A planetary roller screw pair electric cylinder as an energy-regenerative active suspension for automobiles

Abstract

This invention discloses a planetary roller screw-type electric cylinder as an active suspension system for automobiles, belonging to the field of automotive technology. It includes a planetary roller screw-type electric cylinder, a cylindrical permanent magnet linear generator set, springs and connecting components, and a protective sleeve assembly. The electric cylinder provides the active force to work with the springs and the stiffness of the suspension system to dampen vibrations. Relative motion occurs within the suspension system along the axial direction, and the permanent magnet linear generator converts this energy into electrical energy, which is then supplied to the electric cylinder. This invention converts the vertical bumps generated by the car while driving into electrical energy by installing the cylindrical permanent magnet linear generator in the active suspension system. This saves energy and improves driving range. Furthermore, this invention can adapt to the complex working conditions faced by automotive suspensions, and compared to currently used active suspension systems, it can effectively reduce the size of the automotive suspension.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, specifically to an active suspension system for automobiles that uses a planetary roller screw pair electric cylinder as an energy-regenerating mechanism. Background Technology

[0002] Currently, active suspension systems for automobiles can be classified into different types based on their working principles, such as hydraulic active suspension, electromagnetic active suspension, and air pressure active suspension. However, drawbacks such as high manufacturing cost, high maintenance cost, and insufficient precision still exist in the current mainstream active suspension systems.

[0003] Planetary roller screw pairs, as a precision power transmission mechanism, can convert rotary motion into linear motion, transforming the rotary motion of a motor into the linear motion of the suspension system. Planetary roller screw pairs offer advantages such as small size, high precision, high load capacity, and long lifespan. Their linear motion output perfectly meets the requirements of automotive active suspension systems. Therefore, planetary roller screw pairs with electric cylinders are used in automotive active suspension systems.

[0004] Currently, various new energy vehicles are booming, and range has become a key data point of great concern for major automakers. Energy-regenerating active suspension can recover the energy generated by the vertical vibrations encountered by the car during driving, which can save energy and improve the range of electric vehicles. Summary of the Invention

[0005] To address the problems existing in the background technology, this invention proposes an active suspension system for automobiles that uses a planetary roller screw pair electric cylinder as an energy-recovering system. This suspension system has the advantages of small size, high precision, high load capacity, long service life, and energy recovery capability.

[0006] This invention uses a planetary roller screw with high transmission precision as the transmission mechanism of an active suspension system for automobiles, an electric motor as the power source, and a cylindrical permanent magnet linear generator as the power source.

[0007] A planetary roller screw electric cylinder is used as an active suspension for automobiles with energy regeneration, comprising a planetary roller screw electric cylinder, a cylindrical permanent magnet linear generator set, a spring and connecting parts assembly, and a protective sleeve assembly.

[0008] The planetary roller screw electric cylinder includes a motor assembly, a screw, planetary rollers, a nut, an internal gear ring, a cage, an end cover, a coupling, and bearings.

[0009] The motor assembly includes a motor housing, a motor, and a bottom cover;

[0010] The internal gear ring includes an upper internal gear ring and a lower internal gear ring;

[0011] The cage includes an upper cage and a lower cage;

[0012] The end cap includes an upper end cap and a lower end cap;

[0013] 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 on 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 to accommodate bearings. The outer end of the lower section is connected to the coupling.

[0014] 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, and 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.

[0015] The lower internal gear ring, lower cage, and lower end cap are installed on both sides of the nut. The inner gear of the lower internal gear ring meshes with the gear sections at both ends of the planetary roller. The outer diameter of the internal gear ring is equal to the inner diameter at both ends of the nut, so that the internal gear ring can be inserted into both ends of the nut. The circular holes distributed on the lower cage mate with the cylindrical parts at both ends of the planetary roller. 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 cap. The lower end cap is installed on both sides of the nut by screws. The connection structure of the upper internal gear ring, upper cage, and upper end cap is the same as that of the lower internal gear ring, lower cage, and lower end cap.

[0016] 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 provide load-bearing capacity. The motor housing is connected to the vehicle body.

[0017] The cylindrical permanent magnet linear generator set includes a generator casing, a moving magnetic pole, and a stator coil;

[0018] 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.

[0019] The generator casing and the moving pole are fitted together and then installed in the base.

[0020] When the moving pole and the stator coil are relatively displaced during operation, a current will be generated in the coil.

[0021] The spring and connecting assembly includes an upper spring connecting component, a lower spring connecting component, a spring, and a base;

[0022] The upper spring connector is mounted on the base with screws, and the lower spring connector is mounted on the nut with screws. The spring is installed in the upper and lower spring connectors, and both ends of the spring are fixed to the upper and lower spring connectors respectively.

[0023] The protective sleeve assembly includes an upper protective sleeve connector, a lower protective sleeve connector, and a protective sleeve;

[0024] The upper protective sleeve connector is mounted on the base with screws, and the lower protective sleeve connector is mounted on the nut with screws. The protective sleeve is installed in the upper and lower protective sleeve connectors, and both ends of the protective sleeve are fixed to the upper and lower protective sleeve connectors respectively.

[0025] When the active suspension is working, the suspension receives road bumps and passively absorbs them through the springs and suspension damping. At the same time, it provides active force for active damping. When providing active force, the motor spindle rotates, which drives the lead screw to rotate through the coupling. The lead screw is threaded with the planetary rollers. The rotation of the lead screw drives the planetary rollers to rotate on their own axis and move in a circle around the lead screw. The planetary rollers drive the nut to move up and down. The nut is connected to the spring. The two work together to perform the damping function of the active suspension.

[0026] The motor housing is connected to the vehicle body. Due to the bumps on the road, the base will move up and down back and forth under the force. 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 constitute a linear generator. When the base and the lead screw move relative to each other, current will be generated, which will play the role of recovering the bump energy generated by the suspension system during the car's driving.

[0027] The motor is mounted at the bottom of the motor housing, and the motor shaft is connected to the coupling.

[0028] The lower end of the lead screw is connected to the coupling, and a bearing is installed between the lower part of the lead screw and the motor housing.

[0029] The motor housing and the nut are coaxially fitted, and the groove on the inner side of the motor housing fits with the protrusion on the outer surface of the nut, ensuring that the nut and the electric cylinder housing can move up and down.

[0030] Planetary rollers are distributed circumferentially around the lead screw. The two ends of the planetary rollers are fixed to the upper and lower cages respectively. The gears at both ends of the planetary rollers mesh with the upper and lower internal gear rings respectively. The displacement of the internal gear rings and the cages along the axial direction is fixed by the nut and the upper and lower end caps.

[0031] The upper and lower end caps are connected to the nuts using four screws.

[0032] The spring is installed between the base and the nut, and plays a passive damping role.

[0033] A protective sleeve is installed between the base and the nut to protect the lead screw and the cylindrical permanent magnet linear generator.

[0034] When the suspension system is subjected to road surface excitation, the passive damping part (spring) plays a passive damping role. At the same time, the control system calculates the output power and torque required by the motor based on the data collected by the sensors.

[0035] The motor rotates, which drives the lead screw to rotate. The lead screw rotates, which in turn drives the planetary rollers to rotate on their own axis and revolve 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 damping effect of the suspension system. Under the control of the control system, the active damping part and the passive damping part work together to perform the damping function of the car suspension.

[0036] When the suspension system is working, there is a constant relative movement between the lead screw and the base in the axial direction, and the cylindrical permanent magnet linear generator can recover energy in this process.

[0037] Beneficial technical effects of the present invention:

[0038] 1. This invention uses a planetary roller screw pair as an electric cylinder to provide active force for the active suspension of a car. It cleverly utilizes the ability of the planetary roller screw to convert the rotational motion of the motor into linear motion. At the same time, the planetary roller screw has the characteristics of high load, high precision, small size and long service life, which is very suitable for the actual engineering needs of active suspension of cars.

[0039] 2. This invention installs a cylindrical permanent magnet linear generator in the active suspension system of a car, converting the up-and-down bumps generated when the car is driving on the road into electrical energy, which saves energy and improves the driving range.

[0040] 3. This invention can adapt to the complex working conditions that automotive suspensions need to face, and compared with currently commonly used automotive active suspensions, it can effectively reduce the size of automotive suspensions. Attached Figure Description

[0041] Figure 1 This is a cross-sectional view of the present invention;

[0042] Figure 2 This is an exploded perspective view of the generator of the present invention;

[0043] Figure 3 This is a schematic diagram of the planetary roller and lead screw assembly of the present invention;

[0044] Figure 4 for Figure 1 Enlarged view of point A in the image. Detailed Implementation

[0045] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a planetary roller screw electric cylinder is used as an active suspension for automobiles, which includes a planetary roller screw electric cylinder, a cylindrical permanent magnet linear generator set, a spring and connecting parts assembly, and a protective sleeve assembly.

[0046] The planetary roller screw electric cylinder includes a motor assembly, a screw 12, planetary rollers 13, a nut 14, an internal gear ring, a cage, an end cover, a coupling 18, and a bearing 19.

[0047] The motor assembly includes a motor housing 111, a motor 112, and a bottom cover 113;

[0048] The internal gear ring includes an upper internal gear ring 151 and a lower internal gear ring 152;

[0049] The cage includes an upper cage 161 and a lower cage 162;

[0050] The end cap includes an upper end cap 171 and a lower end cap 172;

[0051] like Figure 2 As shown, 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 on the upper section. The outer surface of the middle section has threads for mating with the planetary roller 13. The outer diameter of the lower section is stepped to accommodate the bearing 19. The outer end of the lower section is connected to the coupling 18.

[0052] like Figure 1 As shown, the planetary roller 13 is installed 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 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.

[0053] like Figure 4 As shown, the lower internal gear ring 152, the lower retainer 162, and the lower end cap 172 are installed on both sides of the nut 14. The inner gear of the lower internal gear ring 152 meshes with the gear sections at both ends of the planetary roller 13. The outer diameter of the internal gear ring is equal to the inner diameter at both ends of the nut 14, so that the internal gear ring can be inserted into both ends of the nut. The circular holes distributed around the lower retainer 162 are engaged with the cylindrical parts at both ends of the planetary roller 13. One side of the lower retainer 162 contacts one side of the lower internal gear ring 152, and the other side of the lower retainer 162 contacts one side of the lower end cap 172. The lower end cap 172 is installed on both sides of the nut 14 by screws. The connection structure of the upper internal gear ring 151, the upper retainer 162, and the upper end cap 171 is the same as the connection structure of the lower internal gear ring 152, the lower retainer 162, and the lower end cap 172.

[0054] like Figure 1As shown, the coupling 18 is installed between the lead screw 12 and the motor 112 for connection and transmission, and the bearing 19 is installed between the lead screw 12 and the motor housing 111 to perform the load-bearing function. The motor housing 111 is connected to the vehicle body.

[0055] The cylindrical permanent magnet linear generator set includes a generator housing 21, a moving magnetic pole 22, and a stator coil 23;

[0056] like Figure 2 As shown, the stator coil 23 is installed at one end of the lead screw 12; the mover pole 22 is installed in the generator housing 21. The inner diameter of the mover pole 22 is equal to the minimum inner diameter of the generator housing 21, the outer diameter of the mover pole 22 is equal to the maximum inner diameter of the generator housing 21, the width of the mover pole 22 is equal to the width of the recessed part on the inner surface of the generator housing 21, and the inner diameter of the mover pole 22 is equal to the outer diameter of the stator coil 23.

[0057] The generator housing 21 and the moving pole 22 are fitted together and installed in the base 34;

[0058] When the moving pole 22 and the stator coil 23 are relatively displaced during operation, a current will be generated in the coil.

[0059] The spring and connecting component assembly includes an upper spring connecting component 31, a lower spring connecting component 32, a spring 33, and a base 34;

[0060] like Figure 1 As shown, the upper spring connector 31 is mounted on the base 34 by screws, the lower spring connector 32 is mounted on the nut 14 by screws, and the spring 33 is installed in the upper spring connector 31 and the lower spring connector 32. The two ends of the spring 33 are fixed to the upper spring connector 31 and the lower spring connector 32 respectively.

[0061] The protective sleeve assembly includes an upper protective sleeve connector 41, a lower protective sleeve connector 42, and a protective sleeve 43;

[0062] like Figure 1 As shown, the upper protective sleeve connector 41 is mounted on the base 34 by screws, the lower protective sleeve connector 42 is mounted on the nut 14 by screws, and the protective sleeve 43 is installed in the upper protective sleeve connector 41 and the lower protective sleeve connector 42. The two ends of the protective sleeve 43 are fixed to the upper protective sleeve connector 41 and the lower protective sleeve connector 42 respectively.

[0063] like Figure 1As shown, when the active suspension is working, the suspension receives road bumps and passively absorbs them through the spring 33 and the suspension damping. At the same time, it provides active force for active damping. When providing active force, the main shaft of the motor 112 rotates, which drives the lead screw 12 to rotate through the coupling 18. The lead screw 12 is threaded with the planetary roller 13. The rotation of the lead screw 12 drives the planetary roller 13 to rotate around the lead screw 12 while rotating on its own axis. The planetary roller 13 drives the nut 14 to move up and down. The nut 14 is connected to the spring 33. The two work together to perform the damping function of the active suspension.

[0064] The motor housing 111 is connected to the vehicle body. Due to the bumps on the road, the base 34 will move up and down back and forth under the force. 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 moving magnetic pole 22 installed on the base 34 constitute a linear generator. When the base 34 and the lead screw 12 move relative to each other, current will be generated, which will recover the bump energy generated by the suspension system during the vehicle's operation.

[0065] like Figure 1 As shown, the motor 112 is mounted at the bottom of the motor housing 111, and the motor spindle is connected to the coupling 18.

[0066] like Figure 1 As shown, 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.

[0067] like Figure 1 As shown, the motor housing 111 and the nut 14 are coaxially fitted, and the groove on the inner side of the motor housing 111 fits with the protrusion on the outer surface of the nut 14 to ensure that the nut 14 and the electric cylinder housing can move up and down.

[0068] like Figure 3 , Figure 4 As shown, planetary rollers 13 are distributed circumferentially around the lead screw 12. The two ends of the planetary rollers 13 are fixed on the upper cage 161 and the lower cage 162 respectively. The gears at both ends of the planetary rollers 13 mesh with the upper internal gear ring 151 and the lower internal gear ring 152 respectively. The displacement of the internal gear ring and the cage 16 along the axial direction is fixed by the nut 14 and the upper end cover 171 and the lower end cover 172.

[0069] The upper and lower end caps 171 are connected to the nut 14 by four screws.

[0070] like Figure 1 As shown, spring 33 is installed between base 34 and nut 14, and plays the role of passive damping.

[0071] A protective sleeve 43 is installed between the base 24 and the nut 14 to protect the lead screw 12 and the cylindrical permanent magnet linear generator.

[0072] When the suspension system is subjected to road surface excitation, the passive damping part (spring) plays a passive damping role. At the same time, the control system calculates the output power and torque required by the motor based on the data collected by the sensors.

[0073] The rotation of motor 112 drives the lead screw 12 to rotate. The rotation of lead screw 12 drives planetary roller 13 to rotate on its own axis and revolve around lead screw 12. Finally, planetary roller 13 drives nut 14 to move up and down, providing active force and displacement, and exerting the active damping effect of suspension system. Under the control of control system, active damping part and passive damping part work together to exert the damping function of car suspension.

[0074] When the suspension system is working, the lead screw 12 and the base 34 are constantly in relative motion in the axial direction, and the cylindrical permanent magnet linear generator can recover energy in this process.

Claims

1. A planetary roller screw pair electric cylinder as an energy-regenerating active suspension for automobiles, characterized in that: Includes planetary roller screw electric cylinder, cylindrical permanent magnet linear generator set, spring and connecting parts assembly; The spring and connecting parts assembly includes an upper spring connecting part (31), a lower spring connecting part (32), a spring (33), and a base (34); the upper spring connecting part (31) is mounted on the base (34) by screws, the lower spring connecting part (32) is mounted on the nut (14) by screws, the spring (33) is installed in the upper spring connecting part (31) and the lower spring connecting part (32), and the two ends of the spring (33) are fixed to the upper spring connecting part (31) and the lower spring connecting part (32) respectively; The cylindrical permanent magnet linear generator set includes a generator housing (21), a moving pole (22), and a stator coil (23); the stator coil (23) is installed at one end of the lead screw (12); the moving pole (22) is installed in the generator housing (21), the inner diameter of the moving pole (22) is equal to the minimum inner diameter of the generator housing (21), the outer diameter of the moving pole (22) is equal to the maximum inner diameter of the generator housing (21), the width of the moving pole (22) is equal to the width of the concave part of the inner surface of the generator housing (21), and the inner diameter of the moving pole (22) is equal to the outer diameter of the stator coil (23); the generator housing (21) and the moving pole (22) are fitted together and installed in the base (34); The planetary roller screw electric cylinder includes a motor assembly, a screw (12), planetary rollers (13), a nut (14), an internal gear ring, a cage, an end cover, a coupling (18), and a bearing (19). The motor assembly 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 cap includes an upper end cap (171) and a lower end cap (172). 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 on the upper section. The outer surface of the middle section has threads for mating with the planetary roller (13). The outer diameter of the lower section is stepped for fitting the bearing (19). The outer end of the lower section is connected to the coupling (18). The planetary roller (13) is installed between the nut (14) and the lead screw (12) and engages with the threaded section of the lead screw (12); the nut (14) engages with the planetary roller (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); The upper internal gear ring (151), upper cage (161), upper end cap (171), and lower internal gear ring (152), lower cage (162), and lower end cap (172) are installed on both sides of the nut (14). The inner gear of the lower internal gear ring (152) meshes with the gear section of the planetary roller (13). The outer diameter of the internal gear ring is equal to the inner diameter of the nut (14). The circular holes distributed around the lower cage (162) fit with the cylindrical parts of the planetary roller (13). One side of the lower retainer (162) contacts one side of the lower internal gear ring (152), and the other side of the lower retainer (162) contacts one side of the lower end cap (172). The lower end cap (172) is mounted on the nut (14) by screws. The connection structure of the upper internal gear ring (151), the upper retainer (161), and the upper end cap (171) is the same as the connection structure of the lower internal gear ring (152), the lower retainer (162), and the lower end cap (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) to bear load. The motor housing (111) is connected to the vehicle body. The motor (112) is installed at the bottom of the motor housing (111), and the motor spindle 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 fitted. The groove on the inner side of the motor housing (111) fits with the protrusion on the outer surface of the nut (14) to ensure that the nut (14) and the electric cylinder housing move up and down. Planetary rollers (13) are distributed circumferentially around the lead screw (12). The two ends of the planetary rollers (13) are fixed on the upper cage (161) and the lower cage (162) respectively. The gears at both ends of the planetary rollers (13) mesh with the upper internal gear ring (151) and the lower internal gear ring (152) respectively. The displacement of the internal gear ring and the cage 16 along the axial direction is fixed by the nut (14) and the upper end cover (171) and the lower end cover (172).

2. The method of using a planetary roller screw pair electric cylinder as an energy-regenerating active suspension for automobiles according to claim 1, characterized in that: It also includes a protective sleeve assembly, which includes an upper protective sleeve connector (41), a lower protective sleeve connector (42), and a protective sleeve (43). The upper protective sleeve connector (41) is mounted on the base (34) by screws, the lower protective sleeve connector (42) is mounted on the nut (14) by screws, and the protective sleeve (43) is installed in the upper protective sleeve connector (41) and the lower protective sleeve connector (42). The two ends of the protective sleeve (43) are fixed to the upper protective sleeve connector (41) and the lower protective sleeve connector (42) respectively.

3. The method of using a planetary roller screw pair electric cylinder as an energy-regenerating active suspension for automobiles according to claim 1, characterized in that: The upper end cap (171) and lower end cap (172) are connected to the nut (14) by four screws.

Images