Bearing Plate | A retainer plate fixed to the back of a round bearing used to position the bearing in the yoke. |
Balancing | A procedure in which the distribution of mass in a rotating body is checked and altered where necessary to ensure that vibration does not occur during operation. |
Ball Seat | A full or segmented angular contact bearing located in a socket that supports and centers the ball stud. |
Ball Stud | A yoke generally used in CV applications which incorporates a stud onto which a ball is mounted. |
Brinnelling | Failure that occurs when the static forces between two curved surfaces in contact result in local yielding of one or both mating members to produce permanent surface discontinuity. Example: Needle roller indents on a u-joint trunnion or trunnions. |
Cardan Universal Joint | A non-constant velocity universal joint consisting of two yokes connected by a cross through four bearings and driveable by external sources. |
Center Support | A rolling bearing element surrounded by rubber, mounted in a bracket configuration used to mount the support to an outside structure. |
Centering Socket Yoke | A yoke assembly that functions as a self-aligning bearing and provides support and a means of centering in double cardan universal joints. |
Companion Flange | A flanged member that attaches a driveline to drivetrain components, typically affixed by some bolt-together method. |
Critical Speed | The speed at which the rotational speed of a shaft coincides with the natural vibration frequency of the shaft, causing a dynamically unstable condition. |
Cross and Bearing Kit | Drive member with four equally spaced trunnions in the same plane and four bearing cups with attaching parts. Also referred to as a universal joint kit or u-joint kit. |
Cross Hole | A through hole located in each ear of a yoke used to locate a round bearing. |
Double Cardan Universal Joint | A near constant velocity universal joint consisting of two trunnion type Cardan universal joints whose trunnion yokes are connected by a coupling yoke or H-yoke with internal supporting and centering means. |
Driveline | An assembly of one or more driveshafts with provisions for axial movement, which transmits torque and/or rotary motion. |
Driveshaft | An assembly of one or two universal joints connected to a solid or tubular shaft member. |
Driveshaft Length Center to Center | The distance between the outermost universal joint centers on a driveshaft. |
Drive Train | Term used for the unit of all components from the Transmission to Rear differential. Also referred to as Power Train. |
Ear | One of two projecting parts of a yoke symmetrically located with respect to the rotational axis. |
End Yoke | A yoke which attaches a driveshaft to another drive train component such as the transmission. |
Flange Yoke | The yoke which attaches the driveshaft assembly to a companion flange. |
Flinger | A protective shield used in front of and behind the bearing and rubber on many center supports and end yokes. |
Galling | Failure that occurs when two sliding surfaces are subjected to such a combination of loads, sliding velocities, temperatures, environments, and lubricants, that massive surface destruction is caused by welding and tearing, plowing, and gouging. Example: Bearing cup/trunnion end galling on a cross and bearing kit. |
Glidecote | The blue, nylon, wear-resistant coating on yoke shafts and tube shafts. |
H-Yoke | A double yoke which connects the two halves of a double cardan universal joint. |
Half Round Yoke Cross Hole | A semicircular hole located on the end of each ear of some end yokes and used to locate a round bearing. |
Hub | The central part of a yoke used for attachment to another member. |
Inside Lock-up | Term referring to either a cross and bearing kit or a yoke that utilizes a snap ring seated in a groove in the bearing cups and located inside the yoke ears to retain the kit in the yoke. |
Joint Angle | The angle described by the intersection of rotational axis of the input and output members of a universal joint and measured on the same plane described by these areas. |
Knuckle | A slange term used when referring to some driveshaft joint parts and components. |
Liner | A sound and vibrational deadening material added to the inside surfaces of a tube. |
Lock-Up | The dimensional distance between the two retaining surfaces in a driveline component used to locate the bearing surfaces. |
Midship Stub Shaft. | A short shaft, generally splined, used in applications requiring more than one driveshaft. It mounts through the center of a support bearing and allows an additional driveshaft component to be fixed. |
Outside Lock-Up | Term referring to either a cross and bearing kit or a yoke that utilizes a retaining ring in a groove near the outside edge of the yoke ear, rested against the outside face of the bearing cup. |
Phase/Phase Angle | The relative positioning of the universal joint yokes on a driveshaft or driveline. |
Retaining Ring | A removable ring used as a shoulder to retain and position a round bearing in a hole. |
Ring Groove | The surface used for positioning a round bearing with a retaining ring. Consists of a round bearing cup with needle rollers designed to ride on a trunnion. |
Seal | A flexible member which prevents the escape of lubricant and the entrance of foreign matter. |
Slip Movement | A permissible length of axial movement. |
Slip Stub Shaft | A short, machined shaft, generally splined, which, when used with a slip yoke allows axial movement. |
Slip Yoke | A yoke which allows axial movement. |
Snap Ring | Same as RETAINING RING. |
Strap Bearing Clamp | A semi circular device that conforms to the bearing profile holding them in place in half round and some DC yokes. |
Swaged Tubing | A tube with one or both ends having a smaller diameter then the middle section. |
Swing Diameter | The maximum diameter of the circular path described by a rotating universal joint. |
Thrust End | The end of a cross trunnion used as a thrust surface. |
T.I.R. | Total Indicator Reading on a specific point thru 1 revolution of a shaft. |
Torsional Damper | A mechanical device, generally an inertia ring, attached to a drivetrain component by means of a rubber inner ring to minimize driveline vibration in addition to balancing. |
Trunnion | One of four projecting journals of a cross. |
Tubing | The tubular connecting member of a driveshaft. |
Tube Diameter | The outside diameter of a tube. |
Tube Yoke | A yoke with a piloting hub for attachment of a tube. |
U-Bolt | A clamping bolt with two parallel threaded legs used to retain a round bearing in certain end yoke designs. |
Universal Joint | A device which can transmit torque and/or rotary motion from one shaft to another at fixed or varying angles of intersection of the shaft areas. |
Wall Thickness | The measurement between the inside and outside diameter of a tube. |
Weld Yoke | Same as tube yoke. |
Wing Bearing | A member with a key and projecting wings used as the bearing base and positioning the thrust end of a cross trunnion. |
Yoke Shaft | A one piece member designed to incorporate a tube yoke, tubing and stub shaft. It is used in close-couple applications and eliminates the need to use tubing. |
Zerk | A lubrication fitting, usually threaded into a driveline component that will allow grease to be injected into the component, but does not allow grease to escape. |