tailieunhanh - Mechanical Devices Sourcebook 3rd ed mcgraw hil 2001 Episode 1 Part 5

Tham khảo tài liệu 'mechanical devices sourcebook 3rd ed mcgraw hil 2001 episode 1 part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | _CHAPTER 5 SPECIAL-PURPOSE MECHANISMS NINE DIFFERENT BALL SLIDES FOR LINEAR MOTION Fig. 1 V-grooves and flat surface make a simple horizontal ball slide for reciprocating motion where no side forces are present and a heavy slide is required to keep the balls in continuous contact. The ball cage ensures the proper spacing of the balls and its contacting surfaces are hardened and lapped. Fig. 2 Double V grooves are necessary where the slide is in a vertical position or when transverse loads are present. Screw adjustment or spring force is required to minimize any looseness in the slide. Metal-to-metal contact between the balls and grooves ensure accurate motion. The ball cartridge has the advantage of unlimited travel because the balls are free to recirculate. Cartridges are best suited for vertical loads. A Where lateral restraint is also required this type is used with a side preload. B For flat surfaces the cartridge is easily adjusted. Fig. 4 Commercial ball bearings can be used to make a reciprocating slide. Adjustments are necessary to prevent looseness of the slide. A Slide with beveled ends B Rectangular-shaped slide. 128 Fig. 5 This sleeve bearing consisting of a hardened sleeve balls and retainer can be used for reciprocating as well as oscillating motion. Travel is limited in a way similar to that of Fig. 6. This bearing can withstand transverse loads in any direction. Fig. 6 This ball reciprocating bearing is designed for rotating reciprocating or oscillating motion. A formed-wire retainer holds the balls in a helical path. The stroke is about equal to twice the difference between the outer sleeve and the retainer length. Fig. 7 This ball bushing has several recirculating systems of balls that permit unlimited linear travel. Very compact this bushing requires only a bored hole for installation. For maximum load capacity a hardened shaft should be used. Fig. 8 Cylindrical shafts can be held by commercial ball bearings that are .