Transmission Efficiency of Cycloid–Pinion System Considering the Assembly Dimensional Chain

Abstract

The rotary vector reducer is the core component of industrial robots, and the transmission efficiency is undoubtedly an important indicator of transmission performance. In addition, the assembly dimensional chain leads to clearance between parts, which can have a certain impact on the transmission efficiency. During previous studies, this effect was often ignored. Firstly, the cycloid tooth profile is a relatively large collection of points. Therefore, a more efficient tooth profile model is employed as the basis for the calculation. Secondly, the contact between the cycloid and the pinion is determined by experimental observation to be a point contact rather than a theoretical line contact. Moreover, the dynamics and friction loss models of the cycloid–pinion system are constructed. Finally, the assembly dimensional chain is introduced into the different structural designs. The clearance results were obtained with the extreme value method. The results show that the addition of the pinion sleeve allows the system to have a smoother drive process and a more efficient transmission; this was verified with ADAMS.

An Analysis of Power Friction Losses in Gear Engagement with Intermediate Rolling Elements and a Free Cage

“…Replacing angular velocities in Expression (9) with radii of corresponding circles, we will rewrite formulas of gear ratios between links as follows:…”

“…Many works are devoted to the study of the engagement of cycloid gears [2][3][4][5][6][7][8]. But pin gears, in which there are no intermediate rolling elements, are mainly studied [9][10][11][12][13][14][15][16][17][18]. In [9], the efficiency coefficient in the engagement of a pin gear with pins without bushings and with bushings was investigated.…”

“…But pin gears, in which there are no intermediate rolling elements, are mainly studied [9][10][11][12][13][14][15][16][17][18]. In [9], the efficiency coefficient in the engagement of a pin gear with pins without bushings and with bushings was investigated. It showed that using pins with bushings makes the transmission work smoother, and friction losses decrease.…”

Design and Analysis of a Novel Actuator with a Double-Roller Gear Drive

“…Its diameter is 80 mm and its height is 78.5 mm. It mainly consists of a hexagon socket cylindrical bolt (1), drive housing (2), retaining ring (3), cross roller bearing (4), output end (5), inner needle (6), sleeve (7), outer needle roller (8), retaining ring (9), solid needle roller bearing (10), retainer (11), eccentric sleeve (12), right side of holder (13), motor front end cap ( 14), C-type flat key (15), motor shaft (16), rotor (17), deep groove ball bearing (18), determinant (19), magnetic encoder (20), and motor housing (21). Unlike common involute gear drives, it is a complex eccentric rotating planetary transmission structure.…”

“…In order to devise an efficient cycloid reducer, a compact needle bearing was used instead of a ball bearing [15,16]. The type of contact between a cycloid and pinion is point contact, rather than theoretical line contact, which greatly improves mechanical efficiency [17]. High energy efficiency at a low speed-reducing ratio is a cycloid reducer's main advantage; then, an actuator model was set up by assembling an electrical motor with high torque density.…”