CN218235635U - Closed hydraulic system and engineering vehicle - Google Patents
Closed hydraulic system and engineering vehicle Download PDFInfo
- Publication number
- CN218235635U CN218235635U CN202222269729.1U CN202222269729U CN218235635U CN 218235635 U CN218235635 U CN 218235635U CN 202222269729 U CN202222269729 U CN 202222269729U CN 218235635 U CN218235635 U CN 218235635U
- Authority
- CN
- China
- Prior art keywords
- oil
- pump
- valve
- hydraulic system
- servo
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Fluid-Pressure Circuits (AREA)
Abstract
The utility model relates to an engineering machine tool technical field especially relates to a closed hydraulic system and engineering vehicle. The closed hydraulic system comprises a variable pump, a control output unit and an oil supplementing unit, wherein the control output unit controls the output displacement of the variable pump by controlling the swing angle of a swash plate of the variable pump; the oil supplementing pump and the energy accumulator are both used for providing pilot oil for the control output unit, the oil supplementing pump can provide oil for the energy accumulator and the control output unit, the energy accumulator is respectively communicated with an oil inlet of the control output unit and an oil outlet of the oil supplementing pump, and the oil is enabled to flow from the oil supplementing pump to the energy accumulator through the one-way valve. When the vehicle is emergently braked, the rotating speed of the variable pump is rapidly reduced along with the rotating speed of the engine, the rotating speed of the oil supplementing pump is also rapidly reduced, the energy accumulator releases oil liquid filled inside to be supplemented into the control output unit, the flow and the pressure required by the control output unit can be maintained, the variable response speed of the variable pump is not influenced, and the possibility of stopping and flameout is reduced.
Description
Technical Field
The utility model relates to an engineering machine tool technical field especially relates to a closed hydraulic system and engineering vehicle.
Background
In the field of mobile hydraulic pressure, particularly in the field of walking machinery such as bulldozers and road rollers, closed hydraulic systems, namely closed pumps drive hydraulic motors, are mostly adopted, and the closed hydraulic systems must be provided with oil supplementing loops due to leakage of elements, variable mechanism control, system heat dissipation and other factors. Under the normal condition, the closed pump and the oil supplementing pump are rigidly connected through the spline shaft and the spline sleeve, and the rotating speed of the oil supplementing pump is the same as that of the closed pump, so that the oil supplementing flow and the control oil flow are related to the rotating speed of an engine, when the rotating speed of the engine suddenly changes, the oil supplementing flow and the control flow of the closed pump are suddenly reduced, the response speed of the closed pump is reduced, and particularly when a vehicle is in danger and needs emergency braking, the response speed of the closed pump is reduced, and accidents can be caused.
Therefore, a closed hydraulic system is needed to solve the above technical problems.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a closed hydraulic system and engineering vehicle can carry out the replenishment of hydraulic oil to the control mechanism of closed pump when the closed pump rotational speed reduces along with the engine rapidly, reduces the flameout possibility of parkking.
To achieve the purpose, the utility model adopts the following technical proposal:
closed hydraulic system, comprising:
a variable displacement pump;
a control output unit that controls an output displacement of the variable displacement pump by controlling a swing angle of a swash plate of the variable displacement pump;
the oil supplementing unit comprises an oil supplementing pump and an energy accumulator, the oil supplementing pump and the energy accumulator are both used for providing pilot oil for the control output unit, the oil supplementing pump can provide oil for the energy accumulator and the control output unit, the energy accumulator is respectively communicated with an oil inlet of the control output unit and an oil outlet of the oil supplementing pump, and a one-way valve is arranged between the energy accumulator and the oil supplementing pump so that the oil can be circulated from the oil supplementing pump to the energy accumulator.
As an optimal technical scheme of the closed hydraulic system, the oil supplementing unit further comprises a first overflow valve connected in parallel with the oil supplementing pump, an outlet of the oil supplementing pump is communicated with an oil inlet of the first overflow valve, and an oil outlet of the first overflow valve is communicated with an inlet of the oil supplementing pump.
As a preferable technical scheme of the closed hydraulic system, a filter is further arranged between the oil supplementing unit and the control output unit, and the filter is used for filtering hydraulic oil.
As a preferred technical scheme of the closed hydraulic system, the closed hydraulic system further comprises a second overflow valve connected in parallel with the filter, an outlet of the oil supply pump is communicated with an oil inlet of the second overflow valve, and an oil outlet of the second overflow valve is communicated with the control output unit.
As a preferred technical scheme of the closed hydraulic system, the control output unit comprises a servo oil cylinder and a regulation and control assembly, and the regulation and control assembly is communicated with pilot cavities at two ends of the servo oil cylinder and is used for controlling the pressure at two ends of the servo oil cylinder;
and the servo piston of the servo oil cylinder is mechanically connected to a swash plate of the variable displacement pump.
As a preferable technical solution of the closed hydraulic system, the regulation and control module includes:
the pilot valve, the pilot chamber of the said pilot valve is communicated with the said oil compensating pump through the control valve;
an oil port A and an oil port B of the three-position four-way valve are respectively communicated with the pilot cavities at two ends of the servo oil cylinder; and the valve core of the pilot valve is mechanically connected to one end of the valve core of the three-position four-way valve, and the other end of the valve core of the three-position four-way valve is connected to the valve core of the servo oil cylinder and the swash plate of the variable pump through a feedback rod.
As a preferred technical solution of the above-mentioned closed hydraulic system, the servo cylinder includes:
the servo piston is arranged in the servo cylinder in a sliding mode and connected to the swash plate of the variable displacement pump, the servo piston divides the servo cylinder into a first chamber and a second chamber, the first chamber is communicated with an oil port A of the three-position four-way valve, and the second chamber is communicated with an oil port B of the three-position four-way valve;
the servo spring is arranged in the first cavity and the second cavity, one end of the servo spring is abutted to the servo piston, and the other end of the servo spring is abutted to the inner wall of the servo cylinder body.
As a preferable technical scheme of the closed hydraulic system, the control valve is an electric proportional pressure reducing valve.
As an optimal technical scheme of the closed hydraulic system, two oil outlets of the variable pump are respectively communicated with an inlet of the first pressure control valve and an inlet of the second pressure control valve, an outlet of the first pressure control valve and an outlet of the second pressure control valve are both communicated with the shell, and the first pressure control valve and the second pressure control valve control the pressure in the closed hydraulic system.
An engineering vehicle comprises the closed hydraulic system in any scheme.
The utility model discloses beneficial effect:
the utility model provides a closed hydraulic system, the fluid is supplied to the energy storage ware through the check valve to the oil supplementing pump, enters into the control output unit simultaneously and provides the guide oil for the control output unit, controls the variable pump and carries out the variable; when the vehicle is emergently braked, the rotating speed of the variable pump is rapidly reduced along with the rotating speed of the engine, meanwhile, the rotating speed of the oil supplementing pump is also rapidly reduced, at the moment, the accumulator releases oil filled in the accumulator to supplement the oil into the control output unit, the flow and the pressure required by the control output unit can be maintained in a short time, the variable response speed of the variable pump is not influenced, and the possibility of stopping and flameout is reduced.
The one-way valve and the energy accumulator are added in the closed hydraulic system, so that the problems that when the vehicle is emergently braked and the rotating speed of an engine is rapidly reduced, the response speed of the variable displacement pump is reduced and the response time is increased are solved, and the possibility of engine flameout is indirectly reduced.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a closed hydraulic system provided by an embodiment of the present invention.
In the figure:
1. a pilot valve; 2. a three-position four-way valve; 3. a servo cylinder; 4. a first pressure control valve; 5. a second pressure control valve; 6. a third overflow valve; 7. a first overflow valve; 8. an oil replenishing pump; 9. an accumulator; 10. a one-way valve; 11. a variable displacement pump; 12. a control valve; 13. an oil tank; 14. a filter; 15. a second overflow valve.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood as a specific case by those skilled in the art.
In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description of the present embodiment, the terms "upper", "lower", "right", and the like are used based on the orientations and positional relationships shown in the drawings, and are only for convenience of description and simplification of operation, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.
In the existing closed hydraulic system, when the rotating speed of an engine suddenly changes, the oil supplementing flow and the control flow of a pump suddenly decrease, so that the response speed of the pump becomes slow, and particularly when a vehicle is in danger and needs emergency braking, the response speed of the pump becomes slow, so that accidents can be caused.
Therefore, the embodiment of the present invention provides a closed hydraulic system to solve the above technical problem.
As shown in fig. 1, the closed hydraulic system includes a variable pump 11, a control output unit, and an oil supplementing unit, where the variable pump 11 is a bidirectional variable pump, and an oil outlet of the variable pump 11 is communicated with the execution unit, and is used for providing hydraulic oil for the execution unit to operate. The control output unit controls the output displacement of the variable displacement pump 11 by controlling the swing angle of a swash plate of the variable displacement pump 11; the oil supplementing unit comprises an oil supplementing pump 8 and an energy accumulator 9, the oil supplementing pump 8 and the energy accumulator 9 are both control output units for providing pilot oil, the oil supplementing pump 8 can provide oil for the energy accumulator 9 and the control output units, the energy accumulator 9 is respectively communicated with an oil inlet of the control output units and an oil outlet of the oil supplementing pump 8, and a check valve 10 is arranged between the energy accumulator 9 and the oil supplementing pump 8 to enable the oil to be communicated from the oil supplementing pump 8 to the energy accumulator 9.
In the closed hydraulic system provided by the embodiment, the oil supplementing pump 8 supplements oil to the energy accumulator 9 through the check valve 10, and simultaneously enters the control output unit to provide pilot oil for the control output unit and control the variable pump 11 to carry out variable control; when the vehicle is emergently braked, the rotating speed of the variable pump 11 is rapidly reduced along with the rotating speed of the engine, meanwhile, the rotating speed of the oil supplementing pump 8 is also rapidly reduced, at the moment, the accumulator 9 releases oil filled in the accumulator to supplement the oil into the control output unit, the flow and the pressure required by the control output unit can be maintained in a short time, the variable response speed of the variable pump 11 is not influenced, and the possibility of stopping and flameout is reduced.
And a filter 14 is also arranged between the oil supplementing unit and the control output unit, and the filter 14 is used for filtering hydraulic oil. It can be understood that an oil outlet of the energy accumulator 9 and an oil outlet of the variable displacement pump 11 are both communicated with an oil inlet of the filter 14, the filter 14 is used for filtering impurities in the hydraulic oil, and the filter 14 is arranged between the oil outlet of the oil supplementing pump 8 and the variable displacement pump 11, that is, the hydraulic oil flowing out of the oil supplementing pump 8 and the energy accumulator 9 needs to be filtered by the filter 14 before entering the pilot valve 1 again.
The oil supplementing unit further comprises a first overflow valve 7 connected with the oil supplementing pump 8 in parallel, an outlet of the oil supplementing pump 8 is communicated with an oil inlet of the first overflow valve 7, and an oil outlet of the first overflow valve 7 is communicated with an inlet of the oil supplementing pump 8. The first relief valve 7 can circulate the hydraulic oil in the oil replenishment pump 8 at the time of cold start, thereby raising the temperature of the hydraulic oil.
In this embodiment, the closed hydraulic system further includes a second overflow valve 15 connected in parallel with the filter, an outlet of the oil supply pump 8 is communicated with an oil inlet of the second overflow valve 15, and an oil outlet of the second overflow valve 15 is communicated with the control output unit. This prevents the oil replenishing pump 8 from being clogged by the filter 14 and the oil can still be supplied to the control output unit. The closed hydraulic system further comprises a third overflow valve 6 which is arranged in series with the filter 14 and the second overflow valve 15, and the third overflow valve 6 can overflow redundant oil to the housing.
In this embodiment, the control output unit includes a servo cylinder 3 and a regulation and control assembly, the regulation and control assembly is communicated with the pilot cavities at two ends of the servo cylinder 3, and is used for controlling the pressure at two ends of the servo cylinder 3; the servo pistons of the servo cylinders 3 are mechanically connected to the swash plate of the variable displacement pump 11, and specifically, the servo pistons of the servo cylinders 3 are connected to the swash plate of the variable displacement pump 11 through mechanical connecting rods.
The regulating and controlling assembly comprises a pilot valve 1 and a three-position four-way valve 2, and the pilot cavities of the pilot valve 1 are communicated with the oil supplementing unit through a control valve 12; the two control valves 12 are electro proportional pressure reducing valves. The hydraulic oil of the oil supplementing unit is respectively communicated with the oil ports A of the two control valves 12 and the oil inlet P of the three-position four-way valve 2, and the oil ports B of the two control valves 12 are both communicated with the oil tank 13. The oil supply amount of the oil supply unit to the pilot cavities at both ends of the pilot valve 1 is controlled by two control valves 12.
An oil port A and an oil port B of the three-position four-way valve 2 are respectively communicated with the guide cavities at two ends of the servo oil cylinder 3; the valve core of the pilot valve 1 is mechanically connected to one end of the valve core of the three-position four-way valve 2, and the other end of the valve core of the three-position four-way valve 2 is connected to the swash plate of the variable displacement pump 11 through a feedback rod.
In the present embodiment, the pilot valve 1 is engaged with a three-position four-way valve 2 via a servo cylinder 3 to drive the swash plate of a variable displacement pump 11 to swing. The servo oil cylinder 3 comprises a servo cylinder body and a servo spring, wherein a servo piston is arranged in the servo cylinder body in a sliding mode and is connected with a swash plate of the variable displacement pump 11, the servo piston divides the servo cylinder body into a first cavity and a second cavity, oil ports A of the first cavity and the three-position four-way valve 2 are communicated through a pipeline, and an oil port B of the three-position four-way valve 2 is communicated with an oil port B of the second cavity through a pipeline; all set up servo spring in first cavity and the second cavity, servo spring one end and servo piston butt, the inner wall butt of the other end and servo cylinder body. Specifically, one end of a servo spring located in a first cavity is abutted to a servo piston, the other end of the servo spring is abutted to the inner wall of the first cavity, one end of a servo spring located in a second cavity is abutted to the servo piston, and the other end of the servo spring is abutted to the inner wall of the second cavity. The servo piston is capable of sliding within the servo cylinder and compressing one of the servo springs.
An oil port A and an oil port B of the three-position four-way valve 2 are respectively connected with the first chamber and the second chamber. The three-position four-way valve 2 comprises a left position, a middle position and a right position, wherein the middle position is positioned between the left position and the right position. The valve core of the pilot valve 1 is connected with the valve core of the three-position four-way valve 2 through a mechanical connecting rod, and the valve core of the pilot valve 1 drives the valve core of the three-position four-way valve 2 to move through the mechanical connecting rod so as to realize the switching of the three-position four-way valve 2 among the left position, the middle position and the right position. When the three-position four-way valve 2 is positioned at the left position or the right position, the oil pumping direction of the variable displacement pump 11 is opposite.
The oil supplementing pressure enters the servo oil cylinder 3 through the three-position four-way valve 2, then the servo oil cylinder 3 is pushed to drive the swash plate, the swing of the swash plate can be transmitted to the feedback rod and acts on the valve core of the three-position four-way valve 2, when the swing angle is in place, the valve core of the three-position four-way valve 2 can be driven to the middle position by the feedback rod, and the discharge capacity and the swing angle of the variable pump 11 at the moment are kept.
Two oil-outs of variable pump 11 communicate respectively in the entry that first accuse was pressed valve 4 and the entry that the valve 5 was pressed to the second accuse, and the export that the valve 4 was pressed to first accuse and the export that the valve 5 was pressed to the second accuse all communicate in the casing through third overflow valve 6, casing and oil tank 13 intercommunication, and pressure in the valve 5 control closed hydraulic system was pressed to first accuse pressure valve 4 and second accuse. The export of first accuse pressure valve 4 and the export of second accuse pressure valve 5 all communicate to flow back to oil tank 13 behind the pump casing or flow back to oil tank 13 behind the radiator, and first accuse pressure valve 4 and second accuse are pressed the pressure in the valve 5 control closed hydraulic pump system.
When the control valve 12 (MY) on the left side is electrified, the pressure of hydraulic oil on the Y side of the pilot valve 1 rises, and the valve element of the pilot valve 1 is pushed to move rightwards, so that the valve element of the three-position four-way valve 2 is driven to move rightwards, oil of the oil supplementing pump 8 enters a left cavity of the servo oil cylinder 3 through the three-position four-way valve 2, and a swash plate variable is pushed; on the contrary, when the control valve 12 (MZ) on the right side is electrified, the oil supplementing pressure enters the right cavity of the servo cylinder 3, and the swash plate is reversely changed.
The embodiment also provides an engineering vehicle which comprises a closed hydraulic system.
Because including foretell closed hydraulic system, the event the utility model discloses engineering vehicle has all advantages and the beneficial effect of above-mentioned embodiment, and this is no longer described herein.
In addition, the foregoing is only the preferred embodiment of the present invention and the technical principles applied thereto. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (10)
1. Closed hydraulic system, its characterized in that includes:
a variable displacement pump (11);
a control output unit that controls the output displacement of the variable pump (11) by controlling the swing angle of a swash plate of the variable pump;
the oil supplementing unit comprises an oil supplementing pump (8) and an energy accumulator (9), wherein the oil supplementing pump (8) and the energy accumulator (9) are used for providing pilot oil for the control output unit, the oil supplementing pump (8) can provide oil for the energy accumulator (9) and the control output unit, the energy accumulator (9) is respectively communicated with an oil inlet of the control output unit and an oil outlet of the oil supplementing pump (8), and a check valve (10) is arranged between the energy accumulator (9) and the oil supplementing pump (8) so that the oil can be circulated from the oil supplementing pump (8) to the energy accumulator (9).
2. The closed hydraulic system according to claim 1, wherein the oil supplementing unit further comprises a first overflow valve (7) connected in parallel with the oil supplementing pump (8), an outlet of the oil supplementing pump (8) is communicated with an oil inlet of the first overflow valve (7), and an oil outlet of the first overflow valve (7) is communicated with an inlet of the oil supplementing pump (8).
3. Closed hydraulic system according to claim 1, characterized in that a filter (14) is further arranged between the oil supply unit and the control output unit, and the filter (14) is used for filtering hydraulic oil.
4. The closed hydraulic system according to claim 3, further comprising a second overflow valve (15) connected in parallel with the filter (14), wherein an outlet of the oil replenishment pump (8) is communicated with an oil inlet of the second overflow valve (15), and an oil outlet of the second overflow valve (15) is communicated with a control output unit.
5. The closed hydraulic system according to claim 1, wherein the control output unit comprises a servo cylinder (3) and a regulating assembly, and the regulating assembly is communicated with pilot cavities at two ends of the servo cylinder (3) and is used for controlling the pressure at two ends of the servo cylinder (3);
and a servo piston of the servo oil cylinder (3) is mechanically connected to a swash plate of the variable pump (11).
6. The closed hydraulic system of claim 5, wherein the regulation assembly comprises:
the pilot valve (1), the pilot chambers of the pilot valve (1) are communicated with the oil replenishing pump (8) through a control valve (12);
an oil port A and an oil port B of the three-position four-way valve (2) are respectively communicated with the guide cavities at two ends of the servo oil cylinder (3); and the valve core of the pilot valve (1) is mechanically connected to one end of the valve core of the three-position four-way valve (2), and the other end of the valve core of the three-position four-way valve (2) is connected to the swash plate of the variable pump (11) through a feedback rod.
7. Closed hydraulic system according to claim 6, characterized in that the servo cylinder (3) comprises:
the servo piston is arranged in the servo cylinder in a sliding mode and connected to the swash plate of the variable pump (11), the servo piston divides the servo cylinder into a first chamber and a second chamber, the first chamber is communicated with an oil port A of the three-position four-way valve (2), and the second chamber is communicated with an oil port B of the three-position four-way valve (2);
the servo spring is arranged in the first cavity and the second cavity, one end of the servo spring is abutted to the servo piston, and the other end of the servo spring is abutted to the inner wall of the servo cylinder body.
8. Closed hydraulic system according to claim 6, characterized in that the control valve (12) is an electro proportional pressure reducing valve.
9. The closed hydraulic system according to claim 1, wherein two oil outlets of the variable pump (11) are respectively communicated with an inlet of a first pressure control valve (4) and an inlet of a second pressure control valve (5), an outlet of the first pressure control valve (4) and an outlet of the second pressure control valve (5) are both communicated with a housing, and the first pressure control valve (4) and the second pressure control valve (5) control the pressure in the closed hydraulic system.
10. A working vehicle, characterized in that it comprises a closed hydraulic system according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222269729.1U CN218235635U (en) | 2022-08-26 | 2022-08-26 | Closed hydraulic system and engineering vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222269729.1U CN218235635U (en) | 2022-08-26 | 2022-08-26 | Closed hydraulic system and engineering vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218235635U true CN218235635U (en) | 2023-01-06 |
Family
ID=84683485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222269729.1U Active CN218235635U (en) | 2022-08-26 | 2022-08-26 | Closed hydraulic system and engineering vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218235635U (en) |
-
2022
- 2022-08-26 CN CN202222269729.1U patent/CN218235635U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110497760B (en) | Active and passive dual-mode switchable vehicle suspension system and switching method thereof | |
| CN108533546B (en) | Hydraulic excavator power system adopting double-pump direct drive and differential fast forward automatic switching | |
| CN108136707B (en) | Electrohydraulic drive unit | |
| CN213088564U (en) | Hydraulic system of hybrid transmission | |
| CN113669312A (en) | Closed hydraulic control system and engineering machinery | |
| CN218235635U (en) | Closed hydraulic system and engineering vehicle | |
| CN212717428U (en) | Closed hydraulic system, hoisting mechanism and rotary drilling rig | |
| CN110864015A (en) | Hydraulic control system for speed switching of double-acting actuating element | |
| CN214007638U (en) | Power controller of mechanical hydraulic pump and hydraulic system | |
| CN216199342U (en) | Closed hydraulic control system and engineering machinery | |
| CN216478189U (en) | Hydraulic system and vehicle | |
| US4669266A (en) | Closed-loop system for unequal displacement cylinder | |
| CN211599072U (en) | Hydraulic fan drive control system | |
| JP7200385B2 (en) | Variable displacement hydraulic pump set and excavator | |
| CN112211861B (en) | Hydraulic control system of controllable pitch propeller | |
| CN211765848U (en) | Emergency steering hydraulic system and steering system of underground carry scraper | |
| CN110259749B (en) | Power control valve block, hydraulic pump assembly and engineering machinery | |
| CN219911015U (en) | Hydraulic motor | |
| CN212717429U (en) | Bidirectional constant-tension hydraulic control system and engineering machinery | |
| CN111720377B (en) | Power control valve block, hydraulic pump assembly and engineering machinery | |
| CN214499588U (en) | Gear pump control asymmetric cylinder closed hydraulic system | |
| CN216343868U (en) | Double-pump oil supply system, gearbox assembly and engineering machinery | |
| CN215257146U (en) | Hydraulic transmission system of pump motor | |
| CN216009078U (en) | Valve block for series-parallel switching of three quantitative motors | |
| CN214366944U (en) | Closed hydraulic system and engineering machinery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 261061 Shandong city in Weifang province Fu hi tech Industrial Development Zone, East Street No. 197 Patentee after: WEICHAI POWER Co.,Ltd. Patentee after: Weichai Hydraulic Transmission Co.,Ltd. Address before: 261061 Shandong city in Weifang province Fu hi tech Industrial Development Zone, East Street No. 197 Patentee before: WEICHAI POWER Co.,Ltd. Patentee before: LINDE HYDRAULICS (CHINA) Co.,Ltd. |