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| Worm Gear transmission principle and the use of |
First, the worm reducer basic parameters:
Modulus m, pressure angle, worm diameter coefficient q, lead angle, the first few worm, worm gear teeth, addendum coefficient (take 1) and top clearance coefficient (take 0.2). Among them, the modulus m and the pressure angle is the worm axis, the modulus and the pressure angle, that worm axis, the modulus and the pressure angle, and are the standard value; worm diameter coefficient q for the worm pitch diameter with mold the ratio of the number of m,
Second, with the spur gear geometry calculation is basically the same, should pay attention to several issues:
Worm lead angle () is the worm indexing tangent cylinder helix angle between the worm end, and the relation between the screw helix angle, worm’s helix angle, for big high transmission efficiency, while smaller than the tooth meshing friction angle between the equivalent, the agency self-locking.
Worm diameter coefficient q introduced to limit the number of worm hob, so that the worm pitch diameter was standardized m is constant, q large is large, worm shaft increases the stiffness and strength of the corresponding; is constant, q is a small lead angle increases, a corresponding increase in transmission efficiency.
1,2,4,6 worm is recommended for the first few, when taking a small value, the transmission ratio, and has a self-locking nature; when to take a large value, the transmission efficiency.
And cylindrical gear different, Worm gear ratio is not equal to agencies, but rather, the center distance worm gear sector is not equal, but.
Worm gear drive in turn determine the method, according to the mesh points at the direction of K, the direction (parallel to the spiral tangent) and the worm should be perpendicular to the axis of the velocity vector triangle to determine the painting; also be used "right-hand worm left hand, left Rotating worm right hand, four fingers thumb "to determine.
Third, the conditions are properly engaged worm
1, the middle plane of the worm and worm wheel module and pressure angle are equal, that is the end worm gear worm shaft modulus is equal to the number of surface modes and the standard value; worm gear pressure angle should be equal to the ends of the worm and the axial pressure angle standard value, that is, == m, ==
2, when the crossing angle worm too, need to ensure, and worm and worm helix spiral to be the same.
Fourth, the characteristics of worm and worm gear transmission ratio can be much more than compact crossed helical gears
Two mating tooth surfaces line contact between its carrying capacity much higher than the crossed helical gears
Equivalent to screw worm drive transmission, multi-tooth gear transmission, so the smooth transmission, noise is very small
With self-locking nature. When the worm lead angle is less than the equivalent of friction between the meshing gear tooth angle, the body of a self-locking, reverse self-locking can be achieved, that can only be driven by the worm gear, worm gear driven by the worm can not. If heavy machinery is used in its self-locking worm gear, the reverse self-locking security protection can play the role of
Lower transmission efficiency, wear more serious. Worm gear transmission, the meshing gear teeth relative sliding velocity between the large, so the friction loss, low efficiency. On the other hand, the relative sliding speed wear of tooth surfaces Ambassador serious, serious heat, to heat and reduce wear and tear, often in the more expensive the better friction reduction and wear resistance of materials and good lubrication devices, and thus higher costs Worm larger axial force
Fifth, use:
Worm and worm wheel used to transfer between the two cross-axis motion and power. In which inter-worm and worm gear and rack is equivalent to the plane, and the screw worm and similar shape.
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| Add Date：2011/5/13 From：艾克森 Hits: 2648 |
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