Design of the main gearbox of the helicopter

Contents

Legend List

Introduction

Kinematic and energy calculation of reduction gear box

Determination of total gear ratio

Determination of shaft speeds

Transmission Efficiency Assignment

Determination of capacities on shafts

Determination of torques on shafts

Planetary transmission design

Select Gear Material

Definition of allowable contact stresses

Defining Allowable Bending Stresses

Determining the main dimensions of the transmission

Define Module and Tooth Numbers

Defining Geometric Transmission Parameters

Test calculation for contact and bending strength

Definition of the main dimensions of the "crown"

Conical Transmission Design

Select Gear Material

Definition of allowable contact, bending stresses

Determining the main dimensions of the transmission

Define Module and Tooth Numbers

Defining Geometric Transmission Parameters

Test calculation for contact and bending strength

Gearbox alternative design

Analysis of Design Results

Evaluation of shaft diameters

Preliminary selection of bearings

Calculation of shafts for strength and selection of bearings for the specified life and reliability

Input shaft calculation

Calculation of intermediate shaft

Output shaft calculation

Satellite Calculation

Calculation of splined joints

Calculation of helicopter gearbox attachment bolts to the frame

Reduction gear box lubrication

Conclusion

List of sources used

Applications

Project Description

Course project.

Explanatory note: 28 pages, 5 fig., 1 table, 4 sources, annex

Graphic documentation: 3 sheets A1, 2 sheets A3, 2 sheets A4.1 sheets 3xA4, 3 sheets A4 specification.

ANALYSIS, SHAFT, DIMENSIONS, EFFICIENCY, MODULE, POWER, VOLTAGE, GEAR RATIO, CONICAL TRANSMISSION, PLANETARY TRANSMISSION, BEARING, GEARBOX

The course project considered synthesis, as well as kinematic, energy, design calculation and analysis of the helicopter reduction gear. The number of teeth of gear wheels was selected, the main dimensions of the gears were determined, the gearbox was checked for contact and bending strength. An alternative version of the gearbox was designed. Shaft diameters were evaluated and bearings were pre-selected. Forces in engagement are calculated. Calculations were made: bearings for durability, shafts for strength, splined joints, bolts for attachment of the reduction gear box to the helicopter frame. The reduction gear box lubrication system is created.

Introduction

To transfer motion from the engine to the actuator, a reduction gear is used, due to which the torque increases and the speed decreases. It is compact, reliable and durable. Therefore, gearboxes are widely used in mechanical engineering. Gear gears in the gearbox have high efficiency and can transmit high loads.

In this work, the main gearbox of the helicopter is designed. The main requirements for the designed machine are reliability and durability, convenience and ease of maintenance.

To meet these requirements, parts must meet a number of criteria, the most important of which are strength, reliability, stability, wear resistance, stiffness, vibration resistance, heat resistance, processability.

Gearbox alternative design

To reduce the dimensions of the gearbox, recalculate the conical gear by taking ¼ bd = 0.5. Calculation of an alternative version of the gearbox was carried out on the machine.

Calculation results are given in Appendix

Analysis of Design Results

Calculating the alternative version, we received new dimensions of the conical gear: the width of the wheels increased, the diameters of the wheels decreased. All strength conditions are met. Therefore, this embodiment is preferred. In the future, we will count him.

Calculation of helicopter gearbox attachment bolts to the frame

Calculation of the gear box attachment bolts to the frame is considered in the appendix. Calculation was made on the computer using data on bolts, their location, as well as on the data of the housing.

The design stress does not exceed the allowable voltage.

Lubrication system

To reduce friction power losses and wear intensity of friction surfaces, as well as to prevent them from jamming, gouging, corrosion and better heat removal, the parts should be lubricated.

In the designed reduction gear, the lubrication system is flowing, recirculating. As part of the course design, oil supply through the housing was considered. We use oil grade IMP-10. Oil is supplied through nozzles under pressure All pairs of reducer are lubricated:

For bearings installed on the output shaft, the oil supply through the nozzle is designed, and the LPG jet enters the rolling bodies.

For bearings installed on the satellite and the entire planetary transmission, a lubrication system is also provided through the nozzle

For the input shaft system, LPG from the planetary gear, oil pairs are used, and oil supply is also provided to the splines of the intermediate shaft from the inside.

The designed reduction gear has a waste LPG discharge system for its cooling and cleaning.

Conclusion

The results of the work were the acquisition of skills in calculating, designing and designing a helicopter gearbox, creating process documentation, specification and assembly drawing of the designed gearbox.

The main gearbox of the helicopter was designed, kinematic, energy calculations of the drive were carried out, geometric parameters were determined, permissible and contact stresses were calculated, a lubrication system was designed, bearings were calculated for durability, splined joints were calculated.