RU2239738C1 - Mechanical holonomic part of continuous-action transmission at variable change of ratios - Google Patents

Abstract

FIELD: holonomic transmissions at variable change of torque; mechanical engineering; transport facilities; machine-tool industry.

SUBSTANCE: proposed transmission includes input shaft 1 and output shaft 12, planetary train with twin satellites and differential mechanism. Input shaft 1 is rotatable relative to output shaft 12. Gear wheel 3 of planetary train is secured on input shaft 1 and is engaged with rim 11 of twin satellites. Axle 10 of twin satellites is free to rotate in output shaft 12. Second rim 9 of twin satellites is engaged with gear wheel 8 rigidly secured on shaft of carrier 7 of differential mechanism. Satellites 4 of differential mechanism connect it with sun gear 2 and epicycle 5. Sun gear 2 is rigidly mounted on input shaft 1. Gear wheels 6 and 14 for connection of additional mechanisms are rigidly mounted on epicycle 5 and on input shaft 1.

EFFECT: simplified construction; increased rotation speed of output shaft as compared with input shaft.

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Description

The invention relates to holonomic gears with a stepless change in gear ratios (with a stepless change in torque) and can be used in mechanical engineering, in vehicles, machine tools, in other objects and systems that use automatic or forced smooth change of the output shaft speed depending on the load moment on it at a constant or variable speed of the input shaft.

Known transmission with a friction variator, disclosed in the book Pronin B.A., Revkova G.A. Stepless V-belt and friction gears. - M.: Mechanical Engineering, 1980, p. 290, Fig. 178.

The disadvantages of the known technical solutions are the high pressure on the shafts and bearings associated with the use of friction forces to transmit a useful moment, the rigidity of the transmission characteristics, low durability and low efficiency due to sliding in the contact zones, restrictions on the transmitted power.

The closest in technical essence to the proposed design is “Electromechanical transmission E.K. Korotkova with a self-regulating continuously variable holonomic variator of continuous operation ”, containing drive and driven shafts kinematically connected by a torque transformer. The torque transformer is a self-regulating continuously variable holonomic variator of continuous operation made of gear cylindrical wheels and including two single-row differential mechanisms, one of the same links of which are connected to each other by a planetary gear transmission with a given gear ratio, with the drive of which the drive motor is connected, the second links of the same name are rigidly interconnected, one of the third links is rigidly connected to the support in the form of a rack, and the other, the link is connected to the shaft of the generator supplying the electric motor, the shaft of which is connected to the drive shaft of the variator, and one of the first links mentioned is the driven shaft of the variator (RF Patent No. 2053895 of 02/10/1996).

The known design contains a second differential mechanism, which is associated with the first planetary gear with a certain gear ratio.

The disadvantages of the known design are the occurrence of additional losses due to the fact that in the direct transmission mode all the links of the mechanism relative to their axes and each other are stopped, i.e. a solid shaft was organized, but the carrier of differential mechanisms, rigidly sitting on one shaft, rolled around on motionless sun wheels and rotated with a frequency slightly lower than the engine and output shaft speeds, which are equal in direct transmission mode.

In addition, the shaft of the means for connecting with external devices for transmitting rotation to the input shaft has a rotation speed significantly higher than the input shaft rotation speed.

The technical problems solved by the proposed mechanical part of the continuous transmission with a stepless change in gear ratios are:

- simplifying the design of the mechanical part of the transmission by eliminating the differential mechanism on the output shaft;

- the possibility of stepless changes in gear ratios both automatically and forcefully, moreover, with the possibility of providing a speed of the output shaft greater than the speed of the input shaft;

- providing a reduced rotational speed of the shaft of the means for transmitting rotation to the input shaft;

- exceptions to such an unpleasant knot as a clutch.

The technical result in the proposed design is achieved by creating a mechanical holonomic part of a continuous transmission with a stepless change in gear ratios, including an input shaft, with which the differential gear (DM) sun gear and planetary gear (PM) gear are rigidly and coaxially connected. With the sun’s wheel, the DM engages the satellites, which in turn are engaged with the epicycle, on which the gear wheel is rigidly and coaxially mounted to connect to external devices - additional mechanisms (hydraulic pump, electric motor, etc.).

Satellites rotate on the axes of the DM carrier. At the other end of the carrier DM, in the hollow shaft of which the input shaft passes, a gear wheel is rigidly and coaxially mounted, with which one of the rims of a paired satellite rigidly mounted on an axis is engaged, at the other end of which a second rim of a paired satellite is also rigidly mounted meshing with a gear rigidly mounted on the end of the input shaft. The axles of the twin satellites are freely mounted in the output shaft. The input and output shafts coaxially and freely rotate relative to each other. The range of gear ratios provided by the mechanical holonomic part of continuous operation with a stepless change in gear ratios is from 0.75 to infinity. Depending on the ratio of the selected gears included in the device, the number 0.75 may vary.

The proposed device is compact and has no restrictions on the transmitted power.

The essence of the proposed mechanical holonomic part of the continuous transmission with a stepless change of gear ratios is illustrated by the following design description and drawings, where:

figure 1 shows the kinematic diagram of the proposed mechanical holonomic part of the transmission with a stepless change in torque;

figure 2 shows a block diagram of a transmission with a stepless change in torque (one of the options, others are possible);

figure 3 presents graphs of the dependence of n _o , n _in , n _pump, j _transmission depending on the load moment on the output shaft for the variant presented in figure 2 ([pu] - relative units).

The mechanical holonomic part of a continuous transmission with a stepless change in gear ratios includes an input shaft 1 on which the sun wheel 2 of the differential mechanism and the gear wheel 3 of the planetary mechanism are rigidly and coaxially mounted. With the sun wheel 2, the satellites 4 are engaged, which in turn are meshed with the epicycle 5, on which the gear wheel 6 is rigidly and coaxially mounted for connection with external devices - additional mechanisms (hydraulic pump, electric motor, etc.). Satellites 4 rotate on the axes of carrier 7 of the differential mechanism. A gear wheel 8 is rigidly and coaxially mounted on the other end of the drive shaft 7 and engages the crown 9 of the twin satellite rigidly mounted on the axis 10. At the other end of the axis 10, the second ring 11 of the twin satellite is also rigidly mounted, which engages with the wheel 3. The axis 10 is freely installed in the output shaft 12.

The work of the proposed mechanical part of the continuous transmission with a stepless change in gear ratios will be considered using it in a vehicle, the block diagram of which is shown in FIG. 2.

The block diagram includes additional mechanisms, for example, a hydraulic pump 18 connected to the proposed mechanism through gears 17 and 6, an internal combustion engine 13, a hydraulic motor 16 connected through gears 15 and 14 to the input shaft of the proposed device.

Additional mechanisms in the proposed block diagram are well known and the author does not claim to be new.

The internal combustion engine 13 operates at a constant speed that is optimal from the point of view of fuel consumption and power output and minimum emission of harmful exhaust gases.

The constancy of the engine speed for the performance of the system is not necessary.

The required power of the hydraulic pump 18 and the hydraulic motor 16 in the region of large gear ratios (from 3 to ∞) should be from ≈50 to 100% of the engine power. In the range of average gear ratios (from 2 to 3) from 25 to 50%, and for small gear ratios (from 0.75 to 2) ≈ from 0 to 25%.

Given that the vehicle during acceleration in the region of large gear ratios is located very briefly (1-2 sec), as well as the overload short-term capability of hydraulic machines, their required power should be selected 40-70% of the engine power (determined experimentally for each vehicle). In the proposed mechanical holonomic part of a continuous transmission with stepless variation of continuous numbers, the gear ratios in the differential mechanism and planetary gear are connected in a strictly defined way.

At the beginning of the operation of the mechanical holonomic part of a continuous transmission with continuously variable gear ratios, the rotation from the input shaft 1 is transmitted through the DM sun wheel 2 to the satellites 4 and the epicycle 5, to the carrier 7, which transmits rotation through the gear wheel 8 rigidly fixed to its other end of the shaft the crown of 9 twin satellite. Another crown 11 of the twin satellite is engaged with the gear 3, rigidly sitting on the input shaft. The paired satellites 9 and 11 are rigidly and coaxially mounted on the axis 10, which rotates freely in the output shaft 12. Thus, the rotation is transmitted to the output shaft 12 in two streams: on the one hand, through the DM to the crown of the paired satellite 9, and on the other, with the input shaft, through the wheel 3, the crown of the twin satellite 11.

After starting the engine 13, the output shaft is stopped, and until a counteracting moment appears on the shaft intended to be connected through the wheel 17 to the hydraulic pump 18, the entire gear rotates at idle. The swash plate of the reversible hydraulic pump 18 is set to “0”. Therefore, the use of clutch is not required. The torque on the output shaft 12 is also equal to zero. If, using the appropriate calculation, tilt the washer of the hydraulic pump 18 to a position corresponding to the forward movement, pressure will appear in the hydraulic system, and the moment created by the hydraulic pump 18, repeatedly amplified, will create a moment tending to infinity on the output shaft, as the rotational speed of the hydraulic pump shaft is several times higher than the rotational speed of the drive motor (4 times in this particular design). But since such an opposing moment cannot be created, then the movement of the vehicle will begin much earlier, somewhere at i = 8-10. At the same time, the energy created by the hydraulic pump 18 enters the hydraulic motor 16, which returns it to the input shaft. Thus, all the power developed by the engine 13 in any mode of operation is supplied to the output shaft 12 (with the exception of losses).

In the process of acceleration of the vehicle, and it happens automatically, because as the inertial forces of the vehicle decrease, the moment on the output shaft 12 decreases, its rotation speed automatically increases, and the frequency of rotation of the shaft, on which the epicyclic 5 and gear wheel 6 are fixed (see Fig. 3, the function P _o = f (Mn)), accordingly, the fraction of power transmitted through the hydrochannel decreases, and when the rotation frequencies of the input and output shafts are equalized, the entire mechanical system turns into a solid shaft; none of the links rotate either relative to the axes or relative to each other, while a small part of the power (see the graph in figure 3) is transmitted by hydraulics. If we now turn the inclined washer of the hydraulic motor 16 to the “0” position, then the hydraulic pump stops, stopping the epicycle 5, and this leads to the fact that the speed of the output shaft increases by 25% compared with the speed of the input shaft, accordingly, the moment must be reduced engine (see figure 3, points a and b). Thus, all engine power is transmitted through the mechanical part of the device.

If the control lever of the hydraulic machines on the move of the vehicle is rotated in the opposite direction to the original one, then the hydraulic motor turns into a hydraulic pump, and the hydraulic pump 18 turns into a hydraulic motor, the epicycle is untwisted, accordingly, all links of the mechanism come into motion and the output shaft 12 begins to stop. There is a braking mode due to engine power, which is important in mountainous areas when driving along serpentines.

The main brake system is in hot standby, which increases the reliability of the vehicle. In the parking position, the reverse speed mode is also organized due to the reversibility of the adjustable hydraulic machines. So, hydraulic machines work in four cases: 1 - acceleration; 2 - braking; 3 - organization of rear speed; 4 - when driving uphill.

Point A in figure 3 corresponds to i = 1;

Point B in FIG. 3 corresponds to i = 0.75.

The rotational speed of the shaft 12 can also be adjusted manually by the throttle of the engine with all four modes: acceleration, braking, reverse, ascent to the mountain. In addition, the energy recovery mode is easily used in this system.

In the parking position, after starting the engine and warming it up, the engine is brought to optimum speed, while the frequency of rotation of the epicycle 5 will be ≈4 p _dv, which stores significant kinetic energy, to which the kinetic energy of all parts of the mechanism will be added. At the same time, the washer of the controlled reversible hydraulic pump is tilted and the vehicle is “double-thrusted” —the full engine power plus the stored kinetic energy of the entire mechanism — is accelerated, which leads to a significant reduction in acceleration time. When driving, if a stop is required, part of the braking energy is used to replenish the kinetic energy with all the links of the mechanism, so that during the next acceleration it can be delivered. Thus, the energy recovery mode occurs.

Claims (1)

The mechanical holonomic part of a continuous transmission with stepless change of gear ratios, including input and output shafts, a planetary gear with paired satellites and a differential mechanism, characterized in that the input and output shafts are mounted for rotation relative to each other, the planetary gear is mounted on the input shaft gear wheel meshing with one of the rims of the paired satellites rigidly mounted on an axis mounted with the possibility of free rotation I’m in the output shaft, on the other end of the mentioned axis, a second ring of paired satellites is mounted, which engages with a gear wheel rigidly mounted on the shaft of the differential gear carrier, on the axes of which are mounted satellites connecting the sun wheel and the differential mechanism epicyclic, while the mentioned sun wheel gears are rigidly mounted on the input shaft, and gears are rigidly mounted on the epicycle and on the input shaft to attach additional mechanisms.

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