Structure of rotor for outer rotor type brushless motor

Abstract

The present invention relates to a structure of a rotor for a brushless motor which can improve structural stiffness, restrict noise generation by reducing vibration during the rotation, use cheap materials, reduce a fabrication cost by fabricating a back yoke and a base plate unit in a single body. improve durability, and efficiently cool a heat generated in the motor during the operation by facilitating an external air inflow. The structure of the rotor for the brushless motor includes: a steel plate frame provided with a base plate unit in a disc shape having a plurality of insertion holes at its center portion, a plurality of radiation holes being formed at a circumferential portion of the insertion holes, a plurality of blades being formed at side portions of the radiation holes by cutting: a back yoke unit curved and extended in the upward direction, having a predetermined height at the circumferential portion of the base plate unit; and a radius-direction enhancing unit formed at the upper end portion of the back yoke unit; one or a plurality of ring type permanent magnets fixedly connected to the inner side portion of the back yoke unit; a connecting member inserted into the insertion hole positioned at the center, and connected to the steel plate frame; and a fixing unit fixing a driving shaft inserted into the connecting member and connected to the other constitutional elements.

1. A structure of rotor for an outer rotor type brushless motor, comprising:
 a steel plate frame including: 
 a base plate unit in a disc shape having: 
 a plurality of insertion holes at its center portion;  
 a plurality of radiation holes being formed at a circumferential portion of the insertion holes;  
 a plurality of radially extending blades being formed at side portions of the radiation holes by cutting;  
 a connection guide unit being protrusively formed adjacent a circumferential portion of a shaft insertion hole of the plurality of insertion holes;  
 a plurality of enhancing ribs which are longitudinally embossed in a radial direction formed in intermediate between a center and an outer edge thereof;  
 a back yoke unit curved at the edge portion of the base plate unit and formed integrally therewith and extended in the upward direction, having a predetermined height at an outer circumferential portion of the base plate unit; and  
 a radius-direction enhancing unit formed radially extending outwardly at an upper end portion of the back yoke unit;  
 
 
 one or a plurality of ring type permanent magnets fixedly connected to the inner side portion of the back yoke unit;  
 a connecting member inserted into the shaft insertion hole of the plurality of insertion holes positioned at the center, and connected to the steel plate frame by a fastening member; and  
 a fixing unit fixing a driving shaft inserted into the connecting member which connected to the other constitution elements.  
 
     
     
       2. The structure according to  claim 1 , wherein a jaw having a predetermined width in a horizontal direction and a contact surface extended in a vertical direction to the jaw are formed at an inner surface of the back yoke unit. 
     
     
       3. The structure according to  claim 2 , wherein the permanent magnets are positioned on the jaw, contacted with the contact surface, and fixedly connected to the back yoke unit by an adhesive or by positioning a resin for adhesion at their upper portions. 
     
     
       4. The structure according to  claim 1 , wherein the plurality of insertion holes are formed at the center portion of the base plate unit, and comprise the shaft insertion hole which the driving shaft is inserted into, and a plurality of fastening member insertion holes which are formed at the outer circumferential portion of the shaft insertion hole, and a fastening member is inserted into. 
     
     
       5. The structure according to  claim 4 , wherein a connection guide unit is protrusively formed in the upward direction at the outer circumferential portion of the fastening member insertion hole. 
     
     
       6. The structure according to  claim 1 , wherein the connecting member comprises:
 a ring-shaped flange unit having a predetermined thickness and area;  
 a boss unit upwardly extended at the center portion of the flange unit, and having a predetermined outside diameter and height;  
 a serration hole formed at an inner circumferential portion of a through hole formed at the boss unit in upper and lower directions, and engaged with a shaft serration unit formed at the driving shaft; and  
 a plurality of connecting member combining units formed at the flange unit and fastened to the fastening member.  
 
     
     
       7. The structure according to  claim 6 , wherein a guide hole which the connection guide unit protrusively formed at adjacent a circumferential portion of a shaft insertion hole of the plurality of insertion holes which inserted into is reamed having a predetermined depth at the lower portion of the connecting member combining unit. 
     
     
       8. The structure according to  claim 1 , wherein a cross-section of the enhancing ribs is symmetric in the radius direction. 
     
     
       9. The structure according to  claim 1 , wherein an embossing direction of the enhancing ribs is protruded inwardly toward a stator coil. 
     
     
       10. The structure according to  claim 1 , wherein an embossing direction of the enhancing ribs is protruded outwardly away from where a stator coil is located. 
     
     
       11. The structure according to  claim 1 , wherein a plurality of enhancing ribs embossed and longitudinally formed in a radial shape are formed in the radius direction at a predetermined portion of the base plate unit, and one or more radiation holes and blades are formed between the enhancing ribs. 
     
     
       12. The structure according to  claim 1 , wherein the plurality of radiation holes are longitudinally formed in the radius direction of the base plate unit. 
     
     
       13. The structure according to  claim 12 , wherein a width of the radiation holes is equal to or greater than a height of the blades. 
     
     
       14. The structure according to  claim 1 , wherein the respective blades are sloped inwardly or outwardly toward or away from a stator coil. 
     
     
       15. The structure according to  claim 14 , wherein a slope angle of each of the blades is between 85° and 95° relative to the surface of the base plate unit. 
     
     
       16. The structure according to  claim 1 , wherein the radius-direction enhancing unit is vertically curved and extended in the outward direction at the upper end portion of the back yoke unit. 
     
     
       17. The structure according to  claim 1 , wherein the radius-direction enhancing unit is extendedly formed in a reverse U shape in the outward direction at the upper end portion of the back yoke unit. 
     
     
       18. The structure according to  claim 1 , wherein a support frame is connected to the outer portion of the back yoke unit. 
     
     
       19. The structure according to  claim 18 , wherein a radius-direction enhancing unit is inwardly curved and extended at the upper portion of the back yoke unit, and thus the permanent magnets are supported by an elastic force of the back yoke unit itself. 
     
     
       20. The structure according to  claim 18 , wherein the support frame is curved several times, and thus partially surrounds the outsides of the bottom and side portions of the back yoke unit. 
     
     
       21. The structure according to  claim 18 , wherein a radius-direction enhancing unit is vertically curved and extended in the outward direction at the upper end portion of the back yoke unit, and the support frame is curved, and thus surrounds the whole outsides of the bottom and side portions of the back yoke unit. 
     
     
       22. The structure according to  claim 18 , wherein the radius-direction enhancing unit is vertically curved and extended in the outward direction at the upper end portion of the back yoke unit, and the support frame is formed in a disc shape with its center portion empty, as if covering the upper circumferential portion of the steel plate frame, facing an inner portion thereof. 
     
     
       23. A rotor for an outer rotor type brushless motor for a washing machine, comprising:
   a steel plate frame including:      a base plate unit in a disc shape having:      a plurality of insertion holes at its center portion;        a plurality of radiation holes formed at a circumferential portion of the insertion holes;        a plurality of radially extending blades formed at side portions of the radiation holes;        a connection guide unit protrusively formed adjacent a circumferential portion of a shaft insertion hole of the plurality of insertion holes;        a plurality of enhancing ribs which are longitudinally embossed in a radial direction formed intermediate a center and an outer edge thereof;        a back yoke unit curved at the edge portion of the base plate unit and formed integrally therewith and extended in an upward direction, having a predetermined height at an outer circumferential portion of the base plate unit; and        a radius - direction enhancing unit formed radially extending outwardly at an upper end portion of the back yoke unit;          at least one ring type permanent magnet fixedly connected to the inner side portion of the back yoke unit;        a connecting member inserted into the shaft insertion hole of the plurality of insertion holes positioned at the center, and connected to the steel plate frame by a fastening member; and        a fixing unit fixing a driving shaft inserted into the connecting member which is connected to the other elements of the washing machine.