XRAY-S-2200-200 Grippers Die-Cast Transmission Housing

The customer, a Tier 1 supplier of die-cast parts to the automotive industry, needed a pair of grippers to handle die-cast transmission housings. There are two different housings to be handled a front housing and a rear housing. The grippers would be attached to the end of an industrial robot, one gripper will be tooled to handle the front housing and the other will be tooled to handle the rear housing. After casting a conveyor will carry the parts through a bead-blasting machine to remove flashing. Then, the robot and grippers will pick the parts from the conveyor and rotate them 180 degrees to remove beads and other particulate from the housings. Finally, the robot and grippers will place the parts onto a fixture for an inspection process. While the process seems fairly straightforward a die casting environment can be quite challenging for a gripper.

There are several challenging requirements for the grippers to be specified for this application. First, the grippers will need to be completely sealed from the very dirty die casting environment. Furthermore, the grippers need to be impervious to the bead blast environment. Second, even though there are two very differently shaped parts to be handled the customer is requiring that the same gripper model be used to handle each of the parts. The customer explained that their spare parts room was already over crowded so only having to have one spare would be a necessity. Since, the front housing is circular in shape and would need to be grabbed with an internal grip and the rear housing is a rectangular shape and would need to be grabbed on the external edges this would require the use of grippers with long strokes and a broad reach. Third, the grippers will need to be self centering since they will be picking the parts from undefined position on the conveyor and need to place them accurately on the inspection fixture. Lastly, the customer, fearing a future OSHA requirement, wanted a field installable fail-safe device to be available. At the time they didn’t need a fail-safe and preferred to add this option only when it is necessary.

The XRAY-S-2200-200 was recommended for this application. The XRAY-S grippers are large format, two jaw parallel grippers. These grippers offer grip forces exceeding 495 lbs. and this particular model has 200mm of stroke. The 200mm stroke will be more than enough to handle both the front and rear housings. The XRAY-S is completely sealed, the body is of one-piece construction and the piston rods are wiped free from all debris via an aggressive brass scraper. These grippers utilize a linear bearing rail to isolate the synchronization system from any torque that is generated in the application. The linear bearing rail is triple sealed to ensure that the bearings stay lubed and the contaminants from the environment stay out. The bearing rail itself is constructed of hardened steel, well suited to the bead-blasting environment. The XRAY-S utilizes ZAYTRAN’s patented double helix for the highest degree of accuracy available in the industry. The XRAY-S grippers even have available a field installable fail-safe, the POB. The Power Off Brake kit is a single acting cylinder that can be mounted to the side of the XRAY-S grippers. When pressure is applied the cylinder retracts and allows for normal operation of the gripper. In the event that pressure is lost the cylinder extends to keep the jaws from moving, thus the part from dropping.

It has been three years since the XRAY-S grippers were first installed in this application. At the present time the original 2 grippers are still in the field working and the customer is very happy with their performance. The success of this application has helped gain approval for 3 additional robotic manufacturing cells and the purchase of several new XRAY-S grippers. These cells have allowed to customer to increase the output of their facility by more than 200%.