Application Note

Lexium MDrive Thermal Management

Description

There are many variables affecting MDrive running temperature, it is difficult if not impossible to accurately predict thermal performance in a particular application.

Topics

  • System Design

Applicable Product

  • Lexium MDrive

Requirements

Resource Files

Details

Since there are so many variables affecting MDrive running temperature, it is difficult if not impossible to accurately predict thermal performance in a particular application.  For this reason, the Lexium MDrive and many other servo and stepper drives are designed so that they can produce more power than they can handle from a thermal point of view. If they were designed so they would never overheat, the user with the 5% duty cycle would not benefit from all that time for cooling.  The following are some of the variables can affect thermal performance:

  • Ambient temperature
  • Air flow over the device
  • Heat sinking from the front end-bell to the machine frame
  • Current settings in both run and hold mode. (Rc and Hc)
  • Duty cycle
  • Running speed
  • Load on the shaft
  • hMTechnology settings

When testing an application with Lexium MDrive, the important thing to ensure is that the heat sink temperature never exceeds 85°C and the motor lamination temperature never exceeds 100°C. The preliminary thermal performance graphs below show some of the frame sizes and lengths.  More graphs will be added as they become available.  Note that raising or lowering the ambient temperature raises or lowers the drive temperature by a roughly equivalent amount.

Thermal Performance Graphs

LM57 NEMA23 Single Length

Device: LMDCM571

  • NEMA 23 (57 mm) Single length
  • Speed: 2000 full steps/sec
  • Voltage: 45 VDC
  • Torque ≈ 84 oz-in (59.3 N-cm)
  • Mounting: 6.5” x 6.5” x 1/4” aluminum plate

LM57 NEMA23 Double Length

Device: LMDCM572

  • NEMA 23 (57 mm) Double length
  • Speed: 2000 full steps/sec
  • Voltage: 45 VDC
  • Torque ≈ 95oz-in (67.1 N-cm)
  • Mounting: 6.5” x 6.5” x 1/4” aluminum plate

LM57 NEMA23 Triple Length

Device: LMDCM573

  • NEMA 23 (57 mm) Triple length
  • Speed: 2000 full steps/sec
  • Voltage: 45 VDC
  • Torque ≈ 116oz-in (81.9 N-cm)
  • Mounting: 6.5” x 6.5” x 1/4” aluminum plate