Patent GB-1167570-A (GB)
Title: Rotary Pumps of the Flexible-Tube Type
IPC: C08F2/46
Filed: 1967-08-01
Abstract: 1,167,570. Rotary hydraulic pumps. BIOTEC A.B. Aug.1, 1967 [Aug.1, 1966], No. 35338/67. Heading F1F. A rotary hydraulic pump of the flexible tube type comprises a rotatable driving-shaft 2, Figs. 1 and 3 (not shown), having a disc 1 fixed thereto and carrying a freely-rotatable plate 6 with a hub 5 to which a sun gear-wheel 4 is attached so that it meshes with a plurality of planet gear-wheels 3 rotatably supported by the disc 1, each of the planet gear-wheels being furnished with a roller 7 located adjacent the periphery thereof and a pair of smaller rollers 13, and the plate 6 being provided with screw-threaded pin 9 that engages with an arcuate slot 10 in a plate 8, which is fixed to the shaft 2 so that by means of a nut 12 on said pin the plates 6, 8 can be locked together in a desired angular position relative to each other. In operation of the pump, the rollers 7 engage with a flexible tube or hose (not shown), which is located in a region between'the rollers and the outer peripheral portions of the disc 1 and the plate 6 and is kept in tension so that the rollers effect a peristaltic pumping-action to displace liquid from one end of the tube to the other. When the discs 6, 8 are partially rotated relative to each other, the planet gear-wheels are partially rotated accordingly so that the radial distances of the rollers 7 from the shaft 2 and the distances between adjacent rollers are altered, the rate of displacement of liquid in the tube being thereby changed to a corresponding extent; and when the rollers 7 are in the closest possible proximity to the hub 5, Fig. 2 (not shown), the other rollers 13 also engage with the tube so that the peristaltic pumping-action is rendered negligible.. In a second embodiment, Figs. 4 to 6 (not shown), each of the rollers 7 is mounted on the outermost end of a radial arm (14), which is fixed to the associated planet gear-wheel 3, and the flexible tube (15) has its ends attached to a support (23) that is carried by a vertically-movable plate 16 whereby the tube is rendered in tension by springs (18) connecting said plate to an immovable plate (19) supporting the shaft 2. A flexible band (22) prevents the tube being subjected to excessive tension. In a third embodiment, Figs. 7 to 9 (not shown), the radial distances of the rollers 7 relative to the shaft 2 can be varied by shafts (29) supporting the rollers engaging with arcuate slots (28) and radial slots (33) in two pairs of relatively rotatable discs (27, 30), respectively. In a fourth embodiment, Figs. 12 and 13, the rollers 7 are replaced by balls 37, which engage with a flexible tube 44 and are lodged in radial grooves 38 within a pair of discs 39, 40 upon the shaft 2, the radial distances of the balls from said shaft being variable by rotation of a conic nut 42 upon a screw-threaded hub 41 that is fixed to the shaft and has the disc 39 attached thereto. The discs 39, 40 are connected to each other by bars or bridges 45 and rings 46 retain the balls in said grooves. A locking nut 43 is also provided on said hub. Lubrication may be effected by oil in a bath (50 Figs. 10 and 11 not shown), which is located below the discs 39, 40. A fifth embodiment, Figs. 16 to 18 (not shown) differs from the fourth one chiefly in that the nut 42 is replaced by a nut (55) have tapering vanes (56) thereon that engages with the undersides of the balls (53). In a sixth embodiment, Figs. 19 and 20 (not shown), a plurality of planet gear-wheels (59) are mounted in a manner somewhat similar to that shown in Figs. 1 and 2 upon a disc (64) attached to the shaft 2, each planet gear-wheel being furnished with two diametrically-opposite rollers (57, 58) on one side thereof. A flexible tube (60) is arranged such that both of the rollers on each planet gearwheel effects a pumping action and such that each of its ends are connected to a common inlet (61) for the liquid, a single outlet (63) for the liquid being located between said ends. Owing to the distances of the rollers (57) from the shaft 2 being greater than those of the rollers (58), the rollers effect a differential pumping-action depending upon those distances. Tension in the tube is maintained by a pulley 62 in the region of which the tube is stiffened by a helical sleeve (68) to prevent it flattening. A seventh embodiment, Figs. 20 and 21 (not shown), differs from the sixth one chiefly a set of rollers (77) is arranged on one side of a pair of discs (70, 71) attached to the shaft 2 and another set of rollers (78) is arranged on the other side of said discs. The reduce pulsations of pressure in the liquid leaving the flexible tube, the shaft 2 may be connected to a driving motor 99, Fig.23, by gears 91, 92 and a disc 94 having a radial groove 95 therein engaging with a pin 96 in a further disc 97 on the output shaft 98 of the motor, the latter being movable laterally relative to the disc 94 whereby the varying angular-velocity of the shaft 2 caused by the pin 97 sliding in the slot 95 can be adjusted to bring it into synchronism with said pulsations so as to render them minimal. The radial arms (14) in the second embodiment may be utilized in the seventh embodiment, and the arrangement of balls in the fourth or fifth embodiment may be employed in either of the sixth and seventh embodiments. In the sixth and seventh embodiments one set of rollers may be rendered non-adjustable.