is called a single head worm, which means that when the worm rotates once, the turbine rotates one tooth; If there are two spiral lines on the worm, it is called a double headed worm, that is, when the worm rotates once, the turbine rotates two teeth.

Worm gear mechanisms are commonly used to transmit motion and power between two intersecting shafts. The worm gear and worm gear are equivalent to gears and racks in their middle plane, and the worm gear is similar in shape to a screw.

So, what is the working principle of worm gear? Today we will share.

The worm gear mechanism usually has a 90 ° angle between the two shafts, and is usually driven by the worm gear. From the appearance, the worm is similar to a bolt, while the worm wheel is very similar to a helical cylindrical gear. During operation, the worm gear teeth slide and roll along the helical surface of the worm. In order to improve the contact between the gear teeth, the worm wheel is made into a circular arc shape along the tooth width direction, so that it wraps around the worm part. This way, when the worm wheel and worm wheel mesh, it is in line contact rather than point contact.

The characteristics of a worm gear: 1. It can achieve a large transmission ratio and is more compact than a helical gear mechanism with staggered shafts.

2. The meshing teeth of the two wheels are in linear contact, and their load-bearing capacity is much higher than that of the helical gear mechanism with staggered shafts.

3. Worm gear transmission is equivalent to spiral transmission, which is a multi tooth meshing transmission, so the transmission is smooth and the noise is very low.

4. It has self-locking properties. When the lead angle of the worm is less than the equivalent friction angle between the meshing teeth, the mechanism has self-locking properties and can achieve reverse self-locking, that is, only the worm can drive the worm wheel, not the worm wheel. The self-locking worm mechanism used in lifting machinery can provide safety protection through its reverse self-locking property.

5. Low transmission efficiency and severe wear. When the worm gear is engaged in transmission, the relative sliding speed between the meshing teeth is high, resulting in high friction loss and low efficiency. On the other hand, due to the high relative sliding speed, the tooth surface wear and heat generation are severe. In order to dissipate heat and reduce wear, expensive materials with good anti friction and anti-wear properties, as well as good lubrication devices, are often used, resulting in higher costs. 6. The axial force of the worm is relatively large.