SU1224189A2 - Hydromechanical variable-speed drive - Google Patents

Description

The invention relates to transport machinery, in particular to hydro-mechanical speed variators for self-propelled machines.

The purpose of the invention is to increase efficiency by stabilizing the rotational speed of the output shaft, regardless of its load.

FIG. Figure 1 shows schematically the kinematic diagram of a hydromechanical speed variator; in fig. 2 - hydraulic schematic diagram of the variator; in fig. 3 - structural diagram of the variator; in fig. 4 shows section A-A in FIG. 3; in fig. 5 is a section BB in FIG. 3

The device consists of a planetary gear series, in which the sun gear 1 is the driving link and the carrier 2 is the follower. The satellite gears 3 meshed with the sun gear 1 form the gear pump sections. The epicyclic 4 is rigidly connected to the driving gear 5 of a multisection pump, driven by Iternes of which are installed on the axes in a stationary casing 7. In the discharge line 8 of the planetary pump connecting the injection cavities A of the pump pairs Pletsters 1 and 3 are mounted on the output shaft 9 of the rotary throttle sleeve 10. The output of the choke sleeve 10 by a channel 11 is connected to the cavities B and 1 of the multi-section pump 5 and 6.

A check valve 12 is installed in the channel 11, which prevents the passage of the working fluid to the planetary row 1-3, and the throttle 13 is a backwater with the drain channel 14.

In channel 15, a throttle device 16 is installed, kinematically coupled to the clutch pedal. The throttle 13 of the backpressure and in turn with it the rotation throttle of the sleeve 10 are kinematically connected to the speed pedal. The suction cavities from the planetary rows 1-3 and the multisection pump 5 and 6 are connected to the oil tank by channels 17 and 18, respectively.

The device works as follows.

The clutch pedals and speeds are fully released, the throttle device 16 and the rotary throttle sleeve 10 with throttle 13 back pressure provide the maximum flow area of the discharge channels. In this position of the week, the following occurs. The drive of the sun gear drive 1 is not transmitted through the satellites 3 and 1 cycle 4 and then the driver of gear 5 and the follower 6 of the multi-section pump. The oil entering channel 18 into the pump is freely pumped to the drain through the fully open throttle device 16 in channel 15 and the oil flowing through channel 17 into the planetary row 1-3 from the injection cavity A through the channel of injection line 8 1P1, through the rotary throttle bushing 10, throttle 13 backwater and channel 14 enters

also plums. The output shaft 9 is stationary, since the epicycle 4 is fully unloaded, the machine is provided to stand.

The clutch pedal is gently squeezed all the way and locked. In this case, the flow of fluid leaving the cavity L of the injection of the multi-section pump is blocked by means of a throttle device 16. In the cavity L of the injection, pressure rises, which leads to

deceleration of the pinion gear 5, and, consequently, the epicycle 4. At the same time as the braking of the epicycle 4 begins, the rotation of the carrier 2, which is integral with the shaft 9, begins. The gear ratio of the variator gradually begins to decrease from i oo to in, determined by the geometry of the gear wheels 1, 3 and 4 when the epicycle is completely stopped. 4. The car starts moving off and a uniform motion is established.

Additionally, the speed pedal is partially depressed. Due to the kinematic connection, the backpressure of the throttles 13 of the backwater decreases, through which the working fluid is freely drained from the planetary rows 1, 3 and 4.

A decrease in the flow rate of fluid through the throttle of the overpressure causes an increase in pressure in the cavities A of the pressure and the channels 11 and the line 8 of the pressure. The increasing pressure in cavity A creates a moment that weakens the reactive moment on the epicycle 4, and when a certain pressure level is reached, the teeth of the epicycle and the satellites open. With a further increase in pressure in these channels, the epicycle begins to rotate in the opposite direction, along with the epicycle, the drive gear 5 of the multi-section pump rotates. If the pressure in the Liv cavity of the channels 11 and the injection line 8 exceeds the pressure in the cavity 5, the pump starts working as a hydraulic motor, as the fluid flow from the planetary pumping row enters the cavity 5 through the check valve 12. An additional spinning of the epicycle 4 occurs in one direction rotation drove. The gear ratio of the mechanism is further reduced. With the throttle 13 fully closed, the entire flow from the planetary racks 1, 3 and 4 will go through a multisection pump (in this case, a hydraulic motor) and then through channel 18 to the oil tank. In time

During the whole process of operation, the efficiency of the transfer of the thrust valve 13 will be significantly higher than it would have been without using the energy of the fluid flow on the spin-up of the epicycle, which is especially important when the machine is operated with high tractive effort.

The speed pedal is depressed and locked. In this case, due to the kinematic connection, the flow area of the rotary throttle sleeve 10 will begin to change, which will lead to an increase in pressure in the pumping cavity A of the planetary pump series 1 and 3, a decrease in the circumferential speed and an increase in the satellite speeds, i.e. reduction gear ratio mechanism. With the flow area of the throttle bushing 10 completely closed, the circumferential speed of the satellites will become close to zero, and the transfer speed approaches the rotation speed of the sun gear 1. In this case, the gear ratio of the mechanism will be minimal, close to unity.

In the device, due to the additional channel between the hydromechanical clutch and the planetary mechanism, a stable feedback occurs, allowing ush to stabilize the speed of the machine, regardless of the magnitude of the resistance moment to be overcome. With the constant position of all throttles, a decrease in the moment of resistance causes the flow of fluid from the planetary mechanism into the injection cavity of the clutch and injects the vrash, twisting the epicyclic of the planetary mechanism in one direction with the output shaft.

In this case, the discharge pressure in the planetary mechanism will determine the speed

rotation speed of the output shaft. When the load on the output shaft increases, the clutch epicyclic decelerates until it stops and turns in the opposite direction from the output shaft. The non-return valve will not allow fluid from the planetary mechanism to flow into the discharge channel of the clutch due to the large pressure differential. Naturally, in the discharge channel of the planetary mechanism, the pressure will increase, the speed of rotation of the satellites of the planetary mechanism will increase, i.e. the flow rate of the fluid, and with a constant degree of flow throttling, will increase the speed of rotation of the epicycle from the twist-coupling.

Consequently, a decrease or increase in the speed and direction of rotation of the clutch coupling epicycle will cause a redistribution of the reaction from the moment of resistance to the epicycle of the planetary mechanism to be overcome, a change in the injection pressure

in the planetary mechanism and, as a result, will cause a change in the gear ratio at the same time, i.e. The proposed device is a closed system.

It should be noted that the mechanism with the above hydraulic circuit eliminates the well-known drawback of hydroplanetary gears - the dependence of the rotational speed of the output shaft on the transmitted moment of resistance.

FIG. 2

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Claims (1)

HYDROMECHANICAL SPEED VARIATOR according to ed. St. No. 1184703, characterized in that, in order to increase the efficiency by stabilizing the speed of the output shaft regardless of the load, the discharge cavities of the planetary pump are connected to the discharge cavities of the multi-section pump of the clutch behind the rotary throttle sleeve by an additional channel in which the check valve is placed to prevent fluid flow from the pump to the planetary mechanism and a throttle backwater, with which a rotary throttle sleeve is kinematically connected in series. u GS QO figure 1