IX Международная студенческая научная конференция Студенческий научный форум - 2017

Transmission

Transmission device is serving for power transmission and mechanical movement over a distance and conversion of the motion parameters.

The programs produce energy distribution, rise and fall speed, mutual transformation of types of motion, such as a rotary to linear and vice versa. The gear speed control, start, stop, reverse.

Gear transmission mechanisms

They are intended for transmitting rotation from one shaft to another, there is a change in the magnitude and direction of angular velocity with simultaneous change of the magnitude of torque.

Needs to increase speed appeared in ancient times, when the source of the movement were the wind and water. Then there cogwheels.

There is a need to reduce the speed With the advent of the electric drive. Compact engines were produced at higher speeds.

Currently, the gears have an enormous spread. In engines transmission from the crankshaft to the other shafts (valve mechanism, magnetos. Generator). The machines - Transmission. All transmissions of building and lifting machinery cranes, excavators, loaders - is turning mechanisms of movement, ladle drive chains, rotors, cutters.

Various geared motors and drives power tools have gears.

In these programs contact is specially shaped side surfaces of the teeth. The pressure of the rotating driving wheel is transferred to the driven gear teeth, realizing the rotation.

Gear mechanism, which is a reduction of the angular velocity in the transmission of motion from the input member to the output, called a downshift or reducers. Toothed mechanisms in which the angular velocity increases, called overdrive multiplier. In engineering, more often it is necessary to lower the speed the use of gear, so the calculation and design of gear is given special attention. Requirements to be met by a gear reducer, are in obtaining the necessary gear ratios (often very large) with high-quality indicators, which are the efficiency, kinematic accuracy, torsional rigidity, with perhaps small overall dimensions, weight, and high reliability of the gearbox.

Basic terms and definitions.

Gear ratio - the ratio of the angular velocities of the two rotation-cleaning units.

Fig. 1 is a diagram of a simple three-tier gear mechanism. Two mobile unit (gears a and b) are rotated relative to the third is second, a fixed link (rack c)

The gear ratio denoted «i» letter with indexes, for example (C) AB i. The superscript (in parentheses) indicates which of the links of the mechanism Holy linked coordinate system, which defines the angular velocity (and the very transition datochnoe ratio), and the lower - input and output link between them

The gear ratio is considered. By definition, for two links «a» and «b», with the system of coordinates associated with the link cangular vye speed (C) wA and (C) wB

Angular speed and gear ratios found in the coordinate system ordinates associated with the mechanism of the counter are considered absolute; superscript index in their notation can be omitted. When calculating the transmission Relations are generally used modules of the angular velocity, so i> 0. If the two links are rotated about parallel axes, not substituted units and projection (with sign) of the angular velocity on the axis parallel to them. In this case, maybe i

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