Design and research of mechanisms of electric pump unit

Introduction

In mechanical engineering, reducers, mechanisms consisting of gear or worm gears made in the form of a separate unit and serving to transfer power from the engine to the working machine are widely used. The kinematic drive circuit may include, in addition to the gearbox, open gears, chain or belt gear.

The purpose of the reduction gear is to reduce the angular speed and increase the torque of the driven shaft compared to the driving shaft. Mechanisms for increasing angular velocity are made in the form of separate units, called multipliers.

Structurally, the reduction gear consists of a housing (cast, cast iron or welded steel), in which the transmission elements are placed - gears, shafts, bearings, etc.

The reduction gear is designed either to drive a certain machine, or to a given load (torque on the output shaft) and gear ratio without specifying a specific purpose.

The drive is supposed to be located in a closed, heated, ventilated room equipped with a three-phase AC supply.

The drive to the horizontal shaft consists of a cylindrical reduction gear, the high-speed shaft of which is connected to the motor by belt transmission, and on the slow-speed shaft there is a compensating clutch.

Selection of allowable torsional stresses

Design calculation of shafts is performed by torsion stresses (as in case of clean torsion), i.e. at that bending stresses, stress concentrations and time stress variability are not taken into account. Therefore, to compensate for the approximation of this calculation method, the permissible torsional stresses are used underestimated: 〖 [a] 〗 _ k = 10... 20 MPa. Since for high-speed shafts the lower values are used, and for low-speed shafts the higher values are used, then for further calculation of high-speed shaft we take [a] = 11MPa, for low-speed shaft - [a] = 18 MPa.

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