Design Of High-Density Sensorless BLDC Window Motor

This paper proposes a outer rotor PMBLDC sensorless motor with harmonic gear drive for window lifter.Compared with the PMDC motor with worm gear reducer,the brushless one shows the following advantages:(1)The efficiency of window motor increased from 70% to 83%;(2)Because there has no brush,the motor is lower noise and longer service life;(3)The structure of outer rotor combined with harmonic deceleration structure.It greatly simplifies the structure of the original window motor assembly,and improves the transmission efficiency from 70% to 90%.This study aims to do research in motor applied in rope-wheeled window regulator and has accomplished works as follows:Firstly,through the analysis of existing rope wheel lifter structure,and relevant standard requirements for the window motor,this paper finished the stress analysis to determine the DC brush window motor transmission scheme: the motor with harmonic gear speed reducer structure.And the basic design parameters of the motor are calculated.Secondly,base on the main technical parameters of the window motor,the main structure size of the motor can be calculated.The electromagnetic scheme of motor is preliminarily determined by the method of field circuit.The comparison and selection of stator and rotor structure is completed.And with the help of RMxprt module,this paper modeled for the motor and optimized the parameters calculation of the motor.In the third place,using the Maxwell 2D module to build a 2D model of the window motor,and analyzed the static and transient fields of BLDC motor.The performance calculation and parameter analysis of the window motor model are carried out.Finally,according to the structure size calculation above,the engineering structure design of the window motor is completed and the performance of the prototype is tested.The structural engineering design is mainly completed by the project: the engineering drawings,the development and arrangement of the processing program flow,complete the assembly of the prototype motor.The test items of the prototype are: stator winding test,no-load characteristic test and load characteristic test.The results from these tests verify the feasibility and rationality of the design method of the brushless DC window motor in the article.