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Small, high-rigidity torque detector
RHシリーズ

Expanding the scope of "measuring" and measuring the torque of various products.

In the automotive industry, electrification is rapidly progressing, leading to the use of many types of motors. There is a demand for motors that minimize cogging torque and torque ripple, which cause vibration and noise. Therefore, a highly rigid torque sensor capable of accurately capturing torque fluctuations is necessary. Meanwhile, overseas, there is a growing demand for high-speed rotation specifications in motors for EV scooters and air conditioning compressors. We have developed a torque sensor that can meet these demands.

Features

High rigidity: Provides good responsiveness and enables accurate measurement of torque fluctuations.

In the automotive industry, as electrification rapidly progresses and many motors are used, there is a demand for motors that minimize cogging torque and torque ripple, which are causes of vibration and noise. Therefore, a highly rigid torque sensor that can accurately capture torque fluctuations is required.
The RH series achieves approximately 4.5 times the torsional rigidity of our previous models, enabling accurate measurement of torque fluctuations.

Data comparison between the RH series and a typical low-rigidity torque detector.

This is an example of measuring torque fluctuations between an RH torque detector and a typical low-rigidity torque detector using a CF-9400A FFT analyzer.

  • Data comparison between the RH series and general low-rigidity torque detectors No. 1
  • Data comparison between the RH series and general low-rigidity torque detectors No. 2

The graph above shows the results of frequency analysis of torque fluctuations for an RH torque detector and a typical low-rigidity torque detector.
Because the RH torque detector has higher torsional rigidity compared to general torque detectors with low rigidity, it can raise the resonant frequency of the device, making it possible to accurately measure the torque that is the intended measurement target (in this case, torque ripple caused by the first-order component of cogging torque).
Furthermore, the RH torque sensor achieves smoother and flatter measurements up to higher frequencies.

High-speed rotation: Capable of rotational speeds up to 20,000 r/min.

There is a growing demand for high-speed rotation in applications such as EV scooter motors and air conditioner compressor motors. The RH series can measure rotation speeds up to 20,000 r/min, approximately 2.5 times faster than our previous models, enabling stable measurement from low-speed rotation (*) to high-speed rotation.

Rotation speed detector mounting example

  • Rotation speed detector mounting example

Direct output: Counterless, ideal for integration into equipment.

Previously, it was necessary to use a torque sensor in combination with a calculation display unit, but now it is possible to output a signal from the torque sensor alone. This contributes to cost reduction.

Configuration Examples

  • Configuration Examples
img-rh-05

High precision: Enables accurate performance evaluation tests of motors and other components.

Linearity, including hysteresis, can be achieved at ±0.05% FS (half of our previous standard), enabling highly accurate measurements.
High precision: Enables accurate performance evaluation tests of motors and other components.
For EPS motors, an accuracy of 1% relative to the torque capacity is required.
Furthermore, the torque sensor requires the next lower digit.
(If the torque capacity is 6 N·m, then 0.1% of 6 N·m = 0.006 N·m.)
A torque detector with a torque capacity of 10 N·m will have an accuracy of 0.06% FS.
We have developed a torque detector that can meet this requirement.

Miniaturization: Due to miniaturization, the mass and volume are approximately 1/3 (compared to our previous model).

By making it smaller, lighter, eliminating the counter, and maintaining the same center height, it has become easier to replace and a very user-friendly product.

Dimensional comparison with the SS series

Dimensional comparison with the SS series

SS Series Torque Detector
Axle length: 220 mm
Body width: 117 mm
Height: 167 mm
Center height: 50 mm
Mass: approx. 5.5 kg

RH Series Torque Detector
Shaft length: 119 mm
Body width: 108 mm
Height: 125 mm
Center height: 50 mm
Mass: approx. 2 kg

System Configurations

Configuration without calculator display

  • Configuration without calculator display

Configuration with calculator display

  • Configuration with calculator display

Case Studies

Application examples of the compact, high-rigidity torque detector RH series

Application examples of the compact, high-rigidity torque detector RH series

Graduate School of Frontier Sciences, The University of Tokyo

To minimize "iron loss" generated by the motor, a custom-made motor bench was used to investigate the mechanism.

Specification

Measurement section

  RH-1105 RH-1205
Torque detection unit Rated Torque 10 N・m 20 N・m
Breaking Torque More than 400% of the rated capacity
Limit Torque More than 200% of the rated capacity
Nonlinearity including hysteresis ±0.05% FS or less (Displayed value when connected to TQ-5300)
Temperature influence at zero point ±0.02% FS/°C or less (Displayed value when connected to TQ-5300)
Temperature effect of span points ±0.02% FS/°C or less (Displayed value when connected to TQ-5300)
Rotation speed detection unit Output pulse count (standard) 4 P/R (Detection is performed using Hall IC + magnet)
Number of output pulses
(When the optional RH-0501 rotation detection gear 60 P/R is installed)
60 P/R (Rotation speed detection requires the separately sold MP-981 or MP-9820)

Output section

Torque analog output Output format Voltage output 0 to ±10 V FS
Analog conversion method Periodic conversion method (converts to torque value every cycle and then to analog voltage)
Minimum allowable load 100 kΩ
Linear number ±0.10%FS or less
Zero point offset 0.05 V or less
Connector BNC (female)
Torque frequency output Output format Line driver output 10 kHz ±5 kHz
Connector R03-RB12F
Rotational speed pulse output Output items The pulse output of the Hall IC is waveform-shaped and output.
Output format The open collector output is pulled up to +5V with a 330Ω resistor.
Minimum allowable load 10 kΩ
Connector R03-RB5F

Interface section

Torque-free input section Input fields Torque zero correction value acquisition started.
Contact Input: A function that automatically sets the torque to 0 under no-load conditions via an external contact.
Input signal For voltage-free contact inputs: Open-circuit voltage: 5.25 V or less Short-circuit current: 1 mA or less
For voltage input: H level; 4–5.25 V; L level; 0–1 V
Connector R03-RB5F
READY output section Output items Contact output: When torque is being measured, the contact is closed.
Output format Photomos Relay
Load voltage DC30V or less
load current 100 mA or less
On-resistance 10 Ω or less
Connector R03-RB5F

General specifications

  RH-1105 RH-1205
Power supply voltage DC 24V (18-30V)
Power consumption 20W or less
Power input connector R03-RB12F
Operating temperature range 0~+50 °C
Operating humidity range 20-85%, provided there is no condensation.
Storage temperature range -10 to +60 °C
Storage humidity range 20-85%, provided there is no condensation.
CE marking
Low Voltage Directive: 2014/35/EU Standard EN61010-1
EMC directive: 2014/30/EU Standard EN61326-1
RoHS Directive: Four substances added according to standard 2011/65/EU and EEN IEC 63000 * (EU) 2015/863.
FCC FCC Part 15 Subpart B Class A
ICES ICES-003 Issue7 + Amendment1 ClassA
safety IEC61010-1: Overvoltage Category I, Earth Protection Class III, Pollution Degree 2
Torsional rigidity (design value) 10 N·m: 3.6 kN·m/rad 20 N·m: 6.9 kN·m/rad
Moment of inertia (design value) 10 N·m: 24.3 × 10⁻⁶ kg·m 2 20 N·m: 24.6 × 10⁻⁶ kg·m 2
Rated rotational speed (standard) 16,000 r/min
Rated rotational speed
(Optional RH-0502 when adjusting balance)
20,000 r/min
Outline drawings General specifications
Accessories Instruction manual, inspection chart, key

(1) To ensure accurate measurement, it is recommended to perform a zero torque correction at the start of measurement.
(2) Do not use in environments that exceed the specified temperature and humidity limits.
(3) When using or storing the product for extended periods, avoid high temperature and high humidity environments, as this may affect its performance.

Option

Model name Content
RH-0105 Torque signal cable (5 m)
RH-0110 Torque signal cable (10 m)
RH-0205 Power cable (5 m)
RH-0210 Power cable (10 m)
RH-0305 Rotary signal cable (5 m): For use between RH series and TQ-5300.
RH-0310 Rotary signal cable (10 m): For use between RH series and TQ-5300.
MX-7105 Rotary signal cable (5 m): For use between MP-981/MP-9820 and TM-3000 series.
MX-7110 Rotary signal cable (10 m): For use between MP-981/MP-9820 and TM-3000 series.
MX-8105 Rotary signal cable (5 m): For use between MP-981/MP-9820 and TQ-5300 series.
MX-8110 Rotary signal cable (10 m): For use between MP-981/MP-9820 and TQ-5300 series.
RH-0405 Torque Zero Input Cable (Torque Zero, READY Output, Rotation Signal Cable) (5 m)
RH-0410 Torque Zero Input Cable (Torque Zero, READY Output, Rotation Signal Cable) (10 m)
RH-0501 Rotation detection gear 60 P/R
MP-981 Magneto-Electric Rotation Detector
MP-9820 Magneto-Electric Rotation Detector
RH-0502 Dynamic balance adjustment
MX-101 Signal cable (1.5 m)
MX-105 Signal cable (5 m)

最終更新日:2025/09/03