Construction machine and working device for construction machine

Abstract

A construction machine includes: a support portion; first to third drive units having first to third drive shafts respectively; a boom having a proximal end portion supported on the support portion via the first drive unit; an arm having a proximal end portion supported on the boom via the second drive unit; and an attachment having a proximal end portion supported on the arm via the third drive unit. The first drive shaft is fixed to a distal end portion of the support portion and the proximal end portion of the boom. The second drive shaft is fixed between a distal end portion of the boom and the proximal end portion of the arm. The third drive shaft is disposed between a distal end portion of the arm and the proximal end portion of the attachment. The center of the boom is situated within the width of the arm.

What is claimed is: 
     
         1 . A construction machine, comprising:
 a main body including a support portion;   a first drive unit having a first drive shaft;   a second drive unit having a second drive shaft;   a third drive unit having a third drive shaft;   a boom having a proximal end portion, the proximal end portion being supported on the support portion via the first drive unit;   an arm having a proximal end portion, the proximal end portion being supported on the boom via the second drive unit; and   an attachment having a proximal end portion, the proximal end portion being supported on the arm via the third drive unit,   wherein one end of the first drive shaft is fixed to a distal end portion of the support portion,   wherein the other end of the first drive shaft is fixed to the proximal end portion of the boom,   wherein one end of the second drive shaft is fixed to a distal end portion of the boom,   wherein the other end of the second drive shaft is fixed to the proximal end portion of the arm,   wherein one end of the third drive shaft is fixed to a distal end portion of the arm,   wherein the other end of the third drive shaft is fixed to the proximal end portion of the attachment, and   wherein, in a width direction, a center of the boom is situated within a width of the arm.   
     
     
         2 . The construction machine of  claim 1 , wherein the distal end portion of the boom is disposed on a first side in the width direction,
 wherein the proximal end portion of the arm is disposed on a second side in the width direction, and   wherein the second drive shaft is disposed between the distal end portion of the boom and the proximal end portion of the arm.   
     
     
         3 . The construction machine of  claim 1 , wherein the distal end portion of the support portion is disposed on a first side in the width direction,
 wherein the proximal end portion of the boom is disposed on a second side in the width direction, and   wherein the first drive shaft is disposed between the distal end portion of the support portion and the proximal end portion of the boom.   
     
     
         4 . The construction machine of  claim 1 , wherein the distal end portion of the arm is disposed on a first side in the width direction,
 wherein the proximal end portion of the attachment is disposed on a second side in the width direction, and   wherein the third drive shaft is disposed between the distal end portion of the arm and the proximal end portion of the attachment.   
     
     
         5 . The construction machine of  claim 1 , wherein the first drive unit includes a first drive mechanism and a first reduction mechanism driven by the first drive mechanism,
 wherein the first reduction mechanism includes a first member on which one end of the first drive shaft is disposed, and a second member on which the other end of the first drive shaft is disposed, rotation of the second member being reduced relative to the first member of the first reduction mechanism,   wherein the second drive unit includes a second drive mechanism and a second reduction mechanism driven by the second drive mechanism,   wherein the second reduction mechanism includes a third member on which one end of the second drive shaft is disposed, and a fourth member on which the other end of the second drive shaft is disposed, rotation of the fourth member being reduced relative to the third member of the second reduction mechanism,   wherein the third drive unit includes a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, and   wherein the third reduction mechanism includes a fifth member on which one end of the third drive shaft is disposed, and a sixth member on which the other end of the third drive shaft is disposed, rotation of the sixth member being reduced relative to the fifth member of the third reduction mechanism.   
     
     
         6 . The construction machine of  claim 5 , wherein the first drive mechanism is disposed on an outer side of the distal end portion of the support portion in the width direction,
 wherein the second drive mechanism is disposed on an outer side of the distal end portion of the boom in the width direction, and   wherein the third drive mechanism is disposed on an outer side of the distal end portion of the arm in the width direction,   
     
     
         7 . The construction machine of  claim 1 , wherein the second drive unit includes a second drive mechanism and a second reduction mechanism driven by the second drive mechanism, and
 wherein a centerline of a width of the boom and a centerline of a width of the arm are situated within an application point distance between a pair of bearings disposed in an outer peripheral portion of the second reduction mechanism.   
     
     
         8 . The construction machine of  claim 1 , wherein the first drive unit includes a first drive mechanism and a first reduction mechanism driven by the first drive mechanism,
 a centerline of a width of the support portion and a centerline of a width of the boom are situated within an application point distance between a pair of bearings disposed in an outer peripheral portion of the first reduction mechanism.   
     
     
         9 . The construction machine of  claim 1 , wherein the third drive unit includes a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, and
 wherein a centerline of a width of the arm and a centerline of a width of the attachment are situated within an application point distance between a pair of bearings disposed in an outer peripheral portion of the third reduction mechanism.   
     
     
         10 . A construction machine comprising:
 a boom; and   an arm supported by the boom at its proximal end portion via a drive unit,   wherein the drive unit includes a drive mechanism and a reduction mechanism driven by the drive mechanism, and   wherein the reduction mechanism includes a crankshaft to which output of the drive mechanism is transmitted, a gear driven by the crankshaft, and an output portion meshed with the gear, and   wherein at least a part of the crankshaft overlaps both the boom and the arm in a sectional view along a longitudinal direction of the boom and the arm.   
     
     
         11 . A working device of a construction machine, comprising:
 a main body including a support portion;   a first drive unit having a first drive shaft;   a second drive unit having a second drive shaft;   a third drive unit having a third drive shaft;   a boom having a proximal end portion, the proximal end portion being supported on the support portion via the first drive unit;   an arm having a proximal end portion, the proximal end portion being supported on the boom via the second drive unit; and   an attachment having a proximal end portion, the proximal end portion being supported on the arm via the third drive unit,   wherein one end of the first drive shaft is fixed to a distal end portion of the support portion,   wherein the other end of the first drive shaft is fixed to the proximal end portion of the boom,   wherein one end of the second drive shaft is fixed to a distal end portion of the boom,   wherein the other end of the second drive shaft is fixed to the proximal end portion of the arm,   wherein one end of the third drive shaft is fixed to a distal end portion of the arm,   wherein the other end of the third drive shaft is fixed to the proximal end portion of the attachment, and   wherein, in a width direction, a center of the boom is situated within a width of the arm.