RU2391587C1 - Procedure for continuously variable translation of motion and facility for implementation of this procedure - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: facility for continuously variable translation of motion consists of case, of driving shaft with drive pinion, of carrier, of converting mechanism, of driven shaft and of mechanism adjusting gear ratio. The drive pinion engages intermediary gears arranged along circumference. The intermediary gears transfer rotation via converting mechanisms and differentials installed between them to a tooth gear of internal engagement connected with the case and the driven shaft. Also uniform rotating motion of the driving shaft is converted into two separate, but equal by module continuous motions containing sections with accelerated and retarded motions. Further continuous motions are combined. Notably, uniform rotating motion transmitted to the driven shaft is resultant. Gear ratio between the driving and driven shafts is adjusted by phase shift of two separate continuous motions.

EFFECT: simplification of mechanism control and increased service life of transmission.

4 cl, 16 dwg

Description

The invention relates to mechanical engineering. In particular, to stepless gears of movement, which provide a smooth and continuous change in power and kinematic gear ratio.

It is known that gears that provide a smooth, stepless change in the angular speed of the driven shaft, at a constant angular speed of the drive shaft, are called variators (I.I. Ustyugov “Machine Details”, “Higher School”, Moscow, 1973, p. 45). CVTs are classified by several main types: frontal, conical, ball, with a ring, with pads, torus, etc. In all of the listed variators, the movement from one shaft to another is transmitted due to friction excited between the working surfaces of the rotating rollers, therefore, such transfers are called friction ones. So, for example, in the frontal variator, the driving and driven rollers touch each other. When the point of contact of the driven roller changes relative to the center of rotation of the driving roller, the circumference (described) by the point of the rotating driven roller increases (decreases). In this case, the angular velocity of the driven shaft also changes. Friction variators have several advantages: simplicity of design and low cost of manufacture, smooth and quiet operation, the possibility of stepless speed regulation; when overloaded, the rollers slip, protecting the drive mechanism from damage. At the same time, all the types of friction variators listed above have inherent disadvantages: the variability of the gear ratio due to slippage of the rollers, limited transmitted power (10-20 kW), high loads on their shafts and bearings (bearings), relatively low efficiency, wear of workers roller surfaces and their heating. Therefore, in mechanical engineering, power transmission based on friction variators are used extremely rarely.

In addition to friction gears in mechanical engineering, belt and chain variators are used. The main structural elements of the chain variator are two pairs of sliding gear cones and an endless chain with sliding plates. Such variators transmit power up to 75 kW, at a peripheral speed of 6-9 m / s. The efficiency of the variator, depending on the gear ratio, varies between 0.85-0.95. The largest range of gear ratio changes is 7. The disadvantage of the variator is the low reliability of the belt and chain, which limits the transmitted power.

The closest in technical solution to the proposed invention are continuously variable pulses, which can be selected as a prototype. In particular, a pulse automatic transmission is known (V.F. Maltsev, "Mechanical Pulse Transmissions, Moscow," Mechanical Engineering ", 1978, p. 71). The gearbox includes a drive shaft with a drive gear around which the intermediate gears are engaged. During rotation, the intermediate gears give impulses to the carrier, causing it to oscillate. Further, the movement is transmitted in a certain way through the freewheel mechanism (MOA) to the driven shaft. The mechanism that converts the rotational movement of the drive shaft of the transmission into the oscillatory motion of a link rigidly connected to the drive link of the Ministry of Agriculture is called a conversion mechanism.

According to this principle, not only this gearbox works, but also all pulse continuously variable transmissions. In pulsed continuously variable transmissions, unlike other types of transmissions, energy is transmitted not continuously, but in the form of periodic pulses. Typically, the rotational motion of the drive shaft in these gears is converted into an oscillatory motion, which, with the help of the Ministry of Agriculture, is again transformed into rotational motion, but of the driven shaft. The mechanism built on this principle allows the transfer of very large energies, but at the same time it is also a significant drawback: the rotation of the driven shaft is intermittent, which limits their use only in special mechanisms. For example, they are used in feed drives of metal-cutting machines, presses, conveyors, dispensers, etc. A similar mechanism cannot be used in the transmission of a car as a variator to change the speed of movement.

It is also known from the literature (NI Koshkin, MG Girshkevich "Handbook of Elementary Physics", publishing house "Nauka", Moscow, 1966) that a movement in which the speed changes by the same amount for equal periods of time is called equal . The value measured by the change in speed per unit time is called acceleration. Acceleration can be positive (accelerated motion) and negative (slow motion). Uniform is a movement in which a point passes equal distances at any equal intervals of time.

The technical problem solved by the invention consists in the development of a continuously variable gear transmission (variator), which could be used in the transmission of a car or other mechanism, for smooth and continuous changes in power and kinematic gear ratios. This facilitates the management of the mechanism (for example, a car), allows you to get close to ideal traction and speed characteristics, increase the service life of the transmission by reducing dynamic loads, and improve cross-country ability.

The stated technical problem is solved by the fact that in the transforming mechanism the uniform rotational movement of the drive shaft is converted into two separate but equal in modulus continuous movements containing sections with accelerated and slowed movements, then the continuous movements are added. In this case, the resulting result will be a uniform rotational movement transmitted to the driven shaft. The gear ratio between the drive and driven shafts is controlled by the phase shift of two separate continuous movements.

Let us explain this principle of superposition with an example. Suppose we have two rotating elements that are interconnected in a certain way. One element rotates fast, the other slows. The resulting addition of two accelerations will be a constant value (see table 1).

Table 1 Accelerated motion one 2 3 four 5 6 7 8 Slow motion 8 7 6 5 four 3 2 one Resulting movement 9 9 9 9 9 9 9 9

Now we will shift the accelerated and decelerated movements in phase relative to each other. In this case, the result will also be uniform movement (constant value), but different in magnitude (see table 2).

table 2 Accelerated motion one 2 3 four 5 6 7 8 Slow motion fifteen fourteen 13 12 eleven 10 9 8 Resulting movement 16 16 16 16 16 16 16 16

A device for continuously variable transmission of motion (hereinafter referred to as the “variator”) is shown in the drawings.

Figures 1 and 2 show a variator with spaced parts, explaining its composition and the relative position of the main assembly units and components.

Figure 3 and 4 shows a drawing of the variator in assembled form (front and rear view).

Figures 5 and 6 show the construction of the driven element (front and rear views).

Figures 7 and 8 show the construction of the driving element (front and rear view).

Figure 9 shows the assembly drawing of the master and slave elements.

Figures 10 and 11 show an assembly drawing of a conversion mechanism (front and rear views).

On Fig shows the design of the differential.

On Fig is a drawing of a mechanism for changing the gear ratio.

On Fig shows a graph explaining the movement of the carrier along the corrective groove.

On Fig and 16 shows graphs of the dependence of the resulting continuous motion on the change in the phase of rotation of the eccentric pairs.

The variator consists of a housing 1 with a driven shaft 2 and internal gear 3. The cages 4 and 5 are bodies of revolution with holes 6 in which the driving 7 and driven 8 elements are mounted on rolling bearings. Each two clips 4 and 5 are rigidly interconnected and constitute a transforming mechanism. The holes 6 in the interconnected cages are eccentrically relative to each other, therefore, the leading and driven elements placed in them, interconnected in a movable certain way, are also eccentric and constitute eccentric pairs. In the conversion mechanism of eccentric pairs may be 3 or more. In the proposed design there are four of them.

The leading element, on the surface of which a diametrical groove 9 is made, is equipped with an intermediate gear 10 and placed in a bearing. A curved corrective groove 11 and a radial groove 12 are made on the surface of the driven element. The driven element is equipped with a bevel gear 13 and is also placed in the rolling bearing 14.

The leading and driven element (eccentric pairs) are interconnected as follows (see Fig. 9): in the diametral groove 9 of the driving element, a slider 16 is movably mounted with an aperture and an adjustment carrier 17, and in the radial groove 12 of the driven element the main carrier 15 is movably installed The main carrier 15 enters the hole (not indicated by position) of the slider 16. The carrier 17 of the slider enters the correction groove 11 of the driven member and slides along it. Since the rotation axes of the driving and driven element are eccentric, the main carrier 15 in the process of rotating the driven element around its axis approaches and moves away from the axis of the uniformly rotating driving element, causing accelerated and slowed movements of the driven element and, accordingly, the bevel gear 13. the main carrier connected with the slider 16 moves it along the diametral groove 9. Each eccentric pair in the conversion mechanism is spaced 360 ° / n relative to each other, (n is the number of exce en- pairs).

As a result of such complex movements, the driven element makes an alternating motion that is sinusoidal in nature. And to us, in accordance with the principle of superimposed movements described above, it is necessary for the driven element to perform not sinusoidal, but equally accelerated and equally slow movements. In order to bring the movement of the driven element to the desired ones, the corrective groove is intended 11. The corrective groove plays the role of a “rectifier” of the ascending and descending branches of the sinusoidal oscillation, which can be seen from the graphs in Figs. 15 and 16. The method for constructing the curve of the corrective groove is not shown. The shape of the curve is calculated individually for each variator, based on the incorporated technical characteristics, and also depends on the structural dimensions of the parts included in individual assembly units.

Differential 18 is designed to remove superimposed and slow motion of driven elements of eccentric pairs of converting mechanisms superimposed on each other and transmitting these movements through internal gearing gear 3 to driven shaft 2. Differentials (4 pcs.) Are located between the converting mechanisms and are in mechanical engagement with them. The differential (Fig. 12) includes a segment gear 19, inside of which a separator 20 is mounted with satellites (bevel gears) 21. The satellites mesh with bevel gears 13 of the driven elements of both converting mechanisms. The pins of the separators on both sides enter the recesses made on the ends of the bevel gears 13, making it possible for the differential to rotate around its axis. Only one segment gear 19 is in contact with the internal gear 3. That is, the gear 3 rotates with the segment gears in turn, providing continuous rotation of the output shaft 2.

The gear ratio change mechanism is designed to control the speed of rotation of the output shaft at a constant speed of rotation of the input shaft. The gear change mechanism comprises a hollow sleeve 22, in which a screw thread 23 is made from one end and straight splines are made from the other end 24. A shaft 25 with straight splines is inserted from one end of the sleeve. At the other end, a shaft 26 is inserted into the sleeve with a screw thread, which simultaneously serves as the drive shaft of the variator. Between the screw threads, balls are inserted to reduce friction. The sleeve is inserted into the housing 27 with the drive gear 28 of the first converting mechanism, which engages with the intermediate gears 10 of the driving elements of the first converting mechanism. At the other end, the shaft 25 is provided with a gear 29 of the second converting mechanism, which also engages with the intermediate gears 10 of the driving elements, of the second converting element.

The gear ratio is changed by the extension (extension) of the sleeve 22 along the drive shaft 26. The reciprocating movement of the sleeve can be accomplished, for example, by creating in the cavity A of the housing 27 a hydraulic pressure pushing the sleeve. In this case, the sleeve 22 plays the role of a piston. In this case, the shafts 25 and 26 are scrolled, which, through the associated gears 28 and 29, rotate the gears 10 of the converting mechanisms, thereby providing a phase shift of the accelerated and slowed movements. Accordingly, the rotation speed of the output shaft 2 also changes.

The range of variation of the gear ratio D of the variator is determined by the shear angle α of the eccentric pairs and depends on the number of eccentric pairs in the conversion mechanism. On Fig and 16 it is seen that the upper and lower limit of the gear ratio depends on the angle of shift of one eccentric pair relative to another. In this case, the size of the uniform motion section also changes.

The variator works as follows:

When the drive shaft 26 rotates, the rotational movement through the gears 28 and 29e is transmitted to the intermediate gears 10 of the drive elements 7, which in turn scroll the driven elements 8. In this case, the driven half-revolution elements rotate rapidly, and the half-revolution slow. The bevel gears 13 of the driven elements of both converting mechanisms rotate the satellites 21 and the segment gears 19. In this case, continuous movements obtained at the output of the two converting mechanisms are superimposed on the segment gear. The resulting folding of continuous movements is uniform movement. The removal of the resulting uniform motion from the segment gears occurs through the internal gear 3 and is transmitted to the driven shaft 2.

Claims (4)

1. A method of steplessly changing the transmission of motion, in which the uniform rotational movement of the drive shaft is transmitted to the driven shaft through a conversion mechanism, characterized in that in the conversion mechanism the uniform rotation of the drive shaft is converted into two separate, but equal in modulus, continuous movements containing sections with accelerated and slowed movements, then continuous movements are added, while the resulting result will be a uniform rotational movement transmitted to the driven shaft, and the gear ratio between the drive and driven shafts is controlled by the phase shift of two separate continuous movements. 2. A device for continuously variable transmission of motion, including a housing, a drive shaft with a drive gear, meshed with intermediate gears arranged around the circumference, a carrier, a conversion mechanism, a driven shaft, a gear ratio adjusting mechanism, characterized in that the intermediate gears transmit rotation through the conversion mechanisms and the differentials placed between them, the internal gear, connected to the housing and the driven shaft. 3. A device for continuously variable transmission of motion according to claim 2, characterized in that the converting mechanism consists of two clips rigidly interconnected, in which holes are made around the circumference, in which eccentric pairs consisting of driving and driven are rotated around their axes elements, and on the surface of each driven element a curved corrective groove and a radial groove are made along which the main carrier installed in it moves, and is equipped with a bevel gear, and on the turn For each driving element, a diametrical groove is made in which the slider with the correcting carrier is movably mounted, while the correcting carrier of the slider of the leading element enters the curved correcting groove of the driven element, and the main carrier of the driven element enters the hole of the slider of the leading element, and the axis of rotation of the driven and leading elements are offset relative to each other, forming an eccentricity. 4. A device for continuously variable transmission of motion according to claim 2, characterized in that the mechanism for regulating the gear ratio consists of two shafts, at the ends of which are made screw cuts and straight splines entering the cavity of the hollow sleeve, in which on one side are made screw cuts, and on the other hand, straight slots are made, and the gear ratio between the drive and driven shafts is adjusted by rotating the eccentric pairs of one converting mechanism relative to the eccentric pairs of the other transforming mechanism, and the rotation of the eccentric pairs is carried out by moving the hollow sleeve along the shaft with a screw thread.

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