Yoke with stiffness ring

#This invention generally relates to a driveline yoke with a stiffness ring that more evenly distributes load forces.

#Vehicle drivelines typically include a series of driveshafts that are connected to each other at connection interfaces. Various connection interfaces can be used to connect these driveshafts, such as flanges or universal joint yokes for example. Flanges and universal joint yokes each include a hub portion with a bore that receives one end of a driveshaft. A flange includes a substantially flat connection interface that connects to another flange component. A yoke is connected to another yoke with a cross member to form a universal joint. The cross member includes four trunnions. One yoke includes a pair of yoke arms that are coupled to two trunnions of the cross member. The remaining pair of trunnions are coupled to another pair of yoke arms on a second yoke to form the universal joint.

#One advantage with a flange connection is that torque loads are evenly distributed across the body of the flange such that torque levels are at an acceptable level when they reach a reduced diameter area at the hub portion. When a flange connection is replaced by a universal joint yoke, due to the opposing connection point interfaces of the yoke arms, stress levels are significantly increased at the hub portion, which can result in premature wear or failure.

#FIG. 1 is an overhead schematic view of driveline for a heavy-duty vehicle.

#FIG. 2 is a magnified exploded view of a portion of the driveline from FIG. 1 showing a plurality of yokes.

#FIG. 3 is a perspective view of a universal joint cross member.

#A heavy-duty vehicle 10 includes a powertrain assembly, shown generally at 12, that transfers driving power from a vehicle power source 14 to a plurality of wheels 16. The power source 14 can comprise an engine or electric motor, for example, and can be operably coupled to a transmission 18 in a known manner. A driveline assembly 20, including at least one driveshaft 22, is used to transfer driving power from the transmission 18 to a drive axle assembly 24 that supports the wheels 16. In the example shown, the drive axle assembly 24 is a tandem drive axle; however, other types of axles could also be utilized. The tandem drive axle includes a forward-rear axle 24a and a rear-rear axle 24b that are interconnected to each other.

#FIG. 2 shows a typical driveshaft arrangement that includes a first driveshaft 22a connected to the transmission 18 at one end and connected to a second driveshaft 22b at an opposite end. The second driveshaft 22b is connected to the drive axle assembly 24 at an end opposite from connection to the first driveshaft 22a. A third driveshaft 22c is used to interconnect the forward-rear axle 24a to the rear-rear axle 24b. A yoke 26 is supported on each end of the driveshafts 22a, 22b, 22c. A cross member 28 is used to interconnect adjoining yokes 26. One cross member 28, coupled to two (2) yokes 26, defines a universal joint assembly (U-joint) 30.

#U-joints allow two adjoining driveline components to be positioned at different angles relative to each other to accommodate relative movement and angular misalignment. Misalignment and relative movement can be caused by adjoining driveline components not being mounted within a common plane, or can be caused by a driveline component, such as a drive axle assembly 24, moving relative to adjoining driveline component, such as a driveshaft 22, in response to interaction with a vehicle suspension.