Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/02—Toothed gearings for conveying rotary motion without gears having orbital motion
  • F16H1/04—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members
  • F16H1/12—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members with non-parallel axes
  • F16H1/16—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members with non-parallel axes comprising worm and worm-wheel
  • F16H1/163—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members with non-parallel axes comprising worm and worm-wheel with balls between the co-operating parts

Definitions

• This invention regards the precision mechanics field and the rotation transmission between two perpendicular orthogonal axles.
• the invention considers a coupling between a worm gear, with a toric threading and a gearwheel or toothed rim.
• Objective of the invention is to overcome the problems of the known technique by supplying a device that is able to apply the advantages given by the use of the sphere interposition to the worm gear - gear wheel type transmission equipment.
• this is obtained by using sphere interposition between the worm and the gear wheel, using a toric threading on the cylinder of the worm gear, and foreseeing a particular type of internal recirculation.
• Figure 1 shows a cylinder upon which a toric surface has been made.
• Figure 2 shows the generation of the toric threading upon a cylinder upon which a toric surface has been made.
• Figure 3 shows a cylinder upon which a toric threading has been made.
• Figure 4 shows a toric worm gear in grip with a toothed rim, with interposed spheres.
• Figure 5 shows two views of a toric worm gear in grip with a toothed rim, with interposed spheres .
• Figure 6 shows a detail of the slots of the rim.
• Figure 7 shows a solution for the recirculation of the small spheres.
• Figure 8 shows a section with the recirculation of the small spheres.
• Figure 9 shows the external holding flange.
• figure 1 shows a cylinder (1), in which a toric surface (2) is obtained, from the rotation of an arch (3), having the centre (5) outside cylinder (1), around the longitudinal axle (4) of the cylinder itself (1).
• Figure 2 shows the centre (5) of the arch (3) with radius (6), outside cylinder (1) upon whose surface is obtained the toric surface (2).
• Figure 3 shows this type of threading (7), whose pitch (8) is not given in metrical measurements of linear lengths, but in angle measurements, being made of angle (9) done by the instrument that rotates with radius (6) in addition to the augmentation desired of incision around centre (5) of arch (3) of the torus (2), with a constant angle speed for one turn of cylinder (1) around its axle (4).
• the tool used to make threading (7) in torus (2) an arch of 10° with a constant angle speed, at the same time that cylinder (1) turns completely around its axle (4), itself with a constant angle speed.
• Figure 4 shows the application of this toric threading (7) in this invention. It represents a rim (10) with slots (11) having the identical pitch angle (9) of the toric threading (7), and small spheres (12) of the same diameter interposed between toric threading (7) and slots (11) of rim (10).
• the pitch angle of threading (7) of cylinder (1) may or may not be identical to pitch angle (9) of slots (11) of rim (10).
• Figure 5 shows the section of the toothed rim (10), in which are posed slots (11) with the proper pitch angle around axle (13) of the rim (10) itself, to assist movement transmission.
• Toric threading (7) has a spiral run upon a toric surface, therefore it will have a maximum diameter (14), a minimum diameter (15) and intermediate diameters between the minimum (15) and the maximum (14).
• Figure 6 shows a detail of slots (11) of rim (10), whose arch (16) may have diameter equal to maximum diameter (14) of toric threading (7), or to the minimum (15) of the same, or to an intermediate diameter between the maximum (14) and the minimum (15), in each case increased of the diameter of the spheres (12), according to the type of desired movement precision.
• Figure 7 illustrates one of the possible solutions to guarantee the recirculation of spheres (12). Because they rotate around their axle, and make a translation, they may emerge from the toric threading (7) of cylinder (1). To prevent this at the opposite ends of toric threading (7), there are two small retaining blocks (17), immediately after hole (18) made within toric threading (7) and that from outside threading enters inside cylinder (1), orthogonally to the axle of cylinder 1 itself.
• Figure 8 illustrates in section the run of spheres (12) within cylinder (1). They enter through hole 18, and through a small cylinder of recirculation (19), placed within cylinder (1), they emerge through the opposite hole (18), thus guaranteeing the continuous recirculation, in both directions.
• Figure 9 shows an external holding flange (20), that has the aim of holding spheres (12) within the slots of toric threading (7), and thus allowing the same to carry out their work without neither emerging from cylinder (1), nor from rim (10) in the contact area.
• the mechanism for the transmission of rotary movement between two shafts (4,13) having non-parallel, non coplanar axes, includes therefore a cylinder (1) in which is obtained a threading (7), a toothed rim
• Another advantage is that the distance in the entire contact zone between the toric threading of the cylinder and the slots of the rim, is constant, and in this manner there is no possibility of emerging of the small spheres from the slots that contain them.
• the worm and the rim have corresponding pitch threadings so the spheres can roll contemporarily on the threads of the worm and on the surface of the slots of the wheel.
• the worm in the contact zone, is shaped as an arch whose centre corresponds to the centre of the gear wheel. The radius of his arch is equal to the sum of the minimum radius of the gear wheel plus the diameter of the spheres.
• a fixed angle threading is made, equal to the pitch of the gear wheel.
• This fixed angle threading is not a variable pitched threading, but a new and different type of threading, that has the aim to make the spheres fit in exactly with the slotted wheel.
• the distance between the wheel and the worm gear depends on the size of the spheres, on the slot of the thread of the worm and on the slot of the thread of the gearwheel.
• This recirculation is carried out through the two retaining blocks that are placed immediately after the appropriate hole, placed suitably on the centre of the threading of the worm. These retaining blocks prevent the spheres from going past the hole and induce the spheres themselves to enter the holed channel that links the external surface of the worm with the axial hole of the same.
• An internal cylinder is placed within the axial hole of the worm, this cylinder is made up of two semicylinders with a corresponding slot, that links the two recirculation holes of the spheres. The two semicylinders, once they are coupled they are held in place by worms or other known system. Through this system the spheres are free to pass from one hole to another.
• the invention foresees an external holding flange, expressly internally shaped to allow free movement of the spheres in the slots of the worm.
• This flange made of two or more pieces in order to facilitate assembly, is also cut to accommodate the rim, with the fitting tolerance that allows the rim to rotate without friction but prevents the spheres from emerging from the system.
• the recirculation of the spheres can be carried out also in another fashion. For example only one recirculation can be carried out, in order to have the spheres return back after they have completed one or more revolutions, or else an "external" recirculation can be carried out, in which the spheres return back to each single thread using an appropriate switch placed on the external holding flange.
• the section of the thread can be a different shape, and the spheres can rotate and translate on a groove with a trapezoidal, semicircular, as a Gothic arch section etc.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gear Transmission (AREA)
• Transmission Devices (AREA)
• Gears, Cams (AREA)
• Friction Gearing (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=11441363

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (3)

• 2001
  • 2001-06-14 IT IT2001CS000002A patent/ITCS20010002A1/it unknown
• 2002
  • 2002-06-13 WO PCT/IT2002/000392 patent/WO2002103220A2/en not_active Application Discontinuation
  • 2002-06-13 AU AU2002314534A patent/AU2002314534A1/en not_active Abandoned

Patent Citations (3)

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