Musashi Seimitsu Industry Co., Ltd.

Shinya Matsuoka

Ryosuke Asai

Kazuma Oyaizu

Shiryu Katoh

Provided is a transmission device including a differential case. The differential case includes at least a part of a contamination pouch. The contamination pouch includes an inlet facing into a body part of the differential case and capable of collecting a contamination in an oil inside the body part. In an inner surface of the differential case, the inlet is arranged in a largest inner diameter part on which a largest centrifugal force acts during rotation of the differential case, or arranged closer to an oil discharging port with respect to the largest inner diameter part in an axial direction.

Transmission device

Provided is a transmission device including a differential case. The differential case is configured to be divided into first and second cases defining therebetween a mechanism chamber housing a differential mechanism therein and capable of storing an oil at a bottom part of the mechanism chamber. Two or more planetary gears are pivotally supported by a carrier of a gear reducer in the vicinity of large-diameter gear parts and pivotally supported by the differential case in the vicinity of small-diameter gear parts. The second case is held between the first case and the carrier coupled to the first case, whereby the second case is fixed to the first case.

Provided is a transmission device including a transmission unit, in which a differential device is arranged on one side in an axial direction and a gear reducer is arranged on the other side in the axial direction. The transmission unit is housed inside a transmission case with an oil storing part at a bottom part of the transmission case. A differential case () includes a body part (); an oil introducing port () open to the one side in the axial direction thereof; and an oil discharging port () open to the other side in the axial direction. A large-diameter gear part (P), which revolves in the same direction as a carrier (C) rotates, is arranged such that a bottom part thereof in a revolution trajectory is dipped below an oil storing surface (f) of an oil storing part (O) at the bottom part of the transmission case (). In the transmission case (), a first oil guide (G) is provided so as to extend toward the one side in the axial direction from a position radially outward of the revolution trajectory for capturing an oil lifted up from the oil storing part (O) by the large-diameter gear part (P) revolving and for guiding the same to the oil introducing port (). Consequently, even when an oil surface of the oil storing part is set to a low level, the oil lifted up by the large-diameter gear part of the planetary gear can be efficiently supplied into the differential case, which suppresses a churning resistance of the oil and improves transmission efficiency.

In a gear pair in which a first gear and a second gear having a larger number of teeth than the first gear share a meshing line (L) of teeth that mesh with each other, at least a part of the meshing line (L) includes a region where a pressure angle (a) is not constant, and the pressure angle (α) weakly increases in a section of the meshing line (L) from a pitch point (Pp) to an end point (Pe) on a tooth-root side of the first gear (G). This allows both desired properties (for example, strength) and smooth meshing to be achieved, and also allows effective increase in strength of the tooth-root side of the gear having the small number of the teeth (that is, the first gear) subject to a large load and susceptible to damages on the tooth-root side.

Gear pair

A transmission device includes a planetary reduction gear and a differential device, wherein a carrier of the reduction gear is dividedly formed from a first carrier portion that supports one end side of a pivot shaft and a second carrier portion that supports the other end side of the pivot shaft, and has a power-transmission case that is supported on a transmission case and includes a power-transmission case main body in which the differential case and the second carrier portion are integrated and the first carrier portion, which is joined to one end wall of the power-transmission case main body, a bearing boss portion is integrally and projectingly provided on a side face, on the sun gear side, of the one end wall, the bearing boss portion extending toward the sun gear side and having an outer peripheral part of one of output shafts rotatably fitted into and supported thereby, the bearing boss portion is present at a position where it overlaps the sun gear at least partially in an axial direction, and an outer peripheral part of the bearing boss portion is relatively rotatably fitted into a center hole of the sun gear.

A transmission device is provided in which a support shaft is supported by a carrier, has planetary gears, supports the planetary gears, and is provided with an oil hole and a discharge hole communicating with the oil hole and having an outer end opening on the support shaft, wherein the support shaft has the oil hole, a discharge hole having an inner end communicating with the oil hole and having an outer end opening on the support shaft, and an engagement part provided on one end portion of the support shaft, the other end portion of the support shaft is fixed to the carrier, and a to-be-engaged part is provided on the transmission member, the engagement part engaging with the to-be-engaged part for positioning the support shaft at a position in which the outer end of the discharge hole faces outward in a radial direction of the carrier.

A transmission device is provided in which a first speed change portion and a second speed change portion are formed. The first speed change portion includes an eccentric shaft having a main shaft portion on a first rotary axis and an eccentric shaft portion on a second rotary axis disposed eccentrically with respect to the first rotary axis; an eccentric unit that is rotatably supported on the eccentric shaft portion, and has external teeth formed on an outer peripheral portion thereof; and a housing having an axial center on the first rotary axis, and having internal teeth that mesh with the external teeth of the eccentric unit. The second speed change portion includes curved wave grooves respectively formed on the eccentric unit and a rotary unit; and rolling elements sandwiched between the curved wave grooves and moving along an orbit defined by the curved wave grooves.

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Toyohashi, Japan

Shinya Matsuoka