Worm-gear. Principle of operation

Worm gear provides conversionMovement according to the principle of the second pair or the inclined plane. In this case, diameters of long and initial cylinders are distinguished. The pole of the link is the point of tangency of the initial cylinders.

The worm gear includes a screw (whichcalled a worm) and a wheel. The angle of the cross between the shafts of the wheel and the screw can be different. However, as a rule, it is equal to ninety degrees. The worm gear has the advantage over the toothed-helical gear. It manifests itself in the fact that the initial contact of the links is not carried out at a point, but along a line. The rim of the wheel, which includes the worm gear, has a concave shape. The screw thread can be left or right, multi-threaded or single-threaded.

Worms are distinguished by the shape of the surface, wherea thread is formed. In accordance with this, there are globoidal and cylindrical. In view of the shape of the profile, curvilinear and rectilinear types are distinguished. The most common are cylindrical worms. In parts with a straight profile in the cross section, the turns are delineated by an Archimedean spiral. Therefore they are called Archimedean worms. They are similar to threaded screws with trapezoidal threads. They can be cut on a thread-milling or conventional lathe.

Practice has shown that the motor is a reducer wormIt is characterized by increased capacity for work, provided the hardness of the thread is increased. In recent years, more and more widespread high-strength polished parts. For processing products, special grinding wheels with a shaped profile are used. However, this makes processing difficult and lowers accuracy in manufacturing. In this regard, the production of archimedean worms is carried out with unpolished coils. For the processed high-hardness elements, involute parts having a corresponding profile in the end section are used. The main advantage of these worms is the ability to grind the turns with the help of the flat side of the circle. But with this special machines are needed.

The worm gear motor NMRV is aexclusive use electric motor. Advantages of the detail in a compact size, quiet and smooth operation. Due to the unified connecting dimensions, this reducer can be used instead of the units of other manufacturers. Due to the fact that the output shaft and the universal housing are deployed under a right angle, somewhat modernized, the part can be placed in places where models with a coaxial shaft arrangement can not be established. Thanks to modern injection molding technology, advanced models of aggregates are being manufactured today.

The worm wheel is cut by the correspondingmilling cutters. They are identical to the screws. However, the cutters have an outer diameter and the cutting edges are twice the size of the radial clearance. When cutting the workpiece, the wheel and the cutter reciprocate along the same principle as the worm gear.