Program 60-546 Enclosed Cylindrical-Wormgear Speed Reducers and Gearmotors Introduction This model covers the design and durability rating of enclosed cylindrical worm gear speed reducers of the following types: Single and multiple reduction speed reducers Single and multiple reduction gearmotors Multiple reduction with other types of gearing combined with cylindrical worm gearing Output shafts of solid or hollow type The model will give ratings for gearsets whether they comply with the standard or not. If the gearset is outside the standard (or does not comply with suggestions of the standard) this condition will be noted in the message area at the top of the report. It is always best to solve enough of the model so that the message area is not blank to ensure that the data has been checked. If you wish to see the possible condition messages go to the TK Solver Function Sheet for the function lim. Example As an example, suppose that we are to find the efficiency and power rating of a cylindrical worm speed reducer at a worm shaft speed range of 100 to 1200 RPM. (Note that the thermal rating is NOT included in this model. See the standard for methods of thermal rating.) Figure 1 shows the required input data for a rating at 1200 RPM worm speed: Report 1 shows the solved model.
UTS Integrated Gear Software Fig. 1 Report 1 Model Title : Program 60-546 Unit System: US Description Value Unit Comment Reference: ANSI/AGMA 6034-B92 DATA Practice for Enclosed Cylindrical WITHIN 2
60-546 Enclosed Cylindrical-Wormgear Speed Reducers and Gearmotors Model Title : Program 60-546 Unit System: US Description Value Unit Comment Wormgear Speed Reducers and Gearmotors STANDARD Number of Threads in Worm 6 Number of Teeth in Gear 36 Gear Ratio (3:1 to 100:1) 6.0000 Axial Pitch of Worm Normal Pitch of Worm and Gear Thread Lead Angle at Mean Worm PD Lead of Worm Thread Mean Worm Dia (Midpoint Working Depth) Mean Gear Dia (Midpoint Working Depth) Center Distance Normal Pressure Angle of Worm Thread Actual Face Width of Gear Effective Face Width of Gear Max Allowable Radial Worm Deflection MATERIAL 1.0000 in 0.880131 in 28.342 deg 6.0000 in 3.5408 in 11.4592 in 7.5000 in 20.000 deg 2.4670 in 2.3605 in 0.0050 in Gear Matl LOAD RATING Worm Rotational Speed (3600 rpm max) Rated Input Power Rated Output Power Rated Wormgear Torque cent 1200.00 rpm 48.97 HP 46.75 HP 14725.1816 lbf-in 3
UTS Integrated Gear Software Model Title : Program 60-546 Unit System: US Description Value Unit Comment LOADS and EFFICIENCY Worm Sliding Velocity (6000 fpm max) Tangential Load on Gear Teeth Frictional Force 1263.8744 ft/min 2570.0191 lbf 58.0333 lbf Coefficient of Friction 0.0187 Efficiency - Worm Driving 95.46 % LOADS and EFFICIENCY Static Conditions Static Coefficient of Friction 0.1500 Start Efficiency - Worm Driving 70.52 % Start Efficiency - Gear Driving 64.82 % RATING FACTORS Material Factor 1000.00 Ratio Correction Factor 0.6863 Velocity Factor 0.2255 If the rating at 1200 RPM worm speed satisfies our requirements (and we will assume that it does) the next step is to find the rating at worm RPM increments from 100 to 1200. The best way to do this is to utilize the list solving capability of TK Solver. Input to the model must include, in this case, a Worm RPM List. We desire output lists for rated input power to the speed reducer, rated output power, power loss at the mesh and efficiency. (We should also include the variable m1 from the message area to be sure that none of our list conditions have gone outside the range of the standard.) Sheets 1A and 1B shows the list requirement. The list for worm speed (n) will be an input list since there is a value in the input column for n. 4
60-546 Enclosed Cylindrical-Wormgear Speed Reducers and Gearmotors Sheet 1A Sheet 1B The next step is to go to the List Sheet for n and fill the list with RPM values. (Use the List Fill button in the Taskbar.) Enter 100 for 1st value, 50 for step size, and 1200 for last value. Your n list should look like Sheet 2. 5
UTS Integrated Gear Software To obtain output list values for our input list, touch the List Solve button on the Toolbar (or F10). The list solver will take the values from the input lists one by one, calculate the values we require and place them in the output lists. Sheet 2 We don't want to look at the lists one at a time so we will make a table of our data. First, go to the TK Solver Table Sheet. Name and title the table (See Sheet 3). Go to the Table Subsheet (See Sheet 4). To set up the table first type the list names under List", and the headings you want under Heading. Under Width you may set the number of characters in each table field. Under Numeric Format we can configure the table output for each variable. Your table should look like Sheet 5. 6
60-546 Enclosed Cylindrical-Wormgear Speed Reducers and Gearmotors Sheet 3 Sheet 4 7
UTS Integrated Gear Software Sheet 5 A large number of good designs are possible for a given set of conditions that stay within the standard. Good engineering practice may indicate the analysis of many designs for economy of production, load capacity, etc. See UTS Models 60-543, 60-548, 60-552 and 60-554 for design and analysis of worms and wormgears. Reference Extracted from ANSI/AGMA 6034-B92, Practice for Enclosed Cylindrical Wormgear Speed Reducers and Gearmotors with the permission of the publisher, the American Gear Manufacturers Association, 1500 King Street, Suite 201, Alexandria, VA 22314 8