FREE STANDING TEETH (FST) GEAR REDUCER

Abstract: Free Standing Teeth (FST) Gear Reducer, is a new single stage gear system that reduces input speed by great gear ratio and provides high torque amounts. In this system the direction of output rotation can be obtained either to the direction of input rotating or the counter direction of it. This gear system consists of one or more eccentric element (7) which is similar either sliding contact element (e.g. cam) or rolling contact (e.g. roller) element, free standing teeth (8) which are drived by these eccentric elements (7) and mate gear (9) which is being internal or external. That is to say free standing teeth work either as an internal or as an external gear's teeth. In summary this system is a rijid body gear system but has also free movable parts that is, different from both conventionnal rigid body gear systems and elastokinesis gear systems.

Description: DESCRIPTION FREE STANDING TEETH (FST) GEAR REDUCER This invention is about the free standing teeth gear reducer which is a gear system On rotating machines and equipments in various industry sectors, gear reducer has been used to convert different rotating speed or torques which is needed The type of gear reducers is determined according to its characteπstics such as gear ratio, torque, efficiency, toughness, volume, lightness wear resistance of teeth, ergonomy, noise level etc by talcing into consideration the importance of the place where it is used In last years new type of gear reducers have been developed having different qualities for vaπous purposes It is important for gear reducers and gear boxes higher gear ratio, lower volume and lighter weight Whenever the gear ratio increases on pairs of spur gears weight, volume and number of stage increases too On worm gears which provide higher gear ratio, weight and volume decrease regard to spur gears However dimensions increase while gear ratio and torks as needed in these type of gears In this gear systems the volume is used so efficiently that the system is set into the middle of internal gear to cover little volume This characteristic also provides the gear reducer placing into motor cover or into the machine which is turned The number of meshed tooth is one, on a gear which is placed in conventional gear systems (e g external and internal spur gears, worm gear system) This number reaches 2 or 3 on Globoid type worm gear systems On planetary gear systems the number of loaded tooth depends on the number of planetary gears and reaches up to 5 However the number of loaded tooth is 10 % of the number of tooth at least depending on number of eccentric element on this system This characteristic provides reducing pressure on tooth surface and decreases wearing And greater number of loaded tooth enable more load transmission and obtain greater amount of torque Any damaging or breaking on all type of present gears, upsets working or becames completely out of work But in this gear system, the teeth around of damaged tooth continue working because of having a great number of meshing teeth In conventional gear boxes, it is imposible to alterate direction of output shaft rotation without changing direction of input shaft But in this reducer, the output shaft can rotate in both two directions without to altereting input shaft direction At high speed on planetary gear system which can fit into small volume, centrifugal forces come into existance depending on mass of planetary gears This creates some beaπng and lubrication problems Tn this system great centrifugal forces do not appear because of not having rotating masses like planet gears On Harmonic Dπve Gear Reducers which has high gear ratio, the gear named flexphne made from spπng material has to be elastic deflection for forming of elhptoidal shape Thus the teeth of the gear mesh at least on two sections This cause the difference number of teeth is 2 or more between meshing two gears But the construction of this gear system gives possibility meshing with one section between two meshing gears That is the internal gear can be meshed with external gear by just an eccentπc element thus it is obtained at least two fold gear ratio regard to harmonic dπve gear reducer On harmonic dπve gear systems the more power and torque increase the thickness of the gear made from spπng mateπal increase and thus the more spπng force to overcome But on this gear system the gears external and internal do not transform but only a small spπng in every independed tooth show resistance For this reason power is transmissioned in high efficiency On conventional gears, damage or weaπng on teeth causes gear to be replaced However in this gear reducer each of independed tooth and every parts of the system can be replaced one by one if necessary This couses reducing the duration and cost of repair very much and also increases the reducer life As independed tooth can be produced without having special tool easily in mass, this reduces production peπods and costs The structure of this system is neither fully πjid nor elastic deflecting Tn general it has to explain in a πjid system having linear moving parts Bπef descπption of drawings Drw 1 Dπve πng having one elhptoidal cam(wave generator) " 2 Dπve πng having two elhptoidal cam(wave generator) Drw 3 Dπve πng having roller element(wave generator) 4 Dπve disk having elhptoidal cam " " 5 Dnve disk having circular cam " " 6 Dπve disk having roller eelement " " 7a Reducer which FST is being an internal gear(Section front view) 7b Section side view of Drw 7c 8 Reducer which FST is being an external gear(Front view semi section) 9 View from upper side of Drw 8 The system has three basic parts which are an internal gear, an external gear mounted m it and dπve πng or disk For the motion 1 e teeth of either internal gear or external gear can be movable freely and fixing of one of three basic elements on The pπncipal of motion of the reducer has been descπbed in sample on drawing 7a, 7b On the drawing the input shaft which is coupled with power unιt(ι e motor) is connected to a dπve πng which is shaped elhptoidal cam (wave generator) (No 1) and output shaft is connected to the external gear (No 4) The earner πng functioned as a internal gear (No 2) is fixed The dπve πng (wave generator) may also be shaped in several types as in drawing 2, 3 The earner πng which is mside of the dπve πng contains teeth (No 3) placed surroundmgly which are movable in their holes freely The teeth which are not put into motion yet by cam on the dπve πng, are pulled into their holes position by their own spπngs into the holes And m the mean time the stems of these teeth are projected outside from the dπve πng In this sample(Drw 7a, 7b) the earner πng is fixed to the reducer housmg I mean the internal gear is fixed The external gear (No 4), located inside of the earner πng is coupled with the output shaft All these parts a m are placed in reducer housmg and the input shaft (No 6) and the output shaft are equipped with rolling contact beaπng at both two side of the reducer body When the input shaft turns, cause turning the dπve πng (wave generator) The stems of the free standing teeth which contact to the elhptoidal cam start moving towards the external gear and begin meshing to its teeth (Drw 7b, Area B) The free standing teeth which are pressed by center area of the cam have been meshed the external gear' s teeth The teeth which the pressure of the cam is decreased by the continuation of the movement, are released from the external gear teeth by the effect of spπng force and they are drawn into their holes in the carrier ring (Drw. 7b, Area D). Since the number of teeth in the carrier ring are more than the number of teeth of the external gear, the movement a.m. makes the output shaft connected to external gear; rotates counter direction of the input shaft in difference number of these teeth of the these mating gears. For example let' s assume that the number of teeth in the carrier ring is Z ι=251 and the number of teeth on external gear inside of the carrier ring is Z 2 =250. The result the gear ratio will be: i= 250/(250-251)- 250/- 1= -250 The minus sign of gear ratio shows the output shaft turns counter direction of input shaft turns. The output shaft a.m. rums counter direction of input shaft. When the parts (Drw 7a, 7b) are used again the input shaft is connected to drive ring (wave generator) and output shaft is connected to the carrier ring and the external gear inside of the carrier ring is fixed in this situation the output shaft turns in the same direction of input shaft turning. In addition to these alternatives it is possible to connect the carrier ring to the outer shaft and fixing drive ring. In this situation the input and output shafts turns same direction but in lower gear ratio. It is possible to locate the carrier ring which has free standing teeth being as an external gear and, drive disk (wave generator) (Drw. 4, 5, 6) being as a drive ring which is located into this external gear(Drw. 8, 9). In this situation by turning the drive disk (wave generator) (Drw 8 No: 7) connected to the input shaft, the eccentric element, go out from the carrier ring and mesh to the internal gear' s teeth. But when free standing teeth are pulled in their holes into the carrier ring it must be prevented to intersect teeth and teeth stems (Drw.8 No: 8c) and the holes of them, and the holes of teeth has to be sufficient strength. For this reason the sequent free standing teeth (No: 8) is placed on carrier disk in a zigzag form (Drw. 9). This type of location can be applied when the free standing teeth are formed as an internal gear' s teeth in order to increase strength of teeth holes. The FST gear reducer is used on rotating machines in industry in the need of high torque and great gear ratio in little volume and added on precision, angular and linear movement mechanism and calibration system.

Claims: CLAIMS This is a gear system and its characteπstic is the basic elements are consist of internal gear and an external gear which is located into it and a dπve πng or disk (wave generator) which has eccentπc element or elements(Drw 1,2,3,4,5,6) or similar elements It is the gear system mentioned claim 1 and its special feature is one of the three basic elements which are the external gear, internal gear and the dπve πng (disk) (wave generator) has to be fixed and in order to the input and output shafts must be connected to the proper elements It is provided turning of output shaft either the direction or counter direction of input shaft depending on fixing element and the elements which are connected to the input and output shaft It is the gear system mentioned claim 1 and 2, its special feature is one of the elements which activate as being internal external geardifferent from conventional gears possess freely movable teeth which move towards from outside to msιde(to the external gear) (Drw 7a, 7b) or from ιnsιde(from external gear) to outsιde(to internal gear)(Drw 8,9) They are located on sunounded of the carπer(No 2, 10) If the element which has free stsandmg teeth is fixed like mentioned in claim 2, the earner πng can be formed in the system housmg to achieve the same task It is the gear system mentioned claim 1 , 2 and 3, if the free standing teeth are located as bemg an internal gear' s teeth (Drw 7a, 7b), in this situation the teeth which are not into motion yet by dπve πng are pulled into their holes position by their own spπng That is these teeth are not meshmg yet By the turning movement the eccentπc elements on the dπve πng(wave generator) (Drw 7a, 7b No 1 ) mentioned claim 1 , start to contact to the teeth' s stem (Drw 7a, 7b No 3 c) and these teeth start moving towards the inside and begin meshing to the external gear' s teeth (Drw 7b Area B) In this way the movement is transmissioned to the basic element which is connected to the output shaft (On Drw 7a, 7b from fixed internal gear to the external gear) By continuing the movement the free standing teeth of the internal gear mesh almost and then completely at Drw 7b Area C On the Area D the teeth start disengage in sequence It is the gear system mentioned claim 1 , 2 and 3 if the free standing teeth are located being as external gear' s teeth (Drw 8, 9) they are pulled in their holes while any force affect them. By movement of turning the drive disk (wave generator) (Drw.8 No: 7) affect the teeth' s stems by pressing of it' s eccentric element and these teeth begin to go outside of the carrier ring and start meshing internal gear' s teeth. In this way the movement is transmissed to the basic part which is connected to the output shaft (On Drw. 8,9 from external gear to internal gear). By continuing the movement the free standing teeth which are meshed to the internal gear' s teeth, start disengage from internal gear in sequence and they are pulled in their holes. 6. Tt is the gear system mentioned claim 1, 2, 3, 4 and 5, its special feature is when the free standing teeth being as an internal or external(especially) gear, in order to prevent to intersect teeth, teeth stems and holes and to increase strength of teeth holes for both situations , the free standing teeth in sequence can be located in two (Drw. 9) or more zigzag formed rows.

Inventors: ALTUG KEMAL SUEKRUE, ALTUG, KEMAL, SUEKRUE
Applicants: ALTUG KEMAL SUEKRUE, ALTUG, KEMAL, SUEKRUE
Application year: 1999
Main classification: F16H25
IPC codes: F16H25