Novel driving mechanism of vehicle braking system
Through the planetary transmission mechanism with a less tooth difference and a pin-type torque output mechanism, combined with the frameless motor and sliding bearing design, the installation and performance challenges of the electric drive mechanism of the vehicle brake system in a limited space are solved, and efficient thrust output and rapid response are achieved, replacing the traditional hydraulic mechanism.
Patent Information
- Application Number
- CN202422446696.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-10-10
AI Technical Summary
When converting the drive mechanism of the existing vehicle brake system to electric drive, it faces the challenges of limited installation space, high output thrust requirements, fast reaction time and total lead screw stroke. In particular, the limitations of axial and radial dimensions are difficult to meet the design needs of the electric drive mechanism.
The planetary transmission mechanism with a less tooth difference and a pin-type torque output mechanism is adopted, combined with the frameless motor and sliding bearing design, through the meshing transmission of the eccentric sleeve and the planetary gear, the direct transmission of torque and the output of thrust is achieved. At the same time, the steel ball blocking mechanism is used to replace the huge thrust bearing to optimize space utilization.
The research and development of the electric drive mechanism has been achieved in a limited space, with an output thrust of 65KN, a reaction time of less than 100 milliseconds, and the product performance is not inferior to the original hydraulic mechanism, meeting the electric drive needs of the vehicle braking system.
Smart Images
Figure CN223203540U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automobile brake system driving, in particular to a novel driving mechanism of a vehicle brake system. Background Art
[0002] Currently, most vehicle brake systems on the market utilize hydraulic actuation mechanisms. However, with the increasing demand for digital and intelligent vehicle control, customers are seeking to achieve the same goals and effects with electric actuation. Electric actuation offers greater programmability and control, significantly improving vehicle digitalization and intelligence while also eliminating the associated challenges of hydraulic systems. However, transitioning to this actuation structure presents a number of challenges.
[0003] The chassis design of the vehicle has been finalized, and the space for placing the drive mechanism, as well as the radial and axial dimensions, has been determined. The electric drive mechanism needs to be replaced, but the chassis design dimensions are limited, and the installation space dimensions left for the drive mechanism do not want to change. At the same time, the thrust output and response time of the drive mechanism must not be inferior to the original hydraulic mechanism. This poses a huge challenge to the development and design of the electric drive mechanism. The present utility model is created to meet these challenges. The main challenges are four points: (1) The axial dimension of the drive mechanism housing is required to be less than 65mm, and the radial dimension is less than 110mm; (2) The clamping thrust is preferably 65KN, and the minimum is 45KN; (3) The clamping action is completed within 100 milliseconds by advancing 1mm; (4) The total stroke of the screw is 10mm. The main challenge is that this reserved space is too small for an electric drive mechanism, especially the axial dimension, which is a very demanding requirement and cannot be achieved without special means. The output thrust is also incomparably large. Utility Model Content
[0004] In order to solve the above problems, the utility model provides a new driving mechanism of a vehicle braking system.
[0005] The utility model is realized through the following technical solutions:
[0006] A new type of driving mechanism of a vehicle braking system includes a rear cover of a driving mechanism housing and a front cover of a driving mechanism housing, a small shaft is provided in the center of the inner side of the rear cover of the driving mechanism housing, the outer cylindrical surface of the small shaft is sleeved in the inner hole of the rear stop head of the nut, the outer ring of the rear stop head of the nut is sleeved in the inner hole of the left end of the nut and torque output disc integrated part, and has a shaft shoulder for positioning, the outer ring of the right end of the nut and torque output disc integrated part is sleeved in the center hole of the front cover of the driving mechanism housing, the left and right ends of the nut and torque output disc integrated part are respectively supported on the small shaft of the rear cover of the housing and in the center hole of the front cover of the housing to form a through shaft, the nut A screw is provided inside the integrated nut and torque output disc, and the output end of the screw extends to the outside of the front cover of the driving mechanism housing. The integrated nut and torque output disc includes a torque output disc and a planetary roller screw nut. The outer sleeve of the planetary roller screw nut is provided with an eccentric sleeve, and the left outer ring of the eccentric sleeve is connected to the motor shaft, and the motor shaft is connected to the motor rotor of its outer ring. A motor stator is provided on the outside of the motor rotor, and a plurality of eccentric cylinders are provided on the right side of the eccentric sleeve. The outer ring of each eccentric cylinder is sleeved with a planetary gear, which rotates around its own eccentricity and meshes with the ring gear to form the planetary transmission mechanism with a small tooth difference;
[0007] The small-tooth-difference planetary transmission mechanism adopts a pin-type output mechanism, each planetary gear has several torque output holes, and a torque output disk is provided on the right side of the planetary gear. Several pins are forcibly inserted into the corresponding torque output holes of the torque output disk in an interference fit manner, and become a whole with the torque output disk. After the several pins pass through the torque output holes of the planetary gears, they are covered by pin covers on the ends of the pins extending outside the torque output holes of the planetary gears. The several pins are also connected as a whole on the left side, and a pin sleeve is provided between the connection between the pins and the torque output holes of the planetary gears. The outer ring of the planetary gear is connected to a gear ring, and the two ends of the gear ring are respectively connected to the rear cover of the drive mechanism housing and the front cover of the drive mechanism housing. The outer surface of the gear ring is the drive mechanism side housing, and a steel ball is provided in the inner small shaft of the rear cover of the drive mechanism housing, and a pressure block is provided between the right end of the steel ball and the rear stop head of the nut.
[0008] The number of the planetary gears is 1 or 2, and the two planetary gears are respectively placed on two eccentric cylindrical surfaces of the eccentric sleeve that are symmetrically distributed at 180 degrees, and the two planetary gears are respectively installed on their own eccentric cylindrical surfaces.
[0009] A spherical concave surface is provided on the left side of the pressing block, and the spherical concave surface abuts against the steel ball.
[0010] The motor shaft is bonded to the motor rotor, and the eccentric sleeve is press-fitted and bonded in the inner hole of the motor shaft.
[0011] The small tooth difference planetary transmission mechanism adopts a pin-type torque output mechanism, the torque output disk of the pin-type torque output mechanism directly forms an integral part with the nut of the planetary roller screw, and the small tooth difference planetary transmission mechanism directly drives the nut of the planetary roller screw mechanism.
[0012] The nut and the torque output disc are an integrated part, and its left end is supported on the small shaft inside the rear cover of the drive mechanism housing through the inner hole of the nut rear stop head. The right end of the nut and the torque output disc are supported in the inner hole in the center of the front cover of the drive mechanism housing. The left end of the nut and the torque output disc are supported on the small shaft inside the rear cover of the drive mechanism housing, and the right end is supported in the inner hole in the center of the front cover of the drive mechanism housing. The nut and the torque output disc are an integrated part forming a through shaft. The eccentric sleeve is connected with two planetary gears, and the motor shaft and the motor rotor are both supported on this through shaft.
[0013] The eccentric sleeve is made of sliding bearing material. The outside of its two eccentric outer cylindrical surfaces are fitted with the planetary gears, playing the role of sliding bearings; its inner circle is fitted on the outer cylindrical surface of the nut, playing the role of a sliding bearing.
[0014] Compared with the prior art, the beneficial effects of the present invention are:
[0015] The gear transmission mechanism of this utility model adopts a small-tooth-difference planetary transmission mechanism. The eccentric sleeve of the small-tooth-difference planetary transmission mechanism is large and hollow, allowing the nut of the planetary roller screw to pass through the middle. The entire gear transmission mechanism is hollowly sleeved outside the planetary roller screw nut. This design ensures that the gear transmission mechanism completely takes up no axial space within the internal structure of the driver. This is particularly important for controlling the axial dimension of the product. It realizes the development of electric drive mechanisms in a limited space, and the product performance is comparable to that of existing hydraulic mechanisms.
[0016] The utility model adopts a pin-type torque output mechanism for the small tooth difference planetary transmission mechanism. A torque output plate is directly raised on the outer cylindrical surface of the planetary roller screw nut, so that the torque output plate and the planetary roller screw nut are integrated into one. With this design, the torque output of the small tooth difference planetary transmission mechanism is directly transmitted to the planetary roller screw nut, which greatly simplifies the mechanism and saves space.
[0017] The utility model provides a steel ball at the center of the inner side of the bottom cover of the shell, and a pressure block with a spherical concave surface of the same radius is provided at the center of the rear stop head of the nut. The pressure block is also made of bearing steel and is embedded in the recess of the rear stop head of the nut. When the huge thrust of the nut acts, the pressure block is pushed to press against the steel ball. Since both are made of bearing steel, they can withstand huge pressure. Moreover, the design size of this structure is extremely small and can be hidden in the motor cavity without occupying any axial size. The steel ball pressure block mechanism replaces the bulky thrust bearing, successfully solving the problem. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of the structure of the utility model Figure 1 ;
[0019] Figure 2 This is a schematic diagram of the structure of the utility model Figure 2 ;
[0020] Figure 3 This is a schematic diagram of the structure of the utility model Figure 3 ;
[0021] Figure 4 This is a schematic diagram of the structure of the utility model Figure 4 ;
[0022] Figure 5 This is a schematic diagram of the structure of the utility model Figure 5 ;
[0023] Figure 6 This is a schematic diagram of the structure of the utility model Figure 6 ;
[0024] Figure 7 This is a schematic diagram of the structure of the utility model Figure 7 ;
[0025] Figure 8 This is a schematic diagram of the structure of the utility model Figure 8 .
[0026] In the figure: 1. Planetary gear; 2. Ring gear; 3. Frameless motor; 3-1. Motor stator; 3-2. Motor rotor; 4. Eccentric sleeve; 5. Motor shaft; 6. Integrated nut and torque output disc; 6-1. Torque output disc; 6-2. Planetary roller screw nut; 7. Rear cover of drive mechanism housing; 8. Screw; 9. Steel ball; 10. Pressure block; 10-1. Spherical concave surface; 11. Pin; 12. Pin sleeve; 13. Pin cover; 14. Front cover of drive mechanism housing; 15. Nut rear stop; 16. Nut rear support point; 17. Nut front support point; 18. Torque output hole. DETAILED DESCRIPTION
[0027] The present invention is further described below with reference to the accompanying drawings: Example
[0028] As attached Figure 1-8 As shown, a new type of driving mechanism of a vehicle braking system is characterized in that it includes a driving mechanism housing rear cover 7 and a driving mechanism housing front cover 14, a small shaft is provided in the center of the inner side of the driving mechanism housing rear cover 7, the outer cylindrical surface of the small shaft is sleeved in the inner hole of the nut rear stop head 15, the outer ring of the nut rear stop head 15 is sleeved in the inner hole of the left end of the nut and torque output disc integrated part 6, and has a shaft shoulder for positioning, the outer ring of the right end of the nut and torque output disc integrated part 6 is sleeved in the center hole of the driving mechanism housing front cover 14, the left and right ends of the nut and torque output disc integrated part 6 are respectively supported on the small shaft of the housing rear cover 7 and the center hole of the housing front cover 14 to form a through shaft, the nut and torque output disc integrated part 6 are respectively supported on the small shaft of the housing rear cover 7 and the center hole of the housing front cover 14 to form a through shaft, A screw 8 is provided inside the torque output disc integrated part 6, and the output end of the screw 8 extends to the outside of the front cover 14 of the drive mechanism housing. The nut and torque output disc integrated part 6 includes a torque output disc 6-1 and a planetary roller screw nut 6-2. The outer sleeve of the planetary roller screw nut 6-2 is provided with an eccentric sleeve 4, and the left outer ring of the eccentric sleeve 4 is connected to the motor shaft 5. The motor shaft 5 is connected to the motor rotor 3-2 of its outer ring. The motor stator 3-1 is provided on the outside of the motor rotor 3-2. A plurality of eccentric cylinders are provided on the right side of the eccentric sleeve 4. The outer ring of each eccentric cylinder is sleeved with a planetary gear 1, which rotates around its own eccentricity and meshes with the ring gear 2 to form the planetary transmission mechanism with a small tooth difference;
[0029] The small-tooth-difference planetary transmission mechanism adopts a pin-type output mechanism. Each planetary gear has several torque output holes 18. A torque output disk 6-1 is provided on the right side of the planetary gear. Several pins 11 are forcibly inserted into the corresponding torque output holes 18 of the torque output disk 6-1 in an interference fit manner, forming an integral part with the torque output disk 6-1. After passing through the torque output holes 18 of the planetary gear 1, the several pins 11 are covered by pin covers 13 on the ends of the pins 11 extending outside the torque output holes of the planetary gear. The several pins 11 are also connected as an integral part on the left side. A pin sleeve 12 is provided between the connection between the pins 11 and the torque output holes 18 of the planetary gear 1. The outer ring of the planetary gear 1 is connected to the ring gear 2. The two ends of the ring gear 2 are respectively connected to the rear cover 7 of the drive mechanism housing and the front cover 14 of the drive mechanism housing. The outer surface of the ring gear 2 is the drive mechanism side housing. A steel ball 9 is provided in the inner small shaft of the rear cover 7 of the drive mechanism housing. A pressure block 10 is provided between the right end of the steel ball 9 and the rear stop head 15 of the nut.
[0030] The number of the planetary gears 1 is 2 or 1. The two planetary gears 1 are respectively placed on two eccentric cylindrical surfaces of the eccentric sleeve that are symmetrically distributed at 180 degrees, and one planetary gear 1 is installed on one eccentric cylindrical surface.
[0031] A spherical concave surface 10 - 1 is provided on the left side of the pressing block 10 , and the spherical concave surface 10 - 1 abuts against the steel ball 9 .
[0032] The motor shaft 5 is bonded to the motor rotor 3 - 2 , and the eccentric sleeve 4 is press-fitted and bonded into the inner hole of the motor shaft 5 .
[0033] The small tooth difference planetary transmission mechanism adopts a pin-type torque output mechanism, the torque output disk 6-1 of the pin-type torque output mechanism directly forms an integral part with the nut 6-2 of the planetary roller screw, and the small tooth difference planetary transmission mechanism directly drives the nut 6-2 of the planetary roller screw mechanism.
[0034] The left end of the nut and torque output disc integrated part 6 is supported on the small shaft inside the rear cover 7 of the drive mechanism housing through the inner hole of the nut rear stop head 15, and the right end of the nut and torque output disc integrated part 6 is supported in the inner hole at the center of the drive mechanism housing front cover 14. The left end of the nut and torque output disc integrated part 6 is supported on the small shaft inside the rear cover 7 of the drive mechanism housing, and the right end is supported in the inner hole at the center of the drive mechanism housing front cover 14. The nut and torque output disc integrated part 6 form a through shaft, the eccentric sleeve 4 is connected with two planetary gears, and the motor shaft 5 and the motor rotor 3-2 are all supported on this through shaft.
[0035] The eccentric sleeve 4 is made of sliding bearing material, and the outside of its two eccentric outer cylindrical surfaces are mounted on the planetary gear 1, playing the role of a sliding bearing; its inner circle is mounted on the outer cylindrical surface of the nut 6-2, playing the role of a sliding bearing.
[0036] As attached Figure 2 As shown, the drive mechanism utilizes a frameless motor 3. The motor shaft 5 is bonded to the motor rotor 3-2, and the eccentric sleeve 4 is press-fitted and bonded into the inner bore of the motor shaft 5. The eccentric sleeve 4 features two eccentric cylinders, symmetrically spaced 180 degrees apart, which drive two planetary gears 1 to mesh with the ring gear 2, forming a small-tooth-difference planetary transmission. The two planetary gears 1 are mounted on the two eccentric cylinders, symmetrically spaced 180 degrees apart, of the eccentric sleeve 4. Alternatively, a single eccentric or planetary gear with a balancing mechanism can be used.
[0037] In this torque transmission mode, the motor shaft drives the eccentric sleeve to rotate, thereby driving the small tooth difference planetary transmission mechanism to operate. The eccentric sleeve 4 plays a triple role as a drive shaft, an eccentric sleeve, and a sliding bearing.
[0038] As attached Figure 3 As shown, the driving mechanism adopts a pin-type output mechanism, and the planetary roller screw nut 6-2 is integrated with the torque output disk 6-1; a number of pins 11 are directly inserted into the output disk connected to the nut to drive the nut to rotate.
[0039] As attached Figure 4 As shown, the eccentric sleeve 4 is made of a sliding bearing material. Internally, it acts as a sliding bearing around the outer diameter of the planetary roller screw nut, supporting its rotation. Externally, the two planetary gears are supported on its two eccentrics, acting as both the planetary gear shaft and bearings. Eccentric sleeve 4 receives driving force from the motor shaft and also acts as an eccentric shaft, a crucial component of power transmission.
[0040] As attached Figure 5-7 As shown, the wires connected to the frameless motor 3 extend to the outside of the rear cover 7 of the drive mechanism housing. When power is applied, the frameless motor 3 starts, and the rotor 3-2 rotates, driving the motor shaft 5, which in turn drives the eccentric sleeve 4. The eccentric sleeve 4 is now equivalent to an eccentric shaft. The rotation of the eccentric sleeve 4 drives the planetary gears and the ring gear of the small-tooth-difference planetary transmission mechanism to engage with each other. The ring gear is fixed, so it forces the planetary gears to rotate. The pin-type torque output mechanism outputs the driving torque generated by the rotation of the planetary gears to the planetary roller screw nut 6-2 through the torque output disk 6-1. The nut and torque output disk integrated part 6 receives the driving torque transmitted from the small-tooth-difference planetary transmission mechanism, and then drives the screw 8 forward or backward to achieve the clamping function.
[0041] The planetary roller screw nut drives the lead screw, generating thrust. The lead screw then exerts an equal counterthrust on the nut. After the nut absorbs the counterthrust from the lead screw, it must transfer this thrust backward. This requires a sufficiently large thrust bearing to support the nut and prevent it from moving backward. A bearing manual reveals that the diameter and height of thrust bearings capable of withstanding such a massive thrust are far beyond our acceptable range. This means that, given the limited space and design requirements, using a conventional thrust bearing is impractical. To address this issue, a steel ball 9 is positioned in the center of the housing bottom cover. A pressure block 10 with a spherical concave surface of the same radius is positioned in the center of the nut rear stop 15. The pressure block 10 has a spherical recess 10-1 in its center. The pressure block, also made of bearing steel, is pressed into the recess of the nut rear stop. When the nut exerts a significant thrust, the pressure block presses against the steel ball. Because both are made of bearing steel, they can withstand significant pressure. Their extremely small size allows them to be hidden within the motor cavity, occupying no axial dimension. The steel ball briquetting mechanism replaces the bulky thrust bearing and successfully solves this problem.
[0042] The total length of this embodiment is 65mm, with 38mm removed for the planetary roller screw and 27mm left in the axial direction for the motor and gearbox, resulting in a radial dimension of 110mm. The gearbox requires a transmission ratio of 20, an output torque of 30NM, and a rated motor speed of 3000RPM. This allows the development of an electric drive mechanism within a limited space, while maintaining performance comparable to existing hydraulic mechanisms.
[0043] In this embodiment, the gear transmission mechanism utilizes a small-tooth-difference planetary transmission. Furthermore, the eccentric sleeve of the small-tooth-difference planetary transmission mechanism is large and hollow, allowing the nut of the planetary roller screw to pass through it. This allows the entire gear transmission mechanism to be hollowed out of the planetary roller screw nut. This design ensures that the gear transmission mechanism takes up no axial space within the internal structure of the driver. This is particularly important for controlling the axial dimensions of the product.
[0044] The small-tooth-difference planetary transmission mechanism utilizes a pin-type torque output mechanism. The innovation lies in the fact that, while conventional designs typically insert a drive pin directly into the disc-shaped end face of the torque output shaft, this embodiment incorporates a torque output disc directly onto the outer cylindrical surface of the planetary roller screw nut, integrating the torque output disc and the planetary roller screw nut into one. This design allows the torque output of the small-tooth-difference planetary transmission mechanism to be directly transmitted to the planetary roller screw nut, significantly simplifying the mechanism and saving space.
[0045] Because the planetary roller screw nut must pass through the hole in the eccentric sleeve, the radial dimensions of the product are very tight. To address this problem, the eccentric sleeve is made of sliding bearing material. Its two outer eccentric cylinders are symmetrically arranged 180 degrees relative to the axis of the inner hole. The two planetary gears are placed on them, acting as sliding bearings for each planetary gear. The planetary roller screw nut, located within its inner hole, also acts as a sliding bearing.
[0046] This embodiment uses a frameless direct-drive torque motor. The motor shaft is directly bonded to the rotor and requires proper and reliable support. Here, our eccentric sleeve is also directly bonded to the inner hole of the motor shaft. The motor shaft is supported on the planetary roller screw nut via the eccentric sleeve. Therefore, the eccentric sleeve serves three purposes: first, it serves as the support shaft and sliding bearing for the two planetary gears; second, it serves as the sliding bearing for the motor shaft and the eccentric sleeve itself on the planetary roller screw nut; and third, it transmits the power of the motor shaft to the two planetary gears.
[0047] In this embodiment, the drive mechanism adopts a frameless direct-drive torque motor, and the motor shaft is directly bonded to the motor rotor. The motor shaft needs to be properly supported and positioned. In the structure, the nut plays the role of a through shaft that runs across the front and back. The front support point 17 of the nut is the hole in the center of the front cover 14 of the drive mechanism housing, which can be regarded as a sliding bearing contact surface. The rear support point 16 of the nut is the small shaft extending from the middle of the rear cover 7 of the drive mechanism housing. The inner hole at the rear of the nut is supported on the small shaft extending from the middle of the rear cover of the housing through the rear stop head 15 of the nut. In this way, the outer cylindrical surface of the nut is securely placed in the housing as a "through shaft" from front to back. The motor shaft is supported on this "through shaft" through an eccentric sleeve. The eccentric sleeve and the two planetary gears are supported on the outer cylindrical surface of the nut and rotate around the outer cylindrical surface of the nut.
[0048] The planetary roller screw nut plays several roles in this product:
[0049] 1. As a planetary roller screw nut, this is its main function, pushing the screw and outputting thrust;
[0050] 2. As a front and rear through-shaft, the eccentric sleeve, two planetary gears, motor shaft, and motor rotor are all supported on its outer cylindrical surface. At this time, its function is an important "through-shaft";
[0051] 3. The outer cylindrical surface of the gearbox has a bulge on it, which is used to receive the power output of the small-tooth-difference planetary transmission mechanism. At this time, its function is also the power output shaft of the small-tooth-difference planetary transmission mechanism.
[0052] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0053] The key technical points protected by this utility model are:
[0054] The gear transmission mechanism utilizes a small-tooth-difference planetary transmission. The eccentric sleeve of this small-tooth-difference planetary transmission is hollow, with a large enough diameter to allow the planetary roller screw nut to pass through it. This allows the entire gear transmission mechanism to be hollowed out of the planetary roller screw nut. This design ensures that the gear transmission mechanism takes up no axial space within the driver's internal structure, which is particularly important for controlling the product's axial dimensions.
[0055] The small-tooth-difference planetary transmission utilizes a pin-type torque output mechanism. Its innovation lies in the following: While conventional designs place a drive pin directly onto the disc-shaped end face of the torque output shaft, the present invention incorporates a torque output disc directly onto the outer cylindrical surface of the planetary roller screw nut. This torque output disc and the planetary roller screw nut are integrated into one unit. This allows the torque output of the small-tooth-difference planetary transmission to be directly transmitted to the planetary roller screw nut, significantly simplifying the mechanism and saving space.
[0056] Because the planetary roller screw nut must pass through the hole in the eccentric sleeve, the radial dimensions of the drive system are very tight. To address this problem, the eccentric sleeve is made of sliding bearing material. Its two outer eccentric cylinders are symmetrically arranged 180 degrees relative to the axis of the inner hole. The two planetary gears are placed on them, acting as sliding bearings for each planetary gear. The planetary roller screw nut, located in its inner hole, also acts as a sliding bearing.
[0057] This product uses a frameless direct-drive torque motor. The motor shaft is directly bonded to the rotor, requiring proper and reliable support. The eccentric sleeve is also bonded directly to the inner bore of the motor shaft. The motor shaft is supported on the planetary roller screw nut via the eccentric sleeve. The eccentric sleeve serves three functions: 1. It serves as the support shaft and sliding bearing for the two planetary gears; 2. It acts as a sliding bearing for the motor shaft and the eccentric sleeve itself on the planetary roller screw nut; and 3. It acts as an eccentric shaft, transmitting the motor shaft's power to the two planetary gears.
[0058] 4. The planetary roller screw nut drives the lead screw, generating thrust, which in turn generates an equal counterthrust on the nut. After the nut absorbs the counterthrust from the lead screw, it must transfer this thrust backward. This requires a sufficiently large thrust bearing to prevent the nut from moving backward. A review of bearing manuals reveals that the diameter and height of thrust bearings capable of withstanding such a significant thrust are far beyond our acceptable size range. This means that a conventional thrust bearing would simply not fit here.
[0059] To solve this problem, a steel ball made of bearing steel is embedded in a recess in the rear cover of the product housing. A pressure block with a spherical concave surface of the same radius is also used. The pressure block, also made of bearing steel, is embedded in a recess in the rear stop of the nut. The immense thrust of the nut pushes the pressure block against the steel ball. Because both are made of bearing steel, they can withstand tremendous pressure. Their extremely small size allows them to be hidden within the motor cavity, eliminating any axial space. This successfully solves this problem.
[0060] The steel ball pressing mechanism is used to replace the bulky thrust bearing.
[0061] 5. The present invention uses a frameless direct-drive torque motor. The motor shaft is directly bonded to the motor rotor, and the motor shaft needs to be properly supported and positioned. Here, the nut plays the role of a through shaft that runs across the front and back. The front support point of the nut is the hole in the center of the front cover of the housing, which can be regarded as a sliding bearing contact surface. The rear support position of the nut is the small shaft extending from the middle of the rear cover of the housing. The inner hole at the rear of the nut is supported on the small shaft extending from the middle of the rear cover of the housing through the rear stop head of the nut. In this way, the outer cylindrical surface of the nut is treated as a "through shaft" from front to back and is securely placed in the housing. The motor shaft is supported on this "through shaft" through an eccentric sleeve. The eccentric sleeve and the two planetary gears are supported on the outer cylindrical surface of the nut and rotate around the outer cylindrical surface of the nut.
[0062] Here is a summary of the roles of the planetary roller screw nut in this product:
[0063] 1. As a planetary roller screw nut, this is its main function, pushing the screw and outputting thrust.
[0064] 2. As a front and rear through shaft, the eccentric sleeve together with the two planetary gears, the motor shaft and the motor rotor are all supported on its outer cylindrical surface. At this time, its function is an important "through shaft"
[0065] 3. The outer cylindrical surface of the gearbox has a bulge on it, which is used to receive the power output of the small-tooth-difference planetary transmission mechanism. At this time, its function is also the power output shaft of the small-tooth-difference planetary transmission mechanism.
[0066] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one such feature.
[0067] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.
[0068] In summary, the above is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. All equivalent changes and modifications based on the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of the claims of the present invention.
Claims
1. A novel driving mechanism for a vehicle braking system, characterized in that: The invention comprises a drive mechanism housing rear cover (7) and a drive mechanism housing front cover (14), wherein a small shaft is provided at the center of the inner side of the drive mechanism housing rear cover (7), and the outer cylindrical surface of the small shaft is sleeved in the inner hole of the nut rear stop head (15), and the outer ring of the nut rear stop head (15) is sleeved in the inner hole of the left end of the nut and torque output disc integrated part (6) and has a shaft shoulder for positioning, and the outer ring of the right end of the nut and torque output disc integrated part (6) is sleeved in the center hole of the drive mechanism housing front cover (14), and the left and right ends of the nut and torque output disc integrated part (6) are respectively supported on the small shaft of the housing rear cover (7) and in the center hole of the housing front cover (14) to form a through shaft, and a lead screw (8) is provided inside the nut and torque output disc integrated part (6) The output end of the screw (8) extends to the outside of the front cover (14) of the driving mechanism housing, the nut and torque output disc integrated part (6) includes a torque output disc (6-1) and a planetary roller screw nut (6-2), the outer sleeve of the planetary roller screw nut (6-2) is provided with an eccentric sleeve (4), the left outer ring of the eccentric sleeve (4) is connected to the motor shaft (5), the motor shaft (5) is connected to the motor rotor (3-2) of its outer ring, the motor stator (3-1) is provided on the outside of the motor rotor (3-2), and one or more eccentric cylinders are provided on the right side of the eccentric sleeve (4), the outer ring of each eccentric cylinder is sleeved with a planetary gear (1), rotates around its own eccentricity, and meshes with the gear ring (2) to form a small tooth difference planetary transmission mechanism; The small tooth difference planetary transmission mechanism adopts a pin-type output mechanism, each planetary gear has a plurality of torque output holes (18), a torque output disk (6-1) is provided on the right side of the planetary gear, a plurality of pins (11) are forcibly inserted into the corresponding torque output holes (18) of the torque output disk (6-1) in an interference fit manner, and become a whole with the torque output disk (6-1), after the plurality of pins (11) pass through the torque output holes (18) of the planetary gear (1), they are covered by pin covers (13) on the ends of the pins (11) extending outside the torque output holes of the planetary gear, The pin (11) is also connected as a whole on the left side, and a pin sleeve (12) is provided between the connection between the pin (11) and the torque output hole (18) of the planetary gear (1). The outer ring of the planetary gear (1) is connected to the ring gear (2), and the two ends of the ring gear (2) are respectively connected to the rear cover (7) of the driving mechanism housing and the front cover (14) of the driving mechanism housing. The outer surface of the ring gear (2) is the driving mechanism side housing, and a steel ball (9) is provided in the inner small shaft of the rear cover (7) of the driving mechanism housing, and a pressure block (10) is provided between the right end of the steel ball (9) and the rear stopper (15) of the nut.
2. The novel driving mechanism of a vehicle braking system according to claim 1, characterized in that: The number of the planetary gears (1) is 2 or 1, the two planetary gears (1) are respectively arranged on two eccentric cylindrical surfaces of the eccentric sleeve that are symmetrically distributed at 180 degrees, and one planetary gear (1) is installed on one eccentric cylindrical surface.
3. The novel driving mechanism of a vehicle braking system according to claim 1, characterized in that: A spherical concave surface (10-1) is provided on the left side of the pressing block (10), and the spherical concave surface (10-1) abuts against the steel ball (9).
4. The novel driving mechanism of a vehicle braking system according to claim 1, characterized in that: The motor shaft (5) is bonded to the motor rotor (3-2), and the eccentric sleeve (4) is press-fitted and bonded into the inner hole of the motor shaft (5).
5. The novel driving mechanism of a vehicle braking system according to claim 1, characterized in that: The small-tooth-difference planetary transmission mechanism adopts a pin-type torque output mechanism, wherein the torque output disc (6-1) of the pin-type torque output mechanism directly forms an integral part with the nut (6-2) of the planetary roller screw, and the small-tooth-difference planetary transmission mechanism directly drives the nut (6-2) of the planetary roller screw mechanism.
6. The novel driving mechanism of a vehicle braking system according to claim 1, characterized in that: The left end of the nut and torque output disc integrated part (6) is supported on the small shaft inside the rear cover (7) of the driving mechanism housing through the inner hole of the nut rear stop head (15), and the right end of the nut and torque output disc integrated part (6) is supported in the inner hole at the center of the front cover (14) of the driving mechanism housing. The left end of the nut and torque output disc integrated part (6) is supported on the small shaft inside the rear cover (7) of the driving mechanism housing, and the right end is supported in the inner hole at the center of the front cover (14) of the driving mechanism housing. The nut and torque output disc integrated part (6) form a through shaft, the eccentric sleeve (4) is connected with two planetary gears, and the motor shaft (5) and the motor rotor (3-2) are all supported on this through shaft.
7. The novel driving mechanism of a vehicle braking system according to claim 2, characterized in that: The eccentric sleeve (4) is made of a sliding bearing material, and the outer surfaces of its two eccentric outer cylindrical surfaces are mounted on the planetary gear (1), playing the role of a sliding bearing; its inner circle is mounted on the outer cylindrical surface of the nut (6-2), playing the role of a sliding bearing.