Abstract: A single-piece air cylinder (“air cylinder”) for a pneumatic fan drive system. The air cylinder is comprised of a single-piece stamping having a stepped tab portion for attaching to a piston rod of the pneumatic fan drive system. The air cylinder has a cylinder portion and a washer portion extending concentrically inward from the cylinder portion. The washer portion defines an aperture and has the stepped tab portion extending into the aperture. This air cylinder has a sufficiently robust construction for resisting fatigue over a significant number of operation cycles. Additionally, the air cylinder has a substantially robust construction for resisting damage associated with dropping or otherwise mishandling the air cylinder.

Abstract: A clutch assembly having an overall diameter and overall axial length. Both the axial length and the ratio of the length to the diameter are reduced. A translatable clutch piston is in communication with a pressure chamber and is movable between a piston neutral position and a piston activated position in response to air pressure. A cone clutch member is moved from a clutch engaged position to a clutch disengaged position in response to the translatable clutch piston moving from the piston neutral position to the piston activated position. The cone clutch member engages the rotating drive shaft when in the clutch engaged position. A clutch spring member biases the cone clutch member into the clutch engaged position with a clutch engagement force. The clutch spring has a primary spring ratio of a wire diameter to a spring diameter optimized such that a maximum spring force is achieved while minimizing the spring length.

Abstract: A clutch assembly is provided comprising a clutch housing having a clutch housing length. A central piston chamber is positioned therein and feeds a pressure chamber. A translatable clutch piston is in communication with the pressure chamber and is movable between a piston neutral position and a piston activated position in response to air pressure fed into the pressure chamber. A rotating drive shaft is positioned within the clutch housing. A cone clutch element is moved from a clutch engaged position to a clutch disengaged position in response to the translatable clutch piston moving from the piston neutral position to the piston activated position. The cone clutch element engages the rotating drive shaft when in the clutch engaged position. A clutch spring biases the cone clutch element into the clutch engaged position with a clutch engagement force.

Abstract: A clutch assembly (20) for a fan drive system (12) of an engine (14) includes a translatable clutch housing (30) that is coupled to a fan (16). A rotating shaft (27) has a non-grooved thermal energy transfer portion (28) that is coupled to a drive pulley (32) of the engine (14). A liner (34) resides between and is engageable with the rotating shaft (27) and the translatable clutch housing (30). The engagement thereof generates thermal energy. The non-grooved thermal energy transfer portion (28) has a cross-sectional thickness (T1) of approximately less than 11 mm and transfers a significant portion of the thermal energy to the drive pulley (32).

Abstract: A single-piece air cylinder (“air cylinder”) for a pneumatic fan drive system. The air cylinder is comprised of a single-piece stamping having a stepped tab portion for attaching to a piston rod of the pneumatic fan drive system. The air cylinder has a cylinder portion and a washer portion extending concentrically inward from the cylinder portion. The washer portion defines an aperture and has the stepped tab portion extending into the aperture. This air cylinder has a sufficiently robust construction for resisting fatigue over a significant number of operation cycles. Additionally, the air cylinder has a substantially robust construction for resisting damage associated with dropping or otherwise mishandling the air cylinder.

Abstract: One advantageous embodiment of the claimed invention is an air cylinder (12) for a pneumatic fan drive system (10). The air cylinder (12) is comprised of a single-piece stamping, which is utilized for covering a piston (22) of the pneumatic fan drive system (10). This single-piece stamping has an e-coating (40) applied thereon for improving a surface finish of the single-piece stamping and inhibiting corrosion of said single-piece stamping.

Abstract: A clutch assembly (20) for a fan drive system (12) of an engine (14) includes a translatable clutch housing (30) that is coupled to a fan (16). A rotating shaft (32) is coupled to a drive pulley (22) of the engine (14). A liner (34) resides between and is engageable with the translatable clutch housing (30) and the rotating shaft (32). A clutch spring (35) engages the translatable clutch housing (30) with the rotating shaft (32). A spring carrier (42) retains a portion of the clutch spring (35) and comprises a passage (46) for fluid pressure adjustment within a clutch spring area (38) of the clutch assembly (20).