Irregular ground travelling vehicle

An irregular ground travelling vehicle comprising:

• a drive source;
• and
• a transmission,
• the transmission including:
• a drive shaft configured to have power input thereto from the drive source;
• a multiple disc clutch configured to connect or disconnect power transmission from the drive source to the drive shaft;
• a transmission case in which a gear for shifting is accommodated and which has a bottom portion including an oil storage portion which is recessed downward from a remaining portion and configured to store oil;
• a transmission shifter for switching an engagement state of the gear for shifting;
• a hydraulic actuator configured to generate a driving force for driving the transmission shifter by pressure-fed oil;
• and
• a pump configured to suck the oil stored in the oil storage portion and pressure-feed the oil to the hydraulic actuator,
• wherein:
• the multiple disc clutch includes a clutch first portion in the oil storage portion;
• the transmission is a dual clutch transmission including, as the multiple disc clutch, an upper clutch and a lower clutch below the upper clutch;
• and
• the lower clutch includes the clutch first portion.

A transmission comprising:

• a drive shaft configured to have power input thereto from a drive source;
• a multiple disc clutch configured to connect or disconnect power transmission from the drive source to the drive shaft;
• a driven shaft;
• a plurality of gear-position gear trains between the drive shaft and the driven shaft, each of the plurality of gear-position gear trains being configured such that a gear that is relatively non-rotatable with respect to one of the drive shaft and the driven shaft and a gear that is relatively rotatable with respect to the other of the drive shaft and the driven shaft are configured to be meshed with each other;
• a plurality of engaging clutches configured to enable power transmission of each of the plurality of gear-position gear trains;
• a transmission case that defines a transmission gear chamber that accommodates the drive shaft, the driven shaft, the plurality of gear-position gear trains, and the plurality of engaging clutches;
• an oil storage portion configured to store oil for hydraulic control of the multiple disc clutch and the plurality of engaging clutches at a bottom portion of the transmission case;
• an oil strainer having a suction port in the oil storage portion;
• and
• a clutch chamber that accommodates the multiple disc clutch,
• wherein:
• the multiple disc clutch includes a clutch first portion in the oil storage portion;
• the oil storage portion extends across the transmission gear chamber and the clutch chamber;
• the multiple disc clutch includes a plurality of friction plates for connection or disconnection of power transmission from the drive source to the drive shaft;
• and
• the transmission is configured to manage an oil level in the oil storage portion, during operation, to be above lower ends of the plurality of friction plates.