RU2095665C1 - Planet stepless variator - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: planet stepless variator has axially alined driving and driven shafts, two planet rows arranged in series, control mechanism, and brakes. Each of the planet rows has small and large central wheels as well as a carrier with satellites. The control mechanism is made up as an electric motor comprising rotor-flywheel and fixed windings of the stator. The rotor-flywheel is made up as a cylinder over periphery of which permanent magnets are built in. The rotor-flywheel can freely rotate about the driving shaft between the fixed windings of the stator. The windings of the stator are connected in an electric circuit. The resistance of the electric circuit of the winding of the stator is controllable. The side surface of the rotor-flywheel is rigidly coupled with the small central wheel of the second planet row through a friction member. The large and small central wheels of the first planet row are rigidly secured to the driven shaft and the driving shaft, respectively. The large and small central wheels of the second planet row are mounted for permitting rotation about the driving shaft. The carrier of this gear transmission is rigidly secured to the same shaft. The large central wheel is rigidly coupled with the carrier of the first planet row. EFFECT: improved design. 4 dwg

Description

 The invention relates to mechanical engineering, and more specifically to methods of controlling the speed of rotation of the shafts of the actuators and can find application, for example, in the design of a car instead of a standard speed gearbox.

 Known stepless planetary gear containing coaxial driven shafts, at least two planetary gears, each of which includes a small and a large central wheels and a carrier with satellites, a control mechanism made in the form of a torque converter, and brakes.

 However, when installing such a transmission on a vehicle, it cannot simultaneously perform the functions of a generator, starter, regulator, flywheel, etc.

 The objective of the invention is to provide a comprehensive and simple design of a planetary continuously variable variator electrically controlled, which, when installed on a vehicle, such as a car, could simultaneously serve as a generator, starter, regulator, flywheel, as well as a clutch.

 This problem is solved by the fact that in a planetary variator, stepless, containing coaxial drive and driven shafts, two planetary gear sets, each of which includes a small and a large central wheel and a carrier with brake satellites and a control mechanism that is rotatable on the drive shaft and made in the form of a cylinder with permanent magnets built around the periphery, located between the fixed stator windings, included in an electrically adjustable circuit, with the large and small central wheels primarily of the planetary gear set are rigidly mounted respectively on the driven and drive shafts, of which the large central wheel is connected to the brake, the large and small central wheels of the second planetary gear are mounted for rotation on the drive shaft, of which the large central wheel is rigidly connected to the carrier of the first planetary gear set and with a second brake, the small central wheel by means of a friction element is rigidly connected to the flywheel rotor, and the carrier with satellites of the same planetary gear set is rigidly fixed to the drive shaft.

 In FIG. 1 shows a kinematic diagram of a variator; in FIG. 2 - electric control circuit of the variator; in FIG. 3 schedule of the variator with a heat engine; in FIG. 4 schedule of the variator with an electric induction motor.

 The planetary variator stepless is arranged as follows.

The drive shaft 1 of the engine (for example, thermal) is aligned coaxially through the bearing assembly 2 with the output shaft 3. Two planetary gears arranged in series on the indicated shafts: the first on the driven 3 and the second on the drive 1. A small central wheel 4 of the first is rigidly mounted on the drive shaft 1 planetary gear set and drove 5 with satellites 6 of the second planetary gear set. A small central wheel 7 and a large central wheel 8 of the second planetary gear set are rotatably mounted on the drive shaft 1. The carrier with the satellites 10 of the first planetary gear set is rigidly connected to the large central wheel 8. The large central wheel 11 of the first planetary gear set is output and rigidly mounted on the output shaft 3. The small central wheel 7 is connected via a friction element 12 to the rotor-flywheel 13, which rotates freely on the drive shaft 1. The friction element 12 only works on-off. The electric machine 9 consists of a rotor-flywheel 13 and windings 14 of a fixed stator. It is used by two variator controls as a current generator, and also as an electric motor-starter in the starting mode of a heat engine. In the first case, the stator windings 14 are connected through an electric circuit containing a rectifier 15 (D _{1 of} Fig. 2), rheostats 16 (R ₁ ) and 17 (R ₂ ), a voltage regulator 18 and a switch 20 to the terminals of the battery 19. In the second case, the windings 14 through the switch 20 are connected directly to the battery 19. The accelerator pedal 21 is correlated with the rheostat 16 (R ₁ ), and the mode control lever 22 is connected with the rheostat 17 (R ₂ ). The large central wheels 11 and 8 are equipped with belt brakes 24 and 23.

 The planetary variator stepless works as follows.

When the heat engine is initially started, the large central wheel 11 with the output shaft 3 is braked by the brake 23. By the switch 20, the stator winding 14 is connected directly to the battery 19. In this case, the electric machine 9 works as an electric motor-starter. The stator winding 14, magnetizing, attracts the disk of the friction element 12, which engages with the rotor-flywheel 13. The rotor-flywheel 13 through the friction element 12, the small central wheel 7 and planetary gears untwists the shaft 1 of the heat engine in the direction of its rotation, starting it . The heat engine, starting up, goes to idle (in Fig. 3 direct AO). The switch 20 disconnects the battery 19 from the stator winding 14 and connects it to the output of the voltage regulator 18. The shaft 1 of the heat engine through the planetary gears and rotates the rotor-flywheel 13. In this case, the electric machine 9 works as a current generator. The angular velocity of rotation of the rotor-flywheel 13 with a braked large central wheel 11 is determined by the angular velocity of rotation of the drive shaft 1 and the angular velocity of rotation of the large central wheel 8. Denote: X is the angular velocity of rotation of the drive shaft 1 of the heat engine. Then:
n ₈ = X • Z ₄ / (Z ₄ + Z ₁₁ ), (1)
where n _{8 is the} angular velocity of rotation of the large Central wheel 8;
Z ₄ and Z _{11 the} number of teeth of small 4 and large 11 central wheels.

где

угловая скорость вращения малого центрального колеса 7;
n₈ угловая скорость вращения большого центрального колеса 8;
Z₇ и Z₈ количество зубьев соответственно малого 7 и большого 8 центральных колес.The large Central wheel 8 through the satellites 6 of the carrier 5 transmits rotation to the small Central wheel 7 in accordance with the ratio:

Where

the angular velocity of rotation of the small Central wheel 7;
n ₈ angular velocity of rotation of the large Central wheel 8;
Z ₇ and Z _{8 the} number of teeth, respectively, small 7 and large 8 central wheels.

Обозначим

обороты малого центрального колеса 7 и ротора-маховика 13. В итоге получаем:
C = (Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ +Z_A•Z_c+Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ )•X/(Z_A•Z_c+Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ), (4)
где: Z_A= Z₁₁= Z₈; Z_c= Z₄= Z₇ поскольку параметры соответствующих колес первого и второго планетарных рядов принимаем одинаковыми.The carrier 5, rotating with the shaft 1, also transmits rotation to the small central wheel 7 relative to the large central wheel 8 in accordance with the ratio:

We denote

revolutions of the small central wheel 7 and the flywheel rotor 13. As a result, we obtain:
C = (Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ + Z _A • Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ) • X / (Z _A • Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ), (4)
where: Z _A = Z ₁₁ = Z ₈ ; Z _c = Z ₄ = Z ₇ since the parameters of the corresponding wheels of the first and second planetary rows are assumed to be the same.

 The rotor-flywheel 13 is untwisted to a value C (Fig. 3 direct OB), which in the optimal case should be equal to the maximum speed of the heat engine necessary for its operation.

After releasing the brake 23, the large central wheel 11 receives additional rotation due to the fact that after pressing the accelerator pedal 21, the total resistance in the electric circuit decreases due to a decrease in resistance in the rheostat 16 (R ₁ ) and increases the torque on the motor shaft. Part of the increasing torque from the engine, numerically equal to the inverse relationship expressed by formula (4), is transmitted to the rotor-flywheel 13, trying to increase its speed. The electromagnetic field of the stator winding 14, increasing due to a decrease in the resistance of the rotor-flywheel 13, creating a braking moment. Thus, with certain design relationships, the rotor-flywheel 13 maintains its speed (in Fig. 3, the straight line BC). But with an increase in the angular velocity of rotation of the carrier 5 together with the drive shaft 1 and a relatively constant angular velocity of rotation of the small central wheel 7, additional rotation is transmitted to the large central wheel 8 due to the circumference of the satellites 6 around the small central wheel 7.

Δn ₈ = ΔX • (Z _A + Z _c ) / Z _A , (5)
where Δn _{8 the} increase in speed of the large Central wheel 8;
ΔX engine speed increase.

где

дополнительный прирост числа оборотов колеса 11, полученный за счет увеличения числа оборотов большого центрального колеса 8.The large central wheel 8, through the satellites 10, runs around the small central wheel 4 and transfers the obtained additional torque to the large central wheel 11 and the output shaft 3 in accordance with the ratio:

Where

additional increase in the number of revolutions of the wheel 11, obtained by increasing the number of revolutions of the large Central wheel 8.

где

прирост числа оборотов колеса 11 за счет увеличения числа оборотов двигателя.The large Central wheel 11 with the output shaft 3 receives rotation from the small Central wheel 4 through the satellites 10 in accordance with the ratio:

Where

an increase in the number of revolutions of the wheel 11 due to an increase in the number of revolutions of the engine.

Обозначим: y угловая скорость вращения выходного вала 3.The revolutions of the output shaft 3 are the sum of:

Denote: y the angular velocity of rotation of the output shaft 3.

Но в соответствии с (5):
Δn₈ = ΔX•(Z_A+Z_c)/Z_A,
Тогда:

Эта зависимость справедлива, если C const или C 0.

But in accordance with (5):
Δn ₈ = ΔX • (Z _A + Z _c ) / Z _A ,
Then:

This dependence is valid if C const or C 0.

The general dependence of y on X will be:
y = X (Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ + Z _A Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ) / Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ (ten)
In general, the value of "y" also depends on the angular velocity of rotation of the rotor-flywheel 13, i.e. from "C". Hence, the dependence of y on C at X 0 is found from the expression:
yn ₈ (Z _A + Z _c ) / Z _A , (11)
and n ₈ = —CZ _c / Z _A ; y = - (Z _A Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ) • C / Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ . (12)
The general dependence of y on X and C will be:
y = (Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ + Z _A Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ) X / Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ - (Z _A • Z _c + Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{c}}$ ) C / Z $\genfrac{}{}{0ex}{}{\text{2}}{\text{A}}$ . (thirteen)
This dependence shows that if C = const (in Fig. 3 the line BC), and X increases, then y also increases. At some point there will be X C. Then y X a direct transfer is realized. In this case, the relative rotation of the wheels will stop, the entire variator will rotate as a whole. With a further increase in engine speed from increasing mutual rotation, friction increases sharply, which will prevent a further increase in engine speed. Thus, when X is increased to values greater than C, a certain self-regulating moment appears, which prevents the engine from operating at revolutions greater than the maximum design speed.

 In direct transmission at maximum speeds of the heat engine, the resistance of the electric circuit will be the smallest, and the current generated by the electric machine 9, operating as a generator, will be maximum. This electricity is used to power the ignition systems, other units that provide the engine to recharge the battery 19. However, the excess generated energy reduces the efficiency of the variator. The amount of generated electricity can be reduced by changing the parameters of the rotor-flywheel 13.

The resistance R ₂ (Fig. 2) is connected in parallel to R ₁ and is an additional regulator independent of the accelerator pedal 21. When the resistance R ₂ and resistance R ₁ change from the accelerator pedal, the total resistance of the electric circuit will decrease in a different way (in Fig. 3 direct DE). The braking moment, due to a faster decrease in the electric circuit resistance, increases faster than the engine torque and will cause the rotor-flywheel rotor 13 to decrease. At a certain moment, the decreasing rotor-flywheel rotations 13 and the increasing engine revolutions coincide in value (in Fig. 3, direct BE and AE accordingly) direct transmission will begin to be realized, but at lower values of the revolutions of the heat engine (in Fig. 3 direct EH).

 Consider the operation of the variator in various modes of operation of the vehicle.

Driving in direct gear. Driving in direct gear is possible at various vehicle speeds. When switching from a higher speed to a lower one, while maintaining the direct transmission of the variators, it is necessary to reduce the resistance of the rheostat 17 with the handle 22 (R ₂ and, releasing the accelerator pedal 21, reduce the engine speed. And vice versa, when changing from a lower speed to a higher one, it is necessary with the handle 22 17 to reduce the resistance of the rheostat (R ₂₎ and pressing on the accelerator pedal 21 to increase engine speed. in this case there may be some "dip" in the dynamics of a set speed, as part increases the motor torque will be expended on the pa Torsional rotor-flywheel 13.

Engine braking. When the steady state of movement, if you sharply release the accelerator pedal 21, the heat engine; due to its throttle response, it will quickly reduce speed, resistance 16 (R ₁ ) will increase, and the braking torque on the flywheel rotor 13 will decrease. The inertia of the rotor-flywheel 13 will seek to maintain the available torque, which through the variator elements will be directed against the rotation of the output shaft 3, creating additional braking torque, and which will be reduced to zero when the steady-state mode of movement again sets in, but at a lower level, at lower engine speed.

 Short-term car stop with the heat engine off. It is used to save fuel and as an environmental measure in city driving conditions. When the engine is stopped and the onboard power is turned off, the stator winding 14 is de-energized, the spring-loaded friction element 12 disengages from the flywheel rotor 13 and allows it to rotate freely, while maintaining inertia of rotation. The next time the power is turned on, the stator winding 14 is magnetized and attracts the disk of the friction element 12, which engages with the rotor-flywheel 13, the rotation energy of which is transmitted through the variator elements to the shaft 1 of the heat engine, starting it. There is no need to brake the large central wheel 11, since the inertia of the stationary vehicle is sufficient to hold the wheel 11 relatively motionless in order to transfer the rotation energy of the rotor-flywheel 13 to the shaft 1 of the hot engine.

 Reverse car. This transmission is ensured by braking of the large central wheel 8 by the brake 24.

 In this case, a reverse rotation is transmitted to the large central wheel 11 and the output shaft 3 in relation to the dependence according to the formula 2. This rotation is not controlled by the variator and depends only on the engine speed.

 The planetary variator stepless works with an electric motor. The mode of operation of the variator in conjunction with an induction motor is different than in the case of a heat engine.

 Before starting the movement, the large central wheel 11 is braked by a belt brake 23. The traction asynchronous electric motor is connected to a power source and is brought to rated mode. In this case, through the drive shaft 1, the friction element 12 spins the rotor-flywheel 13 of the generator according to the gear ratio 4, i.e. several times faster than a traction motor.

 To start the movement, the large central wheel 11 is released and, at the same time, the stator winding 14 of the generator is connected to the electric circuit. The generator, generating electricity, creates a braking torque on the rotor-flywheel, reducing its speed, as a result of which, according to expression 13, a torque occurs on the output shaft 3. By adjusting the resistance with a rheostat included in the electric circuit of the generator stator, it is possible to change the braking torque on the rotor-flywheel 13 and, as a result, the torque on the output shaft 3. When the rotations of the drive shaft 1 and its rotor-flywheel coincide, a direct transmission is realized. The electric energy generated by the generator, through the conversion device is returned to the power supply network.

 In order not to expend part of the power of the traction motor to rotate the generator that generates electricity, in direct transmission mode, an additional clutch can be designed in the design, blocking the drive shaft 1 and the rotor-flywheel 13 when their speeds coincide while the starter winding is disconnected from the electric circuit and, thereby increasing the design efficiency.

 Slow motion is, in contrast to the case with a heat engine, only by braking the output shaft while unlocking the drive shaft 1 and the flywheel rotor 13 (the stator winding is disconnected from the electrical circuit). In this case, part of the mechanical energy of the traction electric motor is spent on spinning the rotor-flywheel, with the aim of accumulating it for the subsequent acceleration mode. For short stops (lasting several minutes), it is advisable to disconnect the traction motor from the mains with the simultaneous separation of the friction element 12, allowing the rotor-flywheel to rotate freely, preserving mechanical energy.

 The output shaft is reversed similarly to a variator with a heat engine, with the friction element 12 disconnected. Wider possibilities of a planetary continuously variable variator with an electric motor can be obtained if instead of a generator, an engine generator (synchronous, asynchronous, collector, etc.) is used.

 The design of the planetary continuously variable variator can be applied in promising vehicles with mixed traction heat and electric motor.

Claims (1)

 The planetary variator is stepless mainly for a vehicle, containing coaxial drive and driven shafts, two planetary gear sets, each of which includes a small and a large central wheel and a carrier with satellites, a control mechanism and brakes, characterized in that the control mechanism is made in the form of an electric machine, the rotor-flywheel of which is mounted to rotate on the drive shaft and is made in the form of a cylinder with permanent magnets built around the periphery located between the stationary windings with tator included in an electrically adjustable circuit, with the large and small central wheels of the first planetary gear set rigidly mounted on the driven and drive shafts, of which the large central wheel is connected to the brake, the large and small central wheels of the second planetary gear set to rotate on the drive the shaft, of which the large central wheel is rigidly connected to the carrier of the first planetary gear set and to the second brake, the small central wheel is rigidly connected by means of the friction element ano with a flywheel rotor, and a carrier with satellites of the same planetary gear set is rigidly fixed to the drive shaft.

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