require design of an industrial automatic sliding door for temperature controlled environments such as coldstores from concept.
The project requires the design of the track complete with guides and space to accomodate a LSM motor and magnets. The magnets for the LSM will be fixed to the inside of the track near the top.
The other component is the design of the carriage. The cariage element is the component that the door leaf is fixed to effectively suspending the door leaf from the guides. The carriage will have the LSM coil unit fixed to it to create the motion. The carriage unit must be designed so that when the door leaf is in the closed position it drops down and in. This function ensures that the perimeter and bottom door seals compress providing a vapourtight seal. When the door opens, the carriage mechanism must lift the door leaf up and away, effectively moving the seals clear of the door frame to prevent wear on the seals. This all needs to be in a smooth operation. previous arts used grooves in the guides so that the wheels would drop in at an angle. this is not possible with this design due to speeds and possible rotation forces caused by the magnets. A second feature of the carriage is a damper feature. The door leaf will be designed to take impacts from forklift trucks. The carriage must have a "knock-out" mechanism for when the door is impacted effectively allowing the door leaf to have a degree of swing but in a controlled manor (damped) and be reset after impact. When in normal operation, the door must be stiff with no swing. The forces from the impact must be controlled so that they do not have an affect on the smooth operation of the guides etc. The door opening speed will be 2m/s, so the guide wheels must be capable of operating at these speeds and have reduced friction and carry the suspended load (circa 150kg). These doors have a cycle of about 1.2 million cycles a year, so everything needs to be durable. The door will be a double leaf door i.e. 2 doors that open away from each other and close towards each other and meet in the middle. Each door leaf will be approx 2m wide and 6m high. Ideally the door leaf should have a minimum of 2 carriages and be balanced. The LSM coil unit will be placed on the carriage near the join of each door leaf to reduce travel distance and minimise amount of magnets.
The designs must take into account ease of assembly and any precision requirements of the LSM. Ease of maintenance (replacing components must be simple and quick. Occasionally these doors are washed for hygiene requirements.