RU2351482C2 - Hydraulic transmission - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: present invention pertains to machine building and can be used in transport and power engineering. The hydraulic transmission comprises an engine, hydraulic pump, pipes and hydraulic motors on traction wheels. The hydraulic pump, kinematimatically linked to the engine, consists of a single main section and one or more additional sections. Each additional section has a switch with "operating stroke" and "non-working stroke" positions, installed on the flow pipes. All sections of the hydraulic pump have bypass lines. The bypass lines of additional sections of the hydraulic pump pass through switches with "operating stroke" and "non-working stroke" positions. The bypass line of the main section of the hydraulic pump passes through the whole system. The hydraulic motors have a bypass line, on which is mounted a switch with "open" and "closed" positions, and have a switch with "operating stroke" and "non-working stroke" positions, installed on the flow pipe, coming from the hydraulic pump and carrying liquid to the hydraulic motors.

EFFECT: design of a compact hydraulic transmission, executing hydraulic transmission for braking and steering.

3 cl, 8 dwg

Description

The invention relates to the field of engineering and can be used in energy, engineering and transport.

Known hydraulic transmission (see Tractors and cars. / Ed. By V. A. Skotnikov / Moscow, Agromizdat, 1985, p. 246), which includes an engine, hydraulic pump, pipelines and hydraulic motors on driving wheels.

Such a transmission can steplessly control the torque on hydraulic motors in a certain range.

However, this range is already the same as that achieved on mechanical transmissions. Its expansion in hydraulic transmissions requires an increase in pressure in the hydraulic system (up to 20 MPa), and this entails increased wear of transmission parts.

The present invention is aimed at solving the problem of expanding the control range at low pressure values (up to 4 MPa) and obtaining new transmission capabilities.

This is achieved due to the fact that:

1. Hydraulic transmission, which includes an engine, hydraulic pump, pipelines and hydraulic motors on the driving wheels, is characterized in that the hydraulic pump consists of one main section and one or more additional sections, which are equipped with a bypass line and a switch with the positions "stroke" and "idle stroke ”installed on the discharge line, and the hydraulic motors have a bypass line on which a switch with the positions“ open ”and“ closed ”and a switch with the positions“ stroke ”and“ idle ”on the liquid supply line are mounted s to the hydraulic motors.

2. The hydraulic transmission according to claim 1 is characterized in that a reverse switch is installed on the discharge pipe leading to the hydraulic motors.

3. The hydraulic transmission according to claim 1 is characterized in that at the branching of the pipeline supplying the fluid to the hydraulic motors, a fluid volume regulator is installed that goes to each of the hydraulic motors.

In Fig.1 shows a diagram of the hydraulic transmission in the idle position.

Figure 2 shows the position of the "start".

Figure 3 shows the operation of the transmission at maximum wheel speed.

Figure 4 shows the "stop" position.

Figure 5 shows a diagram of the "reverse".

Figure 6 shows the rotary mechanism in the "straight" position.

In Fig.7, this mechanism rotates the wheels "to the right."

On Fig shows the rotation of the "left".

Transmission device

1 schematically shows a transmission. It consists of an engine 1, which is kinematically connected to the hydraulic pump 2. Hydraulic motors 3 are kinematically connected to the wheels 4, which are rigidly connected to the gears 5. The hydraulic pump 2 consists of 4 sections 6. Each section 6 except the leftmost (main) has a switch 7 , and the hydraulic motors are equipped with switches 8 and 9. Sectional switches 7 are installed on the discharge pipelines 10.

The discharge pipe 11 is the collector of all discharge pipes and goes to the reverse switch 12. To the reverse switch, on the other hand, a drain pipe 13 is connected, which is connected to the collector 14. The collector 14 goes into the tank with liquid 15.

A pressure reducing valve 16 and a pressure gauge 17 are mounted on a common discharge pipe 11.

All sections 6 have bypass (idle) lines 18. Three of them pass through switches 7, and one through the entire system.

The scheme used rotary vane hydraulic pumps and hydraulic motors, which have synchronizing gears 19. The engine 1 is connected to the drive shaft 20, which is connected through the gears 19 to the driven shaft 21.

Each section has a suction pipe 22. Pipelines 22 have a manifold 23 exiting the fluid tank 15.

From the reversing switch 12 to the hydraulic motors 3 there are lines with branches 24 and 25. The on-off switches 7, 8 and 9, as well as the reversing switches 12 can be of various designs. The diagram shows such structures that should demonstrate the principle of operation within the framework of the images in Figs.

The position on which the left line is open is a “working stroke”, the other is “idling”. Figures 6, 7 and 8 show a hypothetical design of a fluid distributor for hydraulic motors 3. It consists of a housing 26, plug 27, flanges 28, inlet channel 29, left channel 30, right channel 31 and central channel 32.

The operation of the transmissions is to fulfill the following basic provisions: "idle", "start", "maximum speed", "stop" and "reverse".

Idling

Note: the “stroke” in switches 7 and 8 is the one at which the left line is open.

Figure 1 shows the transmission circuit at "idle".

The engine 1 is turned on. The latter drives the drive shaft 20 in a rotational motion. Using the synchronizing gears 19, the rotation is transmitted to the driven shaft 21. The rotors of all sections 6 are set in motion. This causes the liquid to pass from the tank 15 through the manifold 23, the suction lines 22 and exit the pump to the discharge lines 10. Here the liquid is already under pressure and is sent to the switches 7, which are in the "idle" position, that is, the passage to the bypass is open line 18. Thus, in all three auxiliary sections, the fluid circulates through the bypass lines.

From the main section (leftmost), the liquid enters line 11, then to the reverse switch 12, after it to the distributor 8, which is in the "idle" position. In this case, the liquid again passes through the reverse switch, line 13, line 14 and merges into the tank 15. The switch 9 is in the "open" position, which allows the motors to be fed with liquid.

“Idling” is used not only before starting the vehicle, but also when it is moving by inertia, which corresponds to the neutral position when the vehicle is operating with a mechanical transmission.

Starting off

Figure 2 shows the transmission scheme in the "start" position. First, the switch 8 becomes in the "stroke" position. In this case, the bulk of the liquid will go through the switch 9, and part through the hydraulic pumps 3. The switch 9 is smoothly closed until the transport begins to move. After that, the switch 9 closes completely. During the “start-up”, the pressure can rise to a set high value, for example 4 MPa (40 kgf / cm ² ). After a while, it will begin to fall. When it falls by half, you can turn on additional sections by putting the switches 7 in the "stroke" position. In this case, the pressure in the system rises again, and then drops. After that, you can include the next section. In this case, the order of inclusion sections does not matter. Only the number of sections included is relevant. When all sections are turned on, the moment “maximum speed”, shown in Fig.3. Further acceleration of transport is possible only with the help of an accelerator.

Figure 4 shows the operation of the hydraulic transmission in the "stop" position.

To stop the transport, first put the switch 9 in the “open” position (analogy with neutral gear). In this case, part of the fluid will go through this switch and the wheels will begin to slow down. Now you can put switch 8 in the "idle" position. Now the liquid will no longer flow to the hydraulic motors 3, but they will still rotate from the wheels. In this case, the hydraulic motors will work as hydraulic pumps, and the fluid they drive will circulate through switch 9. If you put it in the “closed” position, the wheels will brake sharply. Thus, the switches 8 and 9 perform the functions of both the clutch and the brakes. This means that the hydraulic transmission performs all the functions of a mechanical transmission and plus a brake system.

Figure 5 shows the position of the reverse switch in the position when the wheels will rotate in the opposite direction.

All the functions that the hydraulic transmission has demonstrated when moving “forward”, it can perform and “back”, which can not be mechanical transmission.

In addition to all this, the hydraulic transmission can operate from two, three engines, it is enough to supply them with oil pumps. Plus, the engines can be placed in any position, even on a towed cart.

But this does not exhaust its capabilities. The entire steering system can be replaced by a regulator of the volume of fluid entering each of the hydraulic motors.

Let's look at Fig 6. The fluid entering through the channel 29 is divided equally between the left 30 channel and the right 31, so the left and right wheels rotate at the same speed and the vehicle moves straight.

7 shows the position when the plug 27 of the steering wheel is turned to the right. In this case, all the liquid will flow to the hydraulic motor that rotates the left wheel. The right one will stand still. This means that the vehicle will turn steeply to the right.

In Fig. 8, the plug is turned to the left. In this case, only the right wheel rotates, and the left one stands still. There is a sharp left turn.

We considered extreme options when one wheel stands still. All intermediate options will occur when one wheel spins faster than another. The steepness of the turn will depend on the ratio of their speeds.

Claims (3)

1. Hydraulic transmission, which includes a hydraulic pump kinematically connected to the engine, hydraulic motors kinematically connected to the wheels, pipelines, characterized in that the hydraulic pump consists of one main section and one or more additional sections, each additional section having a switch with the position "working stroke ”and“ idle ”installed on discharge pipelines; all sections of the hydraulic pump have bypass lines, while the bypass lines of the additional sections of the hydraulic pump each pass through their switch with the positions “stroke” and “idle”, and the bypass line of the main section of the hydraulic pump passes through the entire system; hydraulic motors have a bypass line on which a switch with the open and closed positions is mounted, and have a switch with the working stroke and idle positions installed on the discharge pipe, which is a collector of the above discharge pipes, suitable from the hydraulic pump and feed fluid to hydraulic motors. 2. Hydraulic transmission according to claim 1, characterized in that a reversing switch is installed on the discharge pipe leading to the hydraulic motors. 3. The hydraulic transmission according to claim 1, characterized in that at the branching of the pipeline supplying the fluid to the hydraulic motors, a fluid volume regulator is installed that goes to each of the hydraulic motors.

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