阅读说明：本技术 一种结构对称的多级变量叶片式液压变压器 (Multistage variable blade type hydraulic transformer with symmetrical structure ) 是由 刘忠迅 刘巧燕 郑洪宇 郭娜 于 2021-05-19 设计创作，主要内容包括：本发明提供了一种结构对称的多级变量叶片式液压变压器,其结构包括壳体、芯体、左外定子、右外定子、左内定子以及右内定子,芯体设置在壳体内,外定子套在芯体上。左外定子上开有第一凹槽；右外定子与左外定子对称设置；左内定子为轴状结构,其一端穿出并固定在壳体的左端盖上,且穿出端的端面上开有第二油孔,左内定子的另一端伸在芯体的左内定子腔内,左内定子腔内的左内定子上开有若干第二凹槽,在左内定子的每个第二凹槽的位置开有第三油孔；右内定子与左内定子对称设置。本发明结构紧凑,具有体积小、重量轻、效率高的特点。通过改变通油口的组合,能够对液压变压器的变压比进行大范围的多级式变量调节。(The invention provides a multistage variable blade type hydraulic transformer with a symmetrical structure. The left outer stator is provided with a first groove; the right outer stator and the left outer stator are symmetrically arranged; the left inner stator is in a shaft-shaped structure, one end of the left inner stator penetrates out of and is fixed on the left end cover of the shell, a second oil hole is formed in the end face of the penetrating end, the other end of the left inner stator extends into the left inner stator cavity of the core body, a plurality of second grooves are formed in the left inner stator cavity, and a third oil hole is formed in the position of each second groove of the left inner stator; the right inner stator and the left inner stator are symmetrically arranged. The invention has the characteristics of compact structure, small volume, light weight and high efficiency. By changing the combination of the oil through ports, the variable ratio of the hydraulic transformer can be subjected to large-scale multi-stage variable adjustment.)

1. A structurally symmetrical multi-stage variable blade type hydraulic transformer is characterized by comprising:

the shell comprises a cylindrical shell, a left end cover and a right end cover, wherein the left end cover and the right end cover are plugged at two ends of the shell;

the core body is arranged in the shell and comprises a short shaft, a left inner stator cavity and a right inner stator cavity which are symmetrically arranged on the left end face and the right end face of the short shaft and are cylindrical, blade groups are arranged on the inner surfaces of the left inner stator cavity and the right inner stator cavity and the outer surfaces of the cavities of the left inner stator cavity and the right inner stator cavity, and the central axes of the two inner stator cavities are coincided with the central axis of the short shaft and the central axis of the shell;

the left outer stator is of an annular structure and is sleeved outside the left stator cavity of the core body in a ring mode and fixed inside the shell, a plurality of first grooves are formed in the circumferential direction of the inner surface of the left outer stator, a first oil hole is formed in each first groove of the left outer stator, and an oil distribution hole is formed in the shell opposite to the first oil holes; the inner surface of the left outer stator which is not provided with the groove is attached to the edge of the blade group on the outer surface of the left inner stator cavity;

the right outer stator is the same as the left outer stator in structure and is symmetrically arranged with the left outer stator;

the left inner stator is of an axial structure, one end of the left inner stator penetrates out of and is fixed on a left end cover of the shell, a second oil hole is formed in the end face of the penetrating end, the other end of the left inner stator extends into a left inner stator cavity of the core body, a plurality of second grooves are formed in the axial surface of the left inner stator, the second grooves are arranged corresponding to the first grooves of the left outer stator, and a third oil hole is formed in each second groove of the left inner stator; the second oil hole is communicated with the third oil hole through an inner pipeline of the left inner stator; the outer surface of the left inner stator without the second groove is attached to the edge of the blade group on the inner surface of the left inner stator cavity; and

and the right inner stator has the same structure as the left inner stator and is symmetrically arranged with the left inner stator.

2. The structurally symmetric multi-stage variable vane hydraulic transformer as claimed in claim 1, wherein the axial plane of the short shaft is higher than the vane sets outside the left inner stator cavity and the right inner stator cavity, and the left inner stator cavity of the core is surrounded by a plurality of inserted rods with ends fixed on the left end surface of the short shaft at intervals; similarly, the right inner stator cavity is formed by enclosing a plurality of inserted bars with the ends fixed on the right end face of the short shaft;

the right end of the left inner stator abuts against the left end face of the short shaft of the core body, the left inner stator is a stepped shaft, the shaft diameter of the rightmost end of the left inner stator is larger than that of the rest section, and the width of the rightmost end shaft is equal to that of the left outer stator; similarly, the right inner stator and the left inner stator have the same structure and are symmetrically arranged with the left inner stator.

3. The structurally symmetric multi-stage variable vane hydraulic transformer of claim 2, further comprising a left retainer ring and a right retainer ring;

the left retainer ring is provided with an inserted rod hole corresponding to the inserted rod of the left inner stator cavity, and the right retainer ring is provided with an inserted rod hole corresponding to the inserted rod of the right inner stator cavity; the left retainer ring is sleeved on the left inner stator and is inserted into the left inner stator cavity of the core body through the inserted link hole, and similarly, the right retainer ring is sleeved on the right inner stator and is inserted into the right inner stator cavity of the core body through the inserted link hole;

the right surface of the left check ring penetrating through the left inner stator cavity of the core body is abutted against the left end surface of the left outer stator and a shaft shoulder at the rightmost end of the left outer stator, and the right check ring and the left check ring are symmetrically arranged;

a convex edge extending into the shell is arranged on the left end cover of the shell and used for pressing against the left check ring; similarly, a convex rib extending into the shell is arranged on the right end cover of the shell and used for pressing against the right check ring; the upper convex edge of the left end cover of the shell extends into the left inner stator cavity of the core body and is pressed against the left baffle ring; similarly, the convex edge on the right end cover of the shell extends into the right inner stator cavity of the core body and is pressed against the right baffle ring;

the blade group on the left inner sub-cavity is positioned between the left retainer ring and the short shaft, and the blade group on the right inner sub-cavity is positioned between the right retainer ring and the short shaft.

4. The structurally symmetric multi-stage variable vane hydraulic transformer of claim 3, further comprising a left bearing and a right bearing;

the left bearing is arranged between the left end cover and the left check ring and is sleeved on the left inner stator cavity of the core body between the left end cover and the left check ring in an interference fit mode, and the outer ring of the left bearing is in interference fit with the inner cavity of the shell; the inner ring of the left bearing is pressed against the left surface of the left retainer ring, and the outer ring of the left bearing is pressed against the left end cover; the right bearing and the left bearing are symmetrically arranged.

5. The structurally symmetric multi-stage variable blade hydraulic transformer as claimed in claim 2, wherein adjusting pads are disposed between the rib on the left end cap of the housing and the left retainer ring and between the rib on the right end cap and the right retainer ring.

6. The structurally symmetric multi-stage variable vane hydraulic transformer as claimed in claim 1, wherein the end surface of the end of the left inner stator extending in the left inner stator cavity of the core abuts against the left end surface of the stub shaft located in the left inner stator cavity; the end face of one end, extending into the right inner stator cavity of the core body, of the right inner stator abuts against the right end face of the short shaft in the right inner stator cavity.

7. The structurally symmetric multi-stage variable blade hydraulic transformer as claimed in claim 1, wherein the first grooves are uniformly arranged in a circumferential direction on the inner surface of the left outer stator.

8. The structurally symmetrical multi-stage variable blade hydraulic transformer as claimed in claim 1, wherein a positioning key for preventing the left inner stator and the left end cover from rotating relatively is arranged between the left inner stator and the left end cover; similarly, a positioning key for preventing the right inner stator and the right end cover from rotating relatively is arranged between the right inner stator and the right end cover.

9. The structurally symmetrical multi-stage variable blade type hydraulic transformer as claimed in claim 1, wherein the left end cap and the left inner stator and the right end cap and the right inner stator are fixedly connected by nuts screwed on stators outside the end caps, and adjusting sleeves are arranged between the nuts and the end caps.

Technical Field

The invention relates to a hydraulic transformer, in particular to a multi-stage variable blade type hydraulic transformer with a symmetrical structure.

Background

Hydraulic transformers are not a new concept and as early as 1965, there were us patents that discussed them, which type of hydraulic transformer is actually used as a hydraulic amplifier. The hydraulic transformer is a pump simply connected to a hydraulic motor through a line, and changes the pressure ratio by changing the supply flow rate of the hydraulic pump. The hydraulic transformer of this type is unidirectional in transformation and has a large leakage and energy loss.

At present, the hydraulic transformer can be divided into two types according to the principle: linear and rotary. The linear hydraulic transformer is also called as a hydraulic pressure cylinder, is suitable for working conditions with higher requirements on pressure change range, but has smaller flow output and poor continuous output characteristic. The rotary hydraulic transformer is easy to realize continuous output, and its basic structure is that two hydraulic pumps/motors are rigidly connected, and the change of variable pressure ratio can be realized by regulating the displacement of the pumps/motors. However, since it includes two functionally independent variable displacement pump/motors, a special power driving device is required to control the realization of the variable, and there are problems of large volume and weight, low efficiency, small regulation range of the variable pressure ratio, and severe pressure fluctuation.

Disclosure of Invention

The invention aims to provide a multistage variable vane type hydraulic transformer with a symmetrical structure, which aims to solve the problems that the conventional hydraulic transformer has small flow output and continuous output specific difference, needs a special driving device to control the realization of variables, and has large volume and weight, poor transformation performance and the like.

The invention is realized by the following steps: a structurally symmetric multi-stage variable blade hydraulic transformer comprising:

the shell comprises a cylindrical shell, a left end cover and a right end cover, wherein the left end cover and the right end cover are plugged at two ends of the shell;

the core body is arranged in the shell and comprises a short shaft, a left inner stator cavity and a right inner stator cavity which are symmetrically arranged on the left end face and the right end face of the short shaft and are cylindrical, blade groups are arranged on the inner surfaces of the left inner stator cavity and the right inner stator cavity and the outer surfaces of the cavities of the left inner stator cavity and the right inner stator cavity, and the central axes of the two inner stator cavities are coincided with the central axis of the short shaft and the central axis of the shell;

the left outer stator is of an annular structure and is sleeved outside the left stator cavity of the core body in a ring mode and fixed inside the shell, a plurality of first grooves are formed in the circumferential direction of the inner surface of the left outer stator, a first oil hole is formed in each first groove of the left outer stator, and an oil distribution hole is formed in the shell opposite to the first oil holes; the inner surface of the left outer stator which is not provided with the groove is attached to the edge of the blade group on the outer surface of the left inner stator cavity;

the right outer stator is the same as the left outer stator in structure and is symmetrically arranged with the left outer stator;

the left inner stator is of an axial structure, one end of the left inner stator penetrates out of and is fixed on a left end cover of the shell, a second oil hole is formed in the end face of the penetrating end, the other end of the left inner stator extends into a left inner stator cavity of the core body, a plurality of second grooves are formed in the axial surface of the left inner stator, the second grooves are arranged corresponding to the first grooves of the left outer stator, and a third oil hole is formed in each second groove of the left inner stator; the second oil hole is communicated with the third oil hole through an inner pipeline of the left inner stator; the outer surface of the left inner stator without the second groove is attached to the edge of the blade group on the inner surface of the left inner stator cavity; and

and the right inner stator has the same structure as the left inner stator and is symmetrically arranged with the left inner stator.

The axial surface of the short shaft is higher than the blade group outside the left inner stator cavity and the right inner stator cavity, and the left inner stator cavity of the core body is formed by enclosing a plurality of inserted rods of which the end parts are fixed on the left end surface of the short shaft at intervals; similarly, the right inner stator cavity is formed by enclosing a plurality of inserted bars with the ends fixed on the right end face of the short shaft;

the right end of the left inner stator abuts against the left end face of the short shaft of the core body, the left inner stator is a stepped shaft, the shaft diameter of the rightmost end of the left inner stator is larger than that of the rest section, and the width of the rightmost end shaft is equal to that of the left outer stator; similarly, the right inner stator and the left inner stator have the same structure and are symmetrically arranged with the left inner stator.

The device also comprises a left check ring and a right check ring;

the left retainer ring is provided with an inserted rod hole corresponding to the inserted rod of the left inner stator cavity, and the right retainer ring is provided with an inserted rod hole corresponding to the inserted rod of the right inner stator cavity; the left retainer ring is sleeved on the left inner stator and is inserted into the left inner stator cavity of the core body through the inserted link hole, and similarly, the right retainer ring is sleeved on the right inner stator and is inserted into the right inner stator cavity of the core body through the inserted link hole;

the right surface of the left check ring penetrating through the left inner stator cavity of the core body is abutted against the left end surface of the left outer stator and a shaft shoulder at the rightmost end of the left outer stator, and the right check ring and the left check ring are symmetrically arranged;

a convex edge extending into the shell is arranged on the left end cover of the shell and used for pressing against the left check ring; similarly, a convex rib extending into the shell is arranged on the right end cover of the shell and used for pressing against the right check ring; the upper convex edge of the left end cover of the shell extends into the left inner stator cavity of the core body and is pressed against the left baffle ring; similarly, the convex edge on the right end cover of the shell extends into the right inner stator cavity of the core body and is pressed against the right baffle ring;

the blade group on the left inner sub-cavity is positioned between the left retainer ring and the short shaft, and the blade group on the right inner sub-cavity is positioned between the right retainer ring and the short shaft.

The device also comprises a left bearing and a right bearing;

the left bearing is arranged between the left end cover and the left check ring and is sleeved on the left inner stator cavity of the core body between the left end cover and the left check ring in an interference fit mode, and the outer ring of the left bearing is in interference fit with the inner cavity of the shell; the inner ring of the left bearing is pressed against the left surface of the left retainer ring, and the outer ring of the left bearing is pressed against the left end cover; the right bearing and the left bearing are symmetrically arranged.

Adjusting pads are arranged between the convex edge on the left end cover of the shell and the left check ring and between the convex edge on the right end cover and the right check ring.

The end surface of one end of the left inner stator, which extends into the left inner stator cavity of the core body, is abutted against the left end surface of the short shaft in the left inner stator cavity; the end face of one end, extending into the right inner stator cavity of the core body, of the right inner stator abuts against the right end face of the short shaft in the right inner stator cavity.

The first grooves are uniformly distributed on the inner surface of the left outer stator along the circumferential direction.

A positioning key for preventing the left inner stator and the left end cover from rotating relatively is arranged between the left inner stator and the left end cover; similarly, a positioning key for preventing the right inner stator and the right end cover from rotating relatively is arranged between the right inner stator and the right end cover.

The left end cover is fixedly connected with the left inner stator, the right end cover is fixedly connected with the right inner stator through nuts screwed on the stator outside the end covers, and adjusting sleeves are arranged between the nuts and the end covers.

The hydraulic oil cavity is formed by the groove between the stator and the core body, and the oil holes communicated with the hydraulic oil cavity are combined in different numbers to be used as the input end and the oil discharge end together, so that the multi-stage transformation ratio of the hydraulic oil can be realized. The structure is compact, and the device has the characteristics of small volume, light weight and high efficiency. Through changing the combination of the oil through ports, the variable pressure ratio of the hydraulic transformer can be subjected to large-scale multi-stage variable adjustment, the hydraulic transformer can be used for secondarily adjusting a hydraulic system, and the flexibility and the efficiency of the hydraulic system can be enhanced.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a view from a-a of fig. 1.

Fig. 3 is an exploded view of the core, left retainer and right retainer.

Fig. 4 is a schematic structural view of the left inner stator.

Fig. 5 is a schematic structural view of the outer stator.

In the figure: 1. a left nut; 2. a left adjusting sleeve; 3. a left key; 4. a left inner stator; 5. a left end cap; 6. a left tapered roller bearing; 7. a left adjustment pad; 8. a left retainer ring; 9. a left outer stator; 10. a left side blade group; 11. a housing; 12. a core body; 13. a right vane set; 14. a right outer stator; 15. a right retainer ring; 16. a right adjustment pad; 17. a right tapered roller bearing; 18. a right end cap; 19. a right inner stator; 20. a right key; 21. a right adjusting sleeve; 22. a right nut; 23. a bolt; 24. a cylindrical pin; 25. a minor axis; 26. a second oil hole; 27. a second groove; 28. a first oil hole; 29. a first groove.

Detailed Description

As shown in fig. 1 and 2, the present invention includes a housing, a core 12, a left outer stator 9, a right outer stator 14, and a right inner stator 19. The shell comprises a cylindrical shell 11, and a left end cover 5 and a right end cover 18 which are plugged at two ends of the shell 11, wherein the inside of the cylindrical shell 11 is a circular surface, and the left end cover 5 and the right end cover 18 are fixed at the end parts of the two ends of the shell 11 of the shell through bolts 23.

As shown in fig. 3, the core 12 is disposed in a housing, and includes a cylindrical short shaft 25, and a left inner stator cavity and a right inner stator cavity symmetrically disposed on both end surfaces of the short shaft 25, and the left inner stator cavity and the right inner stator cavity are symmetrically disposed. The left inner stator cavity is a cylindrical cavity formed by enclosing a plurality of inserted rods with end parts fixed on the left end face of the short shaft 25 at intervals, the section of each inserted rod is a fan-shaped section, and the inserted rods are actually manufactured by processing a circular ring sleeve. A left blade group 10 is arranged between the two insertion rods, the left blade group 10 extends out of the inner cavity surface and the outer cavity surface of the left inner stator cavity, the structure of the right inner stator cavity is symmetrical to that of the left inner stator cavity, and a right blade group 13 is arranged in the same mode. The center line of the left and right stator cavities of the invention is coincident with the center line of the short shaft 25 and the center line of the shell 11.

As shown in fig. 5, the left outer stator 9 is a ring-shaped structure, which is sleeved outside the left stator cavity of the core 12 and fixed on the inner shell surface of the shell 11 by the cylindrical pin 24. A plurality of first grooves 29 are uniformly formed in the inner surface of the left outer stator 9 in the circumferential direction, a first oil hole 28 is formed at each first groove 29 of the left outer stator 9, and an oil distribution hole is formed in the outer shell of the housing at a position opposite to the first oil hole 28. The left outer stator 9 mounted on the core 12 is fitted to the edge of the vane assembly 10 on the outer surface of the left inner stator chamber so that the first groove 29 and the vane assembly form a hydraulic oil chamber, as shown in fig. 2. The right outer stator 14 has the same structure as the left outer stator 9, and will not be described herein too much. The right outer stator 14 is disposed symmetrically to the left outer stator 9.

As shown in fig. 1, 2 and 4, the left inner stator 19 is a shaft-shaped structure, the left end of which penetrates out of the left end cover 5 of the housing, and the left inner stator 4 is fixed on the left end cover 5 by the left nut 1 screwed on the penetrating end, and the left adjusting sleeve 2 is arranged between the left nut 1 and the left end cover 5. The end surface of the penetrating end of the left inner stator 4 is provided with a second oil hole 26. The right end of the left inner stator 4 extends within the left inner stator cavity of the core 12 and the end face of the right end abuts against the left end face of the stub shaft 25 located within the left stator cavity. The left stator 10 is provided with a plurality of second grooves 27 on the axial surface in the left inner stator cavity, and the second grooves 27 are arranged corresponding to the first grooves 29 on the left outer stator 9. A third oil hole is formed at the position of each second groove 27 of each left inner stator 4. The second oil hole 26 and the third oil hole are communicated through a pipeline inside the left inner stator 4. And the outer face of the left inner stator 4 where the second groove 27 is not provided is fitted to the edge of the vane group on the inner surface of the left inner stator cavity so that the second groove 27 and the vane group form an oil chamber for containing hydraulic oil, as shown in fig. 2. The right inner stator 19 and the left inner stator 4 have the same structure and are symmetrically arranged, a right nut 22 is used for fixing the right inner stator 19, and a right adjusting sleeve 21 is arranged between the right nut 22 and the right inner stator 19.

The axial surface of the short shaft 25 in the invention is higher than the height of the blade group edge outside the left inner stator cavity and the right inner stator cavity, so that the right end surface of the left inner stator 4 is abutted against the left end surface of the short shaft 25 of the core body 12. The left inner stator 4 is a stepped shaft, the shaft diameter at the rightmost end is larger than the shaft diameter of the rest section, the width of the shaft at the rightmost end is equal to that of the left outer stator 9, and the same right inner stator 19 has the same structure as the left inner stator 4 and is symmetrically arranged with the left inner stator 4.

As shown in fig. 1 and 3, the present invention further includes a left retainer ring 8 and a right retainer ring 15, wherein the left retainer ring 8 is provided with an insertion rod hole corresponding to the insertion rod of the left inner stator cavity, the left retainer ring 8 is sleeved on the left inner stator and is inserted into the left inner stator cavity of the core body 12 through the insertion rod hole, a retainer step is provided on the left inner stator cavity, and the left retainer ring 8 abuts against the retainer step. The right retainer ring 15 is of the same construction and is mounted on the right inner stator cavity in the same manner as the left retainer ring 8. After the installation, the right surface of the left check ring 8 which is arranged on the left inner stator cavity of the core body 12 in a penetrating way is just abutted against the left end surface of the left outer stator 9 and the shaft shoulder at the rightmost end of the left outer stator 9. The right retainer rings 15 are symmetrically arranged. The invention is characterized in that a convex rib extending into the shell is arranged on the left end cover 5 of the shell and used for pressing the left check ring 8, the convex rib is a ring-shaped convex rib arranged on the left end cover 5, and the convex rib penetrates from the inside of the left inner stator cavity of the core body 12 and is pressed against the left check ring 8. The same right end cap is provided with a ring of annular ribs which bear against the right retainer ring 15 in the same manner. The blade group on the left inner sub-cavity is positioned between the left retainer ring 8 and the short shaft 25, and the blade group on the right inner sub-cavity is positioned between the right retainer ring 15 and the short shaft 25.

As shown in figure 1, the invention also comprises a left bearing and a right bearing, wherein the left bearing is a left tapered roller bearing 6, the left bearing is arranged between a left end cover 5 and a left retainer ring 8 and is sleeved on a left inner stator cavity of a core body 12 between the left end cover and the left retainer ring in an interference manner, and an outer ring of the left bearing is arranged with an inner cavity of the shell in an interference fit manner. The inner ring of the left bearing is pressed against the left surface of the left retainer ring 8, and the outer ring is pressed against the left end cover 5. The right bearing is a right tapered roller bearing 17 and is arranged symmetrically with the left bearing.

The invention also arranges a left key 3 between the left inner stator and the right end cover to prevent the relative rotation of the two. Similarly, a right key 20 is provided between the right inner stator 19 and the end cap to prevent relative rotation therebetween.

In order to improve the assembly precision, the adjusting pads are arranged between the convex rib of the left end cover 5 and the right stop ring 15 of the shell and between the convex rib of the right end cover and the right stop ring 15, the left adjusting pad 7 is arranged at the left part, and the right adjusting pad 16 is arranged at the right part.

As shown in fig. 4 and 5, the left inner stator of the present embodiment is provided with four second oil holes 26, a1, a2, A3 and a4, respectively, and four third oil holes, one of which is a0, respectively. The corresponding upper portion of the peripheral surface of the left outer stator 14 is provided with 4 first oil holes B1, B2, B3 and B4.

The invention can form a vane pump/motor structure with 2 small displacements at local parts by the left inner stator 4, the core body 12, the left retainer ring 8 and the left vane group 10. The 4 oil through ports in the left inner stator 4 are respectively the oil inlet and outlet ports of the two vane pump/motors formed locally, and can be independently connected with an external pipeline, wherein the oil through ports A1 and A2 are respectively used as an oil inlet and an oil outlet corresponding to one of the vane pump/motors, and the oil through ports A3 and A4 are respectively used as an oil inlet and an oil outlet corresponding to the other vane pump/motor.

Or the surface of the outer shell 11 of the vane pump/motor structure with 2 large displacement formed by the left outer stator 9, the core 12, the left retainer ring 8 and the left vane group 10 can be provided with 4 oil inlets and outlets of the two locally formed large displacement vane pump/motors respectively, and the oil inlets and outlets can be independently connected with an external pipeline. The oil through ports B1 and B2 are respectively used as oil inlet and oil outlet ports corresponding to one of the vane pump/motors, and the oil through ports B3 and B4 are respectively used as oil inlet and oil outlet ports corresponding to the other vane pump/motor.

The hydraulic transformer has a bilaterally symmetrical structure, and also has 2 vane pump/motor structures with small displacement and 2 vane pump/motor structures with large displacement on the right side. Thus, a total of 4 small displacement vane pump/motors and 4 large displacement vane pump/motors are formed inside the hydraulic transformer. The displacement of the pump/motors depends on the shape of the stator curve corresponding to each pump/motor, and the oil through port corresponding to each vane pump/motor structure can be independently connected with an external pipeline.

When the hydraulic motor is used, oil inlets of different numbers of pump/motors can be communicated through corresponding control systems, so that pressure oil enters, and the pump/motor has the function of a hydraulic motor; meanwhile, oil discharge ports of a certain number of pumps/motors are communicated, oil is output to an external load, and the pumps/motors play a role of a hydraulic pump; the other oil through openings are connected with the oil tank. Therefore, under the drive of external input pressure oil, the part inside the hydraulic transformer as a hydraulic motor drives the part of the hydraulic pump to rotate, and simultaneously outputs hydraulic oil with different pressure flow rates to the outside: when only the vane pump/motor structures corresponding to the oil ports A1 and A2 work as the motors, and the other vane pump/motor structures all work as the pumps to output oil outwards, the transformation ratio of the hydraulic transformer is minimum; when only the vane pump/motor structures corresponding to A1 and A2 output oil to the outside as the pump work and the other pump/motor structures all work as motors, the transformation ratio of the hydraulic transformer is the largest; the oil ports are connected together to form motor input oil liquid by controlling different quantities of oil, the oil ports are connected together to form pump output oil liquid by controlling different quantities of oil, and the oil ports are connected with an oil tank to realize multi-stage transformation ratio which is between the former two conditions.

In the hydraulic transformer, 4 pump/motors with small displacement and 4 pump/motors with large displacement are arranged, and the combination form is shown in table 1. It should be noted that in the hydraulic transformer of this structure, the number of the pump/motors that can be formed is determined by the number of the protrusions of the surface profile of the inner stator and the outer stator, and when the number of the protrusions is increased, the number of the large and small pump/motors that can be formed is increased.

TABLE 1