Cylindrical cam with oscillating follower is widely applicable and used in many mechanical devices and machines. However, a common error exists in the methods of designing planar profile for oscillating follower cylin...Cylindrical cam with oscillating follower is widely applicable and used in many mechanical devices and machines. However, a common error exists in the methods of designing planar profile for oscillating follower cylinder cam. In this study, we propose a new hypothesis to solve this design problem with the inclusion of deviation angle. On the basis of this new concept, equations for planar profile expansion and methods of calculating pressure angle are deduced by applying 3D expansion formula of the follower＇s motion orbit. When the pressure angle is less than allowable value, the minimum base radius can be determined by using MATLAB software. Accordingly, the planar profile of oscillating follower cylinder cam is generated by CAD software. This new method is practical and can be easily adopted for the design of oscillating follower cylindrical cam with desirable accuracy. We applied the method in the design of cylindrical cam for paper feeding mechanism used in high-speed printers. We calculated the planar profile and used it to direct the NC machine for the manufacture of the groove of cylindrical cam. The improved cylindrical cam met all of the requirements of speed and accuracy demanded by high-speed printers. Therefore, our new method has been validated by practical application.展开更多
It is well known that if X is an arc or a circle, then there is no expansive homeomorphism on X. In this paper we prove that there is no expansive Z^d action on X, which answers the two questions raised by us before, ...It is well known that if X is an arc or a circle, then there is no expansive homeomorphism on X. In this paper we prove that there is no expansive Z^d action on X, which answers the two questions raised by us before, In 1979, Mané proved that there is no expansive homeomorphism on infinite dimensional spaces. Contrary to this result, we construct an expansive Z^2 action on an infinite dimensional space. We also construct an expansive Z^2 action on a zero dimensional space but no element in Z^2 is expansive.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50575205)National Hi-tech Research and Development Program of China (863 Program, Grant No. 2006AA04Z233)+1 种基金Zhejiang Provincial Natural Science Foundation of China (Grant No. Y104243)Ningbo Municipal Natural Science Foundation of China (Grant No. 2008A610038, Grant No. 200703B1003018)
文摘Cylindrical cam with oscillating follower is widely applicable and used in many mechanical devices and machines. However, a common error exists in the methods of designing planar profile for oscillating follower cylinder cam. In this study, we propose a new hypothesis to solve this design problem with the inclusion of deviation angle. On the basis of this new concept, equations for planar profile expansion and methods of calculating pressure angle are deduced by applying 3D expansion formula of the follower＇s motion orbit. When the pressure angle is less than allowable value, the minimum base radius can be determined by using MATLAB software. Accordingly, the planar profile of oscillating follower cylinder cam is generated by CAD software. This new method is practical and can be easily adopted for the design of oscillating follower cylindrical cam with desirable accuracy. We applied the method in the design of cylindrical cam for paper feeding mechanism used in high-speed printers. We calculated the planar profile and used it to direct the NC machine for the manufacture of the groove of cylindrical cam. The improved cylindrical cam met all of the requirements of speed and accuracy demanded by high-speed printers. Therefore, our new method has been validated by practical application.
文摘It is well known that if X is an arc or a circle, then there is no expansive homeomorphism on X. In this paper we prove that there is no expansive Z^d action on X, which answers the two questions raised by us before, In 1979, Mané proved that there is no expansive homeomorphism on infinite dimensional spaces. Contrary to this result, we construct an expansive Z^2 action on an infinite dimensional space. We also construct an expansive Z^2 action on a zero dimensional space but no element in Z^2 is expansive.
