To provide a balancer device for an internal combustion engine enabling to minimize a friction loss which is generated between a balancer shaft and a bearing.
The balancer device 5 comprises a driving shaft 12 and a driven shaft 13 supported by an upper housing 10 and a lower housing 11. At both ends of a balancer weight 16 provided at one end of the driving shaft, first and second journal portions 12a, 12b are provided which are supported by first and second driving side bearing portions 17a, 17b formed of both housings. A third journal 17c formed near the other end to be consistently pulled upward by the tension of a chain 7 has an upper half only supported by a third driving side bearing 17c provided only on the upper housing 10 by the third bearing, and a lower half opened.
Hiromichi Kobayashi
Tomioka Kiyoshi