Automobile energy feedback type active suspension using planetary roller lead screw pair electric cylinder

Abstract

The invention discloses an automobile energy feedback type active suspension using a planetary roller screw pair electric cylinder, which belongs to the technical field of automobiles and comprises the planetary roller screw pair electric cylinder, a cylindrical permanent magnet linear generator set, a spring and connecting piece group and a protective sleeve group. Relative motion can be generated in the suspension system in the axial direction, and the permanent magnet linear generator can convert the energy into electric energy and then provide the electric energy to the electric cylinder. According to the invention, the cylindrical permanent magnet linear generator is installed in an automobile active suspension system, so that up-and-down bumping generated when an automobile runs on a road surface is converted into electric energy. The energy is saved, and the cruising ability is improved. And 3, the automobile active suspension can adapt to complex working conditions needing to face when the automobile suspension works, and meanwhile, compared with an automobile active suspension commonly used at present, the automobile active suspension can effectively reduce the size of the automobile suspension.

Description

Technical Field

[0001] The present invention relates to the technical field of automobiles, and particularly relates to an electric cylinder using a planetary roller screw pair as an energy-fed active suspension for automobiles. Background Art

[0002] At present, automotive active suspensions can be divided into different types such as hydraulic active suspensions, electromagnetic active suspensions, and pneumatic active suspensions according to their working principles. However, disadvantages such as high cost, high maintenance cost, and insufficient precision still exist in current mainstream active suspensions.

[0003] As a precision power transmission mechanism, the planetary roller screw pair can achieve the conversion between rotational motion and linear motion, and can convert the rotational motion of the motor into the linear motion of the suspension system. The planetary roller screw pair has the advantages of small volume, high precision, high load, long life, etc., and its output form of linear motion fully meets the requirements of automotive active suspensions. Therefore, an electric cylinder using a planetary roller screw pair is used as an automotive active suspension.

[0004] Currently, various new energy vehicles have started to develop vigorously, and endurance has become a data that major automobile manufacturers pay special attention to. The energy-fed active suspension can recover the energy generated by the up and down vibrations encountered by the vehicle during driving, which can save energy and improve the endurance of electric vehicles. Summary of the Invention

[0005] To solve the problems existing in the above background art, the present invention proposes an energy-fed active suspension for automobiles using an electric cylinder with a planetary roller screw pair, which has the advantages of small volume, high precision, high load, long life, and energy recovery.

[0006] The present invention uses a planetary roller screw with high transmission precision as the transmission mechanism of the automotive active suspension, a motor as the power source, and a tubular permanent magnet linear generator as the power generation source.

[0007] An energy-fed active suspension for automobiles using an electric cylinder with a planetary roller screw pair includes an electric cylinder with a planetary roller screw pair, a tubular permanent magnet linear generator set, a spring and connecting piece group, and a protective sleeve group; The electric cylinder with a planetary roller screw pair includes a motor group, a lead screw, planetary rollers, a nut, an internal gear ring, a cage, end covers, a coupling, and bearings; The motor group includes a motor housing, a motor, and a bottom cover; The internal gear ring includes an upper internal gear ring and a lower internal gear ring; The cage includes an upper cage and a lower cage; The end covers include an upper end cover and a lower end cover; The lead screw is divided into an upper section, a middle section, and a lower section. The outer diameter of the upper section is smaller than that of the middle section. The stator coil is wound around the upper section. The outer surface of the middle section has threads for mating with planetary rollers. The outer diameter of the lower section is stepped for sleeving bearings, and the outer end of the lower section is connected to a coupling. The planetary rollers are installed between the nut and the lead screw and mesh with the threaded section of the lead screw. The nut meshes with the planetary rollers. The nut is installed outside the threaded section of the lead screw, and the maximum stroke of the nut does not exceed the threaded section of the lead screw. The lower internal gear ring, the lower cage, and the lower end cover are installed on both sides of the nut. The inner ring gear of the lower internal gear ring meshes with the gear segments at both ends of the planetary rollers. The outer diameter of the internal gear ring is equal to the inner diameter at both ends of the nut, enabling the internal gear ring to fit into both ends of the nut. The circular holes distributed circumferentially on the lower cage cooperate with the cylinders at both ends of the planetary rollers. One side of the lower cage contacts one side of the lower internal gear ring, and the other side of the lower cage contacts one side of the lower end cover. The lower end cover is installed on both sides of the nut by screws. The connection structure of the upper internal gear ring, the upper cage, and the upper end cover is the same as that of the lower internal gear ring, the lower cage, and the lower end cover. The coupling is installed between the lead screw and the motor for connection and transmission. The bearing is installed between the lead screw and the motor housing to play a load-bearing role, and the motor housing is connected to the vehicle body.

[0008] The cylindrical permanent magnet linear generator set includes a generator housing, a mover magnetic pole, and a stator coil. The stator coil is installed at one end of the lead screw. The mover magnetic pole is installed in the generator housing. The inner diameter of the mover magnetic pole is equal to the minimum inner diameter of the generator housing, the outer diameter of the mover magnetic pole is equal to the maximum inner diameter of the generator housing, the width of the mover magnetic pole is equal to the width of the concave part on the inner surface of the generator housing, and the inner diameter of the mover magnetic pole is equal to the outer diameter of the stator coil. The generator housing and the mover magnetic pole are installed in the base after being assembled. When relative displacement occurs between the mover magnetic pole and the stator coil during operation, an electric current will be generated in the coil.

[0009] The spring and connector group includes an upper spring connector, a lower spring connector, a spring, and a base. The upper spring connector is installed on the base by screws. The lower spring connector is installed on the nut by screws. The spring is installed in the upper spring connector and the lower spring connector, and both ends of the spring are fixed to the upper spring connector and the lower spring connector respectively.

[0010] The protective sleeve group includes an upper protective sleeve connector, a lower protective sleeve connector, and a protective sleeve. The upper protective sleeve connector is installed on the base by screws. The lower protective sleeve connector is installed on the nut by screws. The protective sleeve is installed in the upper protective sleeve connector and the lower protective sleeve connector, and both ends of the protective sleeve are fixed to the upper protective sleeve connector and the lower protective sleeve connector respectively.

[0011] When the active suspension works, after the suspension receives road surface bumps, it will perform passive shock absorption through the spring and the damping of the suspension. At the same time, it will provide active force for active shock absorption. When providing active force, the motor main shaft rotates, drives the lead screw to rotate through the coupling. The lead screw meshes with the threads of the planetary rollers. The rotation of the lead screw drives the planetary rollers to perform circular motion around the lead screw while rotating on their own axes. The planetary rollers drive the nut to move up and down. The nut is connected to the spring, and the two cooperate to exert the shock absorption function of the active suspension.

[0012] The motor housing is connected to the vehicle body. Due to the bumps on the road surface, the base is subjected to force and moves up and down reciprocally. There will be relative movement between the base and the lead screw. The stator coil on the lead screw and the moving magnetic pole installed on the base form a linear generator. When there is relative movement between the base and the lead screw, an electric current will be generated, which plays a role in recovering the bump energy generated by the suspension system during the vehicle driving process.

[0013] The motor is installed at the bottom of the motor housing, and the motor main shaft is connected to the coupling.

[0014] The lower end of the lead screw is connected to the coupling, and at the same time, a bearing is installed between the lower part of the lead screw and the motor housing.

[0015] The motor housing and the nut are coaxially matched. The groove on the inner side of the motor housing cooperates with the protrusion on the outer surface of the nut to ensure that the nut and the electric cylinder housing move up and down.

[0016] The planetary rollers are distributed around the lead screw in a circular pattern. The two ends of the planetary rollers are respectively fixed on the upper cage and the lower cage. The gears at both ends of the planetary rollers are respectively meshed with the upper internal gear ring and the lower internal gear ring. The displacements of the internal gear rings and the cages in the axial direction are fixed by the nut and the upper end cover and the lower end cover; Both the upper and lower end covers are connected to the nut with four screws.

[0017] The spring is installed between the base and the nut, playing the role of passive damping.

[0018] A protective sleeve is installed between the base and the nut to protect the lead screw and the tubular permanent magnet linear generator.

[0019] When the suspension system is excited by the road surface, the passive damping part (spring) exerts the passive shock absorption effect. At the same time, the control system calculates the required output power and torque of the motor based on the data collected by the sensors.

[0020] The rotation of the motor drives the lead screw to rotate. The rotation of the lead screw drives the planetary rollers to rotate on their own axes while revolving around the lead screw. Finally, the planetary rollers drive the nut to move up and down, providing active force and displacement, and exerting the active shock absorption effect of the suspension system. The active shock absorption part and the passive damping part, under the control of the control system, together exert the shock absorption function of the vehicle suspension.

[0021] When the suspension system is working, there is always relative movement in the axial direction between the lead screw and the base, and the tubular permanent magnet linear generator can recover energy during this process. The beneficial technical effects of the present invention: 1. In the present invention, the planetary roller screw pair is used as an electric cylinder to provide the active force for the automotive active suspension. The ability of the planetary roller screw to convert the rotational motion of the motor into linear motion is ingeniously utilized. At the same time, the planetary roller screw has the characteristics of high load, high precision, small volume, and long life, which well meets the actual engineering needs of the automotive active suspension.

[0022] 2. By installing the tubular permanent magnet linear generator in the automotive active suspension system, the present invention converts the up-and-down bumps generated when the vehicle is driving on the road surface into electrical energy, which not only saves energy but also improves the endurance.

[0023] 3. The present invention can adapt to the complex working conditions faced by the automotive suspension, and at the same time, compared with the commonly used automotive active suspensions at present, it can effectively reduce the volume of the automotive suspension. Description of the Drawings

[0024] Figure 1 is a cross-sectional view of the present invention; Figure 2 is a three-dimensional exploded view of the generator of the present invention; Figure 3 is a schematic diagram of the cooperation between the planetary roller and the lead screw of the present invention; Figure 4 is Figure 1 an enlarged view of part A in Detailed Embodiments

[0025] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, an automotive energy-feeding active suspension using a planetary roller screw pair electric cylinder includes a planetary roller screw pair electric cylinder, a tubular permanent magnet linear generator set, a spring and connecting member group, and a protective sleeve group; The planetary roller screw pair electric cylinder includes a motor group, a lead screw 12, planetary rollers 13, a nut 14, an internal gear ring, a cage, end covers, a coupling 18, and a bearing 19; The motor group includes a motor housing 111, a motor 112, and a bottom cover 113; The internal gear ring includes an upper internal gear ring 151 and a lower internal gear ring 152; The cage includes an upper cage 161 and a lower cage 162; The end covers include an upper end cover 171 and a lower end cover 172; As shown Figure 2 in FIG. 1, the lead screw 12 is divided into an upper section, a middle section and a lower section. The outer diameter of the upper section is smaller than that of the middle section. The stator coil 23 is wound around the upper section. The outer surface of the middle section has threads for mating with the planetary rollers 13. The outer diameter of the lower section is stepped for sleeving the bearing 19. The outer end of the lower section is connected to the coupling 18; As shown Figure 1 in FIG. 2, the planetary rollers 13 are installed between the nut 14 and the lead screw 12 and mesh with the threaded section of the lead screw 12; the nut 14 meshes with the planetary rollers 13. The nut 14 is installed outside the threaded section of the lead screw 12, and the maximum stroke of the nut 14 does not exceed the threaded section of the lead screw 12; As shown Figure 4 in FIG. 3, the lower internal gear ring 152, the lower cage 162 and the lower end cover 172 are installed on both sides of the nut 14. The inner ring gear of the lower internal gear ring 152 meshes with the two end gear sections of the planetary rollers 13. The outer diameter of the internal gear ring is equal to the inner diameter of both ends of the nut 14, so that the internal gear ring can be placed into both ends of the nut. The circular holes distributed circumferentially on the lower cage 162 cooperate with the cylinders at both ends of the planetary rollers 13. One side of the lower cage 162 contacts one side of the lower internal gear ring 152, and the other side of the lower cage 162 contacts one side of the lower end cover 172. The lower end cover 172 is installed on both sides of the nut 14 by screws. The connection structure of the upper internal gear ring 151, the upper cage 162 and the upper end cover 171 is the same as that of the lower internal gear ring 152, the lower cage 162 and the lower end cover 172; As shown Figure 1 in FIG. 4, the coupling 18 is installed between the lead screw 12 and the motor 112 for connection and transmission. The bearing 19 is installed between the lead screw 12 and the motor housing 111 to play a bearing role, and the motor housing 111 is connected to the vehicle body.

[0026] The tubular permanent magnet linear generator set includes a generator housing 21, a mover magnetic pole 22, and a stator coil 23; As shown Figure 2 in FIG. 5, the stator coil 23 is installed at one end of the lead screw 12; the mover magnetic pole 22 is installed in the generator housing 21. The inner diameter of the mover magnetic pole 22 is equal to the minimum inner diameter of the generator housing 21, the outer diameter of the mover magnetic pole 22 is equal to the maximum inner diameter of the generator housing 21, the width of the mover magnetic pole 22 is equal to the width of the concave part on the inner surface of the generator housing 21, and the inner diameter of the mover magnetic pole 22 is equal to the outer diameter of the stator coil 23; The generator housing 21 and the mover magnetic pole 22 are installed in the base 34 after being fitted; When the mover magnetic pole 22 and the stator coil 23 generate relative displacement during operation, an electric current will be generated in the coil.

[0027] The spring and connector group includes an upper spring connector 31, a lower spring connector 32, a spring 33 and a base 34; As shown Figure 1 As shown, the upper spring connecting member 31 is mounted on the base 34 by screws, the lower spring connecting member 32 is mounted on the nut 14 by screws, the spring 33 is mounted in the upper spring connecting member 31 and the lower spring connecting member 32, and both ends of the spring 33 are fixed to the upper spring connecting member 31 and the lower spring connecting member 32 respectively.

[0028] The protective sleeve group includes an upper protective sleeve connecting member 41, a lower protective sleeve connecting member 42, and a protective sleeve 43; As shown Figure 1 As shown, the upper protective sleeve connecting member 41 is mounted on the base 34 by screws, the lower protective sleeve connecting member 42 is mounted on the nut 14 by screws, the protective sleeve 43 is mounted in the upper protective sleeve connecting member 41 and the lower protective sleeve connecting member 42, and both ends of the protective sleeve 43 are fixed to the upper protective sleeve connecting member 41 and the lower protective sleeve connecting member 42 respectively.

[0029] As shown Figure 1 As shown, when the active suspension works, after the suspension receives road surface bumps, it will perform passive shock absorption through the spring 33 and the damping of the suspension, and at the same time, it will provide an active force for active shock absorption. When providing the active force, the main shaft of the motor 112 rotates, drives the lead screw 12 to make a rotational motion through the coupling 18. The lead screw 12 is in threaded engagement with the planetary roller 13. When the lead screw 12 rotates, it drives the planetary roller 13 to make a circular motion around the lead screw 12 while rotating itself. The planetary roller 13 drives the nut 14 to move up and down. The nut 14 is connected to the spring 33, and the two cooperate to exert the shock absorption function of the active suspension.

[0030] The motor housing 111 is connected to the vehicle body. Due to the bumps on the road surface, the base 34 is subjected to a force and will move up and down reciprocally. There will be relative movement between the base 34 and the lead screw 12. The stator coil 23 on the lead screw 12 and the mover magnetic pole 22 mounted on the base 34 form a linear generator. When there is relative movement between the base 34 and the lead screw 12, an electric current will be generated, which plays a role in recovering the bump energy generated by the suspension system during the vehicle driving process.

[0031] As shown Figure 1 As shown, the motor 112 is mounted at the bottom of the motor housing 111, and the motor main shaft is connected to the coupling 18.

[0032] As shown Figure 1 As shown, the lower end of the lead screw 12 is connected to the coupling 18, and at the same time, a bearing 19 is installed between the lower part of the lead screw 12 and the motor housing 111.

[0033] As shown Figure 1 As shown, the motor housing 111 and the nut 14 are coaxially matched. The groove inside the motor housing 111 cooperates with the protrusion on the outer surface of the nut 14 to ensure that the nut 14 can move up and down between the electric cylinder housing.

[0034] As Figure 3 , Figure 4 shown, the planetary rollers 13 are circumferentially distributed around the lead screw 12. Both ends of the planetary rollers 13 are respectively fixed on the upper cage 161 and the lower cage 162. The gears at both ends of the planetary rollers 13 are respectively meshed with the upper internal gear ring 151 and the lower internal gear ring 152. The displacements of the internal gear rings and the cages 16 in the axial direction are fixed by the nut 14 and the upper end cover 171 and the lower end cover 172; Four screws are used to connect between the upper and lower end covers 171 and the nut 14.

[0035] As Figure 1 shown, the spring 33 is installed between the base 34 and the nut 14, playing the role of passive damping.

[0036] A protective sleeve 43 is installed between the base 24 and the nut 14 to protect the lead screw 12 and the tubular permanent magnet linear generator.

[0037] When the suspension system is excited by the road surface, the passive damping part (spring) plays the passive shock absorption effect. At the same time, the control system calculates the required output power and torque of the motor based on the data collected by the sensors.

[0038] The motor 112 rotates to drive the lead screw 12 to rotate. When the lead screw 12 rotates, the planetary rollers 13 rotate around the lead screw 12 while revolving around it. Finally, the planetary rollers 13 drive the nut 14 to move up and down, providing the active force and displacement, and playing the active shock absorption effect of the suspension system. The active shock absorption part and the passive damping part work together to play the shock absorption function of the vehicle suspension under the control of the control system.

[0039] When the suspension system works, there is always relative movement in the axial direction between the lead screw 12 and the base 34. The tubular permanent magnet linear generator can recover energy during this process.

Claims

1. A planetary roller screw pair electric cylinder is used as an automotive energy-feeding active suspension, characterized in that: It includes a planetary roller screw auxiliary electric cylinder, a cylindrical permanent magnet linear generator set, a spring and a connecting parts set; The planetary roller screw auxiliary electric cylinder comprises a motor group, a screw (12), a planetary roller (13), a nut (14), an inner gear ring, a retaining frame, an end cover, a coupling (18) and a bearing (19); The motor assembly comprises a motor housing (111), a motor (112) and a bottom cover (113); The inner gear ring comprises an upper inner gear ring (151) and a lower inner gear ring (152); The retaining frame comprises an upper retaining frame (161) and a lower retaining frame (162); The end cover comprises an upper end cover (171) and a lower end cover (172); The lead screw (12) is divided into an upper section, a middle section and a lower section. The upper section has an outer diameter smaller than that of the middle section. The stator coil (23) is wound on the upper section. The outer surface of the middle section has a thread for cooperating with the planetary roller (13). The outer diameter of the lower section is stepped for sleeve-mounting the bearing (19). The outer end of the lower section is connected to the coupling (18). The planetary roller (13) is mounted between the nut (14) and the lead screw (12) and meshes with the threaded section of the lead screw (12); the nut (14) meshes with the planetary roller (13), the nut (14) is mounted outside the threaded section of the lead screw (12), and the maximum stroke of the nut (14) does not exceed the threaded section of the lead screw (12); The lower inner gear ring (152), the lower retaining frame (162) and the lower end cover (172) are mounted on both sides of the nut (14); the inner ring gear of the lower inner gear ring (152) meshes with the gear segments at both ends of the planetary roller (13); the outer diameter of the inner gear ring is equal to the inner diameter at both ends of the nut (14); the circular holes distributed circumferentially on the lower retaining frame (162) match with the cylinders at both ends of the planetary roller (13); one side of the lower retaining frame (162) contacts one side of the lower inner gear ring (152); the other side of the lower retaining frame (162) contacts one side of the lower end cover (172); the lower end cover (172) is mounted on both sides of the nut (14) by screws; the connection structure of the upper inner gear ring (151), the upper retaining frame (162) and the upper end cover (171) is the same as the connection structure of the lower inner gear ring (152), the lower retaining frame (162) and the lower end cover (172); The coupling (18) is installed between the lead screw (12) and the motor (112) for connection and transmission. The bearing (19) is installed between the lead screw (12) and the motor housing (111) for bearing. The motor housing (111) is connected to the vehicle body.

2. The cylindrical permanent magnet linear generator set comprises a generator housing (21), a mover magnetic pole (22), and a stator coil (23); the stator coil (23) is mounted on one end of the lead screw (12); the mover magnetic pole (22) is mounted in the generator housing (21); the inner diameter of the mover magnetic pole (22) is equal to the minimum inner diameter of the generator housing (21); the outer diameter of the mover magnetic pole (22) is equal to the maximum inner diameter of the generator housing (21); the width of the mover magnetic pole (22) is equal to the width of the inner concave portion of the inner surface of the generator housing (21); the inner diameter of the mover magnetic pole (22) is equal to the outer diameter of the stator coil (23); the generator housing (21) and the mover magnetic pole (22) are mounted in a base (34) after being matched; The spring and connecting member assembly comprises an upper spring connecting member (31), a lower spring connecting member (32), a spring (33) and a base (34); the upper spring connecting member (31) is mounted on the base (34) by means of screws, the lower spring connecting member (32) is mounted on the nut (14) by means of screws, the spring (33) is mounted in the upper spring connecting member (31) and the lower spring connecting member (32), and two ends of the spring (33) are respectively fixed to the upper spring connecting member (31) and the lower spring connecting member (32); The motor (112) is mounted on the bottom of the motor housing (111), and the motor main shaft is connected to the coupling (18); The lower end of the lead screw (12) is connected to the coupling (18), and a bearing (19) is installed between the lower part of the lead screw (12) and the motor housing (111); The motor housing (111) and the nut (14) are coaxially matched, and the groove on the inner side of the motor housing (111) is matched with the protrusion on the outer surface of the nut (14), so as to ensure that the nut (14) and the electric cylinder housing can maintain up and down movement; The planetary rollers (13) are distributed around the lead screw (12) in a circumferential manner. The two ends of the planetary rollers (13) are respectively fixed on an upper retaining frame (161) and a lower retaining frame (162). The gears at the two ends of the planetary rollers (13) are respectively meshed with an upper inner gear ring (151) and a lower inner gear ring (152). The displacement of the inner gear ring and the retaining frame 16 along the axial direction is fixed by a nut (14) and an upper end cover (171) and a lower end cover (172).

3. The method of using a planetary roller screw pair electric cylinder as an automotive energy-feeding active suspension according to claim 1, characterized in that: The protective sleeve assembly also includes an upper protective sleeve connecting piece (41), a lower protective sleeve connecting piece (42), and a protective sleeve (43); the upper protective sleeve connecting piece (41) is mounted on the base (34) by means of screws, the lower protective sleeve connecting piece (42) is mounted on the nut (14) by means of screws, the protective sleeve (43) is mounted in the upper protective sleeve connecting piece (41) and the lower protective sleeve connecting piece (42), and two ends of the protective sleeve (43) are respectively fixed to the upper protective sleeve connecting piece (41) and the lower protective sleeve connecting piece (42).

4. The method of using a planetary roller screw pair electric cylinder as an automotive energy-feeding active suspension according to claim 1, characterized in that: The upper and lower end covers (171) and the nuts (14) are connected by four screws.

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