Intelligent Motion Systems MDriveAC manual Calculating the Shock Load Output Torque TAB, Factors

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Calculating the Shock Load Output Torque (TAB)

Note: The following examples are based on picking “temporary variables” which may be adjusted.

The shock load output torque (TAB) is not the actual torque generated by the MDrive and Planetary Gearbox combination, but is a calculated value that includes an operating factor (CB) to compensate for any shock loads applied to the Planetary Gearbox due to starting and stopping with no acceleration ramps, payloads and directional changes. The main reason the shock load output torque (TAB) is calculated is to ensure that it does not exceed the maximum specified torque for a Planetary Gearbox.

Note: There are many variables that affect the calculation of the shock load output torque. Motor speed, motor voltage, motor torque and reduction ratio play an important role in determining shock load output torque. Some variables must be approximated to perform the calculations for the first time. If the result does not meet your requirements, change the variables and re-calculate the shock load output torque.

Use the equation compendium below to calculate the shock load output torque.

Factors

 

i

= Reduction Ratio - The ratio of the Planetary Gearbox.

nM

= Motor Speed - In Revolutions Per Minute (Full Steps/Second).

nAB

= Output Speed - The speed at the output shaft of the Planetary Gearbox.

TN

= Nominal Output Torque - The output torque at the output shaft of the Planetary

 

Gearbox.

TM

= Motor Torque - The base MDrive torque. Refer to MDrive Speed Torque Tables.

η= Gear Efficiency - A value factored into the calculation to allow for any friction in the gears.

TAB

=

Shock Load Output Torque - A torque value calculated to allow for short term loads

 

 

greater than the nominal output torque.

CB

=

Operating Factor - A value that is used to factor the shock load output torque.

sf

=

Safety Factor - A 0.5 to 0.7 factor used to create a margin for the MDrive torque

 

 

requirement.

Reduction Ratio

Reduction ratio (i) is used to reduce a relatively high motor speed (nM) to a lower output speed (nAB). With: i = nM ⎟ nAB or: motor speed ⎟ output speed = reduction ratio

Example:

The required speed at the output shaft of the Planetary Gearbox is 90 RPM.

You would divide motor speed (nM) by output speed (nAB) to calculate the proper gearbox ratio. The MDrive speed you would like to run is approximately 2000 full steps/second or 600 RPM.

NOTE: In reference to the MDrive speed values, they are given in full steps/second on the Speed/Torque Tables. Most speed specifications for the Planetary Gearbox will be given in RPM (revolutions per min- ute). To convert full steps/second to RPM, divide by 200 and multiply by 60.

Where: 200 is the full steps per revolution of a 1.8° stepping motor.

2000 full steps/second ⎟ 200 = 10 RPS (revolutions per second) ⋅ 60 Seconds = 600 RPM

For the Reduction Ratio (i), divide the MDrive speed by the required Planetary Gearbox output speed. 600 RPM ⎟ 90 = 6.67:1 Reduction Ratio

Referring to the Available Ratio Table at the end of this section, the reduction ratio (i) of the Planetary Gearbox will be 7:1. The numbers in the left column are the rounded ratios while the numbers in the right column are the actual ratios. The closest actual ratio is 6.75:1 which is the rounded ratio of 7:1. The slight difference can be made up in MDrive speed.

Note: The MDrive23 and the numbers and values used in these

examples have been chosen randomly for demonstration purposes. Be certain you obtain the correct data for the MDrive you have purchased.

Appendices

A-7

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Contents 34 TM Low Voltage Installation Information UL Application Details and Conditions of AcceptanceTable Of Contents Appendices List Of Figures List of Tables MDriveAC Plus Microstepping Connecting AC PowerConnect Opto Power and Logic Inputs Before You BeginConnecting Parameter Setup Cable Install the IMS SPI Motor InterfacePart Hardware Specifications Intentionally Left Blank Features and Benefits ConfiguringIntroduction to the MDrive34AC Plus Microstepping Page MDrive34AC Plus Microstepping Detailed Specifications General SpecificationsSetup Parameters Single LengthMechanical Specifications Dimensions in Inches mmP1 19-Pin M23 Connector I/O and SPI Communications Pin Assignment and DescriptionPin Assignment P1 I/O, SPI and Encoder Connections P3 Connector AC Power Options and AccessoriesPin Introduction to the MDrive42AC Plus Microstepping Page MDrive42AC Plus Microstepping Detailed Specifications Setup Parameters 76.2 Pin Assignment and Description Pin Assignment P1 I/O, SPI and Encoder Connections Outside Pins 1 Options and Accessories Part Interfacing Configuring Intentionally Left Blank Logic Interface and Connection Isolated Logic Input Pins and ConnectionsOptically Isolated Logic Inputs Quadrature Step ClockDirection Up/DownChannel a DirectionStep Channel BOptocoupler Reference Optocoupler ReferenceInput Connection Examples Open Collector Interface ExampleSwitch Interface Example Fault Temperature Warning OutputSwitch 7 Fault Output interfaced to an LED Minimum Required ConnectionsConnecting SPI Communications SPI Master with Multiple MDriveAC Plus Microstepping SPI Pins and ConnectionsSPI Clock Configuration Parameters and Ranges Using the IMS SPI Motor Interface InstallationColor Coded Parameter Values File Motion Settings Screen Read-Only Part Serial Number ScreenIMS SPI Motor Interface Menu Options ViewRecall UpgradeHelp Screen 1 The Motion Settings Configuration Screen Msel Microstep Resolution SelectionSet Connected/Disconnected IndicatorFactory ExitInput Clock Type Screen 2 I/O Settings Configuration ScreenEnable Active High/Low Input Clock FilterIMS Part Number/Serial Number Screen Fault IndicationIMS IMS Serial Number Upgrade Instructions IMS SPI Upgrader ScreenUpgrading the Firmware in the MDriveAC Plus Microstepping Initialization Screen Port MenuSPI Timing Notes Using User-Defined SPICheck Sum Calculation for SPI SPI Commands and Parameters MSBWrite SPI Communications SequenceIntentionally Left Blank Appendices MDriveAC Plus Microstepping Hardware Revision R121707 MDrive34AC 240VAC MDriveAC Plus Microstepping Motor PerformanceMDrive34AC 120VAC Single LengthMDrive42AC Plus Microstepping Double LengthTriple Length MDrive42AC 120VACOz-in/810 N-cm Product Overview MDrive with Planetary GearboxSection Overview Selecting a Planetary GearboxFactors Calculating the Shock Load Output Torque TABReduction Ratio Nominal Output Torque Speed in Full Steps per SecondShock Load Output Torque =1.6 =1.7 =1.9Type of System System InertiaLead Screw Conveyor Belt Rack and PinionRotary Table Belt DriveChain Drive Figure B.6 Chain Drive System Inertia ConsiderationsMDrive34AC Plus2 Planetary Gearbox Parameters Planetary Gearbox for MDrive34AC Plus2PM81 Gearbox Ratios and Part Numbers MDrive42AC Plus2 Planetary Gearbox Parameters PM105 Planetary Gearbox for MDrive42AC Plus2PM105 Gearbox Ratios and Part Numbers MDrive42AC Plus2 Planetary Gearbox Parameters PM120 PM120 Gearbox Ratios and Part NumbersInstalling the Cable/VCP Drivers MD-CC300-000 USB to SPI Parameter Setup CableInstallation Procedure for the MX-CC300-000 Optional Cables and CordsetsFigure C.4 Hardware Update Wizard Screen Figure C.7 Hardware Update Wizard Finish Installation Determining the Virtual COM Port VCPAdapter To Controller InterfacePin Assignment and Wire Colors MD-CS10x-000 CordsetMD-CS20x-000 Cordset MD-CS201-000Interfacing the Internal Differential Optical Encoder Pin ConfigurationFactory Mounted Encoder Encoder Signals Differential EncoderMDrive34Plus Linear Slide FeaturesLinear Slide Option Speed-Force Limitations†Specifications Mechanical SpecificationsWarranty Excellence in Motion
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