Balancer shaft 5 and 6 rotatably set through bearings 1114 and an oil pump 2 driven by power from the balancer shaft 5 and 6 are provided in a balancer housing. Oil discharged from an outlet portion 42 of the oil pump 2 is supplied to a main oil gallery 10 through an outlet passage 48. A bearing filter 55 that filters a part of the oil is provided in the outlet passage 48 that extends from the outlet portion 42. A communication passage 50 that branches off from the outlet passage 48 and communicates with the bearings 1114 supplies a part of the oil having been filtered by the bearing filter 55 to the bearings 1114. By filtering the oil that is going to be supplied to the bearing portion, decrease in durability of the bearing portion can be suppressed.

An object of the present invention is to improve design flexibility of a balancer apparatus. A balancer apparatus includes a balancer shaft, a balancer housing, and an oil pump including an oil pump housing formed separately from the balancer housing and attached to the balancer housing. The balancer housing includes an upper housing and a lower housing formed separately from the upper housing. The lower housing includes first to third bosses configured to fasten the oil pump to the lower housing. The first and second bosses protrude downward on one end side of an axial direction of the balancer shaft. The third boss is disposed on an upper side with respect to the first and second bosses. The first and second bosses are disposed so as to be spaced apart from each other in a direction orthogonal to the axial direction in such a manner that a recessed portion is formed therebetween. The oil pump includes an intake portion having an opening portion. The intake portion is disposed at least partially in the recessed portion.

Provided is a balancer device for an internal combustion engine capable of effectively decreasing gear rattle between gears of a drive mechanism. A balancer drive gear and a balancer driven gear are arranged on a second end side of a drive-side balancer shaft and a second end side of a driven-side balancer shaft, respectively, and an oil pump is arranged on a first end side of the driven-side balancer shaft via the drive mechanism.

There is provided a balancer device for an internal combustion engine that suppresses lubricating oil from failing onto a reduction gear and a pump drive gear provided to drive and rotate an oil pump and thereby suppresses an increase in resistance against rotation between the reduction gear and the pump drive gear. The balancer device for the internal combustion engine includes a lower side housing on which a balancer drive gear, a first balancer shaft including a first balance weight, a first gear, a second gear, a second balancer shaft including a second balance weight, and the reduction gear are mounted. The balancer device also includes an upper side housing formed in such a shape that covers the balancer drive gear, the first balancer shaft including the first balance weight, the first gear, the second gear, the second balancer shaft including the second balance weight, the reduction gear, and the pump drive gear from above in the state that the oil pump is assembled with the upper side housing such that the pump drive gear is meshed with the reduction gear. The upper side housing is assembled with the lower side housing. The balancer device further includes an exposure opening formed in the upper side housing such that only the balancer drive gear is exposed from the upper side housing to be meshed with an engine-side gear.

Balancer shaft 5 and 6 rotatably set through bearings 1114 and an oil pump 2 driven by power from the balancer shaft 5 and 6 are provided in a balancer housing. Oil discharged from an outlet portion 42 of the oil pump 2 is supplied to a main oil gallery 10 through an outlet passage 48. A bearing filter 55 that filters a part of the oil is provided in the outlet passage 48 that extends from the outlet portion 42. A communication passage 50 that branches off from the outlet passage 48 and communicates with the bearings 1114 supplies a part of the oil having been filtered by the bearing filter 55 to the bearings 1114. By filtering the oil that is going to be supplied to the bearing portion, decrease in durability of the bearing portion can be suppressed.

A balancer structure for an internal combustion engine and the internal combustion engine are provided. A transmission driving gear are arranged to be rotatable integrally with a crankshaft. A transmission driven gear is arranged to be rotatable integrally with a first balance shaft. The transmission driven gear meshes with the transmission driving gear. A balancer driving gear is arranged to be rotatable integrally with the first balance shaft. A balancer driven gear is arranged to be rotatable integrally with the second balance shaft. The balancer driven gear meshes with the balancer driving gear. The first balance shaft includes an output portion. The output portion outputs torque to an engine-driven accessory.

Oil pump and oil pump-integrated balancer device each have a pump housing formed by housing body 31 and cover member 32, pump shaft 33 having driven side helical gear 43 at which thrust force occurs when transmitting rotation force and rotating a rotor by the rotation force provided from drive side helical gear 13 that is engaged with driven side helical gear 43, first and second thrust receiving portions 47, 46 formed close to hole edges of bearing holes 32a, 31a of the cover member and the housing body, and first and second thrust limiting portions 49, 48 provided at the driven side helical gear and the pump shaft, contacting the thrust receiving portions from axis direction and limiting thrust movement of the pump shaft. With this configuration, oil pump and oil pump-integrated balancer device which are capable of securing stable support of the pump shaft are provided.

A balancer device for an internal combustion engine is provided, wherein the drive mechanism 8 and the oil pump 3 are arranged on the side opposite to driven balancer weight 135 in the axial direction of the driven balancer shaft 5.

Provided is a balancer device for an internal combustion engine capable of effectively decreasing gear rattle between gears of a drive mechanism. A balancer drive gear and a balancer driven gear are arranged on a second end side of a drive-side balancer shaft and a second end side of a driven-side balancer shaft, respectively, and an oil pump is arranged on a first end side of the driven-side balancer shaft via the drive mechanism.

Provided is a balancer device for an internal combustion engine, which includes: an upper-side housing to be mounted to an internal combustion engine; a lower-side housing fixed to the upper-side housing; a balancer main body accommodated in a space defined by the upper-side housing and the lower-side housing; and an oil pump fixed at least to the upper-side housing. An end surface portion of the upper-side housing and an end surface portion of the oil pump are mounted in contact with each other, and an end surface portion of the lower-side housing and the end surface portion of the oil pump are mounted to each other so as to define a predetermined gap.