Transmission

A transmission comprising:

• an input shaft connected to a prime mover, and supported by a transmission-case member;
• an output shaft arranged parallel to the input shaft and supported by the transmission-case member;
• a primary disk stack constructed by a plurality of axially-arranged input disks which are installed on the input shaft and whose outer peripheral edges are arranged in close proximity to the output shaft;
• a secondary disk stack constructed by a plurality of axially-arranged output disks which are installed on the output shaft and whose outer peripheral edges are arranged in close proximity to the input shaft;
• and
• a pair of pressure-application devices configured to be movable along a two-axes connecting line, interconnecting an axis of the input shaft and an axis of the output shaft, within a disk overlapping area that the input and output disks overlap with each other, and further configured to sandwich both outside faces of the input and output disk while applying contact pressure from the outside disk faces within the disk overlapping area at a position corresponding to a required transmission ratio, for creating torque-transmission contacting portions of the input and output disks, arising from elastic deformation of the input and output disks, and further configured to shut off torque transfer from the input disks to the output disks by elastic recovery power of the input and output disks when the contact pressure is removed, the pair of pressure-application devices comprising:
• (a) a biasing device for producing a first biasing force from which the contact pressure exerted on the torque-transmission contacting portions of the input and output disks arises, the biasing device comprising a first mechanical spring device that produces a second biasing force acting in a direction for decreasing the contact pressure and a second mechanical spring device that produces a third biasing force acting in a direction increasing the contact pressure, the first biasing force being determined as a biasing-forcing difference between the third biasing force and the second biasing force;
• and
• (b) a biasing-force adjustment device for adjusting the first biasing force by varying the biasing-force difference to produce the contact pressure of a pressure value suited to a shifting condition.