RU2313019C2 - High-torque non-friction variable-speed drive - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention is designed for stepless change of gear ratio in transmissions at high transmitted power. Proposed variable-speed drive contains input and output shafts, vibratory mechanism set into operation by input shaft with pair of vibratory shafts operating at relative 90° phase shift, flywheels, three-shaft gear differential mechanically coupled with output shaft by carrier and pair of vibration equalizers. Driving shafts of vibration equalizers are vibratory shafts, and driven shafts are shaft of differential gears. Variable-speed drive is furnished with flywheel rigidly connected with shafts of differential gears with inertia moment J applied to said shafts. Inertia moment J is related to moment on carrier M_c according to expression M_c<4Jω²(λ/π)u, where ω is speed on input shaft, λ is swing of vibrations of vibratory shaft and u is gear ratio between vibratory shaft and shaft of differential gear.

EFFECT: improved operating characteristics, simplified design and reduced cost of variable-speed drive.

2 cl, 5 dwg

Description

The present invention relates to mechanical engineering and is intended to smoothly change the gear ratio of the transmission of machines with a large transmitted power.

Variators are known in which the moment from the input to the output shaft is transmitted by means of an oscillating mechanism with vibrational shafts, vibration rectifiers with freewheels and a three-shaft differential, and a smooth change in the gear ratio is achieved by changing the amplitude of the vibrational shafts [2-6]. The differential provides high uniformity of rotation of the output shaft of the variator.

Oscillatory mechanisms are divided into dynamic and kinematic. In dynamic oscillatory mechanisms, the amplitude of the oscillations depends on the moment on the output shaft [1, p. 125, Fig. 72a], i.e. there is an automatic change in the gear ratio of the variator: with an increase in the load moment, the speed of the output shaft decreases and vice versa. The disadvantage of such variators is the large uneven rotation of the output shaft of the variator. Kinematic oscillatory mechanisms (cam [2-4] and non-cam [5, 6]) are equipped with a mechanism for forcibly changing the amplitude of oscillation of the vibrational shafts, due to which the gear ratio of the variator changes. The disadvantage of this type of variator is the lack of automatism of the gear ratio and the complexity of the design. In [7] it was shown that in the variators [2-4] with a fixed range of vibration of the vibrational shafts, the output shaft speed changes due to the overtaking action of the overrunning clutches, but only at relatively small load moments.

We take for the prototype the closest in technical essence and the achieved result high-torque non-friction type variator [4], containing input and output shafts driven by an input shaft, a cam oscillating mechanism with a pair of oscillating shafts operating with a relative phase shift of 90 °, a three-shaft gear differential with kinematically rigidly connected to the output shaft by a carrier, and a pair of vibration rectifiers, the drive shafts of which are vibrational shafts, and the driven shafts are differential shaft shafts, while the mechanism is equipped with a mechanism for changing the gear ratio of the variator, providing a forced change in the amplitude of oscillation of the vibrational shafts.

Signs of a known mechanism (prototype), coinciding with the claimed invention, are as follows. The known high-torque non-friction type variator contains an input and output shafts, an oscillating mechanism driven by an input shaft with a pair of vibrational shafts operating with a relative phase shift of 90 °, a three-shaft gear differential with a carrier kinematically connected to the output shaft, and a pair of oscillation rectifiers, the drive shafts of which are vibrational shafts, and driven shafts - differential wheel shafts.

The known variator has a rather cumbersome design due to the presence of a mechanism for changing the gear ratio of the variator, and the automatism of changing the gear ratio due to the overtaking action of the overrunning clutches takes place only at small moments on the output shaft, which affects its operational characteristics.

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

The proposed high-torque variator non-friction type has the following essential features. It contains input and output shafts, an oscillating mechanism driven by the input shaft with a pair of vibrational shafts operating with a relative phase shift of 90 °, flywheels, a three-shaft gear differential with a carrier kinematically connected to the output shaft, and a pair of oscillation rectifiers, the drive shafts of which are oscillating shafts and the followers are the shafts of the differential wheels, which are kinematically connected with the flywheels.

These essential features are supplemented by the following: flywheels are made with a force-changing moment of inertia.

A distinctive feature of the prototype of the invention is the following: the proposed mechanism is equipped with flywheels kinematically connected with the shafts of the differential wheels.

In addition, in the claimed mechanism, the flywheels are made with a force-changing moment of inertia.

Figure 1 shows a design diagram of a high-torque variator non-friction type, figure 2 and 3 - the speed of the variator shafts, figure 4 and 5 is a design variant.

The variator (Fig. 1) contains the input 2 and output 3 shafts installed in the bearings of the housing 1, the oscillating mechanism 4 functioning from the input shaft with a pair of vibrational shafts 5a and 5b, which are the driving shafts of the vibration rectifiers 6a and 6b. It also contains a three-shaft gear differential with shafts of the differential wheels 7a and 7b, carrier 8, satellites 9 and differential wheels 10a and 10b. The differential carrier 8 is connected by gears 11 and 12 to the output shaft 3. The driven shafts of the vibration rectifiers are the shafts of the differential wheels 7a and 7b, which are connected by gears 13 and 14 to the flywheels 15a and 15b (J _M is the moment of inertia of the flywheel). Rectifiers contain a pair of overrunning clutches 16, transmitting from the vibrational shafts 5 by means of gears 17 and wheels 18 unidirectional rotation to the shafts of the differential wheels 7. The output shaft 3 transmits the rotation to the consumer of mechanical energy 19.

The variator works as follows (figure 1). An oscillation mechanism 4 is driven from an input shaft rotating at a speed of ω ₂ , the output links of which — the vibrational shafts 5a and 5b — have an oscillation amplitude λ and rotate with alternating speeds ω _5a and ω _5b , while these shafts operate with relative phase a shift of 90 ° (figure 2), i.e.

where α is the angle of rotation of the input shaft.

Oscillating shafts through oscillation rectifiers 6a and 6b, by means of overrunning clutches, give unidirectional rotation to the shafts of the differential wheels 7a and 7b, ω _a and ω _b - their angular velocities, and the differential wheels 10 through the satellites 9 transmit rotation to the carrier 8, whose speed is equal to

Drove through the gears 11 and 12, rotates the output shaft 3, loaded with a moment of resistance M _{3 by the} consumer of mechanical energy 19, the angular velocity of the output shaft (Z is the number of teeth of the wheels)

M _B and J _B - moment of resistance and moment of inertia, reduced to the axis of the carrier. J _B is big enough because depends on the inertia of the consumer. J is the moment of inertia reduced to the axis of each shaft of the differential wheels 7 and depends mainly on the moment of inertia of the flywheel J _M , which rotates together with the shaft of the differential wheel.

Denote the threshold moment

u - передаточное отношение между колебательным валом Where

u is the gear ratio between the oscillatory shaft

5 and differential shaft 7.

The speeds ω _a and ω _b , and therefore, ω _B , depend, as follows from (1), on the speeds of the vibrational shafts, as well as on the operation of overrunning clutches in the overtaking mode. As shown in [7], for a variator with a cam oscillation mechanism, the overtaking mode takes place at M _B <2 M _P. Figure 3 shows the speeds of the shafts of the wheels of the differential and the carrier at J _B = 100J and different moment of resistance M _B , where it can be seen that the speed varies automatically: at M _B = 0 we have the maximum speed ω _B = 2ω ₀ , and at M _B ≥2M _P - minimum ω _B = ω ₀ , i.e. the speed changes without changing the amplitude of the oscillations λ of the vibrational shafts. The range of variation of M _B substantially depends, as follows from (2), on the moment of inertia J _{M of the} flywheels.

Figures 4 and 5 show a design variant of the flywheels made with a force-changing moment of inertia J _M. Massive sliders 21 are mounted in grooves 20 of the flywheel 15, connected by earrings 22 to the layering 23. The axial movement of the layering is carried out by the handle 24, which causes radial movement of the sliders 21, therefore, the moment of inertia of the flywheel J _M changes. This design greatly extends the operational characteristics of the variator.

The presence of the differential in the proposed design provides high uniformity of rotation of the output shaft of the variator.

In the proposed variator, the oscillatory mechanism can be either dynamic [1] or kinematic [2-5]. And kinematic oscillatory mechanisms - cam or non-cam, with a fixed oscillation range (λ = const) or with a variable (λ = var), the latter option has a larger range of functionality, but is structurally more complex and more expensive.

CVT reverse is provided by reversing overrunning clutches.

Information sources

1. A.A. Blagonravov. Non-friction mechanical stepless gears. - M.: Mechanical Engineering, 1977.

2. RU 2169870 C2, F16H 29/08, 05/14/1999 (B.V. Pylaev).

3. RU 2204749 C1, F16H 29/08, 11/05/2001 (B.V. Pylaev).

4. RU 2242654 C2, F16H 29/08, 01/20/2003 (B.V. Pylaev).

5. RU 2179673 C1, F16H 29/08, 07/03/2000 (B.V. Pylaev).

6. RU 2263240 C2, F16H 29/08, 11/25/2003 (B.V. Pylaev).

7. B.V. Pylaev. Fundamentals of the dynamics of high-torque variators. // Bulletin of mechanical engineering. 2004. No. 7. S.16-22.

Claims (2)

1. High-torque non-friction type variator containing input and output shafts, an oscillating mechanism driven by an input shaft with a pair of vibrational shafts operating with a relative phase shift of 90 °, a three-shaft gear differential with a carrier kinematically connected to the output shaft, and a pair of oscillation rectifiers, drive shafts which are oscillatory shafts, and driven ones are differential shaft shafts, characterized in that they are equipped with flywheels kinematically rigidly connected to the differential shaft shafts with the resulting Am J moment of inertia, associated with the point M on the carrier _in the relation _M <4Jω ² (λ / π) u, where ω is the input shaft speed; λ is the amplitude of the oscillation shaft; u is the gear ratio between the oscillatory shaft and the shaft of the differential wheel. 2. High-torque variator non-friction type according to claim 1, characterized in that the flywheels are made with a force-variable moment of inertia J.

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