There are so many rotating mechanism around us. The more you search, the more you can find rotating mechanism such as doorknobs, laptop hinges, bicycles and PET bottle caps. Force is required to rotate or stop these rotations. This force is known as torque, and torque meter is a device to measure the force in rotating direction..
In the pictures below, both force is applied in the direction of rotation with respect to the axis, and both of these forces are torque. The dust cloth becomes stiff at some point and does not turn any further once it is equal to the force of the hand. Even if you keep stepping on the bicycle, the pedal shaft will continue to rotate. These are both same torque, but the situation changes a bit when it comes to measuring these force. Especially, it is necessary to get creative to measure the rotating torque.
The force applied to the dust cloth is Non-rotating Torque.
The pedal of the bicycle keeps rotating, thus the stepping force is Rotating Torque.
It is important to measure the rotating torque! (with constant rotating force) In conventional strain gauges Torque gauges typically extract torque data from a rotating body via a slip ring. A slip ring is a mechanism for transmitting electric power and signals through an annular electric circuit and a brush arranged concentrically with respect to a rotating body. Usually, the shaft is fitted with 2 or 3 slip rings, which are pushed with a constant force to maintain contact and extract electrical signals. The slip ring contacts are made of carbon and are worn by friction with the silver ring. Since dust is scattered inside, it is necessary to replace the brush unit and clean the torque meter body. In addition, pressing the brush unit significantly impedes the rotation of the shaft, making it impossible to measure torque accurately.
In UTM III, the rotating shaft with the detection part and the fixed part that outputs data are transmitted by non-contact. It does not interfere with the rotation of the shaft and does not require maintenance. In addition, since it is digital transmission, stable torque measurement is possible in any rotation range. A strain gauge is used for the detection unit. It achieves much higher accuracy than other detection methods.
Contactless transmission is technically complex, but structurally very simple. The main body can be designed smaller, and the conventional viewpoint of "large size torque meter" has been renewed.
Contact torque meter
UTM III is smaller size torque meter (Even for large Nm)
Slip ring type torque meters have contact wear. Therefore, it is necessary to pay attention to rotation speed and the durability time. The carbon contacts wear out and eventually disappear, which can lead to damage to the silver ring. If this happens, repair is impossible and the torque meter itself will need to be replaced. In addition, the worn carbon scatters inside the housing and turns black.
UTM III is developed to not have a slip ring, so you can use it without worrying about maintenance.
Torque meters required a separate dedicated amplifier. However, as shown in the block diagram above, UTM III has a built-in amplifier. You can measure the torque during rotation just by connecting this small unit to the shaft with couplings. Its output is tuned to output ± 10V at rated torque
There are various features of UTM III, but here we will introduce applications that take advantage of contactless transmission.
Advantages of non-contact transmission are…
To measure the starting torque of the motor, the torque meter itself must not be loaded. UTMIII has a light start and can measure the correct starting torque
Check the torque of parts related to human operation such as hinges and levers. You can quantify and manage subtle touches
Durability tests are sometimes conducted over a long period of time. UTMIII is maintenance-free, so making it perfect for long-term testing.
Torque meters are required to have various needs depending on the purpose and installation. UTM III has a full lineup of capacities and options upon request. We offer a total of 13 types and 4 types of options from a small torque of 0.05Nm to 500Nm.
Rotary encoder
Key groove |
Centering location
Square drive