When Selection worm gear reducer, confirm that its self-locking function cannot be generalized, because not all worm gear reducers have reliable self-locking capabilities. You can confirm by following these steps:
1. Step one: Check the product manual
This is the most direct and reliable method. Regular manufacturers" product manuals usually clearly indicate whether the reducer has a self-locking function.
Direct marking: Look for clear instructions such as "with self-locking function", "reverse self-locking" or "static self-locking".
Parameter annotation: If there is no direct explanation in the manual, you can look for the parameter "worm lead angle (λ)". Generally, reducers with a lead angle less than 5° (especially less than 4°) are more likely to be self-locking.
2. Step 2: Judgment through core parameters
If the manual information is incomplete, you can evaluate the possibility of self-locking through the following core parameters.
The fundamental principle of self-locking is: the lead angle (λ) of the worm must be smaller than the equivalent friction angle (ρ) of the worm gear meshing surface.
1. Worm lead angle (λ)
This is the key geometric parameter that determines self-locking. The smaller the lead angle, the stronger the self-locking ability, but the lower the transmission efficiency.
Experience value: Generally, the lead angle of a single-head worm is smaller, making it easier to achieve self-locking; while a multi-head worm has high efficiency, but its self-locking ability will be significantly reduced or even lost.
2. Reduction ratio (i)
The reduction ratio has a strong correlation with self-locking ability and can be used as a basis for quick judgment.
Rule of thumb: It is generally believed that when the reduction ratio is greater than 30:1, the reducer has better self-locking properties; the larger the reduction ratio, the more reliable the self-locking is. On the contrary, when the reduction ratio is less than 25:1, the self-locking function may be unreliable.
3. Friction coefficient (μ) and material
The friction coefficient determines the friction angle (ρ = arctan μ). The material pairing of the worm gear (such as steel worm with bronze worm gear) and lubrication state directly affect the friction coefficient.
Generally speaking, the larger the friction coefficient, the easier it is to achieve self-locking, but the transmission efficiency will decrease.
