tailieunhanh - Sổ tay tính toán cơ khí P20

Source: HANDBOOK OF MECHANICAL ENGINEERING CALCULATIONS SECTION 20 GEAR DESIGN AND APPLICATION Analyzing Gears for Dynamic Loads Helical-Gear Layout Analysis Analyzing Shaft Speed in Epicyclic Gear Trains Speeds of Gears and Gear Trains Selection of Gear Size and Type Gear Selection for Light Loads Selection of Gear Dimensions Horsepower Rating of Gears Moment of Inertia of a Gear Drive Bearing Loads in Geared Drives Force Ratio of Geared Drives Determination of Gear Bore Diameter Transmission Gear Ratio for a Geared Drive Epicyclic Gear Train Speeds Planetary-Gear-System Speed Ratio ANALYZING GEARS FOR DYNAMIC LOADS A two-stage, step-up gearbox. | Source HANDBOOK OF MECHANICAL ENGINEERING CALCULATIONS SECTION 20 GEAR DESIGN AND APPLICATION Analyzing Gears for Dynamic Loads Helical-Gear Layout Analysis Analyzing Shaft Speed in Epicyclic Gear Trains Speeds of Gears and Gear Trains Selection of Gear Size and Type Gear Selection for Light Loads Selection of Gear Dimensions Horsepower Rating of Gears Moment of Inertia of a Gear Drive Bearing Loads in Geared Drives Force Ratio of Geared Drives Determination of Gear Bore Diameter Transmission Gear Ratio for a Geared Drive Epicyclic Gear Train Speeds Planetary-Gear-System Speed Ratio ANALYZING GEARS FOR DYNAMIC LOADS A two-stage step-up gearbox drives a compressor and has a lubrication pump mounted on one of the gear shafts Fig. 1. Tables 1 2 and 3 show the spur-gear data tolerances for tooth errors and polar moments of inertia for the masses in the compressor drive. All gears in the drive have 20 pressure angles. The gears are made of steel the compressor is made of cast iron. A 50-hp motor drives the gearbox at 3550 rpm. What are the dynamic loads on this gearbox Calculation Procedure 1. Determine the pitchline velocity V applied load W at each mesh and shaft speed n In the equations that follow subscripts identify the shaft gear or mesh under consideration. For example the subscript A denotes Shafts A1 and A2 B Shaft B and C Shaft C. Also subscripts 1 2 3 4 refer respectively to Gears 1 2 3 and 4 in the gearbox. The subscripts a and b denote the mesh of Gears 1 and 2 and the mesh of Gears 3 and 4 respectively. Finally subscripts r and n refer to the driver gear and driven gear. Full nomenclature appears at the end of this procedure. For Shaft A1 and A2 Downloaded from Digital Engineering Library @ McGraw-Hill Copyright 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the .