Automatic universal joint assembly method and apparatus

#The present invention is generally related to the field of automated mechanical assembly and more particularly to methods and apparatus for the automated assembly of universal joints.

#Universal joints are common mechanical components in many products such as vehicles of all types and many other products which include the transmission of rotational mechanical power. The process of assembling the components of such universal joints is typically a manually-intensive procedure. As such, the procedure can be complex, time-consuming, difficult to maintain quality, and oftentimes can create unsafe production environments for the assembly personnel. There is therefore a need for a simpler, faster, more repeatable and safer method by which to assemble such mechanical components.

#In the past, there have been some approaches to addressing these needs. U.S. Pat. No. 4,558,502 (Gossman et al.), entitled “Process and Apparatus for Assembling Universal Joints,” discloses a method and the accompanying apparatus for individually assembling a trunnion and its bearing cup in its corresponding yoke arm. Each yoke arm is pretensioned as part of the process disclosed.

#FIG. 1 is an exploded view perspective drawing of one type of universal joint assembly which is assembled by the inventive method and apparatus of this invention.

#FIGS. 2A-2D are sequential schematic drawings illustrating the steps of the snap ring insertion process of the inventive assembly method and apparatus.

#FIG. 3A is a cross-sectional schematic drawing illustrating the step of manually loading the snap rings into the inventive apparatus.

#FIG. 1 illustrates a portion of one type of universal joint assembly 10, hereinafter referred to as U-joint 10. U-joint 10 includes a yoke body 12 which is connected to a shaft such as a drive shaft, not shown but connected to yoke body 12 with a connector 36, and is aligned therein with a yoke body axis 12a. U-joint 10 also includes a trunnion body 14 with four cylindrical trunnions: a first trunnion 24 and a second trunnion 26 each aligned with a first trunnion axis 14a and a third trunnion 42 and a fourth trunnion 44 each aligned with a second trunnion axis 14b which is perpendicular to and coplanar with axis 14a.

#Yoke body 12 of U-joint 10 includes a first yoke arm 38 and a second yoke arm 40. First yoke arm 38 is also herein referred to as upper arm 38 and second yoke arm 40 is also herein referred to as lower arm 40. In similar fashion, first trunnion 24 and second trunnion 26 are also herein referred to as upper trunnion 24 and lower trunnion 26, respectively. The use of “upper” and “lower” as such descriptors is not intended to limit the orientation of such elements but is used herein as a convenience in describing the assembly of U-joint 10 when referring to the elements of FIG. 1 and other figures accordingly.

#Upper and lower arms 38 and 40 include a pair of openings 28 and 32, respectively. Openings 28 and 32 are configured to receive a pair of needle bearings 16 and 18, respectively. Needle bearing 16 includes bearing cup 16c and needles 16n, and needle bearing 18 includes bearing cup 18c and needles (not shown).