Electronic brake actuator, especially electronic parking brake actuator

Abstract

Electronic brake actuator (100) including a gearbox housing (10), a gearbox cover (20), a motor (30), a first-stage transmission gear assembly (40), a second-stage transmission gear assembly (50), a planetary gear transmission assembly (60), and an internal gear ring (13). The internal gear ring is injection-molded and fixed in a gear chamber (12) of the gearbox housing by injection molding. At least an internal gear portion of the internal gear ring is manufactured from powder metallurgy or metal like material. The electronic brake actuator provided in the invention designs the internal gear ring as an independent component, then fixes the internal gear ring in the gearbox housing by means of overmolding.

Description

2024P07497Electronic brake actuator, especially electronic parking brake actuatorTechnical Field

[0001] The invention relates to the field of vehicle braking technologies, and in particular to an electronic brake actuator, especially electronic parking brake actuator, also with important content concerning improved actuator manufacturing or actuator assembly process.Background

[0002] An electronic brake actuator includes a motor and a transmission mechanism. The transmission mechanism reduces an output speed of the motor and simultaneously improves an output torque to be transmitted to a brake caliper to realize a brake function. The transmission mechanism can adopt various transmission modes, such as a belt transmission mechanism, a worm transmission mechanism, a cylindrical gear transmission mechanism, and a planetary gear transmission mechanism. In order to obtain a specific speed reduction ratio, multi-stage transmission can also be used. Compared with other transmission methods, the planetary gear transmission mechanism has advantages of high speed reduction ratio, compact structure, and stable operation.

[0003] An internal gear ring in the brake actuator device is used for being meshed with a planetary gear in the planetary transmission mechanism. An existing internal gear ring and a gearbox housing are formed by integral injection molding, so that an upper limit value of a torque borne by the internal gear ring is low and the internal gear ring cannot meet the requirement of torque transmission.Summary of the Invention

[0004] An objective of the invention is to provide an electronic brake actuator, which can improve strength and manufacturing accuracy of an internal gear ring, improve stability of meshing efficiency, and solve the problem of being unable to adapt to torque transmission requirements.2024P07497

[0005] According to a first aspect of the invention, an electronic brake actuator is provided in connection with a gearbox comprising cavities in a housing, including but not limited to: a gearbox housing, the gearbox housing including a motor accommodating chamber (cavity) and a gear chamber (cavity), the gear chamber (cavity) being provided at a front end of the motor accommodating chamber (cavity) and being in communication with the motor accommodating chamber (cavity); a gearbox cover covering the gearbox housing and sealing the gear chamber (cavity); a motor assembled in the motor accommodating chamber (cavity), an output shaft of the motor extending into the gear chamber (cavity), and a first gear being fixed on the output shaft of the motor; a first-stage transmission gear assembly including a second gear and a third gear arranged coaxially, the second gear in gear teeth engagement with the first gear; a second-stage transmission gear assembly including a fourth gear and a sun gear arranged coaxially, the fourth gear in gear teeth engagement with the third gear; a planetary gear transmission assembly including a planetary gear carrier, a plurality of planetary gears, and an output spline, the plurality of planetary gears being assembled on a first end surface of the planetary gear carrier, the output spline being assembled on a second end surface of the planetary gear carrier, the first end surface and the second end surface being opposite surfaces of the planetary gear carrier, the sun gear being located at a central position of the plurality of planetary gears and respectively meshed with the plurality of planetary gears, and the output spline extending out along a bottom of the motor accommodating chamber (chamber); and an internal gear ring fixed in the gear chamber (chamber) by injection molding, the plurality of planetary gears being located in the internal gear ring and respectively meshed with the internal gear ring, and at least an internal gear portion of the internal gear ring being manufactured from powder metallurgy or metal like material that can involve semi metal material.2024P07497

[0006] A further improvement of the electronic brake actuator according to the invention lies in that the internal gear ring is manufactured from powder metallurgy or metal like material that can involve semi metal material.

[0007] A further improvement of the electronic brake actuator according to the invention lies in that a circumferential side surface of the internal gear ring is provided with a mounting portion, and an inner wall of the gear chamber (cavity) is provided with a mating portion; where before the internal gear ring is fixed in the gear chamber (cavity) by injection molding, the internal gear ring is pre-positioned in the gear chamber (cavity) by adaptively assembling the mounting portion to the mating portion.

[0008] A further improvement of the electronic brake actuator according to the invention lies in that there are a plurality of mounting portions uniformly provided on the circumferential side surface of the internal gear ring, and the mating portions have the same quantity as the mounting portions and one-to-one correspond to the mounting portions.

[0009] A further improvement of the electronic brake actuator according to the invention lies in that the mounting portion is a boss provided on the circumferential side surface of the internal gear ring, the mating portion is a groove provided on the inner wall of the gear chamber, and the boss is adapted to the groove.

[0010] A further improvement of the electronic brake actuator according to the invention lies in that the mounting portion is a recess provided on the circumferential side surface of the internal gear ring, the mating portion is a protrusion provided on the inner wall of the gear chamber, and the recess is adapted to the protrusion.

[0011] A further improvement of the electronic brake actuator according to the invention lies in that the recess is a groove provided on the circumferential side surface of the internal gear ring, and the groove is provided in a direction of a central axis of the internal gear ring.

[0012] A further improvement of the electronic brake actuator according to the invention lies in that after the internal gear ring is fixed in the gear chamber, an injection molding material is used to cover the end surfaces of the internal gear ring2024P07497 and the inner wall of the gear chamber, thereby fixing the internal gear ring in the gear chamber by injection molding.

[0013] A further improvement of the electronic brake actuator according to the invention lies in that internal teeth of the internal gear ring do not exceed the end surfaces at both sides of the internal gear ring in the direction of the central axis of the internal gear ring.

[0014] A further improvement of the electronic brake actuator according to the invention lies in that a central axis of the first gear is parallel to a central axis of the planetary gear transmission assembly and a central axis of the second-stage transmission gear assembly, and the central axis of the second-stage transmission gear assembly coincides with the central axis of the planetary gear transmission assembly.

[0015] The electronic brake actuator provided in the invention designs the internal gear ring as an independent component, then fixes the internal gear ring in the gearbox housing by means of overmolding, and the internal gear portion of the internal gear ring is manufactured from powder metallurgy or metal like material that can involve semi metal material, which enables production of design solutions with different parameters, enhances strength and manufacturing precision of the internal gear ring, and improves stability of meshing efficiency, thereby expanding the range of adaptable torque.Brief Description of the Drawings

[0016] The invention is described in detail below through example embodiments with reference to the following accompanying drawings, and in the drawings:FIG. 1 is an exploded view of an electronic brake actuator according to an embodiment of the invention;FIG. 2 is a sectional view of an electronic brake actuator according to an embodiment of the invention;2024P07497FIG. 3 is a schematic structural view of a second-stage transmission gear assembly according to an embodiment of the invention;FIG. 4 is a schematic view of assembling a gearbox housing and an internal gear ring according to an embodiment of the invention; andFIG. 5 is a schematic view of assembling a gearbox housing and internal teeth according to another embodiment of the invention.The drawings are schematic and not necessarily drawn to scale. Furthermore, they only illustrate those parts necessary for elucidating the invention, while other parts may be omitted or only briefly mentioned. That is, in addition to the components shown in the drawings, the invention may also include other components. The drawings are only schematic and are not necessarily drawn in proportion, and they show only most essential parts as far as necessary for the purpose of clarifying the invention, while other parts may be omitted or referred to. That is, in addition to the components shown in the drawings, the invention may also include other components. The present inventions disclosure is neither limited nor bound alone concerning the claimed inventive actuator structure as such alone but also contains and claims for improved manufacturing skills with manufacturing process issues in terms for manufacturing single components but also at least implicitly contains valuable improvement concerning high efficient automotive industrial component manufacturing i.e. including efficient actuator assembly process improvement. Finally an improved automotive wheel brake assembly that is comprising the above explained electronic brake actuator is included under the disclosure of the present invention. The invention may be implemented in various embodiments. For example the invention is serving and performing in / for automotive electric service brakes as electronic actuator. Then the invention is included in electric service wheel brakes. Another embodiment is possible for automotive electric parking brakes. Then the invention is included and mounted to electric parking wheel brakes. Finally the invention may be mounted / included in the so-called combined wheel brakes that combine the functions of service brake and the parking brake in one wheel brake system. The electronic parking brake can be configured as integrated, preferably currentless and self locked, electronic parking brake system. Then the self locking parking brake function can2024P07497 preferably be implemented with integration of a frictionally self locked spindledrive module which can be held and housed in the wheel brakes caliper module. In preferable alternative embodiment the electronic parking brake can comprise a switchable park lock unit PLU which can be configured as an extra unit that may be integrated or received in total or partly in the actuator housing or in the actuator cover and wherein the PLU can comprise a switchable and translationally movable park lock element with electric park lock actuator for releasable locking cooperation of the said park lock element with at least one rotating gear drivetrain element of the actuator.Detailed Description

[0017] The following describes implementations of the invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the invention from contents disclosed in this specification. Although the description of the invention will be introduced in conjunction with a preferred embodiment, it does not mean that features of the invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the invention. In order to provide a deeper understanding of the invention, the following description includes many specific details. The invention can also be implemented without these details. Furthermore, in order to avoid confusion or blurring key points of the invention, some specific details will be omitted from the description. It should be explained that where no conflict arises, embodiments in the invention may be combined, and features in embodiments may be combined.

[0018] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0019] In the description of this embodiment, it is to be clarified that the orientation or position relationship indicated by the terms “above”, “within”, etc., is based on the orientation or position relationship indicated in the drawings, or is the2024P07497 orientation or position relationship routinely placed when the invention product is used, solely for the purpose of facilitating description of the invention and simplifying the description, and not that the indication or the implication means that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a restriction to the invention.

[0020] Terms such as “first” and “second” are merely used for descriptive purposes, and must not be interpreted as indicating or implying relative importance.

[0021] In the description of this embodiment, it should be further noted that, unless otherwise clearly specified and defined, terms such as “arrange”, “connected”, and “connect” should be interpreted in a broad sense, for example, they may indicate a fixed connection, or a removable connection, or an integral connection; they may indicate a mechanical connection, or an electrical connection; they may indicate a direct connection, or an indirect connection via an intermediate medium, or internal communication between two elements. Those of ordinary skill in the art can interpret the specific meaning of the above-mentioned terms in this embodiment according to particular circumstances.

[0022] In order to make the purpose, technical solutions, and advantages of the invention clearer, implementations of the invention will be described in further detail below with reference to the accompanying drawings.

[0023] FIG. 1 is an exploded view of an electronic parking brake actuator according to an embodiment of the invention; FIG. 2 is a sectional view of an electronic parking brake actuator according to an embodiment of the invention; and FIG. 2 is a schematic structural view of a second-stage transmission gear assembly according to an embodiment of the invention.

[0024] Referring to FIG. 1 to FIG. 3, an electronic parking brake actuator 100 according to an embodiment of the invention includes a gearbox housing 10, a gearbox cover 20, a motor 30, a first-stage transmission gear assembly 40, a second-stage transmission gear assembly 50, a planetary gear transmission assembly 60, and an internal gear ring 13.2024P07497

[0025] The gearbox housing 10 includes a motor accommodating chamber 11 and a gear chamber 12. The gear chamber 12 is provided at a front end of the motor accommodating chamber 11 and is in communication with the motor accommodating chamber 11. The gear chamber 12 is configured to accommodate the first-stage transmission gear assembly 40, the second-stage transmission gear assembly 50, the planetary gear transmission assembly 60, and the internal gear ring 13. The front end of the motor accommodating chamber 11 is an end of the motor 30 where an output shaft thereof is located. The gearbox cover 20 is configured to cover the gearbox housing 10 and seal the gear chamber 12.

[0026] The motor 30 is assembled in the motor accommodating chamber 11, the output shaft of the motor 30 extends into the gear chamber 12, a first gear 31 is fixed on the output shaft of the motor 30, and the first gear 31 is configured to be adapted to the first-stage transmission gear assembly 40. A motor cover 32 is arranged at a rear end of the motor accommodating chamber 11, and the motor cover 32 is assembled at the rear end of the motor accommodating chamber 11 to seal the motor 30 in the motor accommodating chamber 11. A wave spring 33 of the motor 30 is further arranged between the motor cover 32 and the motor 30, and an axial gap of the motor 30 is adjusted by the wave spring 33 covering the motor 30.

[0027] The first-stage transmission gear assembly 40 includes a second gear 41 and a third gear 42 arranged coaxially, and the second gear 41 is meshed with the first gear 31. In the embodiment of the invention, a diameter of the second gear 42 is greater than a diameter of the third gear 41, a first pin 43 is arranged on a central axis of the second gear 41, and the third gear 42 is assembled on the first pin 43 so that the third gear 42 rotates synchronously with the second gear 41. The second gear 41, the first pin 43, and the third gear 42 can be manufactured by integral injection molding, and the second gear 41 and the third gear 42 can also be fixed to the first pin 43 by press fitting, or any of the gears is injection-molded by taking the first pin 43 as a shaft, without being specifically defined herein.

[0028] The first pin 43 extends out of the third gear 42 for press fitting with a positioning pin hole on the gearbox housing 10, and the positioning pin hole is located at a bottom of the gear chamber 12. When the first-stage transmission gear assembly2024P0749740 is assembled, the third gear 42 is remote from a gear cover 20 relative to the second gear 41. By meshing the second gear 41 with the first gear 31, when the motor 30 drives the first gear 31 to rotate, the second gear 41 is synchronously driven to rotate, so that the first-stage transmission gear assembly 40 rotates.

[0029] The second-stage transmission gear assembly 50 includes a fourth gear51 and a sun gear 52 arranged coaxially, and the fourth gear 51 is meshed with the third gear 42 to rotate the second-stage transmission gear assembly 50 by transmission of the third gear 42. The second-stage transmission gear assembly 50 further includes a second pin 53, and the fourth gear 51 and the sun gear 52 are fixed on the second pin 53. The second pin 53 extends out of the fourth gear 51 to fit a shaft hole of the gearbox cover 20. A diameter of the fourth gear 51 is greater than a diameter of the sun gear 52. The fourth gear 51, the second pin 53, and the sun gear 52 can be manufactured by integral injection molding, and the fourth gear 51 and the sun gear52 can also be fixed to the second pin 53 by press fitting, or any of the gears is injection- molded by taking the first pin 43 as a shaft, without being specifically defined herein.

[0030] In this embodiment, the sun gear 52 configured to be meshed with a plurality of planetary gears 62 requires a high output torque, and therefore the sun gear 52 is configured to be manufactured from powder metallurgy or metal like material that can involve semi metal material. The fourth gear 51 can be injection- molded with the second pin 53 as the shaft, and the sun gear 52 is press-fitted on the second pin 53.

[0031] The planetary gear transmission assembly 60 includes a planetary gear carrier 61, a plurality of planetary gears 62, and an output spline 63. The plurality of planetary gears 62 are assembled on a first end surface 611 of the planetary gear carrier 61, the output spline 63 is assembled on a second end surface 612 of the planetary gear carrier 61, the first end surface 611 and the second end surface 612 are opposite surfaces of the planetary gear carrier 61, the sun gear 52 is located at a central position of the plurality of planetary gears 62 and respectively meshed with the plurality of planetary gears 62, and the output spline 63 extends out along a bottom of the motor accommodating chamber 11.2024P07497

[0032] In the embodiment of the invention, the planetary gear carrier 61 is of a frustum of a cone structure, the planetary gear transmission assembly 60 includes four planetary gears 62, the first end surface 611 of the planetary gear carrier 61 is uniformly provided with four planet shafts 64, the four planetary gears 62 are assembled one-to-one corresponding to the four planet shafts 64, so that the four planetary gears 62 are rotatably assembled on the first end surface 611 of the planetary gear carrier 61.

[0033] The planetary gear carrier 61, the four planet shafts 64, and the output spline 63 are integrally injection-molded. In another embodiment, the output spline 63 may be manufactured from powder metallurgy or metal like material that can involve semi metal material, and then the planetary gear carrier 61 and the planet shafts 64 are injection-molded based on the output spline 63. The output spline 63 is located at a central position of the planetary gear carrier 61, and in particular, a central axis of the output spline 63 coincides with a central axis of the planetary gear carrier 61.

[0034] The internal gear ring 13 is arranged in the gear chamber 12, and the plurality of planetary gears 62 are located in the internal gear ring 13 and meshed with the internal gear ring 13 respectively. After the first-stage transmission gear assembly 40, the second-stage transmission gear assembly 50, and the planetary gear transmission assembly 60 are assembled, the sun gear 52 is respectively meshed with the four planetary gears 62 to drive the four planetary gears 62 to perform autobiography, and the four planetary gears 62 revolve through the meshing with the internal gear ring 13, thereby driving the planetary gear carrier 61 to rotate.

[0035] After the first-stage transmission gear assembly 40, the second-stage transmission gear assembly 50, and the planetary gear transmission assembly 60 are assembled, a central axis of the first gear 31 is parallel to a central axis of the planetary gear transmission assembly 60 and a central axis of the second-stage transmission gear assembly 50, and the central axis of the second-stage transmission gear assembly 50 coincides with the central axis of the planetary gear transmission assembly 60. A transmission combination relation of the invention is as follows: the second gear 41 is meshed with the first gear 31, the fourth gear 51 is meshed with the third gear 42, the2024P07497 sun gear 52 is meshed with the four planetary gears 62, and the four planetary gears 62 are meshed with the internal gear ring 13.

[0036] The internal gear ring 13 is fixed in the gear chamber 12 by injection molding, the plurality of planetary gears 62 are located in the internal gear ring 13 and respectively meshed with the internal gear ring 13, and the plurality of planetary gears 62 revolve by the meshing with the internal gear ring 13, thereby driving the planetary gear carrier 61 to rotate. In the invention, the internal gear ring 13 is designed separately, the internal gear ring 13 is assembled in the gear chamber 12, and the internal gear ring 13 is located at the bottom of the gear chamber 12 corresponding to the gearbox housing 10. Specifically, after the internal gear ring 13 is pre-positioned in the gear chamber 12, the injection molding material is used to cover the end surfaces of the internal gear ring 13 and the inner wall of the gear chamber 12, so that the internal gear ring 13 is fixed in the gear chamber 12 by injection molding, such that the internal gear ring 13 is partially overmolded to be integrated with the gearbox housing 10. In the invention, the internal gear ring 13 is separately designed so that the internal gear ring 13 can be replaced as required, including but not limited to the material, the structure, and the like.

[0037] At least the internal gear portion of the internal gear ring 13 is manufactured from powder metallurgy or metal like material that can involve semi metal material. The conventional internal gear ring 13 and the gearbox housing 10 are integrally injection-molded, so that the upper limit value of the torque borne by the internal gear ring 13 is low and the internal gear ring cannot meet the requirement of torque transmission. In the invention, at least the internal gear portion of the internal gear ring 13 is manufactured from powder metallurgy or metal like material that can involve semi metal material, thereby enhancing the output torque of the internal gear ring 13.

[0038] In one embodiment, the internal gear ring 13 is manufactured from powder metallurgy or metal like material that can involve semi metal material, thereby improving the strength and manufacturing precision of the internal gear ring 13, further improving the output torque of the internal gear ring 13, and improving NVH (Noise, Vibration, and Harshness) performance of a product by improving the meshing2024P07497 precision between the internal gear ring 13 and the plurality of planetary gears 62. The internal gear ring 13 of the invention can accurately adapt to different torque requirements by replacing powder metallurgy or metal with different strengths, thereby improving economy.

[0039] Internal teeth of the internal gear ring 13 do not exceed the end surfaces at both sides of the internal gear ring 13 in the direction of the central axis of the internal gear ring 13. In the embodiment of the invention, in the direction of the central axis of the internal gear ring 13, the size of the internal teeth of the internal gear ring 13 is equal to the size between the end surfaces at both sides of the internal gear ring 13, that is, the tooth width of the internal gear ring 13 is consistent with the thickness of the internal gear ring 13. Furthermore, the number of teeth of the internal gear ring 13 can also be designed and adjusted according to the requirements, thereby facilitating the production of design solutions with different parameters without the need for retooling.

[0040] In order to facilitate mounting of the internal gear ring 13, as shown in FIG. 1 and FIG. 2 in conjunction with FIG. 4 and FIG. 5, a mounting portion 131 is provided on a circumferential side surface of the internal gear ring 13 in the invention, and the inner wall of the gear chamber 12 is provided with a mating portion 121. The internal gear ring 13 is pre-positioned in the gear chamber 12 by adaptively assembling the mating portion 121 to the mounting portion 131. The gearbox housing 10 is provided with an annular step 14 in a region of the gear chamber 12 corresponding to the second-stage transmission gear assembly 50, that is, the second- stage transmission gear assembly 50 is arranged above the annular step 14, and the internal gear ring 13 is arranged on the annular step 14, so that the internal gear ring 13 is fixed in the gearbox housing 10. In the invention, the mating portion 121 is provided on a side wall of the annular step 14, the internal gear ring 13 is fixed in the gear chamber 12 in advance by adaptively assembling the mounting portion 131 to the mating portion 121, and then the internal gear ring 13 is fused in the gearbox housing 10 through injection molding, thereby ensuring the stability of the internal gear ring 13.2024P07497

[0041] There are a plurality of mounting portions 131, the plurality of mounting portions 131 are uniformly provided on the circumferential side surface of the internal gear ring 13, and the mating portions 121 have the same quantity as the mounting portions 131 and one-to-one correspond to the mounting portions 131.

[0042] In one embodiment, as shown in FIG. 4, the mounting portion 131 is a boss provided on the circumferential side surface of the internal gear ring 13, and the mating portion 121 is a groove provided on the inner wall of the gear chamber 12. Specifically, the groove is provided on the side wall of the annular step 14, and the boss is adapted to the groove, so thatthe internal gear ring 13 can not only be pre-assembled at the position of the annular step 14 within the gear chamber 12, but also the internal gear ring 13 can be prevented from rotating circumferentially.

[0043] In another embodiment, as shown in FIG. 5, the mounting portion 131 is a recess provided on the circumferential side surface of the internal gear ring 13, and the mating portion 121 is a protrusion provided on the inner wall of the gear chamber12. Specifically, the protrusion is provided on the side wall of the annular step 14, and the recess is adapted to the protrusion, so thatthe internal gear ring 13 can not only be pre-assembled at the position of the annular step 14 within the gear chamber 12, but also the internal gear ring 13 can be prevented from rotating circumferentially. The recess is a groove provided on the circumferential side surface of the internal gear ring13, and the groove is provided in a direction of a central axis of the internal gear ring 13, thereby facilitating assembling of the internal gear ring 13.

[0044] The working principle of the invention is as follows: the motor 30 drives the first gear 31 to rotate, the first gear 31 drives the second gear 41 to rotate through meshing, and the second gear 41 drives the third gear 42 to rotate. The third gear 42 drives the fourth gear 51 to rotate through meshing, the fourth gear 51 drives the sun gear 52 to rotate, the sun gear 52 drives the four planetary gears 62 to rotate through meshing, and the four planetary gears 62 revolve through the meshing with the internal gear ring 13, thereby driving the planetary gear carrier 61 to rotate. The planetary gear carrier 61 drives the output spline 63 to rotate, and finally outputs power.2024P07497

[0045] The electronic parking brake actuator provided in the invention designs the internal gear ring as an independent component, then fixes the internal gear ring in the gearbox housing by means of overmolding, and the internal gear portion of the internal gear ring is manufactured from powder metallurgy or metal like material that can involve semi metal material, which enables the production of design solutions with different parameters, enhances strength and manufacturing precision of the internal gear ring, and improves stability of meshing efficiency, thereby expanding the range of adaptable torque.

[0046] Although the invention has been illustrated and described with reference to certain preferred implementations of the invention, those of ordinary skill in the art should understand that the above content allows for further modification with details of the invention in conjunction with specific implementations, and it cannot be determined that the specific implementation of the invention is limited to written description only. Those skilled in the art can make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

2024P07497Patent claims1. An electronic brake actuator, especially electronic parking brake actuator, is characterized by: a gearbox body, the gearbox body comprising a motor accommodating chamber and a gear chamber, the gear chamber being provided at a front end of the motor accommodating chamber and being in communication with the motor accommodating chamber; a gearbox cover covering the gearbox body and sealing the gear chamber; a motor assembled in the motor accommodating chamber, an output shaft of the motor extending into the gear chamber, and a first gear being fixed on the output shaft of the motor; a first-stage transmission gear assembly comprising a second gear and a third gear arranged coaxially, the second gear in gear teeth engagement with the first gear; a second-stage transmission gear assembly comprising a fourth gear and a sun gear arranged coaxially, the fourth gear in gear teeth engagement with the third gear; a planetary gear transmission assembly comprising a planetary gear carrier, a plurality of planetary gears, and an output spline, the plurality of planetary gears being assembled on a first end surface of the planetary gear carrier, the output spline being assembled on a second end surface of the planetary gear carrier, the first end surface and the second end surface being opposite surfaces of the planetary gear carrier, the sun gear being located at a central position of the plurality of planetary gears and respectively in gear teeth engagement with the plurality of planetary gears, and the output spline extending out along a bottom of the motor accommodating chamber; and an internal gear ring fixed in the gear chamber by injection molding, the plurality of planetary gears being located in the internal gear ring and respectively in gear teeth engagement with the internal gear ring, and at least an internal gear portion of the internal gear ring being manufactured from powder metallurgy or metal-like material that can involve semi metal material.

2. The electronic brake actuator according to claim 1, characterized in that the internal gear ring is manufactured from powder metallurgy or metal-like material that can involve semi metal material.2024P074973. The electronic brake actuator according to claim 1, characterized in that a circumferential side surface of the internal gear ring is provided with a mounting portion, and an inner wall of the gear chamber is provided with a mating portion; wherein before the internal gear ring is fixed in the gear chamber by injection molding, the internal gear ring is pre-positioned in the gear chamber by adaptively assembling the mounting portion to the mating portion.

4. The electronic brake actuator according to claim 3, characterized in that there are a plurality of mounting portions uniformly provided on the circumferential side surface of the internal gear ring, and the mating portions have the same quantity as the mounting portions and one-to-one correspond to the mounting portions.

5. The electronic brake actuator according to claim 4, characterized in that each of the mounting portions is a boss provided on the circumferential side surface of the internal gear ring, each of the mating portions is a groove provided on the inner wall of the gear chamber, and the boss is adapted to the groove.

6. The electronic brake actuator according to claim 4, characterized in that each of the mounting portions is a recess provided on the circumferential side surface of the internal gear ring, each of the mating portions is a protrusion provided on the inner wall of the gear chamber, and the recess is adapted to the protrusion.

7. The electronic brake actuator according to claim 6, characterized in that the recess is a groove provided on the circumferential side surface of the internal gear ring, and the groove is provided in a direction of a central axis of the internal gear ring.

8. The electronic brake actuator according to any one of claims 1 to 7, characterized in that after the internal gear ring is fixed in the gear chamber, an injection molding material is used to cover the end surfaces of the internal gear ring and the inner wall of the gear chamber, thereby fixing the internal gear ring in the gear chamber by injection molding.2024P074979. The electronic brake actuator according to claim 1, characterized in that internal teeth of the internal gear ring do not exceed the end surfaces at both sides of the internal gear ring in the direction of the central axis of the internal gear ring.

10. The electronic brake actuator according to claim 1, characterized in that a central axis of the first gear is parallel to a central axis of the planetary gear transmission assembly and a central axis of the second-stage transmission gear assembly, and the central axis of the second-stage transmission gear assembly coincides with the central axis of the planetary gear transmission assembly.

11. The electronic brake actuator according to one or several of the claims 1 - 10, wherein the electronic parking brake is integrated thereby comprising a self locking configured spindledrive module that is held and housed in a wheel brake caliper module, or the electronic parking brake comprises a switchable park lock unit PLU that is configured as an extra unit that is held integrated or received in the actuator housing or in the actuator cover and wherein the park lock unit PLU comprises a switchable and translationally movable park lock element that is electrically driven by an electric park lock actuator for performing a releasable park lock cooperation of the said park lock element with at least one rotating gear drivetrain element of the actuator.

12. Industrial manufacturing process for an electronic brake actuator comprising the features of one or more of the claims 1-11.

13. Industrial assembly process for an electronic brake actuator comprising the features of one or more of the claims 1-11.

14. Automotive wheel brake assembly comprising an electronic brake actuator according to the features of one or more of the claims 1-13.

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