Worm gearbox with gear ratio 20

Contents

Introduction

Kinematic calculation of power drive

Select and check the electric motor

Determination of rotation speeds of drive shafts

Determination of angular speeds of drive shafts

Determination of capacity on drive shafts

Determination of torque on drive shafts

Worm Gear Calculation

Source Data

Select worm pair material and allowable stresses

Defining the Geometry of the Worm Engagement

Transmission check calculations

Determination of forces engaged and transmission efficiency

Thermal calculation and cooling of worm gears

Worm and Worm Wheel Design

Open Gear Cylinder Gear

Define Allowable Stresses

Determining Gear Sizes and Engagement Parameters

Check calculation of open cylindrical transmission

Determining the Forces Engaged

Gear Design

Driving wheel

Design calculation of gear box shafts

Structural dimensions of gearbox housing

Preselection of bearing

Pinch Pick

Design of bearing assemblies

Select Connections

Calculation of key connections

Lubrication of clutches

Coupling selection and check calculation

Gearbox Assembly Order

Conclusion

List of sources used

Appendix A

Appendix B

Appendix B

Summary

The course project is devoted to the development of the design of the worm gear box and its parts. This gearbox is used if it is necessary to monitor and then change the torque and, if necessary, angular speed. The work considers the development of the design of modern conical gearboxes using progressive design methods and computer technologies, as well as reference books and methodological literature.

The calculation and explanatory note to the course project contains 32 pages of basic typewritten text (without annexes), including: 29 tables, 11 figures, a list of 6 sources used and 3 annexes.

Attachments include: gearbox assembly drawing, specification to worm gearbox assembly drawing, low-speed shaft working drawing, worm wheel working drawing.

The graphic part is made on 1 sheet of A1 format, 2 sheet of A2 format. The graphic part of the project includes: gearbox assembly drawing and working drawings of two parts of the gearbox, made using the COMPAS graphic editor.

9 Gearbox Assembly Procedure

Prior to assembly, inner parts of body parts are cleaned and covered with oil-resistant paint. Before the general assembly, shafts with fitted parts are assembled. Upper bearing, bushing, lower bearing are put on slow-moving shaft. Assembled shaft is inserted into casing hole. Bearings are heated in oil before assembly. A collar is installed in the bearing cover. Then a bearing cover is put on the shaft, which is attached to the housing. Rolling bearings preheated in oil are put on high-speed shaft-worm. The reduction gear case together with the installed high-speed shaft is installed on the base and fixed with bolts. The cover of the housing is put on top of the reduction gear case and fixed with bolts. Bearing covers are put on the high-speed shaft from above, which are attached to the housing with screws. Prior to installation, collar seals pre-impregnated with oil are inserted into the grooves of bearing covers. Then adjustment gaskets (set) are put on bearing covers. Assembled covers are inserted into housing sockets and attached to it. After assembly the gear box is adjusted. Adjustment of bearings is performed by a set of adjusting gaskets installed between the housing and bearing covers. Adjustment of low-speed shaft bearings (radial bearings are installed on the shaft) consists in creating a gap between the end face of the external bearing ring and the end face of the bearing cover. The required clearance is obtained by adjusting the thickness of the adjusting gaskets. Adjustment of high-speed shaft bearings (radial bearings) consists in creation of preliminary tension in bearings (displacement of external ring of bearing relative to internal one) due to change of thickness of adjusting gaskets. In the assembled gearbox, the high-speed shaft must rotate freely. The plug of the oil outlet is twisted. Oil is poured. The assembled reduction gear is rolled.