Worm Gear Design Calculation Pdf

A box must contain a worm and a mating gear (helical gear) and normally the axis of the worm is perpendicular to the axis of the gear. Look at the picture below: Where, D1 – Pitch Diameter of Worm D2 – Pitch Diameter of Gear C – Centre to Centre Distance between the Worm and the Gear This worm gear design tutorial will discuss up to the selection of the module and pitch and the calculation of the number of teeth, pitch circle diameter and centre to centre distance between the worm and gear. We will use the AGMA formulae for doing the calculations. Design calculations of the other aspects of the worm gear will be discussed in a subsequent part of the tutorial. Steps of the Design Calculation • The axial pitch of the worm and the circular pitch of the gear must be same for a mating worm and gear. We will use the term Pitch (P) for both the pitch in this tutorial. • Also, the module of the worm as well as the gear must be equal for a mating worm and gear. Pongal Related Songs Free Download.

• Now, let’s say we have the following design input: Speed of the Worm (N1) = 20 RPM Speed of the Gear (N2) = 4 RPM • And, we have to find out the Module (m), Pitch (P), Number of helix of Worm (T1), Number of teeth of Gear (T2), Pitch circle diameter of Worm (D1), Pitch circle diameter of Gear (D2), Centre to centre distance(C). • Select the suitable module and its corresponding pitch from the following AGMA specified table: Module m (in MM) - Pitch P (in MM) 2 -------------------------6.238 2.5 ---------------------- 7.854 3.15 --------------------- 9.896 4 ------------------------- 12.566 5 ------------------------- 15.708 6.3 ----------------------- 19.792 8 -------------------------- 25.133 10 ------------------------- 31.416 12.5 ----------------------- 39.27 16 -------------------------- 50.625 20 -------------------------- 62.832 • Say, we are going ahead with the Module as 2 and the Pitch as 6.238. • Use the following gear design equation: N1/N2 = T2/T1 And, we will get: T2 = 5 * T1.Eqn.1 • Now use the following AGMA empirical formula: T1 + T2 >40Eqn.2 • By using the two equations ( Eqn.1 & Eqn.2), we will get the approximate values of. T1 = 7 and T2 = 35 • Calculate the pitch circle diameter of the worm ( D1) by using the below AGMA empirical formula: D1 = 2.4 P + 1.1 = 16.0712 mm • The following AGMA empirical formula to be used for calculating the pitch circle diameter of the gear ( D2): D2 = T2*P/3.14 = 69.53185 mm • Now, we can calculate the centre to centre distance ( C) by the following equation: C = (D1 + D2)/2 = 42.80152 mm • The below empirical formula is the cross check for the correctness of the whole design calculation: (C^0.875)/2.

ZAR3 Worm Gear Calculation ZAR3+ Software for Cylindrical Worm Gear Design (C) Copyright 1993-2017 by HEXAGON Software, Berlin Bases for Calculation ZAR3 calculates all dimensions of cylindrical worm gear pairs with ZI, ZA, ZK, ZN or ZH worms, as well as efficiency, tooth forces and the safety margins against root fatigue fracture and pitting. Pre-dimensioning In pre-dimensioning recommendations are made for axial distance, modulus and number of teeth based on gear ratio, drive power, drive rotational speed and material. The recommendations can be used in the following geometry and strength calculations.

Geometry Calculation In dimensioning you can adjust the recommended values to match available sizes or company standards. Or by varying the axial distance ratio and addendum modification you can determine the optimum worm gear for your application. Strength Calculation The strength calculation computes the factors SF (fatigue fracture) and SH (pitting) along with tooth forces on the worm and worm gear, as well as the efficiency of the gear. Efficiency ZAR3 calculates the toothing efficiency, toothing and idling loss of power.

This formula for the speed ratio is the same as it for spur gears. Screw Gear (Crossed Helical Gear). The ABC's of Gears Basic Guide. Speed Ratio ＝. Of teeth of Drive Gear. Of teeth of Driven Gear. Fig.1.14 Direction of Rotation and Thrust Force. R helical combination. Thrust bearing. Gear dimensions are determined in accordance with their specifications, such as Module (m), Number of teeth (z), Pressure angle (α), and Profile shift coefficient (x). This section introduces the dimension calculations for spur gears, helical gears, gear rack, bevel gears, screw gears, and worm gear pairs.

The program provides recommended values and help graphics for determination of the tooth friction value. Material Data Base The program already includes a data base containing the most important gear materials and their values. Users of the ZAR1+ spur gear and ZAR2 bevel gear programs can access this as a common data base. Tooth Forces Axial and radial forces, as well as tangential force and normal force are calculated. These values can be transfered to the WL1/WL1+ software for shaft calculation.

Plus-Version ZAR3+ The extended version ZAR3+ provides additional functions: ZAR3+ generates true-scale drawing of worm and worm gear. ZAR3+ provides an additional input window for modifications of tooth height factors and profile shift coefficient x. These functions are useful for design of complementary gears of steel worm and plastic worm gear. ZAR3+ calculates tooth thickness and over pin/ball diameters (OPD).

You can enter pin diameter and flank tolerances or select from tolerance system according to DIN 3967. CAD Interface A true-scale drawing of worm and worm wheel, as well as tables with the gear data can be exported to CAD via the DXF or IGES interfaces. The drawings can of course also be displayed on screen and printed out. Gbxperience Anthems Vol 1 Free Download. Import/Export Text printout can be generated as HTML table and exported to Excel.

Input data may be loaded from an Excel worksheet. HEXAGON Help System For all entries a help text or auxiliary picture can be displayed. For example, there are diagrams for input of the tooth friction value µz0 in relation to lubricant and average slide speed. There are also diagrams for optimizing the diameter-to-center distance ratio dm1/a in relation to fatigue stress or efficiency. Users can modify and append help texts and auxiliary pictures.

When error messages occur you can have an error description and remedy suggestion displayed. Hardware and Software Requirements ZAR3+ is available as 32 bit and 64 bit application for Windows 7, Windows 8, Windows 10. Scope of Delivery CD-ROM or zip file for download with program and pdf manual, License agreement for indefinite period of time. Information and Update Service HEXAGON Software is continuously improved and updated.

Licensed users can obtain new versions at the update price. Each program is provided with an individual license number and user files. No extra charge is made to registered users for telephonic support and hotline use. .