This paper presents some results of research concerning the calculation of u-bolts for above mentioned purpose with goal to ensure elevator safe performance. Different angles of contact between the rope and the traction pulley were considered to estimate their influence on the stress in the u-bolt and the standard bolt, then gives some recommendations when choosing or making u-bolts for fixing the deviation pulley axle. | Journal of Science & Technology 122 (2017) 012-016 Using U-Bolt for Fixing the Axle of Elevator Deviation Pulleys Trinh Dong Tinh Hanoi University of Science and Technology, No. 1, Dai Co Viet, Hai Ba Trung, Hanoi, Viet Nam Received: March 24, 2017; Accepted: November 03, 2017 Abstract Deviation pulleys are used on the elevator traction machines to ensure given distance between the suspension ropes attached to elevator car and counterweight or/and to increase the number of suspension rope falls (roping 2:1 or 4:1). With simple structure, the u-bolts are used widely to fix the axle of these pulleys. In many cases, these bolts are selected or made approximately and it can lead to inadequate selection. This paper presents some results of research concerning the calculation of u-bolts for above mentioned purpose with goal to ensure elevator safe performance. Different angles of contact between the rope and the traction pulley were considered to estimate their influence on the stress in the u-bolt and the standard bolt, then gives some recommendations when choosing or making u-bolts for fixing the deviation pulley axle. Keywords: U-bolt, Rope deviation pulley, Elevator 1. Introduction * specific cases of using the u-bolts are analyzed [1, 2], but the method of adequate selection of the u-bolts are not shown. Fig. 1 presents a typical configuration of electric elevator with traction drive. The car and counterweight are connected to each other by the steel ropes through traction and deviation pulleys. The traction pulley is mounted on the output shaft of the motor or the reduction box and transfers power to the ropes, so the car/counterweight can move up and down. The deviation pulleys are mounted on the traction machine to fulfill the given distance between suspension ropes at the car and the counterweight, also on the car/counterweight to increase the number of rope falls, which leads to increase of the rope diameter and dimensions of the traction machine, and also