Kinematic optimization of ball-screw transmission mechanisms

2007 ◽  
Vol 42 (1) ◽  
pp. 34-47 ◽  
Author(s):  
D. Mundo ◽  
H.S. Yan
2016 ◽  
Vol 9 (5) ◽  
pp. 324 ◽  
Author(s):  
Zain Retas ◽  
Lokman Abdullah ◽  
Syed Najib Syed Salim ◽  
Zamberi Jamaludin ◽  
Nur Amira Anang

2021 ◽  
Vol 70 ◽  
pp. 1-11
Author(s):  
Vibhor Pandhare ◽  
Xiang Li ◽  
Marcella Miller ◽  
Xiaodong Jia ◽  
Jay Lee

2021 ◽  
Vol 504 ◽  
pp. 116121
Author(s):  
Li Yuehao ◽  
Cheng Zhe ◽  
Hu Niaoqing ◽  
Yang Yi ◽  
Xiao Zhuo
Keyword(s):  

Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rong Zhang ◽  
Ning Dong ◽  
Zhangqi Shen ◽  
Yu Zeng ◽  
Jiauyue Lu ◽  
...  

Abstract Emergence of tigecycline-resistance tet(X) gene orthologues rendered tigecycline ineffective as last-resort antibiotic. To understand the potential origin and transmission mechanisms of these genes, we survey the prevalence of tet(X) and its orthologues in 2997 clinical E. coli and K. pneumoniae isolates collected nationwide in China with results showing very low prevalence on these two types of strains, 0.32% and 0%, respectively. Further surveillance of tet(X) orthologues in 3692 different clinical Gram-negative bacterial strains collected during 1994–2019 in hospitals in Zhejiang province, China reveals 106 (2.7%) tet(X)-bearing strains with Flavobacteriaceae being the dominant (97/376, 25.8%) bacteria. In addition, tet(X)s are found to be predominantly located on the chromosomes of Flavobacteriaceae and share similar GC-content as Flavobacteriaceae. It also further evolves into different orthologues and transmits among different species. Data from this work suggest that Flavobacteriaceae could be the potential ancestral source of the tigecycline resistance gene tet(X).


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4378
Author(s):  
Jorge A. Reyes-Avendaño ◽  
Ciro Moreno-Ramírez ◽  
Carlos Gijón-Rivera ◽  
Hugo G. Gonzalez-Hernandez ◽  
José Luis Olazagoitia

Energy harvesting shock absorbers (EHSA) have made great progress in recent years, although there are still no commercial solutions for this technology. This paper addresses the question of whether, and under what conditions, an EHSA can completely replace a conventional one. In this way, any conventional suspension could be replicated at will, while recovering part of the wasted energy. This paper focuses on mimicking the original passive damper behavior by continuously varying the electrical parameters of the regenerative damper. For this study, a typical ball-screw EHSA is chosen, and its equivalent suspension parameters are tried to be matched to the initial damper. The methodology proposes several electrical control circuits that optimize the dynamic behavior of the regenerative damper from the continuous variation of a load resistance. The results show that, given a target damper curve, the regenerative damper can adequately replicate it when there is a minimum velocity in the damper. However, when the damper velocity is close to zero, the only way to compensate for inertia is through the introduction of external energy to the system.


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