Flat coreless vibrator motor having no output shaft

Abstract

One end of a shaft is fixed to a first portion of a housing. An eccentric rotor is located in the housing rotatably on the shaft. The other end of the shaft is fitted into a concave portion on a second portion of the housing, so the rotor may be assembled in the housing in a simple manner and radial movement of the shaft can be prevented without enlarging the fixing portion of the shaft. Even if the diameter of the shaft is small, the shaft can withstand an impact resulting from dropping of the motor.

What is claimed is:  
     
       1. A flat vibrator motor having no output shaft, the motor comprising: 
       a housing comprising a casing and a bracket connected to the casing;  
       an eccentric rotor having a plurality of armature coils and disposed in the housing;  
       a commutator attached to the rotor;  
       a pair of brushes in sliding contact with the commutator;  
       a magnet confronting and spaced from the rotor; and  
       a shaft having a first end fixed to a portion of the housing  bracket, supporting the eccentric rotor, and a second end not projecting outside of the housing and fitted in a concave portion of the bracket  casing for preventing radial movement of the shaft, wherein the eccentric rotor is rotatably mounted on the shaft,  and the eccentric rotor being brought into sliding contact with  is urged toward the housing  casing when the shaft  eccentric rotor moves axially on the shaft.  
     
     
       2. The flat vibrator motor having no output shaft as claimed in  claim 1 , wherein each of said brushes applies pressure to the commutator, urging the eccentric rotor toward the casing. 
     
     
       3. The flat vibrator motor having no output shaft as claimed in  claim 2 , including an  a first electrically insulating member having a favorable degree of slidability disposed at one of  in the casing and engaging the ends  second end of the shaft and shaft, wherein the eccentric rotor slidingly contacts the insulating member when the eccentric rotor moves axially on the shaft. 
     
     
       4. The flat vibrator motor having no output shaft as claimed in  claim 3 , including lubricating agent retaining means disposed where the eccentric rotor is in sliding contact with the first electrically insulating member. 
     
     
       5. The flat vibrator motor having no output shaft as claimed in  claim 3 , wherein lubricating agent retaining means is disposed at each of portions where the pair of brushes are brought into sliding contact with the commutator. 
     
     
       6. The flat vibrator motor having no output shaft as claimed in  claim 3 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the rotor. 
     
     
       7. The flat vibrator motor having no output shaft as claimed in  claim 3 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the housing. 
     
     
       8. The flat vibrator motor having no output shaft as claimed in  claim 2 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the eccentric rotor. 
     
     
       9. The flat vibrator motor having no output shaft as claimed in claim  2 , including   4 , wherein the lubricating agent retaining means comprising  comprises a groove concentric with the shaft and disposed on  in the housing  first electrically insulating member. 
     
     
       10. The flat vibrator motor having no output shaft as claimed in  claim 1 , wherein the casing includes a hole and including an insulating member having a favorable degree of slidability disposed at one of  covering the hole and contacting the ends  second end of the shaft and wherein the eccentric rotor slidingly contacts the insulating member. 
     
     
       11. The flat vibrator motor having no output shaft as claimed in  claim 10 , including lubricating agent retaining means disposed where the eccentric rotor is in sliding contact with the insulating member. 
     
     
       12. The flat vibrator motor having no output shaft as claimed in  claim 10 , wherein lubricating agent retaining means is disposed at each of portions where the pair of brushes are brought into sliding contact with the commutator. 
     
     
       13. The flat vibrator motor having no output shaft as claimed in claim  10 , including   11 , wherein the lubricating agent retaining means comprising  comprises a groove concentric with the shaft and disposed on  in the eccentric rotor. 
     
     
       14. The flat vibrator motor having no output shaft as claimed in  claim 10 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the housing. 
     
     
       15. The flat vibrator motor having no output shaft as claimed in  claim 1 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the eccentric rotor. 
     
     
       16. The flat vibrator motor having no output shaft as claimed in  claim 1 , including lubricating agent retaining means comprising a groove concentric with the shaft and disposed on the housing. 
     
     
       17. The flat vibrator motor having no output shaft as claimed in  claim 3 , including a second electrically insulating member interposed between, contacting and connecting together the casing and the bracket so that the casing and the bracket are electrically insulated from each other, and a conducting flexible plate electrically connecting a first of the brushes to the casing, wherein a second of the brushes is electrically connected to the bracket and the first electrically insulating member electrically insulates the shaft from the casing. 
     
     
       18. The flat vibrator motor having no output shaft as claimed in  claim 1 , wherein the magnet is annular and extends from the casing toward but not reaching the bracket, generally parallel to the shaft, the magnet having a central plane transverse to the shaft, one half of the magnet being disposed on each side of the central plane, and the eccentric rotor having a central plane transverse to the shaft, one half of the eccentric rotor being disposed on each side of the central plane of the eccentric rotor, wherein the central plane of the eccentric rotor is disposed farther from the second end of the shaft than is the central plane of the magnet, whereby the eccentric rotor is urged toward the casing when the eccentric rotor moves axially on the shaft. 
     
     
       19. The flat vibrator motor having no output shaft as claimed in  claim 18 , including an electrically insulating member having a favorable degree of slidability disposed in the casing and engaging the second end of the shaft wherein the eccentric rotor sliding contacts the insulating member when the eccentric rotor moves axially on the shaft. 
     
     
       20. The flat vibrator motor having no output shaft as claimed in  claim 19 , including lubricating agent retaining means disposed where the eccentric rotor is in sliding contact with the electrically insulating member. 
     
     
       21. The flat vibrator motor having no output shaft as claimed in  claim 20 , wherein the lubricating agent retaining means comprises a groove concentric with the shaft and disposed in the electrically insulating member.