Abstract:
An elevator motor assembly includes a motor for driving an elevator, a temperature sensor for detecting a temperature of the motor and a blower configured to blow air onto the motor to cool the motor, and configured to blow air at varying speeds that vary according to a temperature detected by the temperature sensor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to elevator motors, and in particular to a system for cooling an elevator motor with a variable-speed blower. 
         [0002]    Conventional elevator cooling systems using forced ventilation run at full speed, resulting in significant noise and energy consumption. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    According to one aspect of the invention, an elevator motor assembly includes a motor for driving an elevator, a temperature sensor for detecting a temperature of the motor and a blower configured to blow air onto the motor to cool the motor, and configured to blow air at varying speeds that vary according to a temperature detected by the temperature sensor. 
         [0004]    According to another aspect of the invention, an elevator assembly includes an elevator carriage, an elevator motor configured to drive the elevator carriage, a temperature sensor configured to detect a temperature of the elevator motor, and a blower configured to blow air onto the motor to cool the motor, and configured to blow air at varying speeds that vary according to a temperature detected by the temperature sensor. 
         [0005]    According to another aspect of the invention, a method of cooling an elevator motor includes detecting a temperature of the elevator motor and varying a speed of a blower that blows air onto the elevator motor based on detecting varying temperatures of the elevator motor. 
         [0006]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0008]      FIG. 1  illustrates an elevator assembly according to an embodiment of the invention; 
           [0009]      FIG. 2  illustrates a blower assembly according to one embodiment of the invention; and 
           [0010]      FIG. 3  is a block diagram of a method of varying a blowing air onto a motor according to an embodiment of the invention. 
       
    
    
       [0011]    The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    Conventional elevator motor cooling systems that utilize forced ventilation remain on full speed when turned on, resulting in noise and in excessive energy usage. Embodiments of the invention relate to a system for adjusting the speed of a cooling blower based on the detected temperature of the elevator motor. 
         [0013]      FIG. 1  illustrates an elevator system  100  according to an embodiment of the invention. The system  100  includes an elevator carriage  110  and an elevator motor assembly  120  that drives the carriage  110 . The elevator motor assembly  120  includes a motor  121  and a blower  122  that blows air onto the motor  121  to cool the motor  121 . Blower  122  may direct air onto an outside surface of motor  121  or blow air internal to motor  121 , over windings of motor  121 . In embodiments of the invention, a temperature sensor  123  is provided on, or in, the motor  121  to monitor temperature of the motor  121 . 
         [0014]    The elevator motor assembly  120  is illustrated in further detail in  FIG. 2 . The elevator motor assembly  120  includes the motor  121 , the blower  122  and a blower controller  127 . The sensor  123  is located on, or in, the motor  121  to detect a temperature of the motor  121 . The sensor  123  outputs the sensed temperature to the blower controller  127  via the temperature feedback line  126 , and the blower controller  127  adjusts a speed of the blower  122  according to the detected temperature. As a result, if the motor  121  is at a lower temperature, the blower speed may be reduced, which reduces a noise output from the blower  122  and an energy level consumed by the blower  122 . 
         [0015]    In one embodiment, the elevator mower includes a stator  125  that includes windings, and a rotor portion  124  that includes permanent magnets. The motor  121  may drive the elevator carriage  110  based on an electrical current being applied to the windings of the stator  125 , which drives a shaft of the rotor portion  124 . In one embodiment, the temperature sensor  123  is located on the stator  125 , such as in the windings of the stator  125 . Motor  121  may be a multiphase (e.g., three phase) motor, however, embodiments of the invention encompass any type of motor that drives an elevator. 
         [0016]      FIG. 3  illustrates a method of controlling the blower  122  based on the temperature detected by the temperature sensor  123 . In block  301 , the temperature of the motor is detected by the temperature sensor. The detected temperature is compared to one or more thresholds to adjust the speed of the blower  122 . In  FIG. 3 , only two thresholds are illustrated. However, embodiments of the invention encompass any number of thresholds, from one threshold to a sufficient number of thresholds such that the variable speed of the blower  122  appears to be continuous between an off state and a full power state. In  FIG. 3 , if it is determined that the detected temperature is less than a first and second threshold, then the blower  122  may be turned off at block  302 . In such a state, the elevator motor  121  may be off, or may be operating at a very low power level that does not result in substantial heating of the motor. 
         [0017]    If it is determined that the detected temperature is greater than a first threshold but less than a second threshold, then the blower  122  may be operated at a first speed in block  303 . The first speed may be a low speed that results in a relatively low noise level and relatively low power consumption. On the other hand, if it is determined that the detected temperature is greater than the first and second thresholds, then the blower  122  may be run at a second speed in block  304 . The second speed may be a high speed, such as full speed, resulting in a relatively high noise level and relatively high power consumption level. 
         [0018]    According to embodiments of the invention, a blower for cooling an elevator motor may be run at variable speeds according to a detected temperature of the motor. Accordingly, noise levels may be reduced and power consumption may be reduced by not operating the blower at full power all the time. 
         [0019]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.