NO116832B

NO116832B -

Info

Publication number: NO116832B
Application number: NO157789A
Authority: NO
Original assignee: Flygts Pumpar Ab
Priority date: 1964-08-18
Filing date: 1965-04-22
Publication date: 1969-05-27
Also published as: FR1435729A; IL23529A; GB1039429A; BE665600A; NL6510775A

Description

Kardangleddanordning for skruepumper. Cardan joint device for screw pumps.

Foreliggende oppfinnelse angår en kardangleddanordning for skruepumper av den i hovedkravets innledning angitte art. - , The present invention relates to a gimbal joint device for screw pumps of the type specified in the introduction of the main claim. - ,

Ved slike kardangledd medfarer mellomakselens pendlingsbevegelse at den momentoverfbrende tapp vil gli noe i sitt hull, og denne glidningsbevegelse utsetter uunn-gåelig tappen for en viss slitasje. Et eksempel på et slikt kardangledd vises i tysk patentskrift nr. 5706 som viser et kuleledd med en tversgående, fast, momentoverfOrende tapp, som tvin-ges til å gli med linjekontakt i en gjennomgående åpning i leddet. Gjennom denne glidekontakt under h6ye flatetrykk oppstår en kraftig slitasje av tappen, også ved overforing av små momenter. With such cardan joints, the oscillating movement of the intermediate shaft means that the torque-transmitting pin will slide somewhat in its hole, and this sliding movement inevitably exposes the pin to a certain amount of wear. An example of such a cardan joint is shown in German patent document no. 5706 which shows a ball joint with a transverse, fixed, moment-transmitting pin, which is forced to slide with line contact in a through opening in the joint. Through this sliding contact under high surface pressure, severe wear of the pin occurs, also when transmitting small torques.

Oppfinnelsen har således til formål å tilveiebringe en enkelt kardangleddanordning av den angjeldende art, ved hvilken tappens slitasje reduseres i betydelig grad ved at den så å si "frislippes" og i storst mulig utstn 'ening får rulle istedenfor å gli under sin momentoverforing. - The purpose of the invention is thus to provide a single gimbal joint device of the type in question, in which the pin's wear and tear is reduced to a considerable extent by the fact that it is, so to speak, "released" and to the greatest possible extent is allowed to roll instead of sliding under its torque transmission. -

Dette er ifolge oppfinnelsen oppnådd vedAccording to the invention, this is achieved by

å utforme og anordne kardangleddanordning som angitt i hovedkravets karakteriserende del. Herved oppnår man et enkelt og særdeles slitesterkt kardangledd takket være tappenes momentoverforing under rulling, som muliggjores ved tappenes frittbærende eller flytende montering. - to design and arrange cardan joint device as specified in the characterizing part of the main claim. This achieves a simple and extremely durable cardan joint thanks to the pins' torque transfer during rolling, which is made possible by the pins' free-supporting or floating assembly. -

De nevnte hus kan raed fordel bestå av met-allblokker eller -klosser, som opptas med trang pasning i hver sitt spor i rotorens resp. drivakselens ende, idet sporets kanter hindrer husene fra å gli i den overforte krafts retning. - The aforementioned housings can advantageously consist of metal blocks or blocks, which are taken up with a tight fit in each of the grooves in the rotor's or end of the drive shaft, as the edges of the track prevent the housings from sliding in the direction of the transmitted force. -

Kardangleddanordningen ifolge oppfinnelsen beskrives nærmere i det folgende under henvisning til tegningen, som viser en utforelsesform for oppfinnelsen. - The cardan joint arrangement according to the invention is described in more detail in the following with reference to the drawing, which shows an embodiment of the invention. -

Fig. 1 er et sentralt lengdesnitt gjennom rotorens ene ende med det ene kardangledd ifolge oppfinnelsen;Fig. 2 er et.snitt etter linjen VI-VI i fig. 1; Fig. 3 er et planriss av et av de "tapphus" (sett nedenfra) som opptar den momentover-feirende tapps enderj og Fig. 4 viser tilslutt et snitt etter linjen VH3-VTII i fig. 3. - 1 fig. 1 er skruepunipens mellomaksel beteg-net med 72, og den av akselen drevne pumperotor med 70. Rotoren og akselen er forbundet ved hjelp av et kardangledd ifolge oppfinnelsen. Mellomakselens 72 motsatte ende (ikke vist) er forbundet med skruepumpens drivaksel ved hjelp av et annet kardangledd, som selvsagt er identisk med det i fig. 1 viste. - Fig. 1 is a central longitudinal section through one end of the rotor with one cardan joint according to the invention; Fig. 2 is a section along the line VI-VI in fig. 1; Fig. 3 is a plan view of one of the "pin houses" (seen from below) which occupies the end of the moment-over pin and Fig. 4 finally shows a section along the line VH3-VTII in fig. 3. - 1 fig. 1, the intermediate shaft of the screw pump is denoted by 72, and the pump rotor driven by the shaft by 70. The rotor and the shaft are connected by means of a cardan joint according to the invention. The opposite end of the intermediate shaft 72 (not shown) is connected to the drive shaft of the screw pump by means of another universal joint, which is of course identical to that in fig. 1 showed. -

Ved det viste kardangledd overfores momentet til rotoren over en tversgående tapp 74, som passerer gjennom et hull 34 i mellomakselens 72 kuleformete ende 32 og med sine ender griper inn i et par nedenfor nærmere beskrevne tapphus 76, som er festet på rotoren 70. Aksialkrefter og dreiemomenter holdes folgelig helt atskilte, og hensiktsmessige klaringer omkring tappen 74 sikrer deniie mot å utsettes for noen av aksialkref tene forårsakede påkjenninger. At the gimbal joint shown, the moment is transferred to the rotor via a transverse pin 74, which passes through a hole 34 in the spherical end 32 of the intermediate shaft 72 and engages with its ends in a pair of pin housings 76, described in more detail below, which are attached to the rotor 70. Axial forces and torques are consequently kept completely separate, and suitable clearances around the pin 74 ensure that they are not exposed to any of the stresses caused by the axial forces.

1 rotorens 70 utside er fra rotorenden inn-frest to langsgående, diametralt motsatte, temmelig grunne spor 78, som med trang pasning opptar hver sitt tapphus 76. Tapphusene er fastspent på plass ved hjelp av hver sin skrue 80 som griper inn i et for skruene felles, gjennomgående, diametralt, gjenget hull 82 i rotorenden utenfor det sfæriske sete 42. Skruene har hensikts- -messig i tapphusene 76 forsenkede sylindriske hoder med sekkant-hull. - 1 on the outside of the rotor 70, two longitudinal, diametrically opposite, rather shallow grooves 78 are milled from the rotor end, which each occupy their respective pin housings 76 with a tight fit. common, through, diametrically, threaded hole 82 in the rotor end outside the spherical seat 42. The screws conveniently have in the pin housings 76 countersunk cylindrical heads with secant holes. -

Tapphusene, se fig. 3 og 4, har parallell-epipedisk form og består hensiktsmessig av til ferdig mål presi-sjonsstdpte elementer av rustfritt, herdbart stål. De er forsynt med et gjennomgående, med ansats forsynt hull 84 for skruen 80 The tap houses, see fig. 3 and 4, has a parallel-epipedic shape and appropriately consists of precision-studped elements of stainless, hardenable steel. They are provided with a continuous, shouldered hole 84 for the screw 80

og er videre utformet med et rektangulært, utad lukket kammer 86 for opptagelse av tappens ende. - and is further designed with a rectangular, outwardly closed chamber 86 for receiving the end of the pin. -

Tappen 74 har som det fremgår av tegningen en enkel, rett sylindrisk form med rett avskårne ender og holdes på plass av kammernes 86 bunner. Som det videre fremgår har det gjennomgående hull 34 i mellomakselens 72 kuleformede ende 32 As can be seen from the drawing, the pin 74 has a simple, straight cylindrical shape with straight cut ends and is held in place by the bottoms of the chambers 86. As can be seen further, the through hole 34 in the intermediate shaft 72 has a ball-shaped end 32

en dobbeltkonisk form, slik at dets vegger divergerer utad fra sentrum. Her er konisiteten ol i det for hullet og mellomakselen felles plan (fig. l), mens den er /3 i hullets på akselen vinkel-rette plan (fig. 2). ot er storre enn/3, og hullveggen kan ved 34a (se fig. 2) utformes med små plane eller nesten plane, kile-formede flater. - a double-conical shape, so that its walls diverge outwards from the center. Here, the taper is ol in the common plane of the hole and the intermediate shaft (fig. 1), while it is /3 in the perpendicular plane of the hole on the shaft (fig. 2). ot is greater than /3, and the hole wall can at 34a (see fig. 2) be designed with small flat or almost flat, wedge-shaped surfaces. -

En sammenlikning mellom fig. 1 og 2 viser hvordan drivmomentet overfores og hvordan tappene 74 arbeider.Det forutsettes at rotasjonen skjer medurs sett i fig. 2, hvorved mellomakselens kuleende 32 vil drives rundt tappen 74, som gjennom sitt inngrep i tapphusene 76 forer•rotoren med seg rundt. Av fig. 2 fremgår videre hvordan tappen gjor kontakt med tapphus resp. mellomaksel. Her er konisiteten/3slik avpasset i forhold til hulldiameteren at det blir linjekontakt mellom tappen og hullets 34 vegger, og videre er klaringen mellom tappen og tapp-husets 76 sidevegger moderat, slik at det også her forekommer praktisk talt linjekontakt. - A comparison between fig. 1 and 2 show how the drive torque is transferred and how the pins 74 work. It is assumed that the rotation takes place clockwise as seen in fig. 2, whereby the ball end 32 of the intermediate shaft will be driven around the pin 74, which, through its engagement in the pin housings 76, guides the rotor around. From fig. 2 also shows how the pin makes contact with the pin housing or intermediate shaft. Here, the conicity/3 is adjusted in relation to the hole diameter so that there is line contact between the pin and the walls 34 of the hole, and furthermore the clearance between the pin and the side walls of the pin housing 76 is moderate, so that line contact practically occurs here as well. -

Under pumpens gang, med skruerotoren 70 vandrende eksentrisk rundt i statorhuset under samtidig rotasjon, vil således mellomakselen 72 utfore en konisk pendlingsbevegelse, hvilket innebærer at akselen og dens kuleende 32 vil svinge dels omkring tappens 74 lengdeakse, dels omkring en på denne og mellomakselens lengdeakse vinkelrett akse gjennom den sfæriske flates og dermed kuleendens sentrum C. Sistnevnte dreiningsakse (gjennom C) står således vinkelrett på tegnepapirets plan i fig. 1. £n enkel betraktning av bevegelsesforholdene viser at tappen 74 vil rulle frem og tilbake i hullet 34 og kammerne 86 under pendling omkring senteret C, hvorved kammerne gir plass til tappendenes bevegelse i rotorens lengderetning, se fig. 1. For å rulle helt uten glidning burde selvsagt tappen utformes med en viss konisitet, men ettersom During the operation of the pump, with the screw rotor 70 moving eccentrically around the stator housing during simultaneous rotation, the intermediate shaft 72 will thus perform a conical oscillating movement, which means that the shaft and its ball end 32 will swing partly around the longitudinal axis of the pin 74, partly around a perpendicular to this and the longitudinal axis of the intermediate shaft axis through the center of the spherical surface and thus the ball end C. The latter axis of rotation (through C) is thus perpendicular to the plane of the drawing paper in fig. 1. A simple consideration of the movement conditions shows that the pin 74 will roll back and forth in the hole 34 and the chambers 86 while oscillating around the center C, whereby the chambers provide space for the pin ends to move in the longitudinal direction of the rotor, see fig. 1. In order to roll completely without slipping, the pin should of course be designed with a certain taper, but depending

bevegelsene er ytterst små har dette ingen praktisk betydning,the movements are extremely small, this has no practical significance,

og den således frittbærende eller flytende tapp 74 vil overfbre momentet under rulling, og den nedslitende glidning er praktisk talt eliminert. - and the thus free-supporting or floating pin 74 will transmit the moment during rolling, and the wear-and-tear sliding is practically eliminated. -

Av ovenstående turde det fremgå at konisiteten (se fig. 2) fra et teoretisk synspunkt kan være lik null eller nær opptil null. I så fall blir imidlertid toleransene for de samvirkende deler 70,72,74 og 76 unodig snevre. Det er således i det hele tatt en, fordel med oppfinnelsens konstruktive side at spillerom er tillatt og onskelig. - From the above it should appear that the conicity (see fig. 2) from a theoretical point of view can be equal to zero or close to zero. In that case, however, the tolerances for the cooperating parts 70,72,74 and 76 become unnecessarily narrow. It is thus, on the whole, an advantage of the constructive side of the invention that leeway is permitted and desirable. -

Kardangleddet som helhet avskjermes eller avtettes hensiktsmessig ved hjelp av en O-tetningsring 88, som plasseres omkring kuleenden 32 rett innenfor tappen 74, som vist i fig. 1. Herved hindres smuss og andre fremmedpartikler fra å komme inn mellom lagerflåtene. The gimbal joint as a whole is suitably shielded or sealed by means of an O-sealing ring 88, which is placed around the ball end 32 just inside the pin 74, as shown in fig. 1. This prevents dirt and other foreign particles from entering between the storage rafts.

Særskilt ved mindre skruepumper kan f.eks. husene 76 utfores i ett stykke i form av en bbyle- eller ring-liknende anordning, som skyves over rotoren, idet kammerne 86 Separate signs for smaller screw pumps can e.g. the housings 76 are made in one piece in the form of a bbyle or ring-like device, which is pushed over the rotor, as the chambers 86

er åpne ved den ene side for tappens 74 innfbring. - are open on one side for the insertion of the pin 74. -

Claims

1. Cardan joint device for screw pumps of the type that comprises a housing with an inlet and an outlet, a stator with an internal double screw thread fixed in the housing between the inlet and outlet, a rotor with an external single screw thread, if pitch is half of the pitch of the stator thread, where the rotor is supported for rotation and simultaneous eccentric movement in the stator under interaction with its screw thread, as well as an intermediate shaft that transmits the drive which is connected by means of gimbal joints at each end between a rotatably supported drive shaft and the rotor, and where the intermediate shaft's gimbal joints each comprise two separate power-transmitting and -absorbing elements, namely a ball joint that absorbs axially directed forces acting exclusively on the rotor, and a transverse pin that absorbs turning moments acting exclusively on the rotor, characterized in that the transverse, moment-transmitting and -absorbing pins consist, as is known per se, of straight, cylindrical pins (74), as with clear ing passes through each of holes (34) in the ends of the intermediate shaft (72) and which are engaged with their ends in two diametrically opposite, arranged on the outside of the end of the rotor (70) or drive shaft, by means of screws (80) or on housing (76) attached in another suitable way, the pins (74) being arranged freely springing and movable in the holes (34) of the intermediate shaft (72) and in chambers (86) in the housings (76), and the intermediate shaft conditioned by the eccentric movement of the rotor (70) Oscillation affects the pins in such a way that during their torque transmission, these also cause a rolling movement. -

2. Device according to claim 1, characterized in that the housings consist of metal blocks or bricks (76) and are taken up with a tight fit in each of their respective slots (78) in the rotor's or end of the drive shaft, as the edges of the track prevent the housings from sliding in the direction of the transmitted force. -