Solar tubes require careful handling and accurate positioning, especially at high duty cycles and in an environment where lubrication needs to be kept to a minimum. Any oil or grease residue from the guidance systems coming into contact with the tube panel could affect the function of the finished product. This solar tube manufacturer needed two 6m systems in parallel to support the cross axis that carries the panels. With only local support available for the 6m structure any system would need to have good functional straightness with sufficient compliance to accomodate inaccuracies in setting.
A HepcoMotion HDS2 system with two × HB25 beams – 6m long with ground vee slides size 25 fitted to one of the beams was chosen for the task. 64mm dia vee bearings were fitted into a custom carriage. The opposing beam used size 25 ground flat track with size 58mm dia rollers, the rollers accommodating any lateral movement. A rack drive was the customers’ preferred driving method, and as the guides have a rack cut into the guide directly, this saved on the need to set a separate rack. The requirement for minimal lubrication was satisfied by the fitting of low maintenance cap wipers CW64.
Two HB25 beams – 6000mm long, one beam with guides PHSS25/ PHSS25R × 5995mm fitted were supplied. The opposing beam was fitted with a PHTS25/ PHTS25R × 5995mm flat track. Blind hole vee bearings BHJ64C/E were chosen for ease of maintenance matched with the vee guides and blind hole rollers BHRR58C/E for the beam with flat tracks, along with CW64 cap wipers.
Many potential problems were solved with standard HDS2 components. The minimal lubrication requirement can put heavy demands on guidance systems and many would fail without adequate supply of lubricant. The low-maintenance cap wipers distribute just enough grease to keep the vee guides lubricated. Vee technology only requires small amounts of lubrication to be effective with the natural wiping action smoothing the lubricant over the vee surface.
The compliance issue was satisfied by the use of flat tracks and rollers and the HB25 beam provides enough rigidity to maintain stiffness as the carriage moves along the 6m beam.
This application was subject to a high duty cycle, working 24/7; the only ongoing maintenance required was to check and update periodically the grease within the cap seals and the grease on the racks.