8 kW cylindrical gearbox

Contents

Introduction

Reduction gear - mechanism for reduction of rotation speed and increase of torque; reduction gear is a complete mechanism connected to the engine and the working machine by clutches or other detachable devices. In the gearbox housing there are gear or worm gears fixed on shafts that rest on rolling or sliding bearings (they are usually used in special cases when the gearbox is subject to increased requirements for vibration and noise at very high speeds of rotation). In this work, it is necessary to perform the task of designing the electromechanical drive of the process equipment. The drive includes a single-stage cylindrical reduction gear in combination with a belt gear.

During the work, it is required to calculate the kinematic parameters of the drive, perform design and check calculations of the cylindrical gear and belt gear and gearbox shafts, design elements of the single-stage gearbox, make a sketched arrangement of the gearbox. It is also necessary to draw the assembly drawing of the gearbox and drive, make specifications to them, draw working drawings of the slow-moving shaft, gear wheel and low-moving shaft bearing cover.

Gearbox assembly

Prior to assembly, inner cavity of housing is cleaned and covered with oil-resistant paint. Assembly is performed in accordance with gearbox assembly drawing, starting from shaft assemblies.

Ball bearings pre-heated in oil to 80100 ° C are fitted on the drive shaft. Key is laid in driven shaft and wheel is pressed until stop against shaft collar. Then bearings preheated in oil are installed.

The assembled shafts are laid in the base of the reduction gear case and put on the cover of the case, covering the surface of the joint of the cover and the case with alcohol varnish. For alignment, a cover is installed on the body using two pins; bolts that attach the cover to the housing are tightened.

Prior to installation of through covers, felt seals impregnated with hot oil are put into grooves. By turning the shafts there is no jamming of bearings (the shafts must be rotated by hand) and the covers are fixed with screws.

Then plug of oil discharge hole with gasket and iron oil indicator are screwed in. Oil is poured into housing and inspection hole is closed with cover with gasket. Cover is bolted.

Shafts of the assembled reduction gear must be rotated by hand without jamming. The assembled gearbox is rolled and tested on the bench according to the program set by the specifications.

Conclusion

In the course of this work, a single-stage cylindrical gearbox with spur gear was calculated and designed.

The large distribution of gears is due to a number of significant advantages. We note the main ones: compactness, the ability to implement a constant transfer ratio, high efficiency, durability, reliability in operation, ease of maintenance, use for the manufacture of economical materials. Rolling bearings are also installed, which have a number of advantages: less moment of friction forces, less heating, insignificant lubrication consumption, ease of maintenance.

During the work, the goal was achieved - to design gearboxes of the simplest and most economical design.