Patent ID: 9347501
Filing Date: 2016-05-24
CPC Classification: F16D

Claim Text:
1. A drive power transmission system comprising: a clutch hub; a clutch drum arranged with respect to the clutch hub to partially defining a sealed space; and a dry clutch configured to disconnect transmission of drive power, the dry clutch being disposed inside the sealed space, the dry clutch comprising: a first clutch plate that is joined by first splines to the clutch hub; a second clutch plate that is joined by second splines to the clutch drum; a friction facing that is provided on one of the first and second clutch plates to form a friction surface, the friction surface pressing against a surface of the other of the first and second clutch plates during clutch engagement; and a cover member arranged adjacent to a side face of the dry clutch and partially defining the sealed space, the cover member having an external air intake hole through which external air enters into the sealed space and an external air discharge hole through which the air flow exits from inside the sealed space to the external air, the external air intake hole passing through the cover member in an axial direction of the drive power transmission system, the external air intake hole being arranged to open toward a radially inward portion of the dry clutch, the external air discharge hole being arranged farther outward in a radial direction of the dry clutch than the external air intake hole such that the external air discharge hole opens toward a radially outward portion of the dry clutch, and the external air discharge hole being arranged such that a radially innermost edge of the external air discharge hole is disposed farther inward radially than an internal circumferential surface of the clutch drum, the external air intake hole and the external air intake hole of the cover member being positioned with respect to the clutch hub and the clutch drum such that, due to rotation of at least one of the clutch hub and the clutch drum, an air flow is generated in an axial direction in which external air is drawn through the external air intake hole along the clutch hub to a radially inward location of reduced air pressure adjacent the clutch hub, then the air flow is directed radially outward to a radially outward location of increased air pressure adjacent the clutch drum, and then the air flow is directed along the clutch drum and passes through the external air discharge hole to the external air.