DC servo gearmotor customised for underwater ROV use.

A dedicated DC motor design for the tight application requirements of an underwater ROV application.

The example servo motor and gearhead solution shown here has been optimised for very specific application requirements for an underwater robot. Low speed under pressure was required for the fine manipulation of devices external to the remote operating vehicle, resulting in a high planetary gearhead reduction ratio selection of 936:1. However for extremely low speed operation it is often the case that the reduction ratio does not slow down the motor speed enough. To overcome this next hurdle a 60V DC winding has been specified even though the system voltage is 24V. From here the speed controller further reduces the motor speed. End result; 0.001 revolutions per minute. (or 1.44 revolutions per day). Even though the entire case bearing shaft and keyway are made from stainless steel the shaft has also been customised with a 50mm length and a keyway isolated to the tip as much as possible to allow clear space for shaft labyrinth seals that provide additional protection. Laser etching of the custom parameters and the customers details on the body of the motor assists with identification long into the future. The complete DC servomotor and planetary gearhead incorporating the customisations was produced in under two weeks.

Contact maxon motor Australia for further information or application assistance. Ph. +61 2 9457 7477.

DC servo gearmotor customised for underwater ROV © maxon motor

Brushless DC servo motor – Quiet and Precise.

Uniquely designed gearhead, high resolution encoder and brushless servo motor combination provides accurate positioning at low noise levels.

The Koaxdrive gearhead supplied by maxon motor is a unique product that provides the typical transmission advantages of a planetary gearhead, offering torque multiplication and speed reduction at high efficiencies with the added benefit of very low operating noise. Its uniqueness lies in the design which is best described a combination of planetary and worm technologies. The special gear forms are still rotating around a central drive similar to planetary gears however they are also spline type gears mounted at a critical angle to achieve the planetary effect. This design results in an efficiency of 78% and input speeds of up to 8000rpm while still maintaining its low noise attributes. In the example pictured the gearhead is mounted to a stainless steel brushless DC motor containing internal hall sensors for motor commutation phasing and a 5000cpt incremental encoder for accurate positioning of the shaft. With a gearhead reduction up to 1091:1 using a maxon quad counting position controller this gives a resolution of 21,820,000qc/revolution or 0.0000165 degree. It is a level far below the resolution of position controllers themselves with a typical 4qc margin allowed for. The motors, gearheads and encoders are freely selectable to create a combination that most accurately matches the application.

Contact maxon motor Australia for technical application assistance Ph: +61 2 9457 7477.

High speed, low noise position control  © 2015 maxon motor

Autonomous robots reaching new heights.

Driven by two maxon brushed DC motors is an electronically powered robot that glides vertically up, or horizontally along, a specially created rail.

An engineering firm based in Zurich has developed a brushed DC motor powered robot to climb up transmission towers. With an integrated motor control unit the robot carries out work in half the time and without personal risk as was previously encountered by technicians.

It is powered by two maxon brushed DC motors mounted with planetary gearheads. Selected for their energy-efficiency of more than 90%, their small size, ironless windings and powerful torque allowing for a load of up to 60kgs. The robot is controlled via the maxon ESCON 50/5 servo motor controller, using software downloaded onto a PC, tablet or smartphone. Equipped with a rotating camera, images and videos are sent back to the technician allowing identification of problems in real time. The robot is fitted with sensors for collision protection and low-battery warning signals. This particular autonomous robot can also be used to fight fires in buildings, cable ducts or wind turbines.

For more information please contact maxon motor Australia Ph. +61 2 9457 7477.

The view inside the robot with maxon drives visible.  © 2014 HighStep Systems AG

Two maxon RE40 motors are used in the climbing robot together with planetary gearheads.

The maxon ESCON 50/5 servo controller.

Interesting servo motor drive solution.

A brushed dc motor fitted with high quality spur gear and DC holding brake.

Pictured here is maxon motors latest release brushed type DC motor. The DCX motor in itself features a high torque per volume ratio because of the utilisation of high grade neodymium rare earth magnets and a coreless winding. The reduction gearhead displays high quality low tolerance machining, hardened stainless steel shaft and stainless steel ball bearings. The holding brake is a solenoid style power-off device.

What are the advantages of such a strange combination of products?

The combined attributes of the combination make it suitable for many robotic applications but in particular this combination of products would suit a robotic arm application requiring tactile feedback, haptics and also elasticity. The motors characteristic zero cogging coreless rhombic design gives detent free controllability both when being driven from the load side or driving a load. Also the reduction gearheads high quality design with each axle supported on individual bearing races increases efficiency in both the drive and driven directions. The features would allow a robotic arm smooth and controllable motion, controllable compliance levels (softness) for use in close proximity with humans and power failsafe holding torque so that the arm would not fall under the influence of gravity when disabled.

Contact maxon motor Australia for unique solutions in demanding applications. Ph +61 2 9476 4777.

New DCX brushed DC motor with high quality spur gearhead and DC holding brake © 2015 maxon motor.

Rising through the ranks.

maxon motor technician Robin Rohrer recently placed 7^th overall in the CNC Turning category at the WorldSkills competition in São Paulo, Brazil.

WorldSkills is held every two years bringing together 59 member countries and regions and 1,100+ world champions, who compete across 50 different skillsets. The participants showcase their skills across four days. maxon motor technician, Robin Rohrer, participated in the category of CNC Turning, an arm of engineering. This is a highly specialised method of turning technical blueprints into actual parts. To qualify for the competition, Robin placed first in the Swiss competition SwissSkills. He achieved 7th place and a medal for Excellence at WorldSkills, ranking him as the best European in his category.  Robin trained for the competition “regularly by scheduling and manufacturing validated tests of old projects”.

For further information please visit the WorldSkills CNC Turning page or call +61 2 9457 7477.

High Torque Brushless DC motor for hand tools.

A high torque brushless DC motor with an 18V DC winding suitable for cordless hand tool applications.

Why are hand tool manufacturers switching to brushless DC motors? The answer is lifespan and battery life. A brushless DC motor simply does not have traditional carbon brush systems or even the lifespan improving precious metal brush systems to wear out. Brushless DC motors use electronics to phase the power around the motor windings. Traditionally hand held power tools running on 18V DC batteries use very high current brush style DC motors. Whilst these motors produce high speed and torque levels required on cordless power tools, they draw very high currents from the battery reducing its lifespan and the number of cycles required before re-charging. Until now, brushless DC motor technology from high quality manufacturers has been focused mainly on application areas such as medical and aerospace. The brushless motors developing the high speeds and power levels for these markets were typically coreless design two pole motors. Recently developed technology that has allowed the increase of the number of motor poles and the lowering of the motors winding resistance specifically for use with 18V DC Lithium batteries, has allowed for the design of high torque, high speed brushless DC motors that are a suitable alternative to the brushed DC motors in industrial cordless power tools.

Contact maxon motor Australia tel +61 2 9457 7477.

40mm High torque 18V Brushless DC motor © 2015 maxon motor

Specialist motors for driver assist systems.

The maxon A-max brushed DC motor features in a Lane Departure Warning System being developed by a luxury car manufacturer.

The use of computers in cars as an aid to assist driving is being explored as a strategy to reduce accidents caused by human error.

A Lane Departure Warning system is one such application being developed by a luxury car manufacturer in conjunction with maxon motor. The vehicle’s position in the lane is determined with the use of various sensors and computers. If the car drifts out of its lane, the system activates an electric motor in the steering wheel making it vibrate, thus alerting the driver to possible danger.  Other driver assist systems include brake assist and adaptive cruise control.

The maxon A-max brushed DC motor was specifically selected for use in the Lane Departure Warning system. Chosen for its small size suitable for applications with restricted space, its quiet operation and high-power output.  The A-max brushed DC motor has been fitted with a special Electro-Magnetic Interference suppression component.  It protects the other systems in the vehicle from being interfered with by the electromagnetic fields of the motor.

For more information please contact +61 2 9457 7747.

The A-max16 brushed DC motor from maxon ©  maxon motor

Starting out: When do I use a DC servo motor controller?

If your application has a brushed or brushless DC motor, you require a DC servo motor controller to control the speed and torque as well as protect the motor from damage. 

A DC servo motor controller is a device that operates on a rotary or linear actuator and allows the user accurate control of angular or linear position, speed and acceleration.

DC servo motor controllers are used for a variety of reasons:

Manage speed and torque: The speed of a motor will increase with a reduction in load; and decrease in speed when the load is heavier. Where the weight of the load is variable, a DC servo controller will sustain the motor at a consistent speed.  Likewise the torque delivery is governed from the motors current. If left uncontrolled the motor can power large currents resulting in excessive torque that potentially could cause application failure, stall the motor or burn it out.

Motor protection: The DC servo motor controller serves to protect the motor from damage incurred by possible short circuiting, offers thermal protection, current-limit protection and safeguards against power surges.

maxon motor Australia has a dedicated web page featuring the range of DC servo motor controllers. To visit the page click here.

For more information call +61 2 9457 7477.

The ESCON Module 50/5 is a small-sized, powerful 4-quadrant PWM servo controller OEM module for the highly efficient control of permanent magnet-activated brushed DC motors or brushless EC motors up to approximately 250 Watts.

maxon motors in another mission to the moon.

maxon brushless DC motors and gearheads feature again in the wheels of a Rover set to explore the moon.

Astrobotic Technology, a small company and offshoot of the Robotics Institute at Carnegie Mellon University, intends to send a lander and rover to the moon in 2016. Astrobotic have been working with maxon motor to develop an economical and practical rover “Andy” using standard parts.  The importance of an economical application lies in the long-term goal of Astrobotic, which is to provide low-cost cargo transport to the moon. The result is the use of maxon brushless DC motors fitted with GP32 planetary gearheads in Andy’s wheels. The brushless DC motor was specifically chosen for its reliable performance under extreme temperatures and conditions, high power density and torque ratio as well as its compact size.

The reliability of the brushless DC motors and gearheads is of utmost importance as rover Andy will be exploring caves. The belief held by Scientists is that some of the caves may be entryways to underground tunnel systems. If so, these concealed spaces would provide protection from small asteroids, temperature fluctuations and radiation making an ideal base for human stations.

Apart from the rich scientific intelligence gathered, success would bestow the honour of being the first private space mission to the moon. Google is also running a competition with $20m in prize money up for grabs.  The “Lunar X Prize” is open to private companies who land a rover, move it 500m and send the captured images back to Google.

For more information please contact +61 2 9457 7477.

The brushless EC-4pole 22 used in Andy is a true powerhouse. The rotor has two pole pairs for very high power density and high torque. The motor is combined with the planetary gearhead GP 32 HD, which was developed specifically for use under harsh environmental conditions.

The compact assembled drive unit.  Image © Carnegie Mellon University