Driving apparatus

Abstract

A geared motor 101 comprising a reduction gear unit 102 of oscillating internal meshing planetary gear structure type and a motor unit 103 coupled to each other, the reduction gear unit 102 having a first shaft 111 and a second shaft 112 located on its center axis L, external gears 115 a and 115 b being fitted on the outer periphery of the first shaft so as to be capable of oscillating rotations, an internal gear 120 with which the external gears mesh internally being provided concentrically with the first shaft, the second shaft being coupled to the external gears via means 117 for extracting the rotational components of the external gears. A simple planetary roller mechanism 202 for transmitting rotational power by means of the friction between rollers is interposed between the reduction gear unit and the motor unit to reduce the vibration and noise levels greatly.

What is claimed is:  
     
         1 . A driving apparatus comprising 
 an oscillating internal meshing planetary gear unit having an internal gear and an external gear making internal contact with said internal gear, the center of said internal gear lying inside the periphery of said external gear, and    an external unit to be connected with said oscillating internal meshing planetary gear unit so as to be capable of inputting or extracting power thereto or therefrom, wherein:    between said oscillating internal meshing planetary gear unit and said external unit is interposed a frictional transmission unit which has a plurality of friction rollers contacting each other, for transmitting rotational power between said oscillating internal meshing planetary gear unit and said external unit by means of friction among said plurality of friction rollers; and    said frictional transmission unit is constituted by a simple planetary roller mechanism including said friction rollers including a sun roller, a plurality of planetary rollers being retained by a planetary carrier and making rolling contact with the outer periphery of said sun roller, and a ring roller with which said plurality of planetary rollers make internal contact.    
     
     
         2 . The driving apparatus according to  claim 1 , wherein 
 said planetary carrier in said simple planetary roller mechanism has a retainer for occupying spaces around said plurality of planetary rollers to retain said planetary rollers at constant mutual positions.    
     
     
         3 . The driving apparatus according to  claim 1 , wherein 
 said planetary carrier in said simple planetary roller mechanism has pins for penetrating through the respective centers of said planetary rollers to retain said planetary rollers at constant mutual positions.    
     
     
         4 . The driving apparatus according to  claim 1 , wherein: 
 said ring roller in said simple planetary roller mechanism is fixed; and    either said planetary carrier retaining said plurality of planetary rollers or said sun roller makes an input side, and the remaining makes an output side.    
     
     
         5 . The driving apparatus according to  claim 1 , wherein: 
 said external unit is a motor unit for supplying a rotational input to said oscillating internal meshing planetary gear unit;    said frictional transmission unit is interposed between a drive shaft of said motor unit and said oscillating internal meshing planetary gear unit; and    said oscillating internal meshing planetary gear unit and said motor unit are integrally connected with each other by a joint casing comprising parts of the casings for these units, said frictional transmission unit being arranged inside said joint casing.    
     
     
         6 . The driving apparatus according to  claim 1 , wherein, 
 of the coupling portions between said frictional transmission unit and said oscillating internal meshing planetary gear unit and between said frictional transmission unit and said external unit, at least one coupling portion has a floating connection structure.    
     
     
         7 . The driving apparatus according to  claim 6 , wherein, 
 of the coupling portions between said planetary carrier in said frictional transmission unit of simple planetary roller mechanism and said oscillating internal meshing planetary gear unit and between said sun roller and said external unit, at least the coupling portion between said planetary carrier and said oscillating internal meshing planetary gear unit has said floating connection structure.    
     
     
         8 . The driving apparatus according to  claim 6 , wherein 
 said floating connection structure is a spline connection structure.    
     
     
         9 . The driving apparatus according to  claim 1 , wherein: 
 a casing for accommodating said frictional transmission unit is provided with a mounting reference surface perpendicular to the direction of the rotation axes of said sun roller, planetary rollers, and ring roller; and    the driving apparatus further comprises fixing means for fixing said ring roller to said casing while pressing said ring roller against the mounting reference surface.    
     
     
         10 . The driving apparatus according to  claim 9 , wherein 
 said ring roller is adjustable in axis position within the mounting reference surface.    
     
     
         11 . The driving apparatus according to  claim 9 , wherein 
 said sun roller is provided with a sun-roller-side shaft insertion hole into which a power transmission shaft of said external unit is insertable, and said planetary carrier is provided with a carrier-side shaft insertion hole into which a power transmission shaft of said oscillating internal meshing planetary gear unit is insertable, so as to form said frictional transmission unit into a shaft coupling structure for allowing relative rotations of said power transmission shafts.    
     
     
         12 . The driving apparatus according to  claim 11 , wherein 
 at least either said sun-roller-side shaft insertion hole or said carrier-side shaft insertion hole has a floating connection structure with respect to said power transmission shaft inserted therethrough.    
     
     
         13 . The driving apparatus according to  claim 9 , wherein: 
 said ring roller is provided with a bolt hole piercing therethrough in the direction of the rotation axis so that said ring roller is fixable to the mounting reference surface by a fixing bolt inserted through said bolt hole and threadedly engaged with a tapped hole formed in the mounting reference surface; and    said bolt hole has a diameter somewhat greater than that of said fixing bolt so that said ring roller is adjustable in axis position within the mounting reference surface as long as said fixing bolt is fitted to said bolt hole with play.    
     
     
         14 . A driving apparatus comprising: 
 a rotating shaft to be connected to an external unit;    an oscillating internal meshing planetary gear unit having an internal gear and an external gear making internal contact with said internal gear, the center of said internal gear lying inside the periphery of said external gear; and    a frictional transmission unit of simple planetary roller mechanism, having friction rollers including a sun roller, a plurality of planetary rollers being retained by a planetary carrier and making rolling contact with the outer periphery of said sun roller, and a ring roller having said planetary rollers arranged inside so as to make internal contact, wherein    one of said sun roller, planetary carrier, and ring roller is fixed, either of the other two is coupled to said oscillating internal meshing planetary gear unit, and the remaining one is coupled to said rotating shaft.    
     
     
         15 . The driving apparatus according to  claim 14 , wherein: 
 said ring roller is fixed, said planetary carrier is coupled to said oscillating internal meshing planetary gear unit, and said sun roller is coupled to said rotating shaft; and,    of the coupling portions between said planetary carrier and said oscillating internal meshing planetary gear unit and between said sun roller and said rotating shaft, at least one coupling portion has a floating connection structure.    
     
     
         16 . The driving apparatus according to  claim 14 , wherein 
 said oscillating internal meshing planetary gear unit has a first shaft and a second shaft located on the center axis of the driving apparatus, an external gear being fitted on the outer periphery of said first shaft via an eccentric body so as to be capable of oscillating rotations with respect to said first shaft, an internal gear with which said external gear meshes internally being provided concentrically with said first shaft, said second shaft being coupled to said external gear via means for extracting only the rotational component of said external gear.    
     
     
         17 . A driving apparatus comprising 
 a drive unit for generating rotational power,    a first reduction mechanism unit coupled to an output shaft of said drive unit to transmit the rotational power, and    a second reduction mechanism unit of support carrier transmission type, including reduction gears to be coupled to said first reduction mechanism unit, and a pair of support carriers rotatably supported by a casing at both axial outsides of said reduction gears via bearings, said support carriers for extracting rotational power of said reduction gears, wherein:    said first reduction mechanism unit has a simple planetary roller structure of friction transmission type, including a sun roller to be coupled to said output shaft of said drive unit, a planetary roller making rolling contact with the outer periphery of said sun roller, a ring roller with which said planetary roller makes internal contact, and a planetary carrier for extracting the revolution component of said planetary roller and transmitting the same to an input shaft of said second reduction mechanism unit, the outside diameter of said ring roller being set within the outside diameter of said bearing supporting the drive-unit-side support carrier of said pair of support carriers in said second reduction mechanism unit; and    said ring roller is situated within said casing, in a space on the drive-unit side of said bearing.    
     
     
         18 . The driving apparatus according to  17 , wherein 
 said second reduction mechanism unit is constituted as an internal meshing planetary gear mechanism comprising: said input shaft to be connected to said first reduction mechanism unit; an external gear for making eccentric rotations with respect to said input shaft; an internal gear fixed to said casing, said external gear internal meshing with said internal gear; said pair of support carriers rotatably supported by said casing at both axial outside positions of said reduction gears via said bearings, said support carriers for extracting the rotational component of said external gear; and an output shaft arranged coaxially with said input shaft, the rotations of said support carriers being transmitted to said output shaft.    
     
     
         19 . The driving apparatus according to  claim 17 , wherein: 
 said casing for accommodating said first reduction mechanism unit is provided with a mounting reference surface perpendicular to the direction of the rotation axes of said sun roller, planetary roller, and ring roller; and    the driving apparatus further comprises fixing means for fixing said ring roller in said space within said casing while pressing said ring roller against the mounting reference surface.    
     
     
         20 . The driving apparatus according to  claim 17 , wherein 
 said ring roller is adjustable in axis position within the mounting reference surface.    
     
     
         21 . The driving apparatus according to  claim 17 , wherein 
 said sun roller is provided with a sun-roller-side shaft insertion hole into which said output shaft of said drive unit is insertable, and said planetary carrier is provided with a carrier-side shaft insertion hole into which said input shaft of said second reduction mechanism unit is insertable, so as to form said first reduction mechanism unit into a shaft coupling structure for allowing relative rotations of said input and output shafts.    
     
     
         22 . The driving apparatus according to  claim 21 , wherein 
 at least either said sun-roller-side shaft insertion hole or said carrier-side shaft insertion hole has a floating connection structure with respect to said input/output shaft inserted therethrough.    
     
     
         23 . The driving apparatus according to  claim 17 , wherein 
 said ring roller is provided with a bolt hole piercing therethrough axially so that said ring roller is fixable to a mounting reference surface by a fixing bolt inserted through said bolt hole and threadedly engaged with a tapped hole formed in the mounting reference surface; and    said bolt hole has a diameter somewhat greater than that of said fixing bolt so that said ring roller is adjustable in axis position within the mounting reference surface as long as said fixing bolt is fitted to said bolt hole with play.