CLOSED RADIAL-CARDAN COUPLING USED SUITABLY IN MOHNO TYPE ECCENTRIC ROLLING SCREW PUMP

Abstract: The screw piston of the Mohno type singlespindle excentric screw pumps as the rotary part performs a complex motion outside the centreline of the pump, for this reason the torque is transmitted from the bearing supported driving shaft with cardan or other coupling realizing eccentric motion. This closed radial-cardan eccentric coupling is formed in such a way, that the torque transmitting elements are radially arranged, thus surrounding each other in annular form, and requiring close installation space. Two carrying bolts fitted opposite each other along the symmetry axis in a tapered, threaded hole on the cylindrical driven head piece. These carrying bolts are tightly fitted in the tapered nest, whereby they ensure constant torque transmission to the carrying ring. The threads ensure the tight fitting of the bolt as well as its tightening in the tapered nest, in order to transmit the torque to the accurately fitting tapered surfaces. The carrying ring transmits the torque through the holes perpendicular to the carrying bolts to the driven eccentric shaft stub with a bolt.

Description: CLOSED RADIAL-CARDAN COUPLING USED SUITABLY IN MOHNO TYPE ΞXCENTRIC ROLLING SCREW PUMP The screw piston of the Mohno type singlespaπdle excentric screw pump as the rotary part performs a complex motion outside the centreline of the pump, for this reason the torque is transmitted from the bearing supported driving shaft with cardan or other coupling realizing excentric motion. Since this pump system - owing to its special construction - is suitable for the delivery of media containing even solids, the sealing of the cardan couplings is essential in respect of the safe operation and life of the pump. Characteristics of the technical and economic requirements related to the cardan couplings: - Production at low cost, - Long life, - Simple construction , the numb er of pa rts res tricted to the minimum, - Transmission of h igh to rque with minimum space requirement . The best cardan solutions used in this field are those it arched tooth, which technically meet the requirements, but are expensive solutions, at the same time they are sensitive to the solid impurities, get easily damaged and as a result of damage the conditions of correct lubrication no longer exist causing fast wear of the coupling, furthermore their angular displacement is limited. As further development of the Streicher type solution described in GFR patent specification Noβ 1 625 815 he subject of the invention is solved as follows: The radial cardan coupling with its simple construction and minimal number of component parts is up to the technical and economic requirements. Its seali system ensures long life. The sealing solution is suitab for the protection against aggressive agents and solvent This closed radial-cardan excentric coupling is formed in such a way, that the torque transmitting elements are radially arranged, thus surrounding each other in annular form, and requiring close installation space. Two carrying bolts 2 - the pinned ends of whic are connected to carrying ring 3 - fitted opposite each other along the symmetry axis in a tapered, threaded hole on the cylindricaldriven head piece 1. These carrying bolts are tightly fitted in the tapered nest, whereby BUKiϊAt C:-;PI they ensure constant torque transmission to the carrying ring. The threads ensure the tight fitting of the bolt as well as its tightening in the tapered nest, in order to transmit the torque to the accurately fitting tapered surfaces. The carrying ring transmit the torque through the holes perpendicular to the carrying bolts to the driven excentric shaft stub 4 with bolt 6. Constant operation of these coupling elements is guaranteed by the tight sealing of the filled-in lubricant. The excentric shaft in this case is closed into a spherical segmental element 7 tightly fitted 8 on shaft with the shaped external packing ring 9 fixed into the accurately fitting head piece 1. The packing ring is protected by backing ring 10 against possible external high operating pressures. Constant pressure of the closing element 7 and packing ring 9 on the internal packing ring 8 is ensured by the spanner ring 13 acting through the backing ring 12. Drawback of the various alternatives closed with rubber bells against this solution is that partly the rubber material is not resistant to aggressive agents and solvents, furthermore its resistivity is limited against destruction caused by solids and against mechanical damages. The applied method of construction ensures total protection against mechanical damages, furthermore its sealing element may be produced from teflon, which protects the machine element against all kinds of aggres substances and solvents. O

Claims: WHAT WE CLAIM IS 1. Closed .radial-cardan coupling, c h a r a c ¬ t e r i z e d in that the head (1) and connected excentric shaft stub (4) are enclosed in a spherical segmental element (7) with the contacting external (9) and internal packing ring (8) and spanner ring (13). 2. Closed radial-cardan coupling as claimed in claim l OΪ c h a r a c t e r i z e d in that the carrying bolts (2) ensuring the connection of the head (1) and carrying ring (3) are fitted in a tapered nest and are pin-shaped. 3. Closed radial-cardan coupling as claimed in " claim 1 or 2., c h a r a c t e r i z e d in that the head (1) and shaft stub (4) are releasably coupled to each other and to the driving and driven shafts. OMPI

Inventors: NADOR A
Applicants: FEMMECHANIKA, FEMMECHANIKA SZIVATTYU ES ANYAGMOZGATOGEPGYARTO
Application year: 1981
Main classification: F16D3
IPC codes: F16D3, F16J15