Updated November 2019 || Integrated motors are not a new concept; they’ve been around for a few decades now. But in that time, the separate components from which integrated motor are built have gotten smaller. So now integrated motors are smaller and more compact than ever. No wonder more motor manufacturers are releasing integrated motors to help OEM design engineers and end users leverage the benefits of integrated motors in compact machine builds.
Another reason for the continued rise of integrated-motor use is that heat-management techniques have gotten better. This combined with shrinking component size means that integrating drives and motors and other components has gotten easier and more practical than in the past.
Integrated motors impart simplicity
Integrated motors mean machine builders don’t have to buy separate components and mechanically and electrically connect them. Instead, engineers simply buy one integrated motor unit (typically with a connection point for a network cable) and link as many motors together as required by the application. This also simplifies purchasing because instead of having to order many different components, engineers can order one unit or as many as are needed for the project.
New integrated motors offer expanded networking options … more control flexibility … and top capacity for withstanding harsh environments.
Because there are fewer parts to connect together, integrated motors also boost design reliability. Fewer external connections mean less cabling and wiring … and that in turn reduces costs …
… as does the fact that separately purchased components (such as the motion controller and the drive) can ultimately be more expensive for a design team than getting them pre-integrated into one motor.
These integrated motors are also designed to be programmed easily and quickly, which can help reduce development times. As we’ll explore, communication options range from simple serial communication links to more advanced network topologies suited to complex motion control.
Integrated servomotors are classified by their design. The motor itself is combined with the other essential components of a complete motion control system including the feedback device (generally an encoder) as well as an amplifier or motor drive, a communication port, and the motion controller itself. So technically, an integrated motor is any motor that has another component combined with it, such as a drive or amplifier, controller or encoder. Consequently, integrated motors come in many different types and sizes — from servo motors to stepper motors and even large ac motors.
Manufacturers can offer a range of combinations and also differing definitions for what constitutes an “integrated” motor. For instance, Lin Engineering sells a variety of combinations — ranging from a simple stepper motor and driver to a stepper motor with driver, controller, and encoder. So design engineers can get different setups to satisfy specific application needs.
A survey of what manufacturers are offering in the integrated motor space reveals the addition of greater control flexibility, increased network offerings and capabilities including seemingly minor hardware and connectivity changes that make the motors more flexible in that they’re suitable for a greater range of applications, as well as more offerings with heavy-duty ratings for use in harsh environments.
Greater control flexibility
One offering from Schneider Electric Motion is the Lexium MDrive — targeted to a range of motion applications needing minimized footprint, reduced wiring, and improved machine reliability. The two original motor sizes are NEMA 23 and 34, and two versions include:
• Pulse-direction versions with a motor and drive and four control modes (torque, speed, velocity, and step clock direction)
• Motion control versions with a motor, drive, and controller for direct programming onto onboard flash memory
Both offerings have a serial RS-422/485 communication interface, with an operating power range from 12 to 70 Vdc. Software allows product configuration and programming. An internal encoder allows operation in closed-loop mode using the hMT technology, which blends stepper and servo motor benefits while eliminating loss of synchronization and stalling. A variable-current control feature can also reduce heat and save energy, where that’s helpful.
Handling harsh environments
In some cases, integrated-motor manufacturers offer specialized variations to satisfy harsh environments — typically to IP65.
One example is the Moog Animatics SM23165MT SmartMotor with M-style connectors and IP65 and IP67 variations. This integrated motor offers the convenience of a smaller frame size for machine designs having tight footprints.
Another example from Applied Motion Products is their IP65-rated integrated drive+motor. The new SWM24 fuses a motion controller to a high torque NEMA 24 step motor. The NEMA 24 frame size mounts like the NEMA 23 motor, but has a 15% larger cross section to deliver more torque in the same length. The entire package is engineered to resist the ingress of water and dust to IP65 standards with sealed M12 connectors.
The SWM24 models provide 340 oz-in. of holding torque and are available with Ethernet or RS-232 communication. All models include a 4,000 count/rev optical encoder to provide features including stall detection, position verification, position maintenance and a proprietary stall prevention algorithm. The auto tuned digital current control and high-resolution microstepping engine provides smooth, quiet motion, while an advanced anti-resonance algorithm with electronic damping ensures maximum torque utilization, rapid acceleration, and fast settling times.
The S and SF models can be used in step direction or velocity control applications while the Q and QF models include stored programming capability using the company’s Q programming language. All models can be configured and programmed using the company’s free ST Configurator software.
Software applications can communicate with the SWM24 in real time, streaming SCL and Q commands over standard 100 megabit Ethernet cabling, addressing and protocols. The RS-232 versions also support streaming commands at bit rates from 9600 to 115,200. EtherNet/IP is also available for connecting to an Allen-Bradley ControlLogix, CompactLogix, or MicroLogix PLC.
Integrated motors simplify networking and connectivity
In line with other trends in automation and motion control, integrated motor manufacturers continue to expand their networking and connectivity options. Moog Animatics, the originator of the integrated motor concept, offers CAN communication options in its SmartMotor line of integrated motors. Some let users connect to a CAN network through a D-sub connector on top of the motor instead of at the rear of the motor — simplifying connections as well as saving space.
Newer Moog Animatics offerings include the Class 6 SmartMotor line, which includes integrated motors having onboard controls to allow for distributed controls across the machine. These motors allow fieldbus communication through EtherCAT, PROFINET, or EtherNet/IP … and the SmartMotor integrated motors support Combitronic (a parallel-processing system) over EtherNet/IP. An onboard dual-port Ethernet switch simplifies wiring. End users can also connect with the motor through an RS-485 half-duplex port that allows access as a Modbus Remote Terminal Unit (RTU) slave.
Other motor manufacturers are adding EtherCAT connectivity. Dunkermotoren of AMETEK sells brushless dc servo motors with integrated intelligence and fieldbus connectivity with ten new models. The extended family now offers EtherCAT interface on all of its BG45, BG65, BG65S and BG75 base models. Available motors range from 50 to 500 W of power in 45 to 75 mm square frame sizes and feature CANopen over EtherCAT (CoE) compatibility. This feature combines the benefits of CANopen’s standardized DS402 motion profile with EtherCAT’s real-time fieldbus. ⚙️ Reprint Info >>
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