RDrive Servo Motor by Rozum Robotics – All-in-One Solution – RDrive 70
RDrive servo by Rozum Robotics is an all-in-one robotic joint. RDrive servomotor unites in a single housing all the main elements: an encoder, a controller, a harmonic gear, and an AC brushless motor. Since the controller is integrated into the robotic actuator, the RDrive is a DC servomotor with a brushless AC core.
The service life of our servo motors is 35,000 hours. Rozum Robotics also provides a 1-YEAR WARRANTY. Our online support team is eager to help you whenever needed. Detailed video instructions and technical documentation are provided. Average servomotor lead-time 2-8 weeks. A network of international dealers and distributors for local support is available.
The first RDrive servo motor was created to drive Rozum Robotics collaborative robot that we designed and built entirely in-house. We were disappointed with the quality of cheap Asian robotic joints and were unwilling to pay for expensive customization in Europe. The factors motivated us to take it upon ourselves to design and create our robotic actuator.
Model: RDrive 70
Power: 65 W
Rated torque: 11 Nm
Peak torque: 28 Nm
Rated rotational speed: 55 RPM
Diameter: 53 mm
Length: 99.5 mm
Hollow shaft diameter: 8 mm
Weight: 795 g
Voltage: 48 V
Work conditions: 0 °C to +35 °С
Encoder: 2×19 bit, magnetic, absolute position
Most robotic joint manufacturers produce a housed brushless robotic actuator coupled with an encoder. They call it a servomotor. Powered by DC, the servomotor is controlled with the help of an external servo controller kit (sometimes called robotic servo drive or robotic actuator). In case you need a gear motor kit, you connect a gearhead to the servomotor. The overall design is whatever, but not a compact servo motor in this case.
Servo Motor Components
The built-in magnetic absolute encoders enable taking position measurements with an accuracy of 19 bits. One of the devices monitors the angular motion of the output shaft, and the other returns feedback on the positions of the rotor shaft. Feedback from the encoders indicates exact servomotor positions at a given moment and is available immediately upon powering up. No homing procedure is required because encoder readings are non-volatile. As a result, the devices are immune to temperature and humidity fluctuations, shock, vibration, and contaminants that are not ferromagnetic.
The controller is the core of the RDrive closed-loop motion control system. Tailored to be compatible with other structural elements, the integrated smart chip generates PWM signals to drive brushless AC motors to deliver the required motion output. The RDrive controller interfaces with other servo components (encoders, temperature transducers) to read or calculate position, speed, and torque. The readings and calculations determine whether the motor has reached the required position and speed and, if needed, tune the motion parameters.
The RDrive series features integrated harmonic gearboxes that use strain-wave gear technology. With a gear ratio of 1:100 and an almost zero backlash, the technology delivers high-torque output without impacting the precision of servos. The integration of the gear into the servo housing eliminates the need for additional couplings while minimizing the risk of bearing failures due to misalignment. In addition, the motor and the gear mechanism are matched to work together and require no separate design and mounting procedures, thus reducing engineering costs.
Brushless motors used in servo motors by Rozum Robotics is a lineup of compact high-torque AC motors designed as frameless rotor and stator kits. The brushless technology employed in the drives enables packing impressive power into a compact footprint while minimizing friction-induced power losses and ensuring noise- and spark-free operation. In addition, with low cogging torque, FMI-series products provide smooth rotation without jerkiness.
Servobox solution allows for the following easy and quick integration of RDrive servos into your application, safe and correct operation of RDrive servos in the designed range of loads, as well as precise control of RDrive servo motion via the Application Programming Interface. Servobox unit is offered as an option to RDrive servos.
- 1x Servomotor
- 1x STEP model
- 1x API reference
- 1x User Manual
- 1x CANopen communication guide
- 1x Servobox (optional)
- 1x Low voltage equipment and electromagnetic compatibility certificate
All of our Rozum products are covered with a 1-year warranty. Each of our customers gets personalized LIVE tech support from the engineering team when requested.
Easy to get—easy to use
Designed with the plug-and-run concept in mind, our RDrive motion solutions are easy to set up and operate. Instructions, drawings, and other information as required for seamless and quick integration are available on our website. In addition, when you need more specific advice, engineers at Rozum Robotics are at your service to guide you through the adoption process and address operating issues, if any.
Frequently Asked Questions
1. Is there an upper voltage limit for the RD60 drives? The datasheet states 48V, but we are wondering if possible to go higher?
The weakest component in the schematics rated 60V maximum, so we set software limits to 52V to have a voltage gap for safety. Servos are tested and proven to work in this voltage range. We didn’t recommend setting this limit higher than 52V.
2. I need to read angles on a computer by visual studio-based application. What packages do I need?
This can be done via API. API can be compiled in the visual studio using mingw-gcc
3. What is the difference between RDrive 60 and RDrive 70? The same motor with a different gearbox or a different motor? Why less power on RDrive 70?
RDrive 60 and RDrive 70 have different frameless motors inside. The power is different because the rated torque and speed are different. Here is the formula for power calculation:
Power (W) = Speed (Rpm) * Torque (Nm) /9.55
For RDrive60: 39Nm * 55rpm / 9.55 = 225W
For RDrive70: 49Nm * 30rpm / 9.55 = 155W
4. Can we operate in temps above 35dC with a derating applied to the torque? If so, what is the derating for 40dC and 45dC?
RDrive servo motors can operate at an ambient temperature range 0….+35 dC. The thermal limit is +85 degrees. The higher the ambient temperature, the shorter the time delta before the safety system gets activated (85-35=50 dC – thermal range). If the ambient temperature is 40 or 45 dC the RDrive servo motors are expected to be operating without derating the torque. But the time delta and the thermal range will be shorter, and the safety system gets activated faster. To avoid this, there are two options: you can either choose a servo with higher-rated torque and use it at a higher ambient temperature, making it bear a smaller load, or apply an additional cooling system and use the servo that exactly meets your torque parameters.
5. Is there a process for returning the motors when the Customer changes the loading conditions? Do the motors support external feedback like a linear encoder on the load?
Built-in control system (controller) allows for a critical mistake ±0.02° throughout the whole dynamic range (there’s no need for retuning when the Customer changes the load). Static error is ±0.005°. Max error during the accelerating stage and the braking phase: ±0.1° when the acceleration is 3 radian per sec2 and ±0.2° at 5 radians per sec2.
Currently, we are working on the advanced functionality “feed-forward.” The expected delivery date of the feature – Q1’19. We assume that the max error will be 0.02-0.05 throughout the whole range. If the Customer would require 10+ motors, we integrate the feature beforehand.
As for the linear motor, for the moment, it is not possible to use external feedback. If the Customer would require that feature (depending on the Quantity request), we could develop a motor with no internal controller but designed for use with an external controller. You can use a different controller, including those supporting external feedback like (a linear encoder).
The FMI-series motors by Rozum Robotics have successfully passed EU/CE certification. The brushless AC engines have been verified for compliance with the EN 60034-1:2011/AC:2011 standard setting forth rating and performance requirements for rotating electrical machines. Performed tests proved that the product type characteristics conform to the technical requirements as stipulated in the standard.
FMI frameless motors are сomply with the requirements of the Technical Regulations of the Customs Union CU TR 020/2011 “Electromagnetic Compatibility of Technical Devices.” IEC 61000-6-4:2006 Electromagnetic compatibility of technical devices. Electromagnetic disturbance from technical devices in industrial environments. Standards and test methods. IEC 61000-6-2:2005 Electromagnetic compatibility of technical devices. Immunity to electromagnetic disturbances from technical devices in industrial environments.
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