-
.jpg)
Theoretical Study of the Load Distribution on the Threads for Roller Screw Mechanisms of a Friction Type(16年摩擦型滾柱絲杠螺紋載荷分布的理論研究)
t
The paper provides theoretical research of load distribution across the thread turns of the planetary roller-screw mechanism
(RSM). A characteristic feature of the theoretical approach of the paper is the use of a RSM rod model with two elastic contact
layers (the first layer is composed of screw-rollers, the second – of nut-rollers). A threaded mating of each elastic layer is
considered as a connection with continuous turns, which is closest to the truth and consistent to classical approaches. A similar
approach was applied for the ball-and-screw mechanisms with a member point contact. Thus, differential analytical closed-form
equations may be used to solve this task.
Based on the initial equation of compatibility of strains, axial offsets of contact layer points and the sum of screw, roller and nut
turn deflections are calculated; then, load distribution across the turns may be determined. Load distribution depends both on the
RSM geometry (pitch, profile angle, entry number, and thread diameter), material of threaded elements, manufacturing accuracy,
and on mating friction forces. With the dependencies of load distribution across the turns of zero-clearance RSMs obtained, we
have determined that maximum load is imposed on the outermost turns, which corresponds to classical solutions proposed by N.
E. Zhukovski.
閱讀:
2016-07-15
-
.jpg)
Static Load Distribution and Axial Stiffness in a Planetary Roller Screw Mechanism(16年行星滾柱絲杠的靜載荷分布和軸向剛度)
In this paper, an original approach is proposed to calculate the static load distribution
and the axial stiffness of a planetary roller screw (PRS) mechanism. Assuming that the
external loading is shared equally over an arbitrary number of rollers, only a sector of
the system is represented to save on computing time. The approach consists in using a
structure of bars, beams, and nonlinear springs to model the different components of the
mechanism and their interactions. This nonlinear model describes the details of the mechanism and captures the shape of the nut as well as the bending deformation of the roller.
All materials are assumed to operate in the elastic range. The load distribution and the
axial stiffness are determined in three specific configurations of the system for both compressive and tensile loads. Further, the influence of the shape of the nut is studied in the
case of the inverted PRS. The results obtained from this approach are also compared to
those computed with a three-dimensional finite-element (3D FE) model. Finally, since the
calculations appear to be very accurate, a parametric study is conducted to show the
impact of the bending of the roller on the load distribution.
閱讀:
2016-01-12
-
.jpg)
Load distribution of planetary roller screw mechanism and its improvement approach(15年行星滾柱絲杠的載荷分布)
A model of load distribution over threads of planetary roller screw mechanism (PRSM) is developed according to the
relationships of deformation compatibility and force equilibrium. In order to make the applied load of PRSM uniformly
distributed over threads, an improvement approach is proposed, in which the parameters of thread form of roller and
nut are redesigned, and the contact conditions of roller with screw and nut are changed to compensate the axial
accumulative deformation of shaft sections of screw and nut. A typical planetary roller screw mechanism is taken as
example to analyze the load distribution, and the effects of installation configurations, load conditions and thread form
parameters on load distribution are studied. Furthermore, the improvement approach is applied to the PRSM, and it is
proved to be beneficial to reach uniform load distribution over threads.
閱讀:
2015-09-01
-
.jpg)
Kinematics Analysis of the Roller Screw Based on the Accuracy of Meshing Point Calculation(15年滾柱絲杠基于嚙合點精度計算的運動學分析)
This paper investigates the meshing behavior of the roller screw, a mechanical transmission device characterized by threaded rollers
that transfer a load between the nut and the screw, by analyzing the meshing characteristics between screw and rollers. This study
seeks to establish a more accurate mathematical model for the thread surface by creating a modeling process in which the max
radiuses of the threads are calculated more precisely. The contact line distribution and the contact location were also calculated in
order to confirm the cross section of the meshing points. In the research presented in this paper, the actual transmission ratio is
analyzed and the study results in a new method to calculate the actual transmission ratio. In this study, the helical angle and the
vertex angle are proven to be of great significance after a careful analysis of their influence is conducted.
閱讀:
2015-03-25
-
.jpg)
Experimental simulation of rolling–sliding contact for application to planetary roller screw mechanism(15年滾動滑動接觸的實驗模擬及其應用)
The planetary roller screw mechanism is used in the aeronautics industry for electro-mechanical
actuators application. It transforms a rotational movement into a translation movement, and it is
designed for heavy loads. The main components are made of martensitic stainless steel, and lubricated
with grease. Like most usual rolling mechanisms, smearing and jamming can occur before the
theoretical fatigue lifetime, especially in defective lubrication conditions.
The actuated load is carried by small contacts between the threads of the screw, the rollers and the
nut. The static single contact can be described as an ellipsoid on flat contact; motion consists of rolling
with sliding perpendicular to the rolling direction. A calculation method based on elastic theories (Hertz,
Carter, Johnson) has been implemented. It calculates the normal and tangential stresses distributions,
generated in the micro-slip and stick zones of the contact area, using several input parameters such as
material properties, normal force, and creep ratio.
A specific apparatus has been developed to support these calculations and to experimentally study
the damage of the contacts in this mechanism. It consists of a freely rolling wheel loaded on a rotating
disc with a component of sliding that simulates the roller screw contact. The tribometer inputs are the
normal load, the speed, the creep ratio, and the lubrication. The wheel rolling speed and the tangential
force generated in the direction perpendicular to rolling are measured.
The experiments reveal a quick adhesive wear in dry or bad lubricated conditions, while a low
friction coefficient remains if the contact is well lubricated. The influence of the input parameters
concurs with the theoretical calculation. The evolution of grease lubrication during duty lifetime and the
influence of the tribo-chemical films on this lifetime are also studied.
閱讀:
2015-03-19
主站蜘蛛池模板:
最新国产精品自在线观看
|
99精品国产高清一区二区麻豆
|
欧美性猛交xxxx乱大交丰满
|
午夜福利无码一区二区
|
国亚洲欧美日韩精品
|
嫖妓丰满肥熟妇在线精品
|
天码av无码一区二区三区四区
|
久久久女人与动物群交毛片
|
天天影视综合网
|
少妇愉情理伦片丰满丰满
|
九九全国免费视频
|
欧洲精品一区
|
粉色视频高清大全免费观看1
|
婷婷亚洲久悠悠色悠在线播放
|
亚洲乱码中文字幕小综合
|
一区二区三区四区国产
|
h无码动漫在线观看
|
韩国A片国产浪潮AV
久久99国产精品
|
日韩国产三级
|
亚洲日韩在线视频
|
国产午夜福利片在线观看
|
亚洲日韩中文字幕一区
|
日韩免费在线观看视频
|
男女拍拍拍无挡免费视频
|
爱婷婷网站在线观看
|
伊人久久大香线蕉av色婷婷色
|
国产成人精品免费午夜
|
成人三级视频
|
欧美3区|
色偷偷色噜噜狠狠成人免费视频
|
毛片在线视频
|
国产精品1区2区
|
国产又黄又免费aaaa视频
|
久久中文字幕2021精品
|
成年人色网站
|
黄色免费在线观看网址
|
国产乱码字幕精品高清av
|
日本黄页在线观看免费
|
国产精品福利视频导航
|
色婷婷av一区二区三区浪潮
|
久久久精品欧美
|
久久久久久一级毛片免费野外
|
把腿张开老子臊烂你多p视频
|
日韩精品一区二区三区中文字幕
|
又色又爽又高潮免费观看
|
亚洲国产精品久久久久秋霞蜜臀
|
av无码免费岛国动作片片段欣赏网
|
国产成人精品久久二区二区91
|
麻豆av电影在线观看
|
日日干夜夜操
|
午夜影视网
|
免费在线国产视频
|
亚洲国产中文字幕
|
乱人伦人妻中文字幕无码
|
超碰在线播
|
日韩成人黄色
|
亚洲欧美一区二区三区
|
亚洲成人午夜在线
|
五月婷婷欧美
|
伊人网综合
|
国产五月色综合
|
91社区在线高清
|
国产看黄网站又黄又爽又色
|
日本久久视频
|
小箩莉末发育娇小性色xxxx
|
毛片免费观看
|
日韩精品射精管理在线观看
|
丰满人妻熟妇乱又伦精品视频三
|
男女裸交免费无遮挡全过程
|
少妇无码一区二区二三区
|
韩漫重考生漫画画免费读漫画下拉式土豪漫
|
999www视频免费观看
|
天天爱天天做天天添天天欢
|
成人精品鲁一区一区二区
|
久久91精品
|
精品久久久网站
|
亚洲国产日本
|
激情 婷婷
|
欧美黑人粗暴多交高潮水最多
|
自拍偷自拍亚洲精品10p
|
久久夜夜操
|
人人妻人人做人人爽
|
性欧美暴力猛交69hd
|
人妻另类 专区 欧美 制服
|
日本高清一区免费中文视频
|
久草视频电影
|
成人无码免费一区二区三区
|
夜夜影院未满十八勿进
|
国产二区在线播放
|
农村乱人伦一区二区
|
一级免费看片
|
国产精品激情福利视频
|
免费xxx8888|
中文字幕伊人久久网
|
少妇精品无码一区二区免费视频
|
亚洲国产精品久久久
|
亚洲国产精品福利片在线观看
|
日本亚洲欧美在线视观看
|
日本玖玖
|