tailieunhanh - Advanced Vehicle Technology Episode 2 Part 8

Tham khảo tài liệu 'advanced vehicle technology episode 2 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | The rotor slots which guide the rollers taper in width towards their base but their axes instead of being radial have an appreciable trailing angle so as to provide better control over the radial movement of the rollers. The hollow rollers made of case- hardened steel are roughly 10 mm in diameter and there are three standard roller lengths of 13 18 and 23 mm to accommodate three different capacity pumps. The cam ring is subjected to a combined rolling and sliding action of the rollers under the generated pressure. To minimize wear it is made from heat treated nickel-chromium cast iron. The internal profile of the cam ring is not truly cylindrical but is made up from a number of arcs which are shaped to maximize the induction of delivery of the fluid as it circulates through the pump. To improve the fluid intake and discharge flow there are two elongated intake ports and two similar discharge ports at different radii from the shaft axes. The inner ports fill or discharge the space between the rollers and the bottoms of their slots and the outer ports feed or deliver fluid in the space formed between the internal cam ring face and the lobes of the rotor carrier. The inner elongated intake port has a narrow parallel trailing transition groove at one end and a tapered leading timing groove at the other end. The inner discharge port has only a tapered trailing timing groove at one end. These secondary circumferential groove extensions to the main inner ports provide a progressive fluid intake and discharge action as they are either sealed or exposed by the rotor carrier lobes and thereby reduce shock and noise which would result if these ports were suddenly opened or closed particularly if air has become trapped in the rotor carrier slots. Operating cycle of roller pump Fig. a and b Rotation of the drive shaft immediately causes the centrifugal force acting on the rollers to move them outwards into contact with the internal face of the cam ring. The functioning of