RU2376512C1 - Mechanism to transmit rotation - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention relates to mechanism transmitting rotation and can be used in agricultural, automotive and the like machinery. Proposed mechanism comprises drive (2) and driven (3) shafts, eccentric mechanism (4) fitted on drive shaft with control system (5), central helical gear wheel (6), satellite helical pinions (7) fitted to run on and shit along crankshafts (8), and friction couplings (11). Central gear wheel (6) runs on shaft of eccentric mechanism (4), linked, via pinion frames (10), with crankshafts. Friction couplings (11) are rigidly linked with satellite pinions (7) and crankshafts (8). With helical central gear wheel displacing in angular direction, satellite pinion gear displaces axially and, depending sense of rotation, friction couplings couple or uncouple. Central gear wheel motion is transmitted by device (14) transmitting motion between misaligned shafts to driven shaft (3).

EFFECT: higher reliability.

3 cl, 2 dwg

Description

The invention relates to mechanical engineering, in particular to rotational motion transmission mechanisms that are regulated, and can be used in agricultural, automotive, mining, road construction machinery, machine tools and other industries for converting rotational speed.

A known transmission mechanism of rotational motion, which includes a housing, shafts, gears mounted on the shafts, as well as levers for changing the position of the gears relative to the shafts.

Such a mechanism has two significant drawbacks: the first is low functionality due to the stepwise conversion of the output link rotation speed. The second is the relatively large values of weight and size indicators. For example, the T-150 tractor’s gearbox has a weight of about 600 kg, or 4 kg per 1 hp.

A rotational motion transmission mechanism is also known, including a housing, a drive shaft and a driven shaft mounted in the housing rotatably, an eccentric mechanism mounted on the drive shaft with a shaft and a control system, a central gear wheel and satellite gears engaged with it.

This rotational motion transmission mechanism allows stepless adjustment of the output shaft rotation speed. It allows 2 ... 4 times in comparison with the previous mechanism to reduce weight and size indicators.

However, its significant drawback is the low reliability due to the characteristics of the dynamics of the interaction of the links in the process of transmitting rotational motion.

The purpose of the invention is to increase the reliability of the transmission mechanism of rotational motion.

An inventive concept is to complete the structure of a known mechanism (prototype) by changing the links and the connections between them in such a way as to achieve the goal.

For this purpose, crank shafts with cranks, a carrier, friction clutches with incoming and outgoing links, and a motion transmission device between non-coaxial shafts that kinematically connects the central gear wheel and the driven shaft, while the cranks of the crank shafts are installed in the housing with the possibility of rocking motion, on the crank shafts mounted with the possibility of rotation and axial displacement of the satellite gears, as well as friction couplings, the input links of which are rigidly connected to the satellite gears, and the output links are connected to the crank shafts, the central gear wheel is mounted to rotate on the shaft of the eccentric mechanism, which is driven by means of the crank shafts carrying the satellite gears, and the central and satellite gears gears are helical. Friction couplings can be multi-plate. The number of friction discs can be determined by the dependence n≥k · ctgβ,

where n is the number of disks (friction), k is the proportionality coefficient, β is the angle of inclination of the teeth of the central and satellite gears.

The invention is illustrated by drawings, where figure 1 shows a General kinematic diagram of the mechanism, and figure 2 - its projection.

The rotational movement transmission mechanism comprises a housing 1, a drive shaft 2 and a driven shaft 3 rotatably mounted on the drive shaft. An eccentric mechanism 4 with a control system 5 is mounted on the drive shaft. The central gear 6 and the gears engaged with it are also included in the mechanism. gears 7. These satellite wheels are rotatably mounted with simultaneous axial movement. In addition, crank shafts 8 with cranks 9, as well as a carrier 10, friction clutches 11 with incoming 12 and outgoing 13 links were introduced into the mechanism. The Central gear wheel 6 and the driven shaft 3 are kinematically connected by the rotation transmission device 14 between the misaligned shafts. The cranks 9 of the crank shafts 8 are installed in the housing 1 with the possibility of rocking motion. On the crank shafts 8 are installed with the possibility of rotation of the satellite gears 7. Coaxially to the satellite gears 7 are installed friction clutches 11, the input links 12 of which are rigidly connected to the satellite gears, and the output links 13 - with the crank shafts 8.

A device 14 for transmitting motion between non-coaxial shafts kinematically connects the central gear wheel 6 and the driven shaft 3.

The central gear 6 is rotatably mounted on an eccentric mechanism 4, which, by means of the carrier 10, is connected to a crank shaft 8 carrying satellite gears 7. The central and satellite gears are helical. Friction couplings can be multi-plate. The number of friction discs can be determined by the dependence: n≥k · ctgβ,

where n is the number of disks (friction), β is the proportionality coefficient, and k is the angle of inclination of the teeth of the central and satellite gears.

The value of k is determined by the design parameters of the friction clutch, first of all, by the radius of its disks.

The mechanism works as follows.

When the drive shaft 2 rotates, in the case where the eccentricity of the eccentric mechanism 4 is equal to zero, free rotation of this shaft occurs, which does not cause a relative displacement of other elements of the mechanism. As a result of this, the driven shaft 3 also does not rotate.

When setting the non-zero value of the eccentricity of the eccentric mechanism 4 from the control system 5, an instant link configuration is formed that is equivalent to the four-link linkage mechanism, which, in addition to the rack of the casing 1, acts as a driving link - the eccentricity of the eccentric mechanism 4, as well as the body of the central gear 6, satellite gear 7 and crank 9 of crank shaft 8. In this four-link mechanism, the angular relative rotation of the central gear 6 occurs under the influence of by the eccentricity of the eccentric mechanism 4 and having in the form of a relative pole of rotation the gearing pole of this wheel with the satellite wheels 7. The angular displacement of the central gear 6 due to its helical gear will cause a proportional angular displacement of the satellite gear 7 with its simultaneous axial displacement. Due to the connection between the satellite gears 7 and the input links 12 of the friction clutches 11, depending on the direction of axial displacement, the friction clutches 11 will be closed, or vice versa, if the friction clutch 11 is closed, the central gear 6 and the satellite gear 7 will work as a whole and the movement of the instant mechanism will be possible due to the installation of the cranks 9 of the crank shafts 8 in the housing 1 with the possibility of swing. In the case where the instantaneous position of the formed four-link mechanism is such that the satellite gear 7 is inhibited by the friction clutch 11, an angular displacement of the central gear 6 by an amount proportional to the eccentricity will occur. This displacement will continue until the angle between the eccentricity and the active radius of the central gear 6 (active radius refers to the radius that passes through the instantaneous pole of engagement) becomes 90 °. With further rotation of the eccentricity, a change in the direction of relative rotation of the central gear in this instantaneous mechanism configuration will cause a reverse axial movement of the satellite gear 7 and the friction clutch 11 to open. This will happen because the output link 13 of the friction clutch 11 is rigidly connected to the crank shaft. The latter will ensure the free rotation of the satellite gear 7, which will prevent the angular movement of the central gear 6. In the further rotation of the drive shaft 2, the eccentric of the eccentric mechanism 4 will periodically occupy the position indicated above, resulting in an almost uniform rotation of the central gear 6 whose angular velocity will be proportional to the magnitude of the eccentricity. The movement of the central gear 6 by means of a motion transmission device 14 between the misaligned shafts, which kinematically connects the central gear 6 and the driven shaft 3, will be transmitted to the driven shaft 3. Due to the presence of the carrier 10, a constant center distance between the central gear 6 and the satellite gears will be provided. wheels 7.

The smooth operation of the output link will be the higher, the greater the number of satellite gears 7.

Due to the fact that the transmitted moment of the friction clutches depends on the number of discs, the mechanism will have increased load capacity when performing friction clutches 11 multi-disc.

If the number of discs is determined according to the above dependence, that is, it is selected in proportion to the cotangent of the angle of inclination of the teeth, minimally sufficient quantities are provided for reliable operation under conditions of closing-opening and transmission of torque.

As a result of the fact that the closing and opening are performed when the angular velocity of the satellites is close to zero, and due to the possibility of choosing the proper parameters of the friction clutches, the above set of links of the mechanism and the connections between them provides increased reliability of the proposed device.

The device can be widely used in agricultural engineering (for example, in seeders for regulating the seeding pitch), in automotive engineering as a basic element for the unit for controlling the speed of movement and in other industries.

ROTARY MOTION TRANSMISSION MECHANISM

Specification

1 - housing;

2 - drive shaft;

3 - driven shaft

4 - eccentric mechanism;

5 - control system;

6 - the central gear

7 - satellite gears;

8 - crank shafts;

9 - cranks; 10-carrier;

11 - friction clutches;

12 - incoming links;

13 - outgoing links;

14 - device for transmitting motion between misaligned shafts

Claims (3)

1. The mechanism of transmission of rotational motion, comprising a housing, drive and driven shafts mounted rotatably in the housing, an eccentric mechanism with a control system mounted on the drive shaft, a central gear and satellite gears engaged with it, characterized in that Its composition includes crank shafts with cranks, a carrier, friction clutches with incoming and outgoing links, and a motion transmission device between non-coaxial shafts that kinematically connects the central tooth the wheel and the driven shaft, while the cranks of the crank shafts are mounted in the housing with the possibility of rocking motion, the satellite gears are mounted on the crank shafts with the possibility of rotation and axial displacement, as well as the friction clutch coaxially located with them, the input links of which are rigidly connected to the satellite gear wheels, and the output links are with crank shafts, the central gear wheel is mounted for rotation on the shaft of the eccentric mechanism, which is connected via a carrier to rivoshipnymi shafts carrying the satellite gears, and the central and the satellite toothed wheels are helical. 2. The mechanism according to claim 1, characterized in that the friction clutch is multi-plate. 3. The mechanism according to claim 2, characterized in that the number of friction discs is determined by the dependence:
n≥c · ctgβ,
where n is the number of disks (friction); k is the coefficient of proportionality; β - the angle of inclination of the teeth of the Central and satellite gears.

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