Constant velocity joint of tripod type

A constant velocity joint for a drive system having a first rotating shaft and a second rotating shaft coupled with the constant velocity joint, the constant velocity joint comprising:

• a hollow housing having an opening at one end, and a closing at its opposite end fixed to an end of the first rotating shaft, an inner face of the housing including a plurality of guide grooves extending in an axial direction of the housing;
• a spider trunnion received in the opening of the hollow housing for transmitting torque between the first and second rotating shafts of the drive system, the spider trunnion including a spherical outer surface;
• and
• a roller assembly operatively attached on the spider trunnion, the roller assembly including an inner roller having a spherical inner surface for contacting with the spherical outer surface of the spider trunnion, an outer roller having a spherical outer surface for contacting and rolling in a corresponding one of the guide grooves of the hollow housing, and a plurality of needle rollers engaged between the inner and outer rollers;
• wherein the inner roller includes a tapered outer surface with a taper angle (θt), and the outer roller includes a tapered inner surface with the same taper angle (θt);
• wherein the taper angle (θt) is in a range defined by the equation of:
• 2 tan−1(0.030/Lt)<θt<2 tan−1(0.3556/P1);
• in which Lt is a length from an upper end surface of the inner roller to a lower end of the needle rollers, and P1 is a pitch circle diameter of the spider trunnion.