Supercharger with variable supercharge ratio and control method

Abstract

The supercharger with the variable supercharging ratio comprises a stator unit, a rotor unit, an oil distribution shaft unit and a hydraulic control unit, and the inner wall of the stator unit is in a curved surface shape; a plurality of radial plunger holes penetrating through the inner cavity of the cylindrical body and the inner wall of the stator unit are formed in the cylindrical body, provided with the inner cavity, of the rotor unit along the circumference at equal intervals, plungers are installed in the plunger holes, and rollers are installed at the ends, close to the stator unit, of the plungers and roll on the curved surface of the stator unit; a primary pressure oil inlet hole is axially formed in the middle of the oil distribution shaft unit, a plurality of radial oil holes are radially formed in the middle of the oil distribution shaft unit, one end of each radial oil hole is communicated with the primary pressure oil inlet hole, and the other end of each radial oil hole is communicated with each plunger hole of the rotor unit when the rotor unit rotates; an oil distribution hole is formed between every two adjacent radial oil holes and is communicated with each plunger hole of the rotor unit when the rotor rotates; the hydraulic control unit comprises a plurality of electromagnetic valves installed on the oil distribution shaft unit. The supercharging ratio of the supercharger is changed by changing the energized number of the electromagnetic valves.

Description

Technical Field

[0001] The invention relates to a supercharger with a variable boost ratio and a control method, belonging to the technical field of hydraulic transmission and control. Background Art

[0002] The main component used in the hydraulic system booster circuit is the booster cylinder, which is used to boost the low-pressure oil input into the hydraulic system through the booster cylinder to increase the pressure to meet the system's pressure requirements. The hydraulic system booster circuit is mainly used in hydraulic circuits where the system oil supply pressure is relatively low and a branch requires a higher pressure but a small flow rate; or in energy recovery, the hydraulic system recovers hydraulic oil with a relatively low pressure. This hydraulic oil cannot be directly used to drive the actuators in the hydraulic system. The booster circuit must be used to increase the pressure to the required pressure before it can be used. The working principle of the booster cylinder is: when the supplied primary pressure oil (low-pressure oil) enters the large piston chamber of the booster cylinder, the pressure oil generates a thrust on the large piston, and the thrust is equal to the product of the input oil pressure and the effective area of ​​the large piston. This thrust pushes the small piston to move through the connecting rod, and pushes the oil output of the small piston chamber through the small piston, that is, the secondary pressure oil (high-pressure oil) output. The oil in this cavity also produces a reaction thrust on the small piston. Without considering the friction force, the thrusts of the oil on the large piston and the small piston are equal, that is, the product of the oil pressure in the large piston cavity and its effective area is equal to the product of the oil pressure in the small piston cavity and its effective area. It can be seen from this that the ratio of the pressures in the large and small piston cavities, that is, the ratio of the primary pressure to the secondary pressure, is inversely proportional to the area of ​​the large and small pistons. The larger the area ratio of the large and small pistons, the greater the ratio of the secondary pressure to the primary pressure.

[0003] At present, according to the different structures of the booster cylinders used in the booster circuit, there are booster circuits for single-acting booster cylinders and booster circuits for double-acting booster cylinders. The booster circuit of a single-acting booster cylinder means that when the piston moves to one side, there is high-pressure oil output, and when it returns, there is no high-pressure oil output. The booster circuit of a double-acting booster cylinder means that when the piston reciprocates, high-pressure oil is output alternately at both ends, which can achieve continuous boosting. However, the boosting ratios of these two booster circuits are fixed, so their applications are relatively simple.

[0004] In the boosting circuit of the above-mentioned boosting cylinder, if the primary pressure increases, the secondary pressure after boosting will also increase year by year. However, when the secondary pressure required by the system is relatively low compared to the secondary pressure after boosting, it needs to be throttled or decompressed before use, which will cause energy loss, heating of the system and reduced efficiency. Or if the required secondary pressure increases but the primary pressure does not change, the secondary pressure oil after boosting cannot meet the pressure requirement of the system. Summary of the invention

[0005] The object of the present invention is to provide a supercharger with a variable boost ratio and a control method, wherein the supercharger and the control method can realize a variable boost ratio and expand the application range of the supercharger.

[0006] In order to achieve the above object, the present invention provides a variable pressure ratio supercharger, comprising a stator unit, a rotor unit, an oil distribution shaft unit and a hydraulic control unit, wherein the stator unit comprises a cylindrical shell, the inner wall of the shell is a plurality of continuous and uniformly distributed inner curved surfaces along its circumferential direction, and each inner curved surface comprises a smooth curved surface ascending section and a curved surface descending section;

[0007] The rotor unit comprises a cylindrical body with an inner cavity, and a plurality of radial plunger holes are opened on the cylindrical body at equal intervals along its circumference, one end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit, a plunger is slidably installed in each plunger hole, and a roller is installed at one end of each plunger close to the inner wall of the stator unit housing, the plunger in each plunger hole is in contact with the roller, and the roller rolls on the inner curved surface of the stator unit housing;

[0008] The oil distribution shaft unit comprises a cylindrical body, a primary pressure oil inlet hole is provided in the middle of the cylindrical body along its axial direction, and a plurality of radial oil holes are provided along its radial direction at equal intervals, one end of each radial oil hole is communicated with one end of the primary pressure oil inlet hole, and the other end is communicated with each plunger hole of the rotor unit when the rotor rotates; an oil distribution hole is also provided between each adjacent radial oil hole, each oil distribution hole comprises a radial hole and an axial hole communicated with the radial hole and provided along the axial direction of the cylindrical body of the oil distribution shaft unit; the oil distribution hole is communicated with each plunger hole of the rotor unit when the rotor unit rotates; the other end of the primary pressure oil inlet hole is communicated with the primary pressure inlet, and the primary pressure inlet is provided on the oil distribution shaft unit;

[0009] The hydraulic control unit includes a plurality of solenoid valves installed on the oil distribution shaft unit, the P port of each solenoid valve is respectively communicated with the axial hole of the oil distribution hole where it is located, the A port is respectively communicated with the secondary pressure outlet, and the T port is communicated with the oil tank through a pipeline; the secondary pressure outlet is opened on the oil distribution shaft unit.

[0010] Furthermore, the stator unit is fixed during operation, the rotor unit is installed inside the stator unit, a plunger and a roller are installed in each plunger hole of the rotor unit, the plunger is sealed with the plunger hole and can move in the plunger hole in the radial direction, the oil distribution shaft unit is installed in the center hole of the rotor unit and is fixed like the stator unit, the stator unit, the rotor unit and the oil distribution shaft unit are kept coaxial, and the mating surfaces of the oil distribution shaft unit and the rotor unit are kept sealed. When initially installed, the radial oil holes on the oil distribution shaft unit correspond one-to-one with the rising section of the stator unit curved surface in the radial direction, and the oil distribution holes on the oil distribution shaft unit correspond one-to-one with the descending section of the stator unit curved surface in the radial direction.

[0011] A control method for a variable boost ratio supercharger comprises the following steps:

[0012] Step 1: Low-pressure oil enters from the primary pressure inlet at P1, and enters the radial oil holes through the primary pressure oil inlet holes on the oil distribution shaft unit. When the radial plunger hole of the rotor unit is connected with the radial oil hole on the oil distribution shaft unit, the primary pressure oil enters the radial plunger hole and pushes the plunger to move in the direction close to the inner curved surface of the stator unit. The plunger pushes the roller to roll on the rising section of the inner curved surface of the stator unit. The roller transmits the hydraulic thrust received by the plunger to the inner curved surface of the stator unit. The tangential component of the reaction force of the inner curved surface of the stator unit on the roller generates torque on the rotor and drives the rotor to rotate. At this time, the supercharger works as a hydraulic motor, and the theoretical torque generated is:

[0013]

[0014] Where V m is the displacement of the supercharger motor under working condition, d is the plunger diameter, e is the amount of expansion and contraction of the plunger, z is the number of plungers in the rotor unit, and n is the number of inner curved surfaces of the stator unit;

[0015] Step 2. Under the action of hydraulic thrust, the plunger of the rotor unit continues to extend. When it is fully extended, the rotor unit rotates until the radial plunger hole is disconnected from the radial oil hole on the oil distribution shaft unit, and no low-pressure oil enters. At this time, the roller is at the highest point of the ascending section of the curved surface, that is, the dead point position on the curved surface; the plunger continues to rotate with the rotor unit to the descending section of the curved surface. When the radial plunger hole of the rotor unit is connected to the oil distribution hole on the oil distribution shaft unit, under the action of the inner curved surface of the stator unit, the roller pushes the plunger to retract in the direction close to the oil distribution shaft unit and discharge oil until the plunger is fully retracted into the radial plunger hole, and the rotor unit rotates to the radial The plunger hole is disconnected from the oil distribution hole on the oil distribution shaft unit. At this time, the plunger is at the lowest point of the descending section of the curved surface, that is, the bottom dead point of the curved surface, and the oil discharge process is over. In this process, the supercharger outputs hydraulic oil in the working condition of the pump; when the roller enters the rising section of the next inner curved surface, the pressure oil enters again, and so on. The rotor unit rotates one circle, each roller rotates one circle along the inner curved surface of the stator unit, and each plunger expands and contracts many times in the plunger hole. For each rotation of the rotor unit, the number of expansion and contraction of the plunger is equal to the number of curved surfaces of the stator unit; the relationship between the reverse torque generated by the hydraulic pump working condition and the secondary oil pressure output under the hydraulic pump working condition is:

[0016]

[0017] Where V b is the displacement of the booster hydraulic pump under working condition, Where d is the plunger diameter, e is the amount of expansion and contraction of the plunger, z is the number of plungers in the rotor unit, and n is bis the number of stator unit surfaces involved in the pump operation;

[0018] Since the torque under motor working condition and hydraulic pump working condition is equal, that is: T m =T b , from the above formula:

[0019]

[0020] Step 3: When all solenoid valves are not energized, the pump plunger discharges oil through the solenoid valve to output the secondary pressure, that is, n b =n, without considering various losses, the secondary pressure outlet pressure P2 = P1;

[0021] When the first solenoid valve is energized, the rotor unit turns to the plunger hole and communicates with the first oil distribution hole, and the oil discharged from the plunger hole is discharged back to the oil tank through the first solenoid valve and does not participate in the output of the secondary pressure; when the plunger hole turns to communicate with other oil distribution holes, the plunger hole outputs the secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is:

[0022]

[0023] When the first solenoid valve and the second solenoid valve are energized, the rotor unit rotates to the plunger hole to communicate with the first oil distribution hole and the second oil distribution hole respectively, and the oil discharged from the plunger hole is discharged back to the oil tank through the first oil distribution hole or the second oil distribution hole, the first solenoid valve or the second solenoid valve, and does not participate in the output of the secondary pressure; when the plunger hole rotates to communicate with other oil distribution holes, the plunger hole outputs the secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-2, the output secondary pressure rises to:

[0024] By analogy, the boost ratio of the supercharger can be changed by changing the amount of power supplied to the solenoid valve.

[0025] The present invention comprises a stator unit, a rotor unit and an oil distribution shaft unit which are coaxially installed from outside to inside, and also comprises a hydraulic control unit. The inner wall of the cylindrical shell of the stator unit is a plurality of pairs of continuously distributed inner curved surfaces along its circumferential direction, and each inner curved surface comprises a smooth curved surface ascending section and a curved surface descending section. The rotor unit is provided with a cylindrical body having an inner cavity, and a plurality of pairs of radial plunger holes which penetrate the inner cavity of the cylindrical body and the inner wall of the stator unit shell are provided at equal intervals along its circumference. Plunger holes are slidably installed in the plunger holes, and a roller is installed at one end of the plunger close to the stator unit, and the roller is arranged on the stator unit. The oil distribution shaft unit rolls on the inner curved surface; a primary pressure oil inlet hole is provided in the middle of the cylindrical body along its axial direction, and a plurality of pairs of radial oil holes are provided along its radial direction at equal intervals, one end of each radial oil hole is connected with the primary pressure oil inlet hole, and the other end is connected with each plunger hole of the rotor unit when the rotor unit rotates; an oil distribution hole is also provided between adjacent radial oil holes, and the oil distribution hole includes an axial through hole and a radial through hole connected with the axial through hole, and the radial through hole is connected with each plunger hole of the rotor unit when the rotor unit rotates; the hydraulic control unit includes a plurality of solenoid valves installed on the oil distribution shaft unit. When the first solenoid valve is energized and the rotor unit rotates to the plunger hole to communicate with the first oil distribution hole, the oil discharged from the plunger hole is discharged back to the oil tank through the first solenoid valve and does not participate in the output of the secondary pressure; when the plunger hole is rotated to communicate with other oil distribution holes, the plunger hole is discharged through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet; when the first solenoid valve and the second solenoid valve are energized and the rotor unit rotates to the plunger hole to communicate with the first oil distribution hole and the second oil distribution hole respectively, the oil discharged from the plunger hole is discharged back to the oil tank through the first oil distribution hole or the second oil distribution hole, the first solenoid valve or the second solenoid valve and does not participate in the output of the secondary pressure; when the plunger hole is rotated to communicate with other oil distribution holes, the plunger hole is discharged through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet, and the secondary pressure value at this time is greater than the secondary pressure value when the number of solenoid valves energized is one, and so on, thereby achieving the change of the boost ratio of the supercharger by changing the number of solenoid valves energized, thereby expanding the scope of application of the supercharger. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the stator unit in the present invention;

[0028] Figure 3 This is a schematic diagram of the oil distribution shaft unit structure in the present invention.

[0029] Figure 4 It is a schematic diagram of the hydraulic control unit in the present invention.

[0030] In the figure: 1, stator unit, 1-A1, first curved surface rising section, 1-B1, first curved surface descending section, 1-A2, second curved surface rising section, 1-B2, second curved surface descending section, 1-A3, third curved surface rising section, 1-B3, third curved surface descending section, 1-A4, fourth curved surface rising section, 1-B4, fourth curved surface descending section, 1-A5, fifth curved surface rising section, 1-B5, fifth curved surface descending section, 1-A6, sixth curved surface rising section, 1-B6, sixth curved surface descending section, 1-A7, seventh curved surface rising section, 1-B7, seventh curved surface descending section, 1-A8, eighth curved surface rising section, 1-B8, eighth curved surface descending section;

[0031] 2. rotor unit, 3. roller, 4. plunger;

[0032] 5. Oil distribution shaft unit, 5-A. primary pressure oil inlet hole, 5-A1. first radial oil hole, 5-A2. second radial oil hole, 5-A3. third radial oil hole, 5-A4. fourth radial oil hole, 5-A5. fifth radial oil hole, 5-A6. sixth radial oil hole, 5-A7. seventh radial oil hole, 5-A8. eighth radial oil hole, 5-B1. first oil distribution hole, 5-B2. second oil distribution hole, 5-B3. third oil distribution hole, 5-B4. fourth oil distribution hole, 5-B5. fifth oil distribution hole, 5-B6. sixth oil distribution hole, 5-B7. seventh oil distribution hole, 5-B8. eighth oil distribution hole;

[0033] 6. The first solenoid valve, 7. The second solenoid valve, 8. The third solenoid valve, 9. The fourth solenoid valve, 10. The fifth solenoid valve, 11. The sixth solenoid valve, 12. The seventh solenoid valve, 13. The eighth solenoid valve. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] like Figure 1 and Figure 2As shown, the supercharger of the present invention comprises a stator unit 1, a rotor unit 2, a roller 3, a plunger 4, an oil distribution shaft unit 5 and a hydraulic control unit; the inner wall of the shell of the stator unit 1 is provided with 8 continuously and evenly distributed inner curved surfaces along its circumferential direction, the first inner curved surface comprises a first curved surface rising section 1-A1 and a first curved surface descending section 1-B1, the second inner curved surface comprises a second curved surface rising section 1-A2 and a second curved surface descending section 1-B2, the third inner curved surface comprises a third curved surface rising section 1-A3 and a third curved surface descending section 1-B4, The fourth inner curved surface includes a fourth curved surface ascending section 1-A4 and a fourth curved surface descending section 1-B4, the fifth inner curved surface includes a fifth curved surface ascending section 1-A5 and a fifth curved surface descending section 1-B5, the sixth inner curved surface includes a sixth curved surface ascending section 1-A6 and a sixth curved surface descending section 1-B6, the seventh inner curved surface includes a seventh curved surface ascending section 1-A7 and a seventh curved surface descending section 1-B7, and the eighth inner curved surface includes an eighth curved surface ascending section 1-A8 and an eighth curved surface descending section 1-B8;

[0036] The rotor unit 2 comprises a cylindrical body with an inner cavity, and 10 radial plunger holes are opened on the cylindrical body at equal intervals along its circumference. One end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit. A plunger 4 is slidably installed in each plunger hole, and a roller 3 is installed at one end of each plunger close to the inner wall of the stator unit housing, and each roller 3 rolls on the inner curved surface of the stator unit 1 housing;

[0037] like Figure 3 As shown, the oil distribution shaft unit 5 includes a cylindrical body, a primary pressure oil inlet hole 5-A is opened in the middle of the cylindrical body along its axial direction, and 8 radial oil holes are opened at equal intervals along its radial direction, namely the first radial oil hole 5-A1, the second radial oil hole 5-A2, the third radial oil hole 5-A3, the fourth radial oil hole 5-A4, the fifth radial oil hole 5-A5, the sixth radial oil hole 5-A6, the seventh radial oil hole 5-A7, and the eighth radial oil hole 5-A8; one end of each radial oil hole is connected to the primary pressure oil inlet hole 5-A, and the other end is opened when the rotor unit 2 rotates. It is connected with each plunger hole of the rotor unit 2; there are also oil distribution holes between each adjacent radial oil hole, which are the first oil distribution hole 5-B1, the second oil distribution hole 5-B2, the third oil distribution hole 5-B3, the fourth oil distribution hole 5-B4, the fifth oil distribution hole 5-B5, the sixth oil distribution hole 5-B6, the seventh oil distribution hole 5-B7, and the eighth oil distribution hole 5-B8; each oil distribution hole includes a radial hole and an axial hole connected thereto and opened along the axial direction of the cylindrical body of the oil distribution shaft unit 5, and the radial oil hole and the oil distribution hole are respectively connected with each plunger hole of the rotor unit 2 when the rotor unit 2 rotates;

[0038] like Figure 4As shown, the hydraulic control unit includes a first solenoid valve 6, a second solenoid valve 7, a third solenoid valve 8, a fourth solenoid valve 9, a fifth solenoid valve 10, a sixth solenoid valve 11, a seventh solenoid valve 12, and an eighth solenoid valve 13, wherein the P port of the first solenoid valve 6 is communicated with the first oil distribution hole 5-B1 on the oil distribution shaft, the P port of the second solenoid valve 7 is communicated with the second oil distribution hole 5-B2 on the oil distribution shaft, the P port of the third solenoid valve 8 is communicated with the third oil distribution hole 5-B3 on the oil distribution shaft, the P port of the fourth solenoid valve 9 is communicated with the fourth oil distribution hole 5-B4 on the oil distribution shaft, and the fifth solenoid valve 10 is communicated with the sixth solenoid valve 11, the seventh solenoid valve 12, and the eighth solenoid valve 13. The P port of the first solenoid valve 6 to the eighth solenoid valve 13 is connected to the eighth oil distribution hole 5-B8 on the oil distribution shaft; the A ports of the first solenoid valve 6 to the eighth solenoid valve 13 are respectively connected to the secondary pressure outlet, and the T ports of the first solenoid valve 6 to the eighth solenoid valve 13 are connected to the oil tank through pipelines; the primary pressure oil inlet hole 5-A on the oil distribution shaft unit is connected to the primary pressure inlet;

[0039] The stator unit 1 is fixed during operation, the rotor unit 2 is installed inside the stator 1, a plunger 4 and a roller 3 are installed in each plunger hole of the rotor unit 2, the plunger 4 is sealed with the plunger hole and can move in the plunger hole along the radial direction, the oil distribution shaft unit 5 is installed in the center hole of the rotor unit 2, and is fixed like the stator unit 1; the stator unit 1, the rotor unit 2 and the oil distribution shaft unit 5 are kept concentric, and the matching surfaces of the oil distribution shaft unit 5 and the rotor unit 2 are kept sealed. The first radial oil hole 5-A1 to the eighth radial oil hole 5-A8 on the oil distribution shaft unit 5 correspond one-to-one with the first curved surface ascending section 1-A1 to the eighth curved surface ascending section 1-A8 on the stator unit 1 along the radial direction, that is, the first radial oil hole 5-A1 corresponds to the first curved surface ascending section 1-A1, the second radial oil hole 5-A2 corresponds to the second curved surface ascending section 1-A2, and so on; the first oil distribution hole 5-B1 to the eighth oil distribution hole 5-B8 on the oil distribution shaft unit 5 correspond one-to-one with the first curved surface descending section 1-B1 to the eighth curved surface descending section 1-B8 on the stator unit 1 along the radial direction, that is, the first oil distribution hole 5-B1 corresponds to the first curved surface descending section 1-B1, the second oil distribution hole 5-B2 corresponds to the second curved surface descending section 1-B2, and so on;

[0040] During operation, low-pressure oil enters from the primary pressure inlet at P1, and enters the radial oil holes through the primary pressure oil inlet holes on the oil distribution shaft unit. When the radial plunger hole of the rotor unit is connected with the radial oil hole on the oil distribution shaft unit, the primary pressure oil enters the radial plunger hole and pushes the plunger to move in the direction close to the inner curved surface of the stator unit. The plunger pushes the roller 3 to roll on the rising section of the curved surface of the stator unit 1. The roller 3 transmits the hydraulic thrust received by the plunger to the inner curved surface of the stator unit 1. The tangential component of the reaction force of the inner curved surface of the stator unit 1 on the roller 3 generates torque on the rotor and pushes the rotor unit 2 to rotate. At this time, the supercharger works in the working condition of a hydraulic motor, and the theoretical torque generated is:

[0041]

[0042] Where V m is the displacement of the supercharger motor under working condition, d is the plunger diameter, e is the amount of expansion and contraction of the plunger, z is the number of plungers in the rotor unit, and n is the number of inner curved surfaces on the inner wall of the stator unit;

[0043] Under the action of hydraulic thrust, the plunger 4 of the rotor unit 2 is continuously extended. When it is fully extended, the rotor unit 2 rotates until the radial plunger hole is disconnected from the radial oil hole on the oil distribution shaft unit 5, and no low-pressure oil enters. At this time, the plunger is at the highest point of the ascending section of the curved surface, that is, the dead point position on the curved surface; the plunger continues to rotate with the rotor unit 2 to the descending section of the curved surface. When the radial plunger hole of the rotor unit 2 is connected with the oil distribution hole on the oil distribution shaft unit 5, under the action of the inner curved surface of the stator unit, the roller 3 pushes the plunger to retract in the direction close to the oil distribution shaft unit 5 and discharge oil until the plunger 4 is fully retracted to the radial In the plunger hole, the rotor unit 2 rotates until the radial plunger hole is disconnected from the oil distribution hole on the oil distribution shaft unit. At this time, the plunger 4 is at the lowest point of the descending section of the curved surface, that is, the bottom dead center of the curved surface, and the oil discharge process is completed. In this process, the supercharger outputs hydraulic oil in the working condition of the pump; when the roller enters the ascending section of the next curved surface, the pressure oil is input again, and so on. The rotor unit 2 rotates one circle, each roller 3 rotates one circle along the inner curved surface of the stator unit 1, and each plunger expands and contracts in the plunger hole many times; the relationship between the reverse torque generated by the hydraulic pump working condition and the secondary oil pressure output under the hydraulic pump working condition is:

[0044]

[0045] Where V b is the displacement of the booster hydraulic pump under working condition, Where d is the plunger diameter, e is the amount of expansion and contraction of the plunger, z is the number of plungers in the rotor unit, and n is b is the number of surfaces of stator unit 1 participating in the pump operation;

[0046] Since the torque under motor working condition and hydraulic pump working condition is equal, that is: Tm =T b , from the above formula:

[0047]

[0048] When all solenoid valves are not energized, the pump plunger discharges oil entirely through the solenoid valve to output the secondary pressure, i.e. n b =n, without considering various losses, the secondary pressure outlet pressure P2 = P1;

[0049] When the first solenoid valve 6 is energized, the rotor unit 2 turns to the plunger hole and communicates with the first oil distribution hole 5-B1, and the oil discharged from the plunger hole is discharged back to the oil tank through the first solenoid valve 6, and does not participate in the output of the secondary pressure; when the plunger hole turns to communicate with other oil distribution holes, the plunger hole outputs the secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is: In this embodiment, when the number of inner wall curved surfaces of the stator unit 1 is 8,

[0050] When the first solenoid valve 6 and the second solenoid valve 7 are energized, the rotor unit 2 rotates to the plunger hole to communicate with the first oil distribution hole 5-B1 and the second oil distribution hole 5-B2 respectively, the plunger hole discharges oil back to the oil tank through the first oil distribution hole 5-B1 or the second oil distribution hole 5-B2, the first solenoid valve 6 or the second solenoid valve 7, and does not participate in the output of secondary pressure; when the plunger hole rotates to communicate with other oil distribution holes, the plunger hole outputs secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-2, the output secondary pressure rises to: In this embodiment, when the number of inner curved surfaces of the stator unit 1 is 8, By analogy, the relationship between the number of energizations of the solenoid valve and the secondary pressure is shown in Table 1:

[0051] Table 1 Relationship between secondary pressure and number of energization of solenoid valve

[0052]

[0053] Generally speaking, boosting the low-pressure oil by about 2 times can meet the actual pressure demand. As can be seen from Table 1, keeping 4 to 5 solenoid valves energized during operation can achieve a double increase ratio. The boost ratio of the supercharger can be changed by controlling the number of solenoid valves energized.

Claims

1. A variable boost ratio supercharger, characterized in that: The invention comprises a stator unit (1), a rotor unit (2), an oil distribution shaft unit (5) and a hydraulic control unit, wherein the stator unit (1) comprises a cylindrical shell, the inner wall of the shell is a plurality of continuously evenly distributed inner curved surfaces along its circumferential direction, and each inner curved surface comprises a smooth curved surface ascending section and a curved surface descending section; The rotor unit (2) comprises a cylindrical body with an inner cavity, a plurality of radial plunger holes are formed on the cylindrical body at equal intervals along its circumference, one end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit (2), a plunger (4) is slidably installed in each plunger hole, and a roller (3) is installed at one end of each plunger (4) close to the inner wall of the stator unit (1) shell, and each roller (3) rolls on the inner curved surface of the stator unit (1) shell; The oil distribution shaft unit (5) comprises a cylindrical body, a primary pressure oil inlet hole (5-A) is provided in the middle of the cylindrical body along its axial direction, and a plurality of radial oil holes are provided along its radial direction at equal intervals, one end of each radial oil hole is connected to one end of the primary pressure oil inlet hole (5-A), and the other end is communicated with each plunger hole of the rotor unit (2) when the rotor unit (2) rotates; an oil distribution hole is also provided between each adjacent radial oil hole, each oil distribution hole comprises a radial hole and an axial hole communicated with the radial hole and provided along the axial direction of the cylindrical body of the oil distribution shaft unit (5); the oil distribution hole is communicated with each plunger hole of the rotor unit (2) when the rotor unit (2) rotates; the other end of the primary pressure oil inlet hole (5-A) is communicated with a primary pressure inlet, and the primary pressure inlet is provided on the oil distribution shaft unit (5); The hydraulic control unit comprises a plurality of solenoid valves mounted on the oil distribution shaft unit (5), wherein the P port of each solenoid valve is respectively communicated with the axial hole of the oil distribution hole where it is located, the A port is respectively communicated with the secondary pressure outlet, and the T port is communicated with the oil tank through a pipeline; the secondary pressure outlet is opened on the oil distribution shaft unit (5).

2. The variable pressure ratio supercharger according to claim 1, characterized in that: The stator unit (1) is fixed and the rotor unit (2) is installed inside the stator unit (1); the oil distribution shaft unit (5) is fixedly installed in the central hole of the inner cavity of the rotor unit (2); the stator unit (1), the rotor unit (2) and the oil distribution shaft unit (5) are kept coaxial, and the mating surfaces of the oil distribution shaft unit (5) and the rotor unit (2) are kept sealed; when initially installed, the radial oil holes on the oil distribution shaft unit (5) correspond one-to-one with the ascending sections of the stator unit (1) curved surface in the radial direction, and the oil distribution holes on the oil distribution shaft unit (5) correspond one-to-one with the descending sections of the stator unit (1) curved surface in the radial direction.

3. A control method for a variable boost ratio supercharger according to any one of claims 1 or 2, characterized in that: The steps include: Step 1: Low-pressure oil enters from the primary pressure inlet at P1, and enters the radial oil holes through the primary pressure oil inlet holes (5-A) on the oil distribution shaft unit (5). When the radial plunger hole of the rotor unit (2) is connected with the radial oil hole on the oil distribution shaft unit (5), the primary pressure oil enters the radial plunger hole and pushes the plunger (4) to move in the direction close to the inner curved surface of the stator unit (1). The plunger pushes the roller (3) to roll on the rising section of the inner curved surface of the stator unit (1). The roller (3) transmits the hydraulic thrust received by the plunger (4) to the inner wall curved surface of the stator unit (1). The tangential component of the reaction force of the inner wall curved surface of the stator unit (1) on the roller (3) generates torque on the rotor and drives the rotor to rotate. At this time, the supercharger works in the working condition of a hydraulic motor, and the theoretical torque generated is: Where V m is the displacement of the supercharger motor under working condition, d is the diameter of the plunger (4), e is the expansion and contraction amount of the plunger (4), z is the number of plungers (4) in the rotor unit (2), and n is the number of inner curved surfaces of the stator unit (1); Step 2: Under the action of hydraulic thrust, the plunger (4) of the rotor unit (2) is continuously extended. When it is fully extended, the rotor unit (2) rotates until the radial plunger hole is disconnected from the radial oil hole on the oil distribution shaft unit (5), and no low-pressure oil is introduced. At this time, the plunger (4) is at the highest point of the ascending section of the curved surface, that is, the dead point position on the curved surface; the plunger (4) continues to rotate with the rotor unit (2) to the descending section of the curved surface. When the radial plunger hole of the rotor unit (2) is connected to the oil distribution hole on the oil distribution shaft unit (5), under the action of the inner curved surface of the stator unit (1), the roller (3) pushes the plunger (4) to retract in the direction close to the oil distribution shaft unit (5) and discharge the oil until the plunger (4) is fully retracted to the radial position. The rotor unit (2) rotates into the plunger hole until the radial plunger hole is disconnected from the oil distribution hole on the oil distribution shaft unit (5). At this time, the plunger (4) is at the lowest point of the descending section of the curved surface, that is, the bottom dead center of the curved surface, and the oil discharge process is completed. In this process, the supercharger outputs hydraulic oil in the working condition of a pump; when the roller (3) enters the ascending section of the next curved surface, the pressure oil is input again, and so on. The rotor unit (2) rotates one circle, each roller (3) rotates one circle along the inner curved surface of the stator unit (1), and the number of expansion and contraction times of each plunger (4) in the plunger hole is equal to the number of curved surfaces of the stator unit (1); the relationship between the reverse torque generated by the hydraulic pump working condition and the secondary oil pressure output under the hydraulic pump working condition is: Where V b is the displacement of the booster hydraulic pump under working condition, Where d is the diameter of the plunger (4), e is the expansion and contraction amount of the plunger (4), z is the number of plungers (4) in the rotor unit (2), and n is b is the number of surfaces of the stator unit (1) involved in the pump operation; Since the torque under motor working condition and hydraulic pump working condition is equal, that is: T m =T b , from the above formula: Step 3: When all solenoid valves are not energized, the pump operating plunger (4) discharges all oil through the solenoid valve output secondary pressure, i.e. n b =n, without considering various losses, the secondary pressure outlet pressure P2 = P1; When the first solenoid valve (6) is energized and the rotor unit (2) rotates to connect the plunger hole with the first oil distribution hole (5-B1), the oil discharged from the plunger hole is discharged back to the oil tank through the first solenoid valve (6) and does not participate in the output of the secondary pressure; when the plunger hole rotates to connect with other oil distribution holes, the plunger hole outputs the secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is: When the first solenoid valve (6) and the second solenoid valve (7) are energized, the rotor unit (2) rotates to the plunger hole to communicate with the first oil distribution hole (5-B1) and the second oil distribution hole (5-B2), respectively, and the oil discharged from the plunger hole is discharged back to the oil tank through the first oil distribution hole (5-B1) or the second oil distribution hole (5-B2), the first solenoid valve (6) or the second solenoid valve (7), and does not participate in the output of the secondary pressure; when the plunger hole rotates to communicate with other oil distribution holes, the plunger hole outputs the secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-2, the output secondary pressure rises to: By analogy, the boost ratio of the supercharger can be changed by changing the amount of power supplied to the solenoid valve.

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