Driving force transmission mechanism

Abstract

A driving force transmission mechanism is equipped with a first gear attached to a drive source, a second gear enmeshed with the first gear, and a damper shaft enmeshed mutually with the second gear and with a rack member of an air mixing damper. A first locator part formed on the second gear is inserted in a first locator groove in the first gear, while additionally, a second locator part is inserted with respect to a second locator groove in a damper gear. Further, a first narrow tooth formed on the first gear enmeshes with a meshing groove of the first locator part, whereas a second narrow tooth formed on the damper gear enmeshes with another meshing groove of the second locator part.

1 . A driving force transmission mechanism for transmitting a driving force from a driving section, comprising:
 a drive gear connected to the driving section and having a plurality of first gear teeth on an outer circumferential region thereof;   a driven gear having a plurality of second gear teeth on an outer circumferential region thereof, which are enmeshed with the first gear teeth, the driven gear being enmeshed with the drive gear;   a positioning member provided on the outer circumferential regions of the drive gear and the driven gear, the positioning member being adjacent to the first gear teeth or the second gear teeth, for performing positioning of the drive gear and the driven gear in a direction of rotation thereof; and   a meshing member disposed at an interior of the positioning member for causing the drive gear and the driven gear to enmesh mutually.   
     
     
         2 . The driving force transmission mechanism according to  claim 1 , wherein the positioning member further comprises:
 a groove disposed on one of the drive gear and the driven gear, and being formed with a diameter smaller than teeth end diameters of the first gear teeth and the second gear teeth; and   an engagement member formed on one of the drive gear and the driven gear that does not have the groove, such that the engagement member is capable of insertion into the groove.   
     
     
         3 . The driving force transmission mechanism according to  claim 1 , wherein the meshing member further comprises:
 a meshing tooth disposed on one of the drive gear and the driven gear, the meshing tooth being formed with the same diameter as a teeth end diameter of the first gear teeth or the second gear teeth; and   a meshing groove formed on one of the drive gear and the driven gear that does not have the meshing tooth, such that the meshing groove is capable of enmeshing with the meshing tooth.   
     
     
         4 . The driving force transmission mechanism according to  claim 3 , wherein the engagement member is constituted from an adjacent pair of the first gear teeth or the second gear teeth, and a wall portion that adjoins the pair of the first gear teeth or the second gear teeth, the meshing groove being disposed in an interior region surrounded by the pair of the first gear teeth or the second gear teeth and the wall portion. 
     
     
         5 . The driving force transmission mechanism according to  claim 2 , wherein the groove is formed between an adjacent pair of the first gear teeth or the second gear teeth, and the meshing tooth is disposed between one of the first gear teeth or the second gear teeth and another of the first gear teeth or the second gear teeth. 
     
     
         6 . The driving force transmission mechanism according to  claim 1 , wherein the driving force transmission mechanism is used in a vehicular air conditioning apparatus for adjusting air introduced from an exterior or interior of a vehicle to a predetermined temperature and supplying the air to the interior of the vehicle, and wherein a driving force of the driving section is transmitted to a switching damper disposed inside a casing via the drive gear and the driven gear.