MELSERVO Vs MPL Servo Motors

Introduction

Servo motors, also known as “servos”, are electric motors with integrated positional feedback. The name “servo motor” is related to the term “servomechanism”–a system in which a motor is continually monitored to precisely control its motion. Servo motors are used to accurately control angular or linear position, speed and torque in closed-loop motion control systems.

There are two (2) types of servo motors: DC servos and AC servos. The key difference between the two servos is their power source. DC servo motors are powered by batteries, while AC servo motors rely on a mains electricity outlet.  Each servo motor type is designed for a different range of motion control applications, but both servos can be found in various domestic and industrial devices and machines.

Servo motors are being widely used in more and more industrial applications to replace stepper motors and conventional motors as well pneumatic and hydraulic systems due to the following advantages: high accuracy, closed-loop control, greater efficiency, increased reliability, high-speed performance, smooth running, small size, high power output relative to their size, high torque to inertia ratio, effective torque control, more constant torque at higher speeds, quiet operation, and more suitability to varying load applications. You’ll often come across servo motors in robotic applications because they are small, easily programmable, powerful, very accurate, and more importantly they allow for near perfect motion repeatability.

In this article, we’ll discuss how two popular servo motor brands–MELSERVO and MPL servo motors–compare with each other in terms of motor types, compatible servo drives/servo amplifiers, and applications.

MELSERVO Servo Motors Overview

The MELSERVO motors are high-performance, industry-leading servo motors from Mitsubishi Electric. They provide motion control solutions for a diverse range of applications from simple single-axis/point-to-point motion systems all through to fully synchronized 96-axis motion systems. It easy to meet the needs of specific motion applications by integrating MELSERVO servo motors with both SSCNET bus modules and standard pulse type output modules. In addition, the Mitsubishi servo system hardware is complimented by various software packages that allow easy programming and set-up of the MELSERVO servo motors.

The MELSERVO Series offers three types of servo motors, namely: Rotary, Linear, and Direct Drive servo motors.

1. Rotary MELSERVO Motors

Rotary servo motors allow for precise control of angular position, acceleration and velocity. They consist of a suitable conventional AC/DC motor coupled to a sensor for actual position feedback. MELSERVO rotary servo motors have power capacities that range from 10 watts (W) up to 220 kilowatts (kW).

The available MELSERVO rotary servo motors are classified into the following series:

• HG Series: These servo motors are compatible with MR-J4 Series servo amplifiers from Mitsubishi Electric. They include:
  • HG-KR Rotary Servos: Low inertia, small capacity servo motors with a wide range of capacities from 50W to 750W (200V AC). They are ideal for general-purpose industrial machines such as embroidery and knitting machines, in-circuit testers, compact robots, inserters, bonders, mounters, and much more.
  • HG-MR Rotary Servos: Ultra-low inertia, small capacity servo motors offering 50 W to 750 W (200V AC) capacities. They are well suited for high-throughput operations like in compact robots, inserters, bonders and mounters.
  • HG-JR Rotary Servos: Low inertia, medium to large capacity servo motors providing 0.5 kW to 22 kW (400V AC/200V AC) capacities. They are perfect for high deceleration/acceleration operations or high-throughput positioning. They are commonly used in food packaging machines, press machines, injection molding machines, and printers.
  • HG-RR Rotary Servos: Ultra-low inertia, medium capacity servo motors offering 1 kW to 5 kW (200V AC) capacities. They are suitable for high-frequency operations like in loaders and unloaders, roll feeders, and in ultra-high-throughput material handling systems.
  • HG-SR Rotary Servos: Medium inertia, medium capacity MELSERVO motors with a wide range of capacities from 0.5 kW to 7kW (400V AC/200V AC). They are fitted for machines with large load inertia such as servo turrets, material handling systems, loaders and unloaders, dedicated machines, winders and tension units, robots, and X-Y tables
  • HG-UR Rotary Servos: Flat type, medium capacity MELSERVO motors providing 0.75 kW to 5 kW (200V AC) capacities. They are ideal for applications with mounting space limitations such as in tension machines, winders, conveyors, robots, and in food processing machines.

• HF Series:  These MELSERVO servo motors are compatible with MR-JE Series servo amplifiers. They include:
  • HF-KN Rotary Servos: Low inertia, small capacity servo motors offering 100 W to 750 W (200V AC) capacities. They are suitable for general-purpose industrial machines such as PCB drilling machines, knitting and embroidery machines, etc.
  • HF-SN Rotary Servos: Medium inertia, medium capacity servo motors with an extensive range of capacities from 0.5 kW – 3 kW (200V AC). They are mainly used in machines with large load inertia such as X-Y tables, servo turrets, material handling systems, tension units, winders, etc.

• HA Series: These MELSERVO rotary servo motors are compatible with MR-J3 Series servo amplifiers. They include:
  • HA-LP Rotary Servos: Low inertia, medium to large capacity servo motors providing a wide range of capacities: 5 Kw – 55 kW (200V AC), and 6 kW- 55 kW (400V AC). They are suitable for large machine systems with large power requirements such as large material handling systems, injection molding machines, semiconductor manufacturing devices, and press machines.
  • HA-JP Rotary Servos: Low inertia, ultra-large capacity servo motors offering 110 kW to 220 kW (400V AC) capacities. They are perfect for ultra-large machines such as LCD manufacturing machines, large press machines, and large material handling systems.
  • HG-AK Series:  These are ultra-compact size, small capacity DC rotary servo motors with capacities ranging from 10 W – 30 W (48V DC/ 24V DC). They are ideal for compact machines such as ultra-compact robots, mounters and bonders, semiconductor manufacturing systems, and X-Y tables.

Key Features of MELSERVO Rotary Servo Motors

• High-Resolution Absolute Encoder

As a standard, each MELSERVO rotary servo motor is equipped with a 22-bit high-resolution absolute encoder of 4,194,304 pulses per revolution (PPR). This encoder increases the positioning accuracy of such servo motors.

• Enhanced Environmental Safety

The HG-KR/HG-RR/HG-MR/HG-UR rotary servo motors are IP65 rated while the HG-JR/HG-SR servos are IP67 rated. The 22 kW rotary servo motor of the HG-JR Series is IP44 rated.

• Reduced Torque Ripples

MELSERVO rotary servo motors optimize the combination of the number of slots and the number of motor poles, thereby greatly reducing torque ripples during conduction. In addition, with these servo motors you can achieve smooth constant-velocity operation of your machines.

2. Linear MELSERVO Motors

MELSERVO linear servo motors are ideal for linear motion control systems requiring high-level accuracy and high speed. They support a maximum thrust of 150 …1800 N and a maximum speed of 3 m/s. It is possible to achieve small size and high thrust with these servos by increasing their winding density and by optimizing their armature core and permanent magnet geometries through the use of electromagnetic field analysis.  Also, high-accuracy tandem synchronous motion control can be achieved by integrating a linear MELSERVO motor with an MR-J4 Series servo amplifier and a SSCNET III/H compatible motion controller.

Available linear servo motors from Mitsubishi Electric include:

• LM-H3 Series: These are core-type linear servos with magnetic attraction force, which contributes to their high rigidity. They are suitable for space-saving applications such as multi-head material handling between machines. They’re compatible with MR-J4/J4W servo amplifiers.
• LM-F Series: This series provides compact, core-type linear servo motors with integrated liquid-cooling systems, which double the continuous thrust. They have a magnetic attraction force structure that contributes to their high rigidity. They’re compatible with MR-J4/MR-J3-B-RJ004 MELSERVO amplifiers. These servo motors are used in press feeders and in NC machine tools.
• LM-K2 Series: These are core-type linear servo motors with magnetic attraction counter-force. The counter-force structure prolongs the service life of their linear guides and it also contributes to reducing audible noise when operating. LM-K2 linear servo motors are used in scanning exposure systems and screen printing systems. These servo motors are compatible with MR-J4/J4W/MR-J3-B-RJ004/J3W servo amplifiers.
• LM-U2 Series: This series offers coreless-type linear servo motors without cogging, which results in small speed fluctuations. Their structure has no magnetic attraction force and this extends the service life of the linear guides. They are compatible with MR-J4/J4W/MR-J3-B-RJ004/J3W servo amplifiers. LM-U2 servo motors are used in scanning exposure systems and screen printing systems.

Key Features of MELSERVO Linear Servo Motors

1. Higher Machine Performance: MELSERVO linear servo motors provide a fully closed-loop control system that enables high-accuracy positioning. Improved productivity is also achieved with these servos, due to their high-speed driving part.
2. Ease of Use: The linear MELSERVO servo motors enable simple and compact industrial machines with high rigidity. They also allow smooth operations, easy maintenance and cleanliness of motion systems.
3. Flexible Machine Configurations: Tandem and multi-head motion systems can be easily configured with MELSERVO linear servos. They are thus fitted for long-stroke applications.

3. Direct Drive MELSERVO Motors

The term “direct drive” refers to a drive whose driving and driven components are directly-connected. This technology reduces the required number of mechanical components, eliminates backlash, and it provides a stiff motion control system for highly dynamic applications. In essence, MELSERVO direct drive servo motors provide high rigidity, improved performance and enhanced flexibility in system configurations that are unique to a direct drive.

Mitsubishi Electric provides the following series of direct drive servo motors:

• TM-RFM Series: This MELSERVO series is suitable for high-torque and low-speed operations requiring high-accuracy control. It is possible to achieve high-accuracy positioning because a TM-RFM servo motor is directly connected to the driving part. Also, since transmission mechanisms are no longer required with the TM-RFM Series, backlash is eliminated and abrasion on system components does not occur; this enables smooth operations with minimal audible noise, easy maintenance, and a clean system.

TM-RFM Series direct drive servo motors are compatible with MR-J4/J4W/MR-J3-B-RJ080W/J3W servo amplifiers from Mitsubishi Electric.

Key Features of MELSERVO TM-RFM Motors

1. High Torque Intensity: TM-RFM MELSERVO motors have the latest technologies of magnetic designs and windings, which help achieve high torque intensity. Also, these servos exhibit minimal torque ripples, enabling extremely smooth rotation.
2. Low-Profile Design: TM-RFM direct drive motors are characterized by industry-leading level of thinness and compact size construction. This contributes to a low-profile design and a low-center of gravity, which enables enhanced machine stability.
3. High-Resolution Encoders: TM-RFM Series servo motors are equipped with a 20-bit high-resolution encoder that enables higher accuracy motion systems.
4. Hollow Shaft: TM-RFM direct drive motors have an inner rotor with a hollow shaft of diameter measuring from 20 mm to 104 mm. This shaft allows cables, air tubing, and pipes to pass through.

MPL Servo Motors Overview

The MPL Series provides high-output, low inertia brushless AC synchronous servo motors designed by Allen-Bradley. They are commonly referred to as MP-Series (Bulletin MPL) Low-Inertia servo motors. These servos use innovative design features to reduce motor size while providing significantly higher torque. They are highly-dynamic servo motors designed to meet the demands of high-performance motion systems in compact packages.

The Allen-Bradley^® MPL Series offers a wide range of peak torque capacities from 0.77 Nm – 278 Nm (6.8 to 2460 lb-in) and continuous stall torque capacities ranging from 0.26 Nm – 163 Nm (2.3 to 1440 lb-in). MPL servo motors are available in nine (9) frame sizes, from smaller frame sizes of 63 mm and 75 mm, to much larger frames measuring from 165 mm to 300 mm. The nine frame sizes include: 63mm, 75 mm, 100 mm, 115 mm, 130 mm, 165 mm, 215 mm, 265 mm, and 300 mm. The rated power output of these motors range from 0.16 – 18.6 kW, with a rated speed of up to 8000 rpm.

Note: The maximum operating speed of MPL servo motors is limited by their motor windings.

Types of MPL Servo motors

While available MELSERVO servo motors are largely classified in terms of the type of motion they provide (linear, rotary or direct-drive), MPL servo motors are largely classified in terms of input voltage classes. The Allen-Bradley^® MPL Series features two input voltage classes:

200V-Class MPL Servo Motors

Examples of servo motors in this category include:

• MPL-A1510V: Motor rated power output 0.16 kW; Continuous stall torque 0.26 Nm (2.3 lb-in); Peak stall torque 0.77 Nm (6.8 lb-in); Maximum speed 8000 rpm; Frame size 63 mm

• MPL-A220T: Motor rated power output 0.62 kW; Continuous stall torque 1.61 Nm (14.2 lb-in); Peak stall torque 4.74 Nm (42 lb-in); Maximum speed 6000 rpm; Frame size 75 mm

• MPL-A310F: Motor rated power output 0.46 kW; Continuous stall torque 1.58 Nm (14 lb-in); Peak stall torque 3.61 Nm (32 lb-in); Maximum speed 3000 rpm; Frame size 100 mm

• MPL-A4540C: Motor rated power output 1.5 kW; Continuous stall torque 10.2 Nm (90 lb-in); Peak stall torque 27.1 Nm (240 lb-in); Maximum speed 1500 rpm; Frame size 130 mm

• MPL-A560F: Motor rated power output 5.3 kW; Continuous stall torque 26.8 Nm (237 lb-in); Peak stall torque 61.0 Nm (540 lb-in); Maximum speed 3000 rpm; Frame size 165 mm
• 400V-Class MPL Servo Motors

400V-Class MPL Servo Motors

Examples of MPL servo motors in this category include:

• MPL-B680H: Motor rated power output 7.5 kW; Continuous stall torque 60.0 Nm (531 lb-in); Peak stall torque 146.9 Nm (1300 lb-in); Maximum speed 3500 rpm; Frame size 215 mm

• MPL-B880D: Motor rated power output 12.6 kW; Continuous stall torque 110.0 Nm (973 lb-in); Peak stall torque 147 Nm (1300 lb-in); Maximum speed 2000 rpm; Frame size 265 mm

• MPL-B960C: Motor rated power output 14.8 kW; Continuous stall torque 124.3 Nm (1100 lb-in); Peak stall torque 226 Nm (2000 lb-in); Maximum speed 1500 rpm; Frame size 300 mm

• MPL-B1520U: Motor rated power output 0.27 kW; Continuous stall torque 0.49 Nm (4.3 lb-in); Peak stall torque 1.58 Nm (14 lb-in); Maximum speed 7000 rpm; Frame size 63 mm

• MPL-B430P: Motor rated power output 2.2 kW; Continuous stall torque 6.55 Nm (58 lb-in); Peak stall torque 19.8 Nm (175 lb-in); Maximum speed 5000 rpm; Frame size 115 mm

Key Features of MPL Servo Motors

High-Performance Feedback

MPL servo motors feature high-performance encoders with the options of single-turn (-E, -S) or multi-turn (-V, -M) high-resolution feedback. Available high-resolution encoders for use with the MP-Series Low-Inertia servos include:

• Encoders (-M and -S) with up to 2 million CPR(counts per revolution) which are coupled onto MPL-B9xx, MPL-B6xx, MPL-A/B5xx, MPL-A/B45xx, MPL-A/B3xx, MPL-B8xx, and MPL-A/B4xx servo motors for precise control and smooth performance.
• Encoders (-E and -V) with up to 260 thousand CPR fitted onto MPL-A/B2xx and MPL-A/B15xx servo motors for smooth performance.
• A multi-turn encoder providing high-resolution feedback for absolute position in 4096 turns. A battery is not necessary with the electromechanical design of this encoder.
• A single-turn encoder providing high-resolution feedback for absolute position in one turn.
• MPL servo motors fitted with high-resolution encoders can be used as a part of the Kinetix^® Safe-Off feature.

Compatible Servo Drives

The MP-Series™ Low-Inertia (MPL) servo motors are compatible with the following Allen‑Bradley^® servo drive families:

• Kinetix 6200/6500
• Kinetix 7000
• Kinetix^® 6000
• Kinetix^® 2000
• Kinetix 300/350
• Ultra™ 3000
• Kinetix 5500: To integrate Kinetix 5500 servo drives with MPL servo motors the 2198-H2DCK Hiperface-to-DSL feedback converter kit is required. Also, for the 200V-Class MP-Series (200V-class) low-inertia servo motors to be compatible with Kinetix 5500 servo drives they require the 2198-H2DCK (series B or higher) converter kit.

Smart Motor Technology

MP-Series Low-Inertia servo motors have an on-board memory, which retains details of motor identity. They also feature a communication link that automatically reports the motor identity to the motion system upon startup; this reduces the commissioning time of the MPL servo system.

Cable Compatibility/ Motor Connector

Allen-Bradley^® MPL servo motors are fitted with SpeedTEC-ready DIN connectors, rotating.

Motor Options

MP-Series™ Low-Inertia (MPL) servo motors are available with the following options:

• Integral 24V DC brake option
• Optional keyless shaft for MPL-A/B5xx, MPL-A/B4xx, MPL-A/B3xx, and MPL-A/B45xx servo motors. This shaft is available in a limited number of frame sizes with extended lead times.
• Shafts seals made of Nitrile, and replacement kits for field installation. The shaft seal kits do include a lubricant as the shaft seals are subject to wear.

Improved Environmental Safety

The standard environmental rating of MPL servo motors is IP50 minimum, in the absence of a shaft seal. But some MPL servos are IP66 rated with an optional shaft seal and they use cable connectors that are environmentally sealed. In addition, Allen-Bradley^® MPL rotary servo motors are UL Certified components to applicable CSA and UL standards. They are also CE Marked for every applicable directives. In addition, these servos include standard IEC 72-1 mounting dimensions.

Typical Applications of MPL Servo Motors

Allen-Bradley^® MPL servo motors are perfect for applications that require more power in a smaller package. These applications include:

• Material Handling and Packaging: MPL servo motors support a wide array of high-speed, high-torque material handling systems, as well as high-accuracy positioning systems.
• Electronics Assembly: High-performance MPL servo motors fitted with high-resolution encoders are used to achieve fast and highly accurate positioning at stable speeds in electronics assembly lines.
• Automotive: MP-Series Low-Inertia servos are used in automobile manufacturing lines to boost the productivity, and even flexibility, of assembly lines.
• Metal Forming: MPL servo motors are used to drive metal forming machines for improved equipment performance and more energy conservation.

This entry was posted on November 17th, 2022 and is filed under Uncategorized. Both comments and pings are currently closed.