RU2263240C2 - Vibratory mechanism for high-torque variable-speed drive - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to mechanisms for converting rotation of drive shaft into vibration of driven shaft with steplessly changing amplitude and it can be used in non-friction variable-speed drives, positive displacement adjustable hydraulic machines and other devices. Proposed mechanism contains control handle, driving and driven shafts installed in housing on bearings, and device converting unidirectional rotation of drive shaft into vibratory rotation of driven shaft with possibility of changing swing by control handle, including tilted crank installed on trunnions of driven shaft and mechanically coupled with driving shaft. Mechanism is provided with carrier made on driving shaft and bevel gear wheel mounted in housing for turning by control handle and planet pinion also installed on carrier, hinge coupled with tilted crank and forming internal engagement with bevel gear wheel. Number of teeth of plant pinion is half as much as that of wheel.

EFFECT: improved service characteristics, simplified design, reduced cost.

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Description

The present invention relates to mechanical engineering and is intended to convert the rotation of the drive shaft into the oscillatory rotation of the driven shaft with a smoothly varying swing, which can be used in non-friction high-torque variators, volumetric adjustable hydraulic machines and other devices.

Known oscillatory mechanisms with a continuously variable amplitude of the driven shaft, for example a linkage mechanism [1], which is quite bulky and dynamically unbalanced. Vibration mechanisms used in high-torque variators, for example [3, 4], use translationally moved carriages or cams, which complicates the design.

We take for the prototype the closest oscillator mechanism [2], which is closest in technical essence and the achieved result, containing a control handle, drive and driven shafts mounted on the bearings of the housing, as well as a device for converting the unidirectional rotation of the drive shaft into oscillatory rotation of the driven shaft with the possibility of changing from the control handle oscillations, including a kerchief mounted on the drive shaft with the possibility of rotation from the control handle, mounted on the trunnions of the driven shaft ny crank forming with the inclined crank rotational-translational pair and is pivotally connected with the rocker scarf.

Signs of a known mechanism (prototype), coinciding with the claimed invention, are as follows. The known mechanism comprises a control handle, drive and driven shafts mounted on the bearings of the housing, as well as a device for converting the unidirectional rotation of the drive shaft into oscillatory rotation of the driven shaft with the possibility of changing the swing range from the control handle, including a kinematically connected to the drive shaft mounted on the axles of the driven shaft inclined crank.

The known mechanism has a complex and heavily loaded kinematic connection of the control handle with the scarf. The force required to change the angle of inclination of the kerchief is comparable to the working moment on the output shaft, the maximum oscillation range λ _{max of the} oscillatory shaft of this variator is limited by the angle of the pressure of the link on the inclined crank, therefore λ _max ≤60 °, which reduces the range of gear ratios of the variator.

The purpose of the invention is to increase operational characteristics, simplify and reduce the cost of construction.

The proposed oscillatory mechanism has the following essential features. It contains a control handle, drive and driven shafts mounted on the bearings of the housing, as well as a device for converting the unidirectional rotation of the drive shaft into oscillatory rotation of the driven shaft with the possibility of changing the swing range from the control handle, including a bevel gear mounted in the housing with the possibility of rotation from the control handle a wheel mounted in the trunnions of the driven shaft; an inclined crank made on the drive shaft of the carrier, and also mounted on the carrier, articulated to Pull the crank and forming a conical internal gear satellite, with the number of teeth two times lower than on a wheel.

Distinctive features of the prototype features of the invention are the following. The proposed mechanism for a high-torque variator is equipped with a carrier made on the drive shaft and mounted in the housing with the possibility of turning from the control handle to the bevel gear, and also mounted on the carrier, pivotally connected to the inclined crank and forming an internal gearing with two gears of the bevel gear times smaller than on the wheel.

Figures 1 and 2 show the design of the proposed mechanism at the extreme positions of the control handle, Figures 3 and 4 show the calculated kinematic diagrams of the mechanism, Figures 5-7 show the design of a high-speed variator, and Fig. 8 show the speeds of the variator links.

The proposed mechanism (figures 1 and 2) comprises a housing 1 mounted on bearings of the housing leading 2 and driven 3 shafts. An inclined crank 5 is mounted on the driven shaft 3 on the pins 4. The drive shaft 2 is made with a carrier 6, on which a satellite 7 is mounted, equipped with a hinge 8, forming a rotational-translational pair with a cylindrical pin 9 of the inclined crank. A bevel gear 10 is mounted rotatably in the housing, which forms internal gearing with the satellite. The number of teeth of a satellite is two times less than that of a wheel. The bevel gear 10 is made with a gear ring 11, coupled to the gear 12, connected by a shaft 13 with a control handle 14. The drive shaft is equipped with a counterweight 15.

We connect with the bevel gear 10 the Cartesian coordinate system 0ξηζ, and with satellite 7 - Axz, z - the axis of rotation of the satellite relative to carrier 6, the x axis passes through the center B of hinge 8. The control handle 14 rotates the bevel gear around the ζ axis by the angle ψ formed by the axis η with the axis of the driven shaft w, in figure 1 - ψ = 0, and in figure 2 - ψ = 90 °, which corresponds to the two extreme positions of the control handle.

The design parameters of the mechanism: θ is the angle of inclination of the z axis (nutation angle); H is the distance of the center A from the ζ axis; R = AB.

The mechanism operates as follows (Fig.1-4). From the rotating drive shaft 2, through the carrier 6, the z axis of the satellite 7 moves, which performs rolling on the bevel gear 10. Together with the satellite, the hinge 8 is moved, from which the driven shaft 3 is rotated by means of an inclined crank 5 acting on the axles 4. FIG. 3 and 4 P ₄ - the plane in which the axis of the pins are rotated.

The oscillation amplitude of the driven shaft is equal to λ, depends on ψ and can smoothly change (vary) by the control handle 14 from λ _min at ψ = 0 (Fig. 1) to λ _max = 2μ ₀ at ψ = 90 ° (Fig. 2), where oscillation amplitude of the inclined crank

The instantaneous axes of rotation of the satellite form conical axoids: movable on the satellite and motionless on the bevel gear. P is the gearing pole at the end of the satellite, and the geometrical places of the points P are centroids: movable C ₇ and fixed C ₁₀ (Fig.3). Centroid wheel radii r _k and the satellite are related by r _with

The trajectory T _{in the} movement of the center B of the joint 8 depends on the parameters of the mechanism, as well as on the type of conical axoids used to cut the teeth, i.e. from the angles δ _c and δ _k between the generators of the cones (instantaneous axis of rotation) and the axes ζ and z, respectively. The coordinates of B in the system 0ξηζ:

where α and β are the angles of rotation of the drive shaft (carrier) and satellite (relative to the z axis) associated with the rolling condition

Let us consider a variant of the design of the mechanism providing λ _min = 0.

In this case, a necessary condition is to move the center of the hinge B in the plane 0ηζ (P _in Figs. 3 and 4), i.e. in the system of equations (3)

where R = H / cosθ.

From (5) it follows

and from conditions (2) and (4)

at the same time, denoting the number of teeth of the satellite and the bevel gear Z _c and Z _k , from (6) we have Z _k = 2Z _c .

The deviation angle of the axis of the cylindrical pin 9 of the inclined crank μ (α) from the axis 0ζ (figure 4)

and the angle of rotation of the driven shaft γ (a) depends on ψ and, as follows from figure 4, is associated with μ by the ratio

This design provides λ _min = 0 at ψ = 0 and at ψ = 90 °

The speed of the driven shaft is

where ω ₂ is the speed of the drive shaft.

An example of the application of the invention in a high-torque variator is shown in FIGS. 5-7, where two oscillatory mechanisms “a” and “b” are applied, operating with a relative phase shift of 90 °, similarly [3, 4]. The drive shaft 2a of the oscillating mechanism "a" is the input shaft of the variator, and the shaft 17 is the output. Shafts 2a and 2b are connected by gears 18a and 18b. Vibration mechanisms equipped with rectifiers. Each rectifier contains a pair of bevel wheels 19, which are driven half-couplings of overrunning clutches 20, the leading half-couplings of which are mounted on the driven shafts 3. A pair of wheels 19 is connected through a conic 21 and gear 22 to the wheel 23 of the hub 24 of the conical differential. The driven shaft 3 is the input link of the rectifier, and the gear 22 is the output. The conical differential comprises conical wheels 25 made on the hubs 24, coupled to the differential gear 26, the carrier 27 of which is mounted on the output shaft 17 of the variator.

High torque variator works as follows. From the rotating drive shaft 2a, the oscillatory movement is transmitted to the driven shafts 3, the speeds of which are 90 ° out of phase. Then, through rectifiers, the hubs of the 24 conic differential are provided with unidirectional rotation with angular velocities ω _a (α) and ω _b (α) = ω _a (α + 90 °),

where, denoting Z _{i the} number of teeth of the i-th wheel, u = (Z ₁₉ / Z ₂₁ ) (Z ₂₂ / Z ₂₃ ). Therefore, the speed of the output shaft of the variator will be without taking into account the overtaking action of the overrunning clutches

Fig. 8 shows the relative speeds of the variator links at θ = 42 °, Н = 1, ψ = 90 ° and u = 1, where it can be seen that the rotation speed Ω of the output shaft has a fairly high uniformity, therefore, this type of variator according to this characteristic comparable with cam variators [3, 4], but structurally simpler.

Consider the design option of the proposed oscillatory mechanism with circular centroids, i.e. with δ _с = const and δ _к = const, with β = 2α, and, as a consequence, ξ _{in в} 0, therefore, λ _min ≠ 0.

For example, at θ = 30 ° and R = 0.76 N, we have

and from (1)

The considered variant of the oscillatory mechanism is structurally simpler than the design discussed above, its use in a high-torque variator is possible, but the variator does not work under the "stop mode".

Crank Length

следовательно, угол давления шарнира на наклонный кривошип равен нулю, что не имеет место в прототипе [2], поэтому потери на трение в предлагаемом механизме меньше и возможен больший угол λ размаха колебания ведомого вала.

therefore, the angle of the hinge pressure on the inclined crank is zero, which does not occur in the prototype [2], therefore, the friction loss in the proposed mechanism is smaller and a larger angle λ of the amplitude of oscillation of the driven shaft is possible.

The axially movable coupling of the cylindrical pin 9 with the hinge 8 is redundant in the considered construction example. However, the use of additional mobility will compensate for the deformation of the mechanism during its operation, as well as inaccuracies in manufacturing and assembly.

Sources of information

1. A.A. Blagonravov. Non-friction mechanical stepless gears. M .: Engineering, 1977, p. 52, Fig. 18.

2. RF patent No. 2207463 C2, F 16 H 23/04. The mechanism with a swash plate. / Author: Pylaev B.V. Prior. 03/06/2001.

3. German patent No. 3309044, F 16 H 29/08. Stufenlos regelbares, mechanisches Schaltwerksgetribe / Anmelder Rindfleisch B.- Anmeldetag: 03/14/1983.

4. RF patent No. 2212574 C2, F 16 H 29/08. High torque variator. / Author: Pylaev B.V. Prior. 11/19/2001.

Claims (1)

An oscillating mechanism for a high-torque variator, comprising a control handle, drive and driven shafts mounted on the bearings of the housing, and a device for converting the unidirectional rotation of the drive shaft into oscillatory rotation of the driven shaft with the possibility of changing the swing range from the control handle, including the shaft mounted in the pins kinetically connected with the drive shaft inclined crank, characterized in that it is provided with a carrier made on the drive shaft and mounted in the housing e rotatable by the bevel gear control arm and mounted on a carrier pivotably connected with an inclined crank and forming with the toothed conical internal gear planet wheel with a number of teeth two times lower than on a wheel.

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