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The use of the linear sliding wear theory for open gear drives that works without lubrication
Published in Klára Szita Tóthné, Károly Jármai, Katalin Voith, Solutions for Sustainable Development, 2019
Another important phenomenon of wear is when the connection of the pinion to the driven gear is not smooth. In this case, the front surfaces of the pinon and the driven wheel contact and act like a “friction drive” for a while. This lasts until the tooth of the pinion jumps into the groove of the driven gear. In this case, the two hardened surfaces seem to be cutting each other. The peeling particles can be placed directly between the meshing tooth surfaces, which further deteriorate the friction conditions between the two gears.
Power Transmission and Gearing Systems
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Archimedes drive, also known compound planetary friction drive in the US patent 10,113,618 [9.58], is designed based on the same configuration as a planetary transmission. However, unlike a conventional planetary gearing system, it uses smooth frictional hollow rollers instead of gear teeth to transmit torque. The Archimedes drive combines the architecture of a compound drive with a friction drive to achieve gear ratios of up to 10,000:1 [9.59].
Miniature direct-drive two-link using a micro-flat ultrasonic motor
Published in Advanced Robotics, 2018
We consider the dynamic model of a micro-flat ultrasonic motor. It is known that the angular velocity of ultrasonic motors can be modeled as a first-order lag system, even to micro ultrasonic motors [20]. In the case that the micro-flat ultrasonic motor generates a torque and the rotor spins with an angular velocity ω, the equation of motion is expressed as where J is the moment of inertia and c is the damping coefficient. is the friction torque and can be ignored at friction drive. The torque transferred to a link from the motor is written as
Control of friction hoist head rope tensions revisited
Published in CIM Journal, 2023
Another fundamental aspect of friction hoists needs to be raised here. The maximum torque that can be transmitted by the hoist’s motor or braking system is limited by the classical friction drive formula due to Euler,
Experimental Study on Cage Dynamic Characteristics of Angular Contact Ball Bearing in Acceleration and Deceleration Process
Published in Tribology Transactions, 2021
Shijin Chen, Xiaoyang Chen, Qingqing Li, Jiaming Gu
The test rig shown in Fig. 1 was used to analyze the dynamic characteristics of the components of angular contact ball bearings in an unstable working state. Motor 1 connects to a shaft through the coupling to drive the inner ring of the test bearing, and motor 2 drives the outer ring of the test bearing through another shaft and the friction wheel. However, in the current study the outer ring is always fixed. The input frequency of the motor 1 is changed for different inner ring starting accelerations while the motor braking time is changed for different stopping decelerations. The outer rings of the pared bearing are slightly wider than the inner rings and can stand against each other, and the axial preload of the bearing can be varied by adjusting the thickness of the gasket between the end cap of the outer ring and the friction wheel 1. The loading wheel and friction wheel 1 installed in the outer ring of the test bearing form the friction drive system, and the radial load is applied to the bearing by friction wheel 1, which is pressed by the spring. By attaching the sensor to the inner ring and marking on the cage, the speed of the inner ring and cage can be measured via the eddy current speed sensor and the photoelectric sensor, respectively. Note that the coordinate definition is shown in Fig. 1c. In addition, the radial and axial displacements of the cage are measured by two vertically positioned laser line displacement sensors as shown in Figs. 1b and 1c. The selected laser sensor is LJ-G015K, the trigger interval is 3.8 ms, the effective axial displacement is 15 ± 2.3 mm, and the effective range of the laser line is equally distributed 800 points, and repetitive accuracy in the axial and radial directions is 0.2 and 2.5 μm, respectively. The laser sensor collects data through software on the computer. The position of the measured object is changed from position 1 to 2 in Fig. 1d by moving it vertically 0.618 mm and horizontally 1.38 mm in the radial plane. At this time, the vertical data change 0.605 mm and horizontal data change 1.34 mm in the software system. From the data, it can be also seen that the error between the actual calibration data and the software display data is small for the test bearing. With two sensors arranged vertically on the side of test bearing, the radial motion in two directions can be collected by the two sensors, an axial motion adopts the average value recorded by the sensors, so the laser sensors can effectively record the axial and radial motions of the cage at the same time.