WO2012151648A2

WO2012151648A2 - Rolling toothed arrangement

Info

Publication number: WO2012151648A2
Application number: PCT/BR2012/000124
Authority: WO
Inventors: Ronen Perlin
Original assignee: BUCHNER NETO, Luiz
Priority date: 2011-05-06
Filing date: 2012-05-04
Publication date: 2012-11-15
Also published as: BRPI1102302A2; WO2012151648A3

Abstract

The present invention refers to a device with applications in gears, replacing the friction of contact via friction by slipping with the friction of contact by rolling resistance.

Description

"ROLLING TOOTHED ARRANGEMENT"

FIELD OF THE INVENTION

Many mechanical devices, with varying degrees of sophistication, require kinetic couplings between the various components thereof. The present invention describes a coupling with a toothed arrangement with gears by means of contact. The aim of the invention is to reduce the loss due to transmission of energy caused by friction, a problem which is already well known.

BACKGROUND OF THE INVENTION

The creative resourcefulness of man was developed to extract the advantage of using primitive levers or bearing, which have been used since early times. Canoes were launched from the banks of rivers more easily if positioned on a set of round logs before they departed.

Shortly after that, someone decided to install a fulcrum in a transmission, wherein a shaft rolled within a larger wheel. While preserving the ability to roll, it spared people from arduous work since the old rollers were relocated in front of the vehicle every few meters along the course travels. Thus, the magnitude of the torque was soon discovered. The force of an object hanging from a central drum could be amplified. The effort to lift a bucket from a well, for example, was substantially reduced by the use of a crank.

Coupling two wheels by way of contact, it was observed that different speeds were reached since the disks possess different radii. Then, it was discovered that the load being lifted by one of the axes was much greater than the effort required to operate the apparatus on the other axis of excitation. Unfortunately, for heavy loads, the disks slid over each other; gears would soon be developed. More stringent requirements made necessary the creation of a rough - toothed arrangement to avoid slippage between the parts, continuing the transmission of motion. Mills, water mills, and water wheels were built with huge domestic or commercial application. They worked with the perfection that was demanded at the time, using pegs in engagement that were essentially made of hard wood with nails, sometimes lubricated with tallow or animal fat.

TECHNICAL DIFFICULTIES

Gears became extremely useful components. At first, the production thereof required the labor of carpenters and craftsmen in carpentry. At a more modern stage, other materials were tested, and metal became better utilized. The toothed arrangement were constructed by carving or milling or by forming molten metal poured into preformed molds. The quality of the gears varied significantly depending on the material used based on the efficiency that was desired for the machine operation. The mechanisms work in pairs by contact between the teeth. Today, they use teeth with surfaces inspired by an involute curve. Let us suppose that a line is detangled from one end of a cylindrical spool. The curve described by the end of involute forms an involute design in a plane orthogonal to the axis of the spool. Even with this degree of sophistication in design, the surfaces show significant wear that, in turn, compromises a better index for the mechanical efficiency of a machine composed of these elements. To minimize the stresses, it is necessary to lubricate said contacts and, in many cases, dissipate heat from the system by using continuous cooling with forced air injection or by impregnation with refrigerant fluids.

STATE OF THE ART

Gear trains are sets the function of which is to reduce the rotating speed of a primary axis, transferring the movement to a secondary axis generally able to withstand higher torques.

Usually, the reels have a grouping of two or three axles wherein the gear ratio operates in sequence. Each coupling represents a loss in the form of friction, heat and noise generally emanating from them. Therefore, the larger the number of components in series, the greater the losses and the damage, recorded as progressively lost work. The reels are widely used in cranes and hoists, and their mechanical efficiency ranges between 75% and 80%.

Winches to lift heavier loads and most common lifts, 95% of the total thereof, adopt the system of gears called crown and endless gears. It provides an efficiency loss from 30% to 35% in the forward direction for greater friction during rotation as well as the reversal of direction.

The system has the advantage its large capacity for reduction (5:1 to 100:1 ) and enjoys a property for inclination of the steps of the spindle situated between 2 and 8 degrees, depending on the components material, which is irreversible. This means that the crown does not trigger the spindle for the highest torque to be applied on it. The yield in these systems varies from 25% to 70% in general. The big challenge, however, is to overcome the frictional forces that occur in the contacts between components. Although for small efforts we do use plastic gears, usually, in most ordinary and heavy applications, metal couplings are used that under the assumption of, continuous operation, must be kept smeared with grease or oil drizzled with great frequency or even permanently bathed in lubricating fluid, wherein the whole system is encapsulated within shielded containers.

Gears suffer wear by the action of tangential drag forces, i.e. forces that are in the plane that is tangent to the contact surface between the teeth. This plain, in a basically statistical view, would be normal to that of the angle of pressure of the teeth. The angle generally employed is 20°. Under special applications, one can modify this default from 14.5° up to 30°.

The concept of mechanical efficiency is intuitive and very practical. Of all the energy used to drive a machine, only a portion is recovered as useful work, while the remainder is wasted, so as to overcome the passive resistance, usually producing heat. This is the so-called lost work (Tp).

Efficiency, therefore, is the ratio of useful work (Tu) and the motor work (Tm). Wherein it can be stated that:

η = Tu/Tm = (Tm-Tp)/Tm = 1 - (Tp/Tm) wherein Tm = Tp + Tu and wherein η <1.

If the machine consists of several elements, then there is η = η1. η2. η3 ... i.e., efficiency is the product of the efficiencies of the parts from which it is composed.

Enumerated hereinbelow, there are some practical examples of the efficiency measured in common mechanisms (one coupling) frequently used in machines. sliding bearings: η = 95-98%

rolling bearings: η = 98%

bearings: η = 99%

cast cylindrical gears: η = 93%

milled cylindrical gears: η = 96%

endless screw and crown (steel/bronze) with 1 entry: η = 50-60%

endless screw and crown (steel/bronze) of 2 entries: η = 70-80%

endless screw and crown (steel/bronze) of 3 entries: η = 80-84%

One can use the results to calculate the aggregate efficiency of reels of the above components. We will not consider the losses in cables or windings bearing axes but only the latching, pairwise, serial components.

A) Reels (castings)

second axis, max reduction. 36:1 , η = 86-90%

third axis, reduction max. 216:1 , η = 80-86%

fourth axis, max reduction. 1296:1 , η = 74-81 %

B) Reels (milled parts)

second axis, max reduction. 36:1 , η = 88-94%.

third axis, reduction max. 216:1 , η = 83-91 %.

fourth axis, max reduction. 1296:1 , η = 78 to 88%.

C) CROWN AND ENDLESS SCREW (steel/bronze)

Crown and endless screw, fuse step 42o, max reduction 15:1 , η = 81 %.

Crown and endless screw, fuse step 4o, max reduction 60:1 , η = 62%

Satisfactory or not, the results presented hereinabove are those which arise as of today, based on the current state of the art and on which we put our efforts regarding reliability and economy of use.

Demonstrations of friction were studied by means of engineering, classified according to origin of the forces that cause them, and posted extensively on practice tables. They involve the nature of the deformation observed and the relationship between the different materials that undergo couplings.

An inclined plane constructed of a certain material can be articulated by a fulcrum.

Another flat part, such as a brick of any material, starts to slide down the ramp. At a given moment when it is observed that the angle has reached the apex of the fulcrum, one can obtain dimensionless indexes to the value of the trigonometric tangent of the angle measured. We call the coefficient μ and designate it the "coefficient of friction for slip".

SOLUTION FOR THE STATE OF THE ART

We can look at another type of friction, caused by the bearing, when a wheel spins on a well or poorly paved floor. The roller and the floor suffer deformations that change the point of rotation taken as a reference torque. The rolling coefficient is measured in units of distance, usually in fractions of inches.

One can state, regarding the frictional resistance by rolling: That it depends on the deformability of the two bodies in contact. One should use hard surfaces.

That it is proportional to the radial-normal force that acts between the roller and the surface of pavement. One should use many rolls to be subject to full charge.

That it is inversely proportional to the diameter of the roller.

We define δ as the coefficient of friction by rolling.

The same formulas exist for calculations of mechanical efficiency and are valid for both μ and δ/R, where R is the radius of the roller. Therefore, in defining R in the same metric unit as δ, we have δ/R as another dimensionless quantity.

The present invention aims to build device gears that reduce speeds between axles and torque gain and that minimize the losses that are noted in the equipment used today or, in other words, to increase efficiency of mechanical devices.

One can compare the present invention with pre-existing tables. One will find that between steel - steel we have μ = 0.12 for the slip. However we find δ/R = 0.005 by taking R =1 cm in choosing the same material.

In order to reduce the value of μ, one can use lubricants, which will bring the new value μ1 = 0.01 , approximately 10 times less than μ.

Still, it is worth noting that δ/R = 0.005 (since R = 1 cm) is two times smaller than μ1 and 20 times smaller than μ!

It is important to note that, to reduce the loss by slip, we must lubricate the contact surfaces. This practice has to be avoided in case of the rolling bearing. If lubrication between surfaces does occur, the roller loses its mechanical function because it slips, thus skidding instead of rolling.

We found that, in practice, the losses due to the slip are larger than those caused by rolling, at least in radii on the order of centimeters. As μ has a fixed value limited by the conditions of materials and lubrication, we must increase the value of R in order to reduce the expression δ/R, allowing a greater degree of freedom to decrease the losses from passive bearing.

Based on this logic, the present invention seeks to replace the existing hard- toothed gear assembly with a rolling-toothed arrangement.

Major geometrical considerations, visible in cylindrical and conical gears, make us predict that the replacement of teeth with an involute profile with rolling teeth with a circular profile presents some initial difficulties. Assuming that a pinion contains the rolls, what would the profile of the teeth of a crown be so as to promote matching? Intuitively, the idea arises that the teeth should be concave or approximately circular with a slippage radius slightly greater than the diameter of a roller that engages it. In 1956, the inventor M. Novikov developed a design for gear teeth that had a remarkable effect on technical and scientific society. Would the widely used involute system be supplanted by another, the purpose of which was aimed at increasing the value of the tangential breaking load threatened by forces at the base of the teeth?

After more than 50 years, the question still lingers. Experimentally, it was found that the Novikov system actually ensured advantages regarding the magnitude of the tangential load applied on the teeth. Research in respect to production costs and mechanical efficiency between the two systems has proven to be equivalent. The author believes that a system close to that of Novikov should be taken as a solution to the toothed rolling gear assembly. Thus, the rollers can be applied on pinions, and beading concave crowns should be applied in pairs without rollers. The system requires great precision in the Novikov assembly wheelbase. In order to minimize this difficulty, a mixed system is employed, called a Simarc gear ratio, and most recently developed in Japan by Ariga and Nagata (1981 ). It comprises a double-circular-arc in which the convex part is similar to the involute profile but now with a geminate curve on a contiguous, concave path added therein, now inspired by Novikov.

As of today, software programs have been developed aiming to assist our search for the perfectly toothed arrangement. The so-called DDS - Direct Digital Simulation Modeling - determined a correction factor for the formulations of Novikov, and it is believed that, making use of these modern accessories, one can always find solutions that are closer to the ideal.

Summing up, we believe that even the involute profile can be advantageously used in models comprising endless screws and rolling crown gear assemblies. ADVANTAGES OF THE INVENTION

The present invention minimizes the friction force imposed on a toothed arrangement for a gear, increasing the longevity of components. The present invention extends the range of the number of pairs used in one machine. We can see reels with 4 or 5 axes reducing to up to 7776 times with acceptable levels of efficiency.

The present invention brings savings in energy costs because it significantly increases the mechanical efficiency of machines.

The present invention does away with intensive lubrication, in particular, in the crown and endless screw systems, achieving an important milestone, dispensing with assemblies in sealed, watertight compartments.

DESCRIPTION OF THE DRAWINGS

Figure 1. Helical cylindrical rolling gears.

Figure 2. Orthogonal beveled or mited rolling gears.

Figure 3. A) Assembly of Rolling toothed arrangement and pinion system inspired by the Novikov system with a circular arc.

Figure 3. B) Assembly of Rolling toothed arrangement and pinion system presenting a double circular profile, inspired in the works of Ariga and Nagata.

Figure 4. Crown and Endless Caster System of gyration. A fillet of the crown forms an angle equal to the thread pitch of the endless helix, keeping a distance equivalent to φ'. The axes of rotation teeth form angles γ with respect to radii of the crown, which are competitors.

Figure 5. A) Detail of a tooth belt mounted showing a convex profile that is radially placed. The endless fillet profile is concave.

Figure 5. B) Detail of a tooth belt mounted featuring a concave profile that is radially placed. The endless fillet profile is convex.

Figure 6. Crown and Endless Caster system with rotation rollers that are perimetrally placed. It shows a crown-shaped fillet at an angle equal to the thread pitch of the endless helix, keeping the distances equivalent. The rotation axes for the tooth form angles of inclination of the threads complementary to that of the crown axis and are, therefore, perpendicular to the threads of the endless helix.

Figure 7. Assembly as described in Figure 6 detailing a set roller with an involute profile that is perimetrally placed.

BEST WAY TO CONDUCT THE INVENTION

Figure 1 shows a pair of cylindrical gears, in which the principal axes are pa disk-shaped pulley is to accommodate in the cavity elements, called rollers (2). By dividing the circle in the manner used for calculating the module in conventional gear wheels, we fix the rollers along the rim of the disc aid of ball bearings. It is remarkable that the line of contact of the gear rolls constitute the pitch circle for the gear belt so configured.

The castors are mounted each forming a helical thread about the axis of the gear. The figure shows an assembly, in which the rollers around the cylindrical surface of the pinion. Alternatively, if Θ = 0, we have a straight-cylinder-type gear. In this construction, the rollers have their shafts mounted parallel to the main shaft gear.

The second gear to complete the pair need not hold bearings. Such a profile should present a toothed arrangement of a concave shape, very similar to the "WN" system created by Wildhaber and improved by Novikov in 1956. However, the angle of the fillet should respect the Θ chosen to be the perfect marriage partner. One should choose the sprocket, the lower gears, which house such items as the rolling elements, in favor of economy. If the space factor is eliminative, it is thought that the bearings can be installed gears. Although Θ can be determined up to 30° in width, it is more often seen with the value ranging around 15°. In order to avoid a severely dispersive axial load, it is advisable to use the gears paired on each axis, differentiating the left and right steps (+Θ and -Θ). Toothed-arrangement bearings must support radial and axial loads, except for the straight spur gears, which should support mainly radial loads.

The pitch angle of Θ ensures a toothed arrangement competitor (2) engaged simultaneously. This gives stronger power tangential to the system.

The mechanical efficiency of spur gears can be computed, in general, by the subtracting power loss ϊ from 100% efficiency.

Therefore η = (100 -

The loss ma be expressed by the equation:

whe

rein, and cos²a]— sen a) provided that:

μ is the friction coefficient of slipping,

a = angle of the tooth front pressure.

Θ is the angle of the thread or helix.

<pn = arc tan (tan a. cos Θ) is normal pressure angle of the tooth.

R0, ro are the outer radii of the crown and pinion respectively.

Rp, rp are the radii of primitive crown and pinion.

Rg is the reduction ratio.

The value of σ of a second equation is obtained by the following table, as appropriate:

It will be interesting to use these tools to calculate results that compare the efficiency of conventional examples and rolling cylindrical gear examples. It is noteworthy that, in rolling cranes, we will replace Δ = Ro - Rp with Δ - (R'o-R'p) = Δ / 2, since their teeth are inspired by the design of Novikov.

The following being set: a = 20 °, Θ = 15 ° where φη = arc. tan (tan a. cos Θ) = 19.37 °.

Then one can deduce σρ = 0.9397 (Straight Pool), ah = 1.0111 (Cylindrical Helix) for two main situations of the table.

The following being set: Rg = reduction factor of 4 as in our examples, and will take Rp = 80 mm and rp = 20 mm.

Using the formula (omitted) for the minimum teeth number without interference, we found z = 16 and conclude that Z = 64. The module is m = 2r_p / z = 40/16.

The pitch diameter 2Rp equals Z/Pd where Pd = 64/160 = 0.4 is the diametric pitch of crown. One can now find 2Ro = (Z +2)/Pd = 66. (160/64) and infer Ro = 82.5.

Similarly, ro = (z +2)/(2.pd) = 18/0,8 = 22.5.

Solving for Hs, one can find 0.4141 and 0.3457 = Ht, in the case of conventional gears.

For cylindrical roller ones, you will get R'O = 81.3 and r'O = 21.3, assuming that the pinion contains casters. One shall get H's = 0.2249 and H't = 0.1990.

When adopting μ = 0.06, ε = δ/ρ is the specific constant for bearing friction, where δ is the coefficient and p the radius of a caster. 2.p will take slightly less than half the pitch Circular pc = ττ/Pd = 7.853 where we see p = 1.95 mm.

Upon checking the tables, in practice, one finds δ 0.001 cm for rolling steel- steel rings, and so we have ε = 0.0051. We are assuming the conjugated gear made of steel also.

We can now use the 1st equation and calculate the deficiencies for the straight exterior spur pool and helicoids examples, inferring their efficiencies.

CONVENTIONAL

Straight exterior spur pool:

l^'(cp) = 1.2220 where η = 98.77%

Helicoids - exterior:

l^'(ch) = 1.1357 where η = 98.86%

ROLLING

Straight exterior pool:

^'l^'(rp) = 0.0577 where η = 99.94%

Helicoids - exterior:

l^'(rh) = 0.0536 where η = 99.95%

We found that a gap of over 1 % was noted, promoting the gear efficiency ratio of the walkways. Even if this advantage is less significant for many applications in cylindrical devices (we shall see that it is more widely relevant in Endless/Crown systems), we must consider that the rolling gear ratio dispenses with the cost and obligation inherent in the lubrication process.

Figure 2 shows straight bevels, when the axes are concurrent. The construction is similar to that already described except that the rollers (2) must have a conical shape, and their axes form angles ψ with respect to the pinion's radii. The crown that makes it up should not even contain rolls, and the profile shape of toothed arrangement should be conical concave, preferably "WN". The crown may constitute the roller where the dimensions of the conical pinion do not allow its installation for reasons of space. Toothed-arrangement bearings must support radial and axial loads. A second inclination can be given to the axes of gyration of the rollers with respect to the generatrix of the conical surface around the shaft, containing them.

Thus, one will be building Rolling, beveled, helical gears (not described in figures).

Figure 3A shows the Novikov/Wildhaber system for tooth profiles tailored to our rolling toothed arrangement. It should be noted that the rollers (2) have the point of tangency with the crown at the same point as a Novikov tooth would have but that its center on the disc (1 ) determines the gap to maintain the clearance between the gears.

Figure 3B shows an adapted system of a double circular arc by Ariga and Nagata, developed in Japan in 1981 , which has certain advantages over the Novikov drawings, eliminating, however, the need for extreme accuracy as to the distance between the axes. This design allows the mounting of casters placed in the region of the convex (involute) curve, wherein the pinion is coupled to the crown. Therefore, one has a pair of Rolling wheels and castors, one from a gear at a time, fitted on both concave cavities (circular arcs) as a host.

Figure 4 shows three views of a system for crown (3) and endless screw (4) setting in which the major axes are generally in orthogonal operating positions but not coplanar. In these cases, the thread of the endless setting should have a convex, trapezoidal profile or concave WN or convex involute, seen in cut-away.

It is important to note that the axes of the rollers (2) are arranged radially.

The multi- plane containing its axis and the axis of the crown (3) are all competitors in the same line that is exactly the central axis of the crown. The design includes the construction of spherical roller bearings so that the rollers rotate with maximum freedom. Toothed-arrangement bearings must withstand heavy radial loads and axial loads due to the small pressure angle of the tooth profile belt (roller).

Two aligned radial rollers (2) replace the fillet of a crown (3) with a helix with an angle and normal feed step φ', similar to the normal angle of the thread and the endless screw (4) axial feed. The tangential load on the crown will be divided, which increases the ability to withstand redoubled torques. One might use three or more wheels per fillet crown to increase the pressure imposed by a tangential load. In these constructions with rollers radially arranged, it is important to offer a clearance spacing (backlash) between a fillet rolling crown and the sides of two walls of the endless gear. Providence is necessary to avoid locking the wheels of each fillet during movement of the gear. One does not want two walls of endless fillets rubbing a fillet bearing the crown, forcing the wheels to rotate simultaneously in directions opposite to that of torque, which is impossible. One would, in practice, get large losses of sliding friction between two non-lubricated surfaces.

Figure 5A illustrates in detail the rotation given to the convex profile roller (2). Note that it is shaped closer to a toothed arrangement WN obtained by rotation around its longitudinal axis. This configuration forces the endless screw (4) to have a concave design.

Figure 5B shows a concave profile for the tooth belt, or caster roller (2). The profile, as follows, was inspired by Novikov. This design favors large axial pressure exerted on the convex endless screw (4).

A similar system is shown in Figure 6, in which the rollers were mounted on the crown except that their gyration axes are perpendicular to the fillet alignment that describes the angular step of the endless screw. This composition allows the thread of the endless casters to fully embrace and thus overcomes the need to adjust the "backlash" relief or to have an excessive gap, as in the example of Figure 4. It should be noted that, with this arrangement, the tangency of rollers to the endless helix occurs by contact with both surfaces of the rollers, whether they are to the front or the back. It is thought that this provision can accommodate a greater number of rolls per unit diametric pitch of the crown, i.e. that it can be built with smaller gear modules. We also believe that the contact ratio can easily be further increased. We will have more flexibility to build globoid enveloping toroidal endless (5) screw, with a toroidal profile, and, thus, there may be multiple threads of the crown gear ratio concurrent with the endless rollers. Beyond these possibilities, we think casters may have different profiles.

Nothing prevents us from constructing a profile where the edge is an involute curve, for example, thus, avoiding any problems encountered in the preparation of Novikov applications.

In Figure 7, the gear ratio represents an assembly for a globular enveloping toroidal endless (5) screw and a toroidal crown (3) in which the rollers (2) have an involute profile. Bearings that are "spherical" (tapered rollers, in fact) must support essentially axial loads.

The formula for the efficiency of conventional crowns and endless screws is:

η = cos 0 - μ . tg Θ / cos 0 + μ. ctg Θ

That was already used for calculations released in previous pages.

We describe below a table that recommends Φ, the normal pressure angle of teeth, depending on the inclination of a propeller spindle Θ.

It was also noted that the formulas remain valid for losses due to bearing friction, simply by replacing μ for δ/R.

From practice tables, we find that δ = 0.001cm for spherical steel bearings. Taking a ball with 1.5mm radius, i.e., 0.15cm, we have ε = δ/R = 0.001/0.15 = 0.0066 ... = 0.007.

Firstly, one will make the angle of the spindle axis of the helix Θ1 = 42° with Φ1 = 30° and then Θ2 = 4° with Φ2 = 14.5°, in accordance with the previous calculations.

Replacing μ by ε = 0.007 in the above formula one finds:

η' (42°) = 99.83%

η' (4°) = 90.58%

Upon comparing with previous results for conventional endless rollers of excellent quality at high-speed sliding (μ = 0.04):

η (42°) = 91.16%

η (4°) = 62.67%

And we are pleased to provide a significant efficiency gain in our invention, especially for systems such as endless crowns featuring large reductions.

INDUSTRIAL APPLICATION The financial savings in energy costs can be calculated from a target of 100% of useful work. When one says that a machine has 70% efficiency, it is also said that 30% have disabilities. It should be noted that 30/70 = 0.4285. This is the percentage of non-financial expenditure made by the machine, but that was actually paid by the user.

Checking the opposite direction:

100% + 42.85% = 142.85% being paid for a service with an efficiency of 70% using the machine. Now 70% .142.85% = 1 = 100% (of useful work as objective).

In light of this, one can formulate the expense of extra cost as being:

d = 1- η / η

The parallel shaft rolling reels can function with one or more additional axes without significant losses in their ultimate efficiency index.

An endless crown (step 4°, entry 1 ) nowadays generates an expenditure (100-62)/62 = 61 % of money or human labor is not exploited.

An endless-crown crane rolling type (step 4°, entry 1 ), the object of this invention, with the same operating characteristics generate (100-90)/90 = 11 % of expenditure, a value much smaller than the previous one.

The above explanation seeks to argue that the project embraces an avid consumer market since the costs of production and installation of the product are comparable to conventional models and the result of use is economically desirable.

Dispensing with the lubricating components comprises another major attraction for the successful launch of such rolling-toothed arrangements.

Claims

1. A device for the manufacture of gears that are coupled in pairs, comprising a contact denture characterized by having rollers (2) to establish a coupling with another gear, replacing the frictional sliding that occurs between the contact surfaces by means of the rolling resistance.

2. A device according to claim 1 comprising cylindrical gears with parallel axes, characterized by having a disc (1) which houses grooved rollers (2), the rotational axes of which pertains to the cylindrical surface formed around the axis of the disc (1 ) and forms an angle of inclination in respect with its direction, that of the main axis of the disc (1 ), forming a gear belt with a pitched, cylindrical, helical rolling arrangement gear that is paired with other gear wheels, preferably without a rolling toothed arrangement, preferably provided with a circular concave profile, with an inclination slope identical but with an opposite sign to the normally pitched gear belt that makes it even, called a cylindrical helical gear conjugate belt.

3. A device according to claim 1 and 2 wherein the inclination of the pitch angle of the rollers (2) is zero regarding the axis of the disc (1 ), wherein the cylindrical roller gear is linear and wherein the conjugated cylindrical gear is linear and they are called spur arrangement rolling gear.

4. A device according to claim 1 comprising competitor gear shafts with bevel or miter gears characterized by housing a set of tapered rollers (2) wherein their axes of rotation form an angle with the radial direction of the main shaft of the gear, forming a rolling bevel or miter linear gear belt, matching a beveled or miter gear that makes this pair preferably with no other rolling wheels and is provided with a tapered, concave, toothed arrangement, preferably arc- circular, to said linear conjugate of a rolling bevel or miter gear belt.

5. A device according to claims 1 and 4 characterized by tapered housing rollers (2) the axes of rotation of which form a fixed inclination angle with the generatrices of a conical surface equidistant from the major axis of the conical pinion or conical crown gear constituting a rolling helical bevel or miter gear, thus making up the pair preferably with no other rolling wheels and provided with a toothed arrangement, preferably a concave, arc-circular gear cone with a slope equivalent to that described for the partner roller thereof, called a conjugate of a rolling helical bevel or miter gear belt.

6. A device according to any of the preceding claims characterized by the fact that the rolling toothed arrangement of a first gear can be mounted in a profile that is called a doublercircular-arc, with the rollers (2) included within the convex region of the double-circular-arc profile, the concave cavity of the curve that continues to serve as a host to engage a separate roller (2) that is mounted in the second gear thereof, which should also have a double-circular-arc profile, so that both gears give an alternating rolling toothed arrangement, or concave cavities, to house the rollers that are mutually coupled thereto.

7. A device according to claim 1 comprising axes that are not parallel and not competitors, say a crown (3) and an endless screw (4), characterized by the fact that it comprises harboring fillets casters of rollers (2) aligned around the perimeter of the crown (3) wheel in which each step represents the front thread of the crown (3) equivalent to the same lead thread pitch of the endless screw (4), the crown being a rolling-toothed crown radially arranged in which the planes containing the axes of rotation of the rollers and the axis of rotation of the crown, are all competitors in the same line that exactly is the axis of the crown, and that the endless roller is said endless conjugate of a radially arranged rolling toothed crown.

8. A device according to claims 1 and 7 characterized by the fact that the rollers (2) are radially mounted on the crown (3), the axial profile of rotation of rollers (2) is convex or involute, paired along with the endless thread which has a longitudinal profile that is respectively concave arc-circular or involute.

9. A device according to claims 1 and 7 characterized by the fact that the rollers (2) are radially mounted on the crown (3) and their axial rotation profile thereof is concave, paired with the endless thread which presents a longitudinal profile that is convex arc-circular.

10. A device according to claim 1 , comprising non-parallel and noncompetitive gear axes, a so-called crown and endless assembly or, alternatively, a so-called crown and enveloping toroidal endless (5) screw assembly, characterized by housing rollers (2) fillets aligned around the perimeter of the rim of the crown (3) in which each thread is the frontal pitch of the crown (3) equivalent to the same lead pitch of the endless screw (4) or the enveloping toroidal endless (5) screw, in which the axis of rotation of the rollers (2) are perpendicular to the threads of the crown, the gears are then called perimetrally arranged rolling crown and endless screw arrangement.

11. A device according to claims 1 and 10, characterized by the fact that perimetrally placed rollers (2) are mounted on the crown and their axial profile of rotation is a concave arc-circular, convex arc-circular or involute, paired with the endless thread that has a combined longitudinal cutting profile, respectively convex arc-circular, concave arc-circular or involute.

12. A device according to any of the preceding claims wherein the surface of contact of the rollers (2) of a gear in which the coupled gear belt engages, dispensing with lubrication, and the assembly of the gear pairs does not require confinement in sealed, watertight compartments.