| 摘要 |
PURPOSE: To obtain a coder with a high resolution by setting the interval between a pair of magnetic poles to a specific value, and setting the reference magnetic flux density of a pair of magnetic poles to a specific value, and relating the value to the range of the value of the interval between magnetic poles. CONSTITUTION: The coder 20 gives relatively a large number of magnetic pole pairs 23 that are accurately positioned at a member that can be magnetized for satisfying request conditions for high-resolution applications. Also, each total number of magnetic pole pairs 23 for one coder 20 have an optimum magnetic flux density related to the magnetic pole pairs 23. The combination of the magnetic flux density - magnetic pole pairs has a new range of values for a specific application such as a bearing. A reference magnetic flux density Fr is obtained by an equation, where K1=158-1,056 Gauss/cm<2> , K2=158-1,056 Gauss/cm<2> , K3=158-1,056 Gauss/cm<2> , X = a magnetic pole interval between adjacent magnetic pole pairs, Fr = a reference magnetic flux density range at centigrade +20 deg.C when K1 , K2 , and K3 are equal. Also, the equation can be applied to a gap of 0.91mm between the outer surface of the coder 20 and the sensing part of a sensor. |
