Heading work on mechanics (cylindrical reduction gear (helical) with chain gear)

Contents

Contents

Introduction

1 Motor selection and kinematic calculation of the drive

2 Determination of power and transmitted torque on drive shafts

3 Calculation of gears

3.1 Calculation of cylindrical transmission

3.2 Calculation of chain transmission

4 Preliminary calculation of shaft diameters

5 Coupling selection

6 Preselection of bearings

7 Layout diagram and selection of lubrication method of gears and bearings, sizing of housing parts

8 Calculation of shafts by equivalent moment

8.1 General parameters

8.2 Calculation of high-speed shaft

8.3 Calculation of low-speed shaft

9 Selection of bearings by dynamic lifting capacity

9.1 Calculation of high-speed shaft bearings

9.2 Calculation of low-speed shaft bearings

10 Selection and check calculation of key connections

11 Assignment of fits, surface roughness, selection of accuracy, and assignment of feature control tolerances

12 Calculation of shafts for endurance

12.1 Calculation of high-speed shaft

12.2 Calculation of low-speed shaft

13 Description of gearbox assembly and adjustment

Literature

13 Description of gearbox assembly and adjustment

Before assembly, the inner cavity of the reduction gear box (17 and 18) must be thoroughly cleaned and covered with oil-resistant paint. Assembly is carried out in accordance with the assembly drawing, starting with shaft assemblies.

Oil-breaking washers (6) and bearings 7209A (35) are put on high-speed shaft (14). Then high-speed shaft bearings are adjusted. Roller conical bearings are installed on the shaft according to the "emergency" scheme. The purpose of the adjustment is to determine the number of gaskets (21) required to install the bearing cover (3 and 4) under the flange to ensure smooth rotation of the shaft in the housing. Preloading is not allowed. Preliminary axial freedom is undesirable. For this purpose shaft assembly with all adjacent parts (spacer rings, collar, high-speed shaft bearing covers - pos. 8,10,32, 3 and 4) must be installed in the housing, after which - the housing cover must be put on the housing. Then one of the bearing covers is removed, and gaskets are installed under its flange. Then the bearing cover is installed in the housing, after which the rotation of the shaft is checked. If necessary, remove the bearing cover again and change the number of gaskets. Once this number of gaskets has been determined, all bolts should be unscrewed, the covers removed from the base and the shaft assembly removed from the housing. In order that the bearings are not jammed as a result of the thermal extension of the shaft, 3-5 pieces must be added to the resulting number of gaskets to provide a preliminary clearance of 0.30.5 mm, which will disappear when the shaft is heated to operating temperature.

Gear wheel (15) with key (44), spacer ring (9) and bearings (36) should be put on slow-moving shaft (13). Then the low-speed shaft bearings are adjusted (in a manner similar to the high-speed shaft bearings).

Now the gaskets should be distributed under the flanges of the bearing covers so that the gear teeth enter the wheel teeth along the entire width of the rim. This is how the engagement is adjusted.

Now, tighten all the bolts. Screw the oil indicator (1) to the housing wall, screw the oil drain hole with plug (11). Pour 1.9 l of oil through the inspection window.

The assembled gearbox shall be run in accordance with the specifications.