Lead screw drive, electromechanical brake and integrated brake control system

Abstract

The application relates to the technical field of automobile parts, and provides a screw rod transmission device, an electronic mechanical brake and an integrated brake control system. The screw rod transmission device comprises a screw rod supported on a shell, an input section and a threaded section, the input section extends into a shell cavity through the shell, the threaded section is arranged in the shell cavity, the threaded section is connected with the input section to form a containing cavity, and the radial projection of the raceway area of the threaded section overlaps the radial projection of the containing cavity; a bearing unit and a force sensor are arranged on the input section and located in the space between the bottom of the containing cavity and the bottom of the shell cavity. The application can effectively solve the problem that the arrangement of the bearing unit and the force sensor occupies more axial space, the screw rod transmission device is compact in structure, is beneficial to arrangement in a whole vehicle, and through the support of the bearing unit and the detection of the force sensor, the screw rod transmission device is stable in operation, accurate in control and excellent in working performance.

Description

Technical Field

[0001] This application relates to the field of automotive parts technology, and more specifically, to lead screw drives, electromechanical brakes, and integrated brake control systems. Background Technology

[0002] Ball screw drive mechanisms are widely used in automotive components such as brakes. For example, the mainstream electromechanical brakes currently use ball screw drive mechanisms, where a motor drives the screw to rotate, and the nut converts the rotational motion into linear motion. The braking and releasing of the vehicle are achieved by the extension and retraction of the nut.

[0003] To support the lead screw and detect its force to adjust the driving force of the power source, thus achieving closed-loop control, bearings and force gauges can be installed in the lead screw drive mechanism. However, the current arrangement of bearings and force gauges occupies a significant amount of axial space, resulting in a large axial dimension of the lead screw drive mechanism, making it difficult to integrate into the vehicle. Taking an electromechanical brake as an example, refer to... Figure 1 As shown, the bearing 11 and the force sensor 12 are located on one side of the lead screw shaft 13. During operation, the gearbox 14 transmits the driving force from the motor to the lead screw shaft 13. The lead screw nut 15 converts the rotational motion of the lead screw shaft 13 into linear motion, pushing out or retracting relative to the housing 16 to apply or release braking force. During this process, the bearing 11 supports the lead screw shaft 13, making the lead screw shaft 13 rotate stably. The force sensor 12 detects the force on the lead screw shaft 13 and feeds it back to the motor to achieve closed-loop control. Figure 1 The disadvantage of the arrangement of bearing 11 and force gauge 12 shown is that it occupies more axial space, resulting in a larger axial dimension of the lead screw transmission mechanism, which is not conducive to its arrangement in the whole vehicle.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] This application provides a lead screw drive device, an electromechanical brake, and an integrated braking control system, which solves the problem that the arrangement of bearing units and force sensors occupies a lot of axial space, resulting in a large axial dimension of the lead screw drive device, which is not conducive to its arrangement in the whole vehicle.

[0006] According to one aspect of this application, a lead screw drive device is provided, comprising: a lead screw supported on a housing, including an input section and a threaded section, the input section extending through the housing into a housing cavity, the threaded section being housed within the housing cavity, the threaded section being connected to the input section to form a receiving cavity, the radial projection of the raceway region of the threaded section overlapping the radial projection of the receiving cavity; a bearing unit and a force sensor disposed on the input section, located in the space between the bottom of the receiving cavity and the bottom of the housing cavity.

[0007] This application designs the lead screw to include an input section and a threaded section, with the threaded section connecting to the input section to form a receiving cavity for accommodating the bearing unit / force sensor. The cavity is positioned so that the radial projection of the raceway region of the threaded section overlaps with the radial projection of the receiving cavity. This effectively reduces the axial space required for arranging the bearing unit and force sensor. Furthermore, the raceway region of the threaded section is a load concentration area during the operation of the lead screw drive; arranging the bearing unit / force sensor here provides effective support and force measurement for the lead screw. The bearing unit and force sensor are specifically arranged in the space between the bottom of the receiving cavity and the bottom of the housing cavity, fully utilizing the remaining axial space in the receiving cavity and housing cavity after the lead screw is installed, achieving a compact layout.

[0008] The lead screw drive device of this application can effectively solve the problem of bearing units and force sensors occupying a lot of axial space, making the lead screw drive device compact and easy to arrange in the whole vehicle. Furthermore, through the support of the bearing unit and the detection of the force sensor, the lead screw drive device can operate stably, control accurately, and has excellent working performance.

[0009] In some embodiments, the lead screw has an axial profile of an m-shape, the lead screw includes a shaft-shaped input section, an annular threaded section and a circular bottom section, one end of the threaded section being connected to the input section via the bottom section and the other end being spaced apart from the input section to form the receiving cavity.

[0010] By utilizing an M-shaped structural design, the threaded section connects to the input section at one end via the bottom section and is spaced apart from the input section at the other end, providing axial space for the arrangement of bearing units / force sensors and reducing the overall axial dimension of the screw drive. Furthermore, the shaft-shaped input section can rotate stably under driving force, the annular threaded section provides stable nut assembly, and the space between the threaded section and the input section houses the bearing units / force sensors for support, resulting in a stable overall structure and excellent performance for the screw drive.

[0011] In some embodiments, the starting raceway region of the threaded segment is located at the free end of the threaded segment, and the radial projection of the starting raceway region overlaps with the radial projection of the receiving cavity.

[0012] During the operation of the lead screw drive, the starting raceway area of ​​the threaded section is the key area where the lead screw bears the working load. The starting raceway area is located at the free end of the threaded section. The radial projection of the starting raceway area is designed to overlap with the radial projection of the receiving cavity, so that the bearing unit / force sensor set here can effectively support / measure the force of the starting raceway area, thereby improving the performance of the lead screw drive.

[0013] In some embodiments, the bearing unit is disposed in the receiving cavity, and the force sensor is disposed between the bearing unit and the bottom of the housing cavity.

[0014] In this way, the bearing unit provides stable support for the threaded section and the input section, and the force measuring device is set close to the threaded section, which enables accurate detection of the force on the lead screw.

[0015] In some embodiments, the force sensor is locked to the bearing unit and the bottom of the housing cavity by axial fasteners.

[0016] This ensures a stable arrangement of the force sensor, preventing the sensor from becoming worn and affecting detection accuracy.

[0017] In some embodiments, the bearing unit includes a spherical bearing and a thrust needle roller bearing disposed between the spherical bearing and the force sensor; the cage portion of the thrust needle roller bearing cooperates with the force sensor and the needle roller portion cooperates with the spherical bearing; the spherical bearing includes a first component and a second component, each having a spherical surface, the first component being press-fitted onto the input section, the second component abutting against the needle roller portion, and the spherical surfaces of the first component and the second component cooperating to form a sliding contact pair.

[0018] Thrust needle roller bearings can bear axial loads, allowing the axial force generated when the lead screw rotates to be transmitted to the thrust needle roller bearings, thus preventing the lead screw from moving axially. The design of the spherical surface of the first component and the spherical surface of the second component of the spherical bearing to cooperate with each other and form a sliding contact pair allows the input section of the lead screw to have a certain angle of deflection, which can stably transmit the load and prevent motion jamming.

[0019] In some embodiments, when the input segment rotates about the axis, the first component, the second component, and the needle roller portion rotate synchronously under the action of friction; when the input segment causes the first component to sway, the spherical surface of the first component and the spherical surface of the second component maintain mutual sliding contact and form a continuous surface contact area.

[0020] During normal operation of the lead screw drive, the input section rotates around its shaft, causing the first component, which is press-fitted onto the input section, to rotate accordingly. The second component, under the influence of friction, follows the rotation of the first component, and the needle rollers of the thrust needle roller bearing also rotate under the influence of friction. When the input section exhibits a certain angle of yaw, the first component yaws relative to the second component. Thanks to the design of the spherical surfaces of the first and second components engaging and forming a sliding contact pair, the two spherical surfaces maintain mutual sliding contact, creating a continuous surface contact area. This ensures uniform stress distribution, avoids excessive local stress concentration, and prevents jamming between the first and second components.

[0021] In some embodiments, the spherical surface of the first component and / or the spherical surface of the second component is coated with a sliding material.

[0022] This optimizes the frictional performance of spherical bearings, reduces wear, and improves transmission efficiency.

[0023] In some embodiments, a rhomboid retaining spring is provided between the bearing unit and the bottom of the receiving cavity, and / or between the bearing unit and the force sensor, and / or between the force sensor and the bottom of the housing cavity; wherein each rhomboid retaining spring includes two conical springs, the concave surfaces of the two conical springs are pressed together to form a rhomboid cavity, the conical surfaces of the two conical springs are respectively pressed against two components adjacent to the rhomboid retaining spring, and the V-shaped bottom of the rhomboid retaining spring is interference-fitted into the V-shaped groove of the input section.

[0024] Due to factors such as machining accuracy and structural design, a good tight fit may not be achieved between the bearing unit and the bottom of the housing cavity, between the bearing unit and the force sensor, and between the force sensor and the bottom of the housing cavity. The two conical surfaces of the rhomboid retaining spring ensure a tight fit with the two adjacent components, compensate for the gap between the two adjacent components, and the rhomboid cavity formed by the two concave surfaces of the rhomboid retaining spring has a self-locking and anti-loosening function, which can absorb axial loads and ensure the overall structural stability of the screw drive device.

[0025] In some embodiments, the portion of the input segment extending out of the cavity is provided with a spline.

[0026] The spline facilitates the connection between the input segment and the drive component, and enables circumferential limiting of the input segment.

[0027] In some embodiments, the input segment extends into the housing cavity through a through hole in the housing, and an elastic retaining ring and a bushing are provided between the input segment and the through hole.

[0028] The elastic retaining ring and bushing provide support and limit for the input section. The elastic retaining ring prevents axial movement of the input section, and the bushing prevents radial movement, thus ensuring stable rotation of the input section.

[0029] In some embodiments, the lead screw drive further includes a nut, which is mounted on the threaded section and is supported by the housing via an anti-rotation mechanism and is capable of linear movement relative to the lead screw.

[0030] The anti-rotation mechanism is used to prevent the nut from rotating with the lead screw, restrict the circumferential rotation and radial movement of the nut, and make the nut move only in a straight line along the axial direction, thus accurately converting the rotational motion of the lead screw into a linear output.

[0031] In some embodiments, the nut and the housing are clearance-fitted, and the outer peripheral surface of the nut is coated with a sliding material.

[0032] By using sliding materials, the frictional properties between the nut and the housing cavity can be optimized, reducing wear and improving transmission efficiency.

[0033] In some embodiments, the lead screw and / or the nut are provided with an axially protruding stop portion, the stop portion being used to adjust the retraction stroke of the nut.

[0034] By increasing or decreasing the size of the protrusion of the stop, the retraction stroke of the nut can be adjusted to prevent the end face of the nut from contacting the end face of the housing during retraction, which would cause the translational movement of the nut to become stuck, and cause the lead screw to move away from the motor under the reaction force of the nut, affecting the overall stability.

[0035] In some embodiments, the stop portion is formed as a ring structure or a circumferentially spaced structure; and / or, the stop portion is integrally formed with the lead screw and / or the nut, or the stop portion is composed of a buffer material embedded in the lead screw and / or the nut.

[0036] The specific structure and forming method of the stop can be set as needed to form a stable stopping function.

[0037] According to another aspect of this application, an electromechanical brake is provided, comprising a caliper housing assembly, a gearbox assembly, and a lead screw drive as described in any of the above embodiments, wherein the caliper cylinder of the caliper housing assembly serves as a housing for supporting the lead screw, and the output component of the gearbox assembly is connected to the input section of the lead screw.

[0038] The electromechanical brake, equipped with the aforementioned screw drive device, can effectively solve the problems of large axial dimensions and inconvenient layout, making the screw drive device and electromechanical brake structure compact, which is conducive to the layout in the whole vehicle, and can achieve stable operation and precise control, with excellent braking performance.

[0039] According to another aspect of this application, an integrated braking control system is provided, which is configured with a lead screw drive as described in any of the above embodiments.

[0040] The integrated braking control system according to this application, which configures the aforementioned lead screw drive device, also has the same or similar technical effects as the electromechanical brake configured with the aforementioned lead screw drive device.

[0041] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0043] Figure 1 A schematic diagram of the current electromechanical brake is shown.

[0044] Figure 2 This invention provides a schematic diagram of the structure of a lead screw drive device according to an embodiment of the present application.

[0045] Figure 3 This invention provides a schematic diagram of the structure of another lead screw drive device according to an embodiment of the present application.

[0046] Figure 4 This diagram illustrates the motion state of the spherical bearing when the input segment wobbles in an embodiment of this application.

[0047] Figure 5 A schematic diagram of the electromechanical brake in an embodiment of this application is shown. Detailed Implementation

[0048] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to those described herein. Rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0049] The accompanying drawings are merely illustrative of this application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted.

[0050] The use of terms such as "first," "second," and similar words in the specific description does not indicate any order, quantity, or importance, but is merely used to distinguish different components. The terms "left," "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, in the description of this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly, for example, it can be a fixed connection, a detachable connection, or an integral 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, or it can be a connection within two elements.

[0051] It should be noted that, unless otherwise specified, the embodiments of this application and the features in different embodiments can be combined with each other.

[0052] Figure 2 The diagram illustrates an axial cross-sectional view of a lead screw drive device according to an embodiment of this application, with reference to... Figure 2 As shown, the lead screw transmission device provided in this application embodiment may include:

[0053] The lead screw 200 is supported on the housing 610 and includes an input section 210 and a threaded section 220. The input section 210 extends through the housing 610 into the housing cavity 611, and the threaded section 220 is built into the housing cavity 611. The threaded section 220 and the input section 210 are connected to form a receiving cavity 612. The radial projection S1 of the raceway region of the threaded section 220 overlaps with the radial projection S2 of the receiving cavity 612.

[0054] The bearing unit 400 and the force sensor 500 are disposed on the input section 210 in the space between the bottom of the receiving cavity 612 and the bottom of the shell cavity 611.

[0055] This application designs the lead screw 200 as including an input section 210 and a threaded section 220, with the threaded section 220 connected to the input section 210 to form a receiving cavity 612 to accommodate the bearing unit 400 / force sensor 500. The threaded section 220 is spaced apart from the input section 210, meaning the threaded section 220 is fitted outside the input section 210 and spaced apart from it. The threaded section 220 and the input section 210 can be coaxially spaced apart, allowing the threaded section 220 to rotate stably with the input section 210; in some special applications, the threaded section 220 and the input section 210 can also be non-coaxial, depending on the specific requirements. The cavity 612 is positioned such that the radial projection S1 of the raceway region of the threaded section 220 overlaps with the radial projection S2 of the cavity 612. This effectively shortens the axial space required for the bearing unit 400 and the force sensor 500. Furthermore, the raceway region of the threaded section 220 is a load-concentrated area during the operation of the screw drive; placing the bearing unit 400 / force sensor 500 here provides effective support / force measurement for the screw 200. The radial projection S1 of the raceway region of the threaded section 220 and the radial projection S2 of the cavity 612 can partially or completely overlap. In this application, "axial" refers to the axial direction Z of the screw 200, and "radial" is the direction perpendicular to the axial direction. The bearing unit 400 and the force sensor 500 are specifically arranged in the space between the bottom of the cavity 612 and the bottom of the housing 611 to fully utilize the remaining axial space after the screw 200 is arranged in the cavity 612 and housing 611, achieving a compact layout. The bottom of the receiving cavity 612 is located at the position where the threaded section 220 connects to the input section 210. Figure 2 The middle refers to the left end of the cavity 612. The bottom of the cavity 611 refers to the part of the housing 610 used to support the lead screw 200, located at the end of the cavity 611 through which the input section 210 extends. Figure 2 The right end of the cavity 611 is in the middle; the other end of the cavity 611 is open to allow the nut 300, which is fitted onto the threaded section 220, to be pushed out and retracted.

[0056] The lead screw drive device of this application can effectively solve the problem that the arrangement of the bearing unit 400 and the force sensor 500 occupies a lot of axial space, making the lead screw drive device compact and easy to arrange in the whole vehicle. Moreover, through the support of the bearing unit 400 and the detection of the force sensor 500, the lead screw drive device can operate stably, control accurately, and has excellent working performance.

[0057] The ball screw drive device of this application can be applied to vehicle brakes such as electro-mechanical brakes (EMB) and integrated brake control systems (IBC), achieving braking and release through the extension and retraction of the nut 300. The ball screw drive device of this application can also be applied to other automotive components such as suspension and chassis systems, similarly improving the performance of the applied automotive components through its compact structure, stable support, and precise force measurement.

[0058] In some embodiments, the lead screw 200 has an axial cross-section that is m-shaped. The lead screw 200 includes a shaft-shaped input section 210, an annular threaded section 220, and a circular bottom section 230. One end of the threaded section 220 is connected to the input section 210 via the bottom section 230, and the other end is spaced apart from the input section 210 to form a receiving cavity 612.

[0059] Utilizing the M-shaped structural design, the threaded section 220 is located at one end ( Figure 2 The middle section (i.e., the left end of the threaded section 220) is connected to the input section 210 via the bottom section 230 and at the other end ( Figure 2 The right end of the threaded section 220 (i.e., the middle section) is spaced apart from the input section 210, providing axial space for the bearing unit 400 / force sensor 500 to be arranged, thus reducing the axial dimension of the entire screw drive. Furthermore, the shaft-shaped input section 210 can rotate stably under the driving force, the annular threaded section 220 provides stable assembly for the nut 300, and the bearing unit 400 / force sensor 500 is arranged in the space between the threaded section 220 and the input section 210 for support, making the overall structure of the screw drive stable and its performance excellent.

[0060] In some embodiments, the starting raceway region S1' of the threaded segment 220 is located at the free end of the threaded segment 220. Figure 2 (i.e., the right end of the threaded section 220), the radial projection of the starting raceway region S1' overlaps with the radial projection S2 of the receiving cavity 612.

[0061] The initial raceway region S1' includes at least the first raceway 221 of the threaded section 220, and may also include several raceways located downstream of the first raceway 221. During the operation of the screw drive, the initial raceway region S1' of the threaded section 220 is the key area where the screw 200 bears the working load, and the initial raceway region S1' is located at the free end of the threaded section 220. The radial projection of the initial raceway region S1' is designed to overlap with the radial projection S2 of the receiving cavity 612, so that the bearing unit 400 / force sensor 500 set here can effectively support / measure force in the initial raceway region S1', thereby improving the performance of the screw drive.

[0062] Reference Figure 1 As shown, in the existing design, the axial distance H1 between the first raceway of the lead screw shaft 13 and the support bottom 16' of the housing 16 is greater than the axial distance H2 between the bottom of the bearing 11 and the support bottom 16' of the housing 16. (Refer to...) Figure 2 As shown in the embodiment of this application, the axial distance H3 between the bottom of the receiving cavity 612 and the bottom of the housing cavity 611 is greater than the axial distance H4 between the first raceway 221 of the threaded section 220 and the bottom of the housing cavity 611, so that the bearing unit 400 and the force sensor 500 have sufficient axial arrangement space without increasing the original axial space of the housing cavity 611. Specifically, in the embodiment of this application, the receiving cavity 612 between the threaded section 220 and the input section 210 of the lead screw 200, and the remaining axial space in the housing cavity 611 after the lead screw 200 is arranged, are used to arrange the bearing unit 400 and the force sensor 500; while in the existing design, it is necessary to extend the axial dimension of the housing 16 or shorten the axial dimension of the support bottom 16' of the housing 16 in order to provide suitable axial space for the bearing 11 and the force sensor 12 to be arranged.

[0063] In some embodiments, the bearing unit 400 is disposed in the receiving cavity 612, and the force sensor 500 is disposed between the bearing unit 400 and the bottom of the housing cavity 611. In this way, the bearing unit 400 provides stable support for the threaded section 220 and the input section 210, and the force measuring device is disposed close to the threaded section 220, which enables accurate detection of the force on the lead screw 200.

[0064] In other embodiments, the positions of the bearing unit 400 and the force sensor 500 can be interchanged, and can be set as needed.

[0065] In some embodiments, the force sensor 500 is connected to the bearing unit 400 and the bottom of the housing 611 by an axial fastener ( Figure 2 (Not specifically shown) Locking. The force sensor 500 can be locked to the bottom of the bearing unit 400 and the housing cavity 611 by axial fasteners such as pins, so as to achieve a stable arrangement of the force sensor 500 and avoid the force sensor 500 from affecting the detection accuracy due to floating wear.

[0066] In some embodiments, the bearing unit 400 is interference-fitted between the input section 210 and the threaded section 220, and / or, the bearing unit 400 and the force sensor 500 are axially pressed between the bottom of the receiving cavity 612 and the bottom of the housing cavity 611. The bearing unit 400 can be interference-fitted between the input section 210 and the threaded section 220 to achieve radial fixation; the bearing unit 400 and the force sensor 500 can be axially pressed between the bottom of the receiving cavity 612 and the bottom of the housing cavity 611 to achieve axial fixation. This achieves a stable arrangement of the bearing unit 400, thereby providing stable support for the threaded section 220 and the input section 210.

[0067] It should be noted that although the above embodiments have exemplarily described the axial fastener locking of the force sensor 500 and the interference fit and pin locking of the bearing unit 400, this application is not limited thereto. For example, the fixing method of the force sensor 500 and the bearing unit 400 can also be set to any other form such as screw connection, riveting, and welding according to actual production needs.

[0068] In some embodiments, a diamond-shaped retaining spring is provided between the bearing unit 400 and the bottom of the receiving cavity 612, and / or between the bearing unit 400 and the force sensor 500, and / or between the force sensor 500 and the bottom of the housing cavity 611. Figure 2 (Not specifically shown in the text); wherein, each rhomboid snap ring includes two conical springs, the concave surfaces of the two conical springs are pressed together to form a rhomboid cavity, the conical surfaces of the two conical springs are respectively pressed into two components adjacent to the rhomboid snap ring, and the V-shaped bottom of the rhomboid snap ring is interference-fitted into the V-shaped groove of the input section 210.

[0069] Between the bearing unit 400 and the bottom of the receiving cavity 612, between the bearing unit 400 and the force sensor 500, and between the force sensor 500 and the bottom of the housing cavity 611, good pressing and fitting may not be achieved due to machining accuracy, structural design, or other reasons. The two conical surfaces of the rhomboid retaining spring ensure a pressing fit with the two adjacent components, compensating for the gap between them. Furthermore, the rhomboid cavity formed by the pressing of the two concave surfaces of the rhomboid retaining spring has a self-locking and anti-loosening function, absorbing axial loads and ensuring the overall structural stability of the screw drive device. Taking the setting of a rhomboid retaining spring between the bearing unit 400 and the force sensor 500 as an example: the rhomboid retaining spring may include a first conical spring and a second conical spring. The conical surfaces of the first and second conical springs respectively press against the bearing unit 400 and the force sensor 500. The concave surfaces of the first and second conical springs press against each other to form a rhomboid cavity, and the V-shaped bottom of the rhomboid retaining spring is interference-fitted into the V-shaped groove of the input section 210. During the operation of the lead screw drive, the rhomboid retaining ring absorbs the axial load on the bearing unit 400 and the force sensor 500, maintaining their stability. Furthermore, the first and second conical springs further decompose the axial load into radial components, strengthening the locking fit between the V-shaped bottom of the rhomboid retaining ring and the V-shaped groove of the input section 210, thus ensuring the overall stable operation of the lead screw drive. The angle between the conical surfaces of the first and second conical springs can be set as needed, for example, by setting the angle between the hypotenuse of the conical surface and the radial direction to 15°, but this is not a limitation.

[0070] In some embodiments, the portion of the input segment 210 extending out of the cavity 611 is provided with a spline 212. The spline 212 facilitates the connection between the input segment 210 and the drive component, and provides circumferential limiting for the input segment 210.

[0071] In some embodiments, the input segment 210 extends into the housing cavity 611 through a through hole in the housing 610. An elastic retaining ring 213 and a bushing 214 are provided between the input segment 210 and the through hole. The elastic retaining ring 213 and the bushing 214 provide support and limit for the input segment 210. The elastic retaining ring 213 prevents axial movement of the input segment 210, and the bushing 214 prevents radial movement of the input segment 210, thereby ensuring stable rotation of the input segment 210. A specific implementation of the elastic retaining ring 213 is, for example, a snap ring, installed in the annular groove of the through hole, with a micro-clear gap or slight contact fit with the input segment 210. When the lead screw 200 receives a driving force from the driving component, the snap ring receives the axial thrust transmitted by the input segment 210 and transmits it to the housing 610, causing the input segment 210 to rotate stably relative to the snap ring. The bushing 214 is implemented in a specific way, for example, by a hollow cylindrical part (e.g., made of rubber, wear-resistant plastic or metal, which can be formed into a hollow cylindrical structure with flanges as needed), which is sleeved in the through hole of the housing 610 through which the input section 210 of the lead screw 200 passes, and has a micro-clear clearance fit or slight contact fit with the input section 210; when the lead screw 200 is subjected to the driving force from the driving component, the hollow cylindrical part is subjected to the radial thrust transmitted by the input section 210 and transmits it to the housing 610, so that the input section 210 rotates stably relative to the hollow cylindrical part.

[0072] In some embodiments, the lead screw drive further includes a nut 300, mounted on the threaded section 220. The nut 300 is supported on the housing 610 by an anti-rotation mechanism 330 and can move linearly relative to the lead screw 200. The anti-rotation mechanism 330 prevents the nut 300 from rotating with the lead screw 200, restricts the circumferential rotation and radial movement of the nut 300, and ensures that the nut 300 moves only in a linear axial direction, accurately converting the rotational motion of the lead screw 200 into a linear output. A specific implementation of the anti-rotation mechanism 330 includes, for example, providing an axially extending guide key and a keyway on the outer circumferential surface of the nut 300 and the inner wall of the housing cavity 611, respectively. The guide key slides into the keyway to achieve circumferential and radial limiting of the nut 300.

[0073] In some embodiments, the nut 300 and the housing 610 are clearance-fitted, and the outer peripheral surface of the nut 300 is coated with a sliding material. The sliding material optimizes the frictional properties between the nut 300 and the housing 611, reduces wear, and improves transmission efficiency. The sliding material can be a self-lubricating material, such as a polymer, which can reduce the coefficient of friction, decrease frictional resistance during the movement of the nut 300, and absorb vibration, preventing wear from affecting the stability of the nut 300.

[0074] In some embodiments, the lead screw 200 is provided with an axially protruding stop portion 260, which is used to adjust the retraction stroke of the nut 300. By increasing or decreasing (e.g., appropriately set according to actual manufacturing and assembly tolerances) the protrusion size of the stop portion 260, the end face 300a of the nut is prevented from contacting the end face 610a of the housing 610 when the nut 300 retracts, thus preventing the translational movement of the nut 300 from becoming stuck. This would cause the lead screw 200 to move away from the motor under the reaction force of the nut 300, affecting the overall stability.

[0075] In some embodiments, the stop portion 260 is formed as a ring structure or a structure with circumferentially spaced distribution; and / or, the stop portion 260 is integrally formed with the lead screw 200 or the stop portion 260 is composed of a buffer material embedded in the lead screw 200.

[0076] It should be noted that although the above description describes an embodiment where the stop portion 260 is provided on the lead screw 200, this application is not limited thereto. For example, in some variations, the stop portion may be provided only at the nut 300, or it may be provided at both the lead screw 200 and the nut 300. Furthermore, in these variations, the structure, forming method, and constituent materials of the stop portion can be referred to the description of the stop portion 260 in the above embodiments.

[0077] The specific structure and forming method of the stop part 260 can be set according to the needs of taking into account factors such as ease of processing and effectiveness of stopping, as long as it can play a stable stopping role.

[0078] Figure 3 This illustration shows the axial cross-sectional structure of another lead screw drive device in an embodiment of this application, combined with... Figure 2 and Figure 3 As shown, in some embodiments, the bearing unit 400 includes a spherical bearing 410 and a thrust needle roller bearing 420 disposed between the spherical bearing 410 and the force sensor 500; the cage portion 420a of the thrust needle roller bearing 420 cooperates with the force sensor 500 and the needle roller portion 420b cooperates with the spherical bearing 410; the spherical bearing 410 includes a first component 410a and a second component 410b, each having a spherical surface, the first component 410a being press-fitted onto the input section 210, and the second component 410b abutting against the needle roller portion 420b, the spherical surfaces of the first component 410a and the second component 410b cooperating with each other to form a sliding contact pair.

[0079] The thrust needle roller bearing 420 can bear axial loads, allowing the axial force generated when the lead screw 200 rotates to be transmitted to the thrust needle roller bearing 420, thus preventing axial movement of the lead screw 200. The spherical surface of the first component 410a and the spherical surface of the second component 410b of the spherical bearing 410 are designed to cooperate with each other to form a sliding contact pair, allowing the input section 210 of the lead screw 200 to have a certain angle of deflection, which can stably transmit loads and prevent motion jamming.

[0080] Specifically, Figure 4 This illustration shows the motion state of the spherical bearing when the input segment wobbles in an embodiment of this application. In some embodiments, such as Figure 3 As shown, when the input section 210 rotates about the axis (i.e., the initial axial direction Z of the lead screw 200), the first component 410a, the second component 410b, and the needle roller portion 420b rotate synchronously under the action of friction. That is, during normal operation of the lead screw drive, when the input section 210 rotates about the axis, the first component 410a, which is pressed onto the input section 210, rotates accordingly, the second component 410b follows the first component 410a under the action of friction, and the needle roller portion 420b of the thrust needle roller bearing 420 follows the second component 410b under the action of friction. In some embodiments, such as Figure 4 As shown, when the input segment 210 drives the first component 410a to sway (at this time, there is an angle θ between the axial direction Z' of the input segment 210 and the initial axial direction Z of the lead screw), the spherical surface of the first component 410a and the spherical surface of the second component 410b maintain mutual sliding contact and form a continuous surface contact area; that is, when the input segment 210 has a certain angle of sway, the first component 410a sways relative to the second component 410b. Thanks to the design of the spherical surface of the first component 410a and the spherical surface of the second component 410b cooperating and forming a sliding contact pair, the two spherical surfaces can maintain mutual sliding contact and form a continuous surface contact area, so that the contact stress distribution between the first component 410a and the second component 410b is uniform, avoiding excessive local stress concentration, thereby preventing jamming between the first component 410a and the second component 410b.

[0081] It should be noted that, Figure 4 In order to clearly illustrate the motion state of the spherical bearing when the input section 210 wobbles, the wobbling angle θ between the axial direction Z' of the input section 210 and the initial axial direction Z of the lead screw is drawn as large; in actual working conditions, the wobbling angle of the input section 210 is smaller.

[0082] Furthermore, in some embodiments, the spherical surface of the first component 410a and / or the spherical surface of the second component 410b is coated with a sliding material, which can optimize the frictional performance of the spherical bearing 410, reduce wear, and improve transmission efficiency.

[0083] Figure 3 Other structures and Figure 2 The same applies, so I will not repeat myself.

[0084] Figure 5 The structure of the electromechanical brake in the embodiment of this application is illustrated, with reference to Figure 5 and combined Figure 2 and Figure 3 As shown, this application embodiment also provides an electromechanical brake, which is configured with a caliper housing assembly 600, a gearbox assembly 700, and a lead screw drive as described in any of the above embodiments. The caliper cylinder of the caliper housing assembly 600 serves as the housing 610 supporting the lead screw 200, and the output component of the gearbox assembly 700 is connected to the input section 210 of the lead screw 200. During operation of the electromechanical brake: the gearbox assembly 700 transmits the driving force from the motor to the input section 210 of the lead screw 200, driving the input section 210 and the threaded section 220 to rotate. The nut 300, mounted on the threaded section 220, converts the rotational motion into linear motion, extending or retracting relative to the housing 611 to apply or release braking force. During this process, the bearing unit 400 supports the lead screw 200, ensuring stable rotation of the lead screw 200, and the force sensor 500 detects the force on the lead screw 200 and feeds it back to the motor to achieve precise closed-loop control of the braking process.

[0085] The electromechanical brake, equipped with the aforementioned screw drive device, can effectively solve the problems of large axial dimensions and inconvenient layout, making the screw drive device and electromechanical brake structure compact, which is conducive to the layout in the whole vehicle, and can achieve stable operation and precise control, with excellent braking performance.

[0086] This application also provides an integrated braking control system (not shown) configured with a lead screw drive device as described in any of the above embodiments.

[0087] The integrated braking control system according to this application, which configures the aforementioned lead screw drive device, also has the same or similar technical effects as the electromechanical brake configured with the aforementioned lead screw drive device.

[0088] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A lead screw transmission device, characterized in that, include: A lead screw, supported by a housing, includes an input section and a threaded section. The input section extends through the housing into a housing cavity, and the threaded section is housed within the housing cavity. The threaded section and the input section are connected to form a receiving cavity, and the radial projection of the raceway region of the threaded section overlaps with the radial projection of the receiving cavity. The bearing unit and force sensor are disposed on the input section in the space between the bottom of the receiving cavity and the bottom of the shell cavity.

2. The lead screw transmission device as described in claim 1, characterized in that, The lead screw has an axial cross-section of m-shape. The lead screw includes a shaft-shaped input section, an annular threaded section, and a circular bottom section. One end of the threaded section is connected to the input section via the bottom section, and the other end is spaced apart from the input section to form the receiving cavity.

3. The lead screw transmission device as described in claim 2, characterized in that, The starting raceway region of the threaded segment is located at the free end of the threaded segment, and the radial projection of the starting raceway region overlaps with the radial projection of the receiving cavity.

4. The lead screw transmission device as described in claim 1, characterized in that, The bearing unit is disposed in the receiving cavity, and the force sensor is disposed between the bearing unit and the bottom of the housing cavity.

5. The lead screw transmission device as described in claim 4, characterized in that, The force sensor is locked to the bearing unit and the bottom of the housing cavity by axial fasteners.

6. The lead screw transmission device as described in claim 4, characterized in that, The bearing unit includes a spherical bearing and a thrust needle roller bearing disposed between the spherical bearing and the force sensor; The cage portion of the thrust needle roller bearing mates with the force sensor, and the needle roller portion mates with the spherical bearing. The spherical bearing includes a first component and a second component, each having a spherical surface. The first component is press-fitted onto the input section, and the second component abuts against the needle roller portion. The spherical surfaces of the first component and the second component cooperate with each other to form a sliding contact pair.

7. The lead screw transmission device as described in claim 6, characterized in that, When the input segment rotates around the axis, the first component, the second component, and the needle roller portion rotate synchronously under the action of friction. When the input segment causes the first component to sway, the spherical surface of the first component and the spherical surface of the second component maintain mutual sliding contact and form a continuous surface contact area.

8. The lead screw transmission device as described in claim 7, characterized in that, The spherical surface of the first component and / or the spherical surface of the second component is coated with a sliding material.

9. The lead screw transmission device as described in claim 4, characterized in that, A diamond-shaped retaining spring is provided between the bearing unit and the bottom of the receiving cavity, and / or between the bearing unit and the force sensor, and / or between the force sensor and the bottom of the housing cavity; Each rhomboid retaining spring includes two conical springs. The concave surfaces of the two conical springs are pressed together to form a rhomboid cavity. The conical surfaces of the two conical springs are pressed together with two components adjacent to the rhomboid retaining spring. The V-shaped bottom of the rhomboid retaining spring is interference-fitted into the V-shaped groove of the input section.

10. The lead screw transmission device as described in claim 1, characterized in that, The portion of the input segment extending out of the cavity is provided with a spline.

11. The lead screw transmission device as described in claim 1, characterized in that, The input section extends into the housing cavity through the through hole of the housing, and an elastic retaining ring and a bushing are provided between the input section and the through hole.

12. The lead screw drive device according to any one of claims 1 to 11, characterized in that, Also includes: A nut, assembled on the threaded section, is supported by the housing via an anti-rotation mechanism and can move linearly relative to the lead screw.

13. The lead screw transmission device as described in claim 12, characterized in that, The nut is clearance-fitted with the inner wall of the housing cavity, and the outer circumferential surface of the nut is coated with a sliding material.

14. The lead screw transmission device as described in claim 12, characterized in that, The lead screw and / or the nut are provided with an axially protruding stop portion, which is used to adjust the retraction stroke of the nut.

15. The lead screw drive device as described in claim 14, characterized in that, The stop portion is formed as a ring structure or a circumferentially spaced structure; and / or The stop portion is integrally formed with the lead screw and / or the nut, or the stop portion is composed of a buffer material embedded in the lead screw and / or the nut.

16. An electromechanical brake, characterized in that, The device is equipped with a caliper housing assembly, a gearbox assembly, and a lead screw drive as described in any one of claims 1 to 15, wherein the caliper cylinder of the caliper housing assembly serves as a housing for supporting the lead screw, and the output component of the gearbox assembly is connected to the input section of the lead screw.

17. An integrated braking control system, characterized in that, It is equipped with a lead screw drive device as described in any one of claims 1 to 15.

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