Company - 27/07/2020
NSK Develops World's First Non-Contact Torque Sensor for Drive Shafts in Motor Vehicles
NSK Ltd. has developed a non-contact torque sensor capable of measuring the torque of drive shafts in real time. This technology is the first sensor in the world with this capability.
This new technology can increase fuel economy (reduce power consumption), improve ride comfort and safety, and expand a world of new possibilities across CASE (Connected, Autonomous, Shared & Services, Electric.)
The sensor uses magnetic fields to detect torque by measuring minute twisting of the drive shaft that occurs naturally as it is rotated by the motor. Conventional torque sensors have been too complicated or expensive for wide scale use, but NSK's new technology makes it possible to have a simple structure in a compact sensor that is ideal for mass production and broad adoption by automakers.
A significant benefit of the new torque sensor is increased fuel economy through reduced power consumption, and improved ride comfort and safety. The sensor expands a whole new world of possibilities across CASE*1. NSK is aiming for 6 billion yen in yearly sales by 2030.
Development Background
The automotive industry is currently amid a once-in-a-century period of profound transformation centered around CASE*1. The car of the near future is expected to maximize safety and comfort and reduce environmental impact. This will require vehicles to be equipped with various sensors to accurately understand the state of the vehicle to execute advanced control methods. NSK’s non-contact drive shaft torque sensor is an industry first.
The drive shaft is a key component that is used to transmit the power of the engine or motor to the wheels. Measuring torque at the drive shaft provides vital information that can be used to increase fuel economy, improve comfort and safety, reduce environmental impact, and even detect abnormalities or malfunctions in the vehicle. However, until the introduction of NSK's new product, conventional torque sensors were too large and too complicated to be suitable for mass production vehicles.
*1 CASE: Connected, Autonomous, Shared & Services, Electric
Product features
1. Non-Contact Sensor
- Achieved a non-contact design with a simple structure ideal for mass production.
- High reliability due to no friction occurring between the sensor and the shaft.
2. Compact
- Reduced the width of the unit by half and improved sensitivity by using a special method of wrapping the sensor coil and employing an optimized material.
3. Ease of Manufacturing
- The sensor requires no grooves, coatings, or other special processing of the shaft.
- Only requires shaft materials and basic surface processing methods that have a history of use in mass-production car models.
Customer Benefits
1. Better Fuel Economy (Lower Power Consumption).
The concept of pairing electric motor with two-speed transmission in EV is gaining attention as an effective method to deliver increased efficiency. NSK's torque sensor can help deliver shock-free gear shifting enabling the use of a larger step ratio to deliver 7% increased fuel economy*2. In belt-driven CVT systems, data from NSK's torque sensor can help to adjust and reduce the hydraulic clamping force applied to the belt to the minimum required, thereby reducing transmission loss for a 1.05% increase in fuel economy*3.
2. Increased Comfort
The torque sensor can be used to achieve a smoother ride through advanced control that softens fluctuations in torque when changing gears and accelerating/decelerating.
3. Identify Abnormalities
By continuously monitoring and tracking torque, it is possible to predict and identify issues and abnormalities in the vehicle at an early stage before they develop into larger problems.
4. Connected
As always-online vehicles become the norm, the data gathered by the sensor can be used to identify the state of nearby vehicles, and can be shared and analyzed to identify collective road usage patterns and deliver new value to society.
As development efforts in CASE accelerate, in addition to mainline solutions for autonomous driving and automotive electrification, NSK is expanding its horizons with new connected products, such as this torque sensor, that can contribute to the further evolution of mobility on a global basis.
*2 Based on in-house simulations.*3 Based on actual in-vehicle WLTC test results.
About NSK
NSK began its journey manufacturing the first bearings in Japan in 1916, and has since developed into a global organization researching, designing, and manufacturing Motion & Control™ solutions essential for mobility and industrial applications. NSK is the top supplier of bearings in Japan and is the third largest supplier in the world by market share.
Our responsive products and technologies enhance automotive performance and industrial productivity while reducing energy consumption to unprecedented low levels. In the early 1960s, we set our sights outside Japan and have established over 200 business locations in 30 countries alongside a vast network of joint ventures and partnerships in all corners of the world.
NSK Corporate Philosophy
NSK contributes to a safer, smoother society and helps protect the global environment through its innovative technology integrating Motion & Control. As a truly international enterprise, we are working across national boundaries to improve relationships between people throughout the world.
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