CN218377103U

CN218377103U - Hydraulic oil supplementing loop system

Info

Publication number: CN218377103U
Application number: CN202222117506.3U
Authority: CN
Inventors: 罗钊; 曾素; 廖金文
Original assignee: Sunward Intelligent Equipment Co Ltd
Current assignee: Sunward Intelligent Equipment Co Ltd
Priority date: 2022-08-11
Filing date: 2022-08-11
Publication date: 2023-01-24
Anticipated expiration: 2032-08-11

Abstract

The utility model discloses a hydraulic pressure oil supplementing loop system relates to oil supplementing loop technical field, and hydraulic pressure oil supplementing loop system includes: the oil tank, the delivery pump, the oil inlet of the multi-way valve, the detection device, the execution element, the oil return port of the multi-way valve, the one-way valve and the execution element are sequentially communicated, and the oil tank further comprises a logic valve block; the oil return port, the second inlet of the logic valve, the second outlet of the logic valve, the control valve and the oil tank are communicated in sequence; the logic valve is internally divided into a first cavity and a second cavity by the valve core, the first inlet and the first outlet are positioned in the first cavity, the second inlet and the second outlet are positioned in the second cavity, and an elastic part for driving the valve core to reset is arranged in the second cavity. The system can reduce the energy loss of the oil return pipeline.

Description

Hydraulic oil supplementing loop system

Technical Field

The utility model relates to an oil supplementing loop technical field, more specifically say, relate to a hydraulic pressure oil supplementing loop system.

Background

In the prior art, an oil return path of the rotary drilling rig is generally provided with a one-way valve with backpressure, and the one-way valve with backpressure is used for providing oil supplementing pressure for a system. However, the disadvantage of this solution is that when the system is working normally, the return oil circuit will generate a certain back pressure, which causes energy loss and heat increase, and does not meet the energy-saving and environmental protection requirements advocated by modern society.

In summary, under the condition of ensuring the safety of the hydraulic system, how to reduce the energy loss of the oil return path is a problem to be solved urgently by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a hydraulic oil supplementing loop system, which can automatically determine whether oil is needed to be supplemented according to the working variation of an execution element, and further adjust the opening and closing operations of a logic valve block, when the execution element does not need to supplement oil, the oil in an oil return path will return to an oil tank with a minimum back pressure, thereby effectively reducing energy loss and the heating phenomenon of a hydraulic system; when the execution element needs oil supplement, the logic valve can respond quickly to supplement oil to the execution element and ensure the stable work of the machine.

In order to achieve the above object, the present invention provides the following technical solutions:

a hydraulic oil replenishment circuit system comprising: the oil tank, the delivery pump, the oil inlet P of the multi-way valve, the detection device, the execution element, the oil return port T of the multi-way valve, the one-way valve and the execution element are sequentially communicated, and the oil tank further comprises a logic valve block internally provided with a logic valve, wherein the logic valve block is used for controlling large-flow oil to flow back to the oil tank or controlling the oil to be supplemented to the execution element;

the oil return port T, the first inlet of the logic valve, the first outlet of the logic valve and the oil tank are communicated in sequence, and the oil return port T, the second inlet of the logic valve, the second outlet of the logic valve, the control valve and the oil tank are communicated in sequence;

the logic valve is divided into a first cavity and a second cavity by a valve core, the first inlet and the first outlet are located in the first cavity, the second inlet and the second outlet are located in the second cavity, and an elastic piece used for driving the valve core to reset is arranged in the second cavity.

Preferably, the actuator comprises a motor.

Preferably, the control valve is an electromagnetic valve for performing on-off operation according to a working signal of the detection device.

Preferably, a first overflow valve is arranged between the inlet and the outlet of the control valve, and the overflow pressure of the first overflow valve is adjustable so as to limit the back pressure of the oil supplementing pipeline S.

Preferably, the logic valve block is a large-bore valve block, and an orifice is arranged in the logic valve block and used for limiting the oil flow entering the control valve and the first overflow valve.

Preferably, the oil return port, the logic valve block and the motor are sequentially communicated through an oil supply pipeline, so that large-flow oil returned to the oil tank from the multi-way valve is supplied to the motor.

Preferably, the logic valve block is provided with a pressure sensor for detecting the pressure of the return line.

Preferably, the motor further comprises an accumulator for rapidly replenishing oil to the motor and an oil source device connected with the accumulator, wherein the oil source device is used for supplying oil to the accumulator.

Preferably, an inlet and an outlet of the oil source device are connected through a second overflow valve, the second overflow valve is used for controlling the output pressure of the oil source device, and the check valve is arranged between the energy accumulator and the motor.

Use the utility model provides a when oil return circuit system is mended to hydraulic pressure, controlling means can control the delivery pump operation for fluid in the delivery pump is carried to the multiple unit valve in with the oil tank, then, fluid accessible multiple unit valve is carried to the execute component in, in order to ensure execute component normal operating. Meanwhile, oil at the oil return port of the multi-way valve enters a first cavity and a second cavity of the logic valve, the flow of the oil entering the second cavity can be very small, the control valve can be kept at a normally open position after receiving an execution element working signal transmitted by the detection device, the small-flow oil returns to the oil tank through the control valve, pressure cannot be built in the second cavity at the moment, the elastic element is very small in set elastic force, the elastic element can be easily ejected by the large-flow oil located in the first cavity, and the oil basically flows back into the oil tank from the first cavity under the condition of zero pressure. Meanwhile, oil at an oil return port of the multi-way valve can also flow to the execution element, but because the working pressure of the execution element is very high at the moment, low-pressure return oil cannot enter the execution element, and the energy loss of an oil return pipeline caused by back pressure can be greatly reduced by the mode.

In addition, in the working processes of rotation of a power head of the rotary drilling rig, lifting and descending of a main winch, walking and the like, due to the conditions of severe geological conditions, large load inertia, frequent braking and the like, oil in an oil return path is often required to be supplemented into a motor so as to ensure the normal work of a hydraulic system of the machine. When oil needs to be supplemented, the execution element has an air suction phenomenon, the signal is transmitted to the control valve after being received by the detection device, the control valve is switched to the open position by power supply, so that oil flowing out of the oil return port cannot flow back to the oil tank from the control valve, pressure difference is generated between the first cavity and the second cavity, and under the influence of pressure in the second cavity and the two-cavity surface area difference, at the moment, certain back pressure can be generated correspondingly by the oil return fluid of the first cavity, the back pressure value can be used as oil supplementing pressure of an oil supplementing way, the oil can directly pass through the one-way valve from the oil return port of the multi-way valve and reach an oil port of the execution element, and therefore large-flow oil supplementing operation is carried out on the execution element.

To sum up, the hydraulic oil supplementing loop system provided by the utility model can automatically determine whether oil is needed to be supplemented according to the working change condition of the execution element, so as to adjust the opening and closing operation of the control valve, when the execution element does not need to supplement oil, the oil liquid of the oil return path returns to the oil tank with extremely small back pressure, thereby effectively reducing the energy loss and the heating phenomenon of the machine body; when the motor needs to be replenished with oil, the logic valve can quickly respond to replenish the oil to the motor and ensure the stable work of the machine.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of the hydraulic oil supply loop system provided by the present invention.

In fig. 1:

the system comprises an oil tank 1, a delivery pump 2, a multi-way valve 3, a motor 4, a one-way valve 5, a logic valve 6, a first inlet 61, a first outlet 62, a second inlet 63, a second outlet 64, a valve core 65, an elastic element 66, a control valve 7, a first overflow valve 8, a throttle 9, a pressure sensor 10, an energy accumulator 11, an oil source device 12, a radiator 13, a logic valve block 14, a detection device 15, a second overflow valve 16, an oil inlet P, an oil return port T and an oil supplementing pipeline S.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

The core of the utility model is to provide a hydraulic oil-supplementing loop system, which can automatically determine whether oil is needed to be supplemented according to the working change condition of the motor, and further adjust the opening and closing operation of the control valve, when the motor does not need to supplement oil, the oil liquid of the oil return path returns to the oil tank with extremely small back pressure, thereby effectively reducing the energy loss and the heating phenomenon of the machine body; when the motor needs to be replenished with oil, the logic valve can quickly respond to replenish the oil to the motor and ensure the stable work of the machine.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a hydraulic oil supply loop system provided in the present invention.

This embodiment provides a hydraulic pressure mends oil circuit system, includes: the oil tank 1 used for storing the fluid, the delivery pump 2 used for conveying the fluid, the multiple-way valve 3, the executive component and the detection device 15 used for feeding back the working condition of the executive component in real time, the oil inlet P of the fluid tank 1, the delivery pump 2, the multiple-way valve 3, the detection device 15, the executive component, the oil return port T of the multiple-way valve 3, the check valve 5 and the executive component are communicated in sequence, the oil tank further comprises a logic valve block 14 internally provided with a logic valve 6, and the logic valve block 14 is used for controlling the large-flow fluid to flow back to the oil tank 1 or controlling the fluid to be supplemented to the executive component;

the oil return port T, the first inlet 61 of the logic valve 6, the first outlet 62 of the logic valve 6 and the oil tank 1 are communicated in sequence, and the oil return port T, the second inlet 63 of the logic valve 6, the second outlet 64 of the logic valve 6, the control valve 7 and the oil tank 1 are communicated in sequence;

the logic valve 6 is internally divided into a first cavity and a second cavity by a valve core 65, the first inlet 61 and the first outlet 62 are positioned in the first cavity, the second inlet 63 and the second outlet 64 are positioned in the second cavity, and an elastic member 66 for driving the valve core 65 to reset is arranged in the second cavity.

It should be noted that the logic valve 6 may be configured as a large-diameter valve, and the elastic force of the elastic element 66 is small, so that after the control device receives the working condition of the actuator detected by the detection device 15, the information is converted into an electric signal and transmitted to the control valve 7, so as to change the on-off state of the control valve 7, and further determine whether to start the oil replenishing operation.

Use the utility model provides a when hydraulic pressure mends oily return circuit system, controlling means can control the operation of delivery pump 2 for fluid in delivery pump 2 carries to the multiple unit valve 3 in with oil tank 1, and afterwards, in fluid accessible multiple unit valve 3 carried to the execute component, wherein, the execute component mainly includes motor 4, in order to ensure motor 4 normal operating. Meanwhile, the oil of the oil return port T of the multi-way valve 3 enters the first cavity and the second cavity of the logic valve 6, the flow of the oil entering the second cavity becomes very small, the control valve 7 can be kept at a normal open position after receiving the operating signal of the execution element transmitted by the detection device 15, the small-flow oil returns to the oil tank 1 through the control valve 7, the pressure cannot be built in the second cavity at the moment, because the set elastic force of the elastic piece 66 is very small, the large-flow oil in the first cavity can easily jack the elastic piece 66, and the oil basically flows back into the oil tank 1 from the first cavity under the condition of zero pressure. Meanwhile, the oil liquid at the oil return port T of the multi-way valve 3 can also flow to the actuator, but because the working pressure of the actuator is very high at this time, the low-pressure return oil cannot enter the actuator, and this way can greatly reduce the energy loss of the oil return pipeline caused by back pressure.

In addition, in the working processes of rotation of the power head of the rotary drilling rig, lifting and descending of the main winch, walking and the like, due to the severe geological conditions, large load inertia, frequent braking and the like, oil in an oil return path is often required to be supplemented into the motor 4 so as to ensure the normal work of a hydraulic system of the machine. When oil needs to be supplemented, the execution element has an air suction phenomenon, the signal is received by the detection device 15 and then transmitted to the control valve 7, the control valve 7 is switched to the open position by power-on, so that oil flowing out of the oil return port T cannot flow back to the oil tank 1 from the control valve 7, pressure difference is generated between the first cavity and the second cavity, and under the influence of pressure in the second cavity and the area difference between the two cavities, at the moment, certain back pressure can be generated correspondingly by the oil return fluid in the first cavity, the back pressure value can be used as oil supplementing pressure of an oil supplementing way, the oil can directly pass through the check valve 5 from the oil return port T of the multi-way valve 3 and reach an oil port of the execution element, and therefore large-flow oil supplementing operation is carried out on the execution element.

To sum up, the hydraulic oil supplementing loop system provided by the utility model can automatically determine whether oil is needed to be supplemented according to the working change condition of the execution element, so as to adjust the opening and closing operation of the control valve 7, when the execution element does not need to supplement oil, the oil liquid of the oil return pipeline returns to the oil tank 1 with extremely small back pressure, thereby effectively reducing the energy loss and the heating phenomenon of the machine body; when the motor needs to be replenished with oil, the logic valve can quickly respond to replenish the oil to the motor and ensure the stable work of the machine.

On the basis of the above embodiment, it is preferable that the actuator includes the motor 4. I.e. the motor 4 is one of the actuators, which can also be provided as other components depending on the actual situation.

Preferably, the control valve 7 is a solenoid valve for on-off operation according to an operation signal of the detection device 15. That is, the electromagnetic valve may receive an operating signal of the detecting device 15, wherein the detecting device 15 is configured to detect the operating signal of the motor 4, convert the operating signal into an electrical signal, and transmit the electrical signal to the logic valve block 14, so as to control the control valve 7 to perform the connection or disconnection operation.

Preferably, a first overflow valve 8 is arranged between the inlet and the outlet of the control valve 7, and the overflow pressure of the first overflow valve 8 is adjustable to limit the back pressure of the oil supplementing pipeline S. It should be noted that the back pressure generated by the logic valve 6 is controlled by the first overflow valve 8, that is, the back pressure of the oil return line can be controlled by adjusting the opening pressure of the first overflow valve 8. Also, the first relief valve 8 may be replaced with a check valve 5 with back pressure, which also has the function of defining the back pressure of the oil supply.

Preferably, an orifice 9 is provided in the logic valve block 14, and the orifice 9 is used for limiting the oil flow entering the control valve 7 and the first relief valve 8. Wherein the logic valve block 14 may be provided as a large-bore valve block, and an orifice 9 may be provided between the oil return port T and the second inlet port 63 to effectively control the flow of the oil into the first overflow valve 8 and the control valve 7.

It should be noted that, under the influence of the working load of the motor 4, the control valve 7 keeps a normally open state after receiving an electrical signal, the oil passes through the oil return port T of the multi-way valve 3 and simultaneously enters the first cavity and the second cavity of the logic valve 6, wherein the flow of the oil entering the second cavity becomes very small after passing through the orifice 9, and the small flow of the oil returns to the oil tank 1 through the control valve 7, so that the pressure cannot be built in the second cavity, at this time, the large flow of the oil in the first cavity can easily push the elastic member 66 open, so that the oil returns to the oil tank 1 from the first cavity under the condition of zero pressure, and the energy loss of the oil returning due to the back pressure can be greatly reduced.

In addition to the above-described embodiment, it is preferable that the oil return port T, the logic valve block 14, and the motor 4 are sequentially communicated through the oil supply line S so that a large flow rate of oil returned from the multi-way valve 3 to the tank 1 is supplied to the motor 4, and that the check valve 5 be provided on the oil supply line S.

It should be noted that, the electromagnetic valve is influenced by the working load change of the motor 4, and may generate a suction phenomenon, so as to switch to the off state, when the oil flowing out from the oil return port T of the multi-way valve 3 passes through the logic valve 6, the oil in the second chamber returns to the oil tank 1 through the first overflow valve 8, so that the pressure in the second chamber is built up, the oil return line may generate a certain back pressure under the influence of the area difference between the two chambers of the logic valve 6 and the pressure in the second chamber, and the oil in the back pressure part may reach the oil inlet P of the motor 4 from the oil supply line S through the check valve 5, so as to provide the oil supply for the motor 4. As shown in fig. 1, the connecting lines between the components in fig. 1 are connecting lines, and each check valve 5 is used for supplying oil to the motor 4 in one direction.

Preferably, the logic valve block 14 is provided with a pressure sensor 10 for detecting the pressure of the oil return line, wherein a pressure measuring port may be provided on the oil supply line S, and the pressure measuring port is connected to the pressure sensor 10 for monitoring the back pressure of the oil return line and preventing adverse effects caused by excessive back pressure. Generally, the larger the return oil flow rate, the larger the passage diameter of the logic valve 6, and the logic valve 6, the control valve 7, the first relief valve 8, the orifice 9, and the like can all be incorporated in the logic valve block 14, and the hydraulic parts can communicate with each other, so that the structure is beautiful, safe, and reliable.

Preferably, the system further comprises an accumulator 11 for rapidly replenishing the motor 4 with oil, and an oil source device 12 connected to the accumulator 11, wherein the oil source device 12 is used for supplying the accumulator 11 with oil. For example, the oil source device 12 may be provided as a hydraulic pump that exclusively replenishes the accumulator 11 with oil. Therefore, when the motor 4 needs to be replenished with oil, the small flow of oil stored in the accumulator 11 by the oil source device 12 can be instantaneously replenished to the motor 4, and a time is provided for suspending the process from the judgment of the logic valve block 14 to the replenishment of the large flow of oil.

Preferably, the inlet and the outlet of the oil source device 12 are connected through a second relief valve 16, the second relief valve 16 is used for controlling the output pressure of the oil source device 12, and a check valve 5 is arranged between the accumulator 11 and the motor 4. When the motor 4 does not need to be replenished with oil, the oil source device 12 can provide oil for the energy accumulator 11, so that the flow at the beginning of oil replenishment of the motor 4 next time is ensured, the energy accumulator 11 can respond quickly, the motor 4 is replenished with oil instantaneously, and the stable operation of the machine is ensured. And, all be provided with check valve 5 in the oil supply pipeline S, can realize one-way oil supply control.

Preferably, a radiator 13 is arranged between the first outlet 62 and the oil tank 1, so that the oil in the oil return circuit flows back to the oil tank 1 after being cooled, and the temperature of the oil is prevented from being too high.

In order to further explain the method of using the hydraulic oil supply circuit system provided by the present invention, the following description is given by way of example.

Firstly, the transfer pump 2 can transfer the oil in the oil tank 1 to the multi-way valve 3, and then the oil can be transferred to the actuator through the multi-way valve 3, wherein the actuator mainly comprises the motor 4, so as to ensure the normal operation of the motor 4. The detection device 15 can then detect the operating process of the actuator to determine whether the actuator needs to be replenished with oil and transmit an actuator operating signal to the control valve 7.

When the execution element does not need to be replenished with oil, the control valve 7 can be kept at a normally open position after receiving the execution element working signal transmitted by the detection device 15, so that oil is driven to enter the first cavity and the second cavity of the logic valve through the multi-way valve, the flow rate of the oil entering the second cavity becomes very small, and the small-flow oil returns to the oil tank 1 through the control valve 7. At this time, pressure cannot be built in the second cavity, and because the elastic force set by the elastic piece 66 is very small, the elastic piece 66 can be easily pushed open by large-flow oil in the first cavity, so that the oil basically flows back into the oil tank 1 from the first cavity under the condition of zero pressure. Meanwhile, the oil in the oil return port T of the multi-way valve 3 can also flow to the actuator, but because the working pressure of the actuator is very high at this time, the low-pressure return oil cannot enter the actuator, and this way, the energy loss of the oil return pipeline caused by the back pressure can be greatly reduced.

When the execution element needs to supplement oil, the execution element has an air suction phenomenon, after the control valve 7 receives a signal transmitted by the detection device 15, the control valve 7 is powered on and switched to the open position, so that oil flowing out of the oil return port T cannot flow back to the oil tank 1 from the control valve 7, pressure difference is generated between the first cavity and the second cavity, certain back pressure can be generated correspondingly by the oil returning oil of the first cavity under the influence of the pressure in the second cavity and the area difference between the two cavities, the back pressure value can be used as oil supplementing pressure of an oil supplementing way, the oil can directly pass through the check valve 5 from the oil return port T of the multi-way valve 3 and reach an oil port of the execution element, and therefore large-flow oil supplementing operation is conducted on the execution element.

It should be noted that, in this document, the first outlet 62 and the second outlet 64, the first inlet 61 and the second inlet 63, and the first relief valve 8 and the second relief valve 16 are mentioned, where the first and the second are only for distinguishing the different positions and are not sequentially distinguished.

It should be noted that the directions and positional relationships indicated by "in and out" and the like in the present application are based on the directions and positional relationships shown in the drawings, and are only for the convenience of simplifying the description and facilitating the understanding, but do not indicate or imply that the device or element referred to must have a specific direction, be constructed in a specific direction and operate, and therefore, should not be construed as limiting the present invention.

In the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The utility model provides an arbitrary compound mode of all embodiments all is in this utility model's a protection scope, does not do here and gives unnecessary details.

It is right above the utility model provides a hydraulic pressure oil supplementing loop system introduces in detail. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.

Claims

1. A hydraulic oil replenishment circuit system comprising: the oil-gas separation device comprises an oil tank (1) for storing oil, a delivery pump (2) for delivering the oil, a multi-way valve (3), an execution element and a detection device (15) for feeding back the working condition of the execution element in real time, wherein the oil tank (1), the delivery pump (2), an oil inlet P of the multi-way valve (3), the detection device (15), the execution element, an oil return port T of the multi-way valve (3), a one-way valve (5) and the execution element are sequentially communicated, and the oil-gas separation device is characterized by further comprising a logic valve block (14) internally provided with a logic valve (6), and the logic valve block (14) is used for controlling large-flow oil to flow back to the oil tank (1) or controlling the oil to be supplemented to the execution element;

the oil return port T, a first inlet (61) of the logic valve (6), a first outlet (62) of the logic valve (6) and the oil tank (1) are communicated in sequence, and the oil return port T, a second inlet (63) of the logic valve (6), a second outlet (64) of the logic valve (6), the control valve (7) and the oil tank (1) are communicated in sequence;

the logic valve (6) is internally divided into a first cavity and a second cavity by a valve core (65), the first inlet (61) and the first outlet (62) are positioned in the first cavity, the second inlet (63) and the second outlet (64) are positioned in the second cavity, and an elastic piece (66) for driving the valve core (65) to reset is arranged in the second cavity.

2. The hydraulic oil circuit system according to claim 1, characterized in that the actuator comprises a motor (4).

3. The hydraulic oil circuit system according to claim 2, characterized in that the control valve (7) is a solenoid valve for on-off operation according to an operation signal of the detection device (15).

4. The hydraulic oil supply circuit system according to claim 2, characterized in that a first overflow valve (8) is arranged between the inlet and the outlet of the control valve (7), and the overflow pressure of the first overflow valve (8) is adjustable to limit the back pressure of the oil supply pipeline S.

5. The hydraulic oil supply circuit system according to claim 4, characterized in that an orifice (9) is arranged in the logic valve block (14), and the orifice (9) is used for limiting the oil flow entering the control valve (7) and the first overflow valve (8).

6. The hydraulic oil supply circuit system according to any one of claims 2 to 5, characterized in that the oil return port T, the logic valve block (14) and the motor (4) are communicated in sequence through an oil supply line S, so that a large flow of oil returned from the multi-way valve (3) to the oil tank (1) is supplied to the motor (4).

7. The hydraulic oil circuit system according to any one of claims 1 to 5, characterized in that the logic valve block (14) is equipped with a pressure sensor (10) for detecting the return line pressure.

8. The hydraulic oil circuit system according to any one of claims 2 to 5, characterized by further comprising an accumulator (11) for rapidly replenishing the motor (4) with oil and an oil source device (12) connected to the accumulator (11), the oil source device (12) being configured to supply the accumulator (11) with oil.

9. The hydraulic oil supply circuit system according to claim 8, characterized in that an inlet and an outlet of the oil source device (12) are connected through a second relief valve (16), the second relief valve (16) is used for controlling the output pressure of the oil source device (12), and the check valve (5) is arranged between the accumulator (11) and the motor (4).