Electric planetary brake system

Abstract

The invention belongs to the field of metro braking, and relates to an electric planetary braking system which realizes a quick-response braking function by combining motor driving with a planetary transmission mechanism. The system adopts a first-stage planet wheel structure and a second-stage planet wheel structure, axial movement is achieved through cooperation of a ball nut and a ball screw, and a subway hub is clamped and braked. Particularly, the first-stage planet wheel, the second-stage planet wheel and the pin shaft adopt a sliding structure design, so that the brake response time is obviously shortened and reaches 0.0035 seconds, and the driving safety is improved. Meanwhile, the system is compact in structure and high in integration level, the maintenance cost is reduced, noise pollution is reduced, and space utilization is optimized. According to the system, through accurate motor control and stable planetary transmission, constant and reliable braking torque is provided, the stability and consistency of the braking effect are ensured, and a new solution is provided for a braking system of a vehicle.

Description

Technical Field

[0001] The invention belongs to the field of subway braking and relates to an electric planetary brake system. Background Art

[0002] In the field of transportation, especially in large transportation vehicles such as subways, trains and trucks, the performance of the brake system is crucial to ensure driving safety. Although the traditional brake system, especially the widely used pneumatic brake system, meets the basic braking needs to a certain extent, its inherent defects are becoming increasingly prominent, becoming a key factor restricting the further improvement of the brake system performance.

[0003] The pneumatic brake system mainly relies on the compression and release of gas to achieve the braking function. However, the response delay problem in this process makes it difficult for the brake system to respond to the driver's braking needs in time, thus affecting the timeliness and safety of braking. In addition, due to the instability of air pressure, the pneumatic brake system is difficult to provide a constant braking torque during the braking process, resulting in unstable braking torque, which further exacerbates the uncertainty of the braking effect.

[0004] In addition to response delays and unstable braking torque, pneumatic brake systems also have the problem of high maintenance costs. Since the system contains multiple complex pneumatic components and pipelines, regular inspection and maintenance are required, which not only increases operating costs but also takes up a lot of time resources. At the same time, the noise generated during the compression and release of gas also causes serious noise pollution to the driving environment and the surrounding environment.

[0005] What’s more serious is that the structural complexity of the pneumatic brake system also increases potential failure points, reducing the reliability and stability of the system. Under extreme temperature or humidity conditions, the performance of pneumatic components may be affected, resulting in reduced braking effect and even safety accidents. In addition, pneumatic brake systems usually require a large space to install and maintain related pneumatic components and pipelines, which is undoubtedly a huge challenge for vehicles with limited space. Summary of the invention

[0006] In view of this, the object of the present invention is to provide an electric planetary brake system to improve the timeliness of brake response, the stability of braking torque, reduce noise, and be environmentally friendly.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an electric planetary brake system, comprising a motor housing, a motor shaft, a primary planetary gear, a primary planetary carrier, a primary internal gear ring, a secondary planetary gear, a secondary planetary carrier, a secondary internal gear ring, a ball nut and a ball screw; the motor housing is used to accommodate and fix various transmission and braking components, and a primary sun gear is integrated on the motor shaft, and the number of primary planetary gears is three, all of which are meshed with the primary sun gear; the primary planetary carrier is connected to the three primary planetary gears through a primary planetary carrier pin and a shaft elastic retaining ring, and a secondary sun gear is designed on the primary planetary carrier; the primary internal gear ring is fixed in the motor housing and meshed with the primary planetary gear; the number of secondary planetary gears is three, all of which are meshed with the secondary sun gear; the secondary planetary carrier is connected to the three secondary planetary gears through a secondary planetary carrier pin, a hole elastic retaining ring, a secondary planetary gear upper washer, and a secondary planetary gear lower washer; the secondary planetary carrier is fixed in the motor housing and meshed with the secondary planetary gear; the ball nut is connected to the secondary planetary carrier; the ball screw cooperates with the ball nut, and axial movement is achieved through the rotation of the ball nut.

[0008] Optionally, the first-stage planet carrier and the second-stage planet carrier are connected through a hole with a wire retaining ring for axial limitation, thereby limiting the axial displacement between the two and allowing relative rotation.

[0009] Optionally, the secondary planet carrier is fixed in the motor housing through a deep groove ball bearing; the axial force generated by the ball screw brake during braking is transmitted to the frame of the motor housing through the ball nut, the secondary planet carrier, the deep groove ball bearing at the right end and the primary inner gear ring.

[0010] Optionally, the planetary reducer and the motor shaft are hollow inside to allow the ball screw to pass through, making the entire brake component compact.

[0011] Optionally, the bearing seat is installed at one end of the motor housing by a first screw and a second screw, and is used to support the deep groove ball bearing and fix the primary inner gear ring and the secondary inner gear ring.

[0012] Optionally, the axial movement of the ball screw is used to axially clamp the wheel hub of the subway to achieve the braking function; when the motor rotates in the reverse direction, the ball screw releases the brake.

[0013] Optionally, the response time of the brake application is 0.0035 seconds, achieving timely brake response.

[0014] Optionally, the secondary planet carrier is connected to the ball nut via a third screw.

[0015] The beneficial effects of the present invention are:

[0016] 1) Improve the timeliness of brake response: The electric planetary brake system is driven by a motor, which can achieve rapid response, significantly shorten the brake response time, and improve driving safety;

[0017] 2) Enhanced braking torque stability: Through precise motor control and stable transmission of the planetary reducer, the electric planetary brake system can provide constant and reliable braking torque, ensuring the stability and consistency of the braking effect;

[0018] 3) Reduce maintenance costs: The structure of the electric planetary brake system is relatively simple, reducing the complex pneumatic components and pipelines in the traditional pneumatic brake system, thereby reducing maintenance costs and time costs; at the same time, the electric system usually has a longer service life, further reducing maintenance requirements;

[0019] 4) Reduce noise pollution: The electric planetary brake system does not generate noise from gas compression and release during braking, which significantly reduces noise pollution and improves the comfort of the driving environment and surrounding environment;

[0020] 5) Optimize space utilization: The electric planetary brake system has a compact structure and high integration, which can save installation space and provide more flexibility and possibilities for the design of vehicles.

[0021] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure numerals: motor shaft 1, motor housing 2, primary planetary gear 3, primary planetary carrier pin 4, elastic retaining ring for shaft 5, primary planetary carrier 6, primary internal gear ring 7, elastic retaining ring for hole 8, secondary planetary carrier pin 9, secondary planetary gear upper washer 10, secondary planetary gear 11, secondary internal gear ring 12, secondary planetary gear lower washer 13, secondary planetary carrier 14, first screw 15, second screw 16, bearing seat 17, deep groove ball bearing 18, wire retaining ring for hole 19, third screw 20, ball nut 21, ball screw 22. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0027] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] See also Figure 1 , please refer to Figure 1 In an electric planetary brake system of the present invention, the motor housing 2 is used to accommodate and fix the transmission and braking components of the entire brake system. A primary sun gear is integrated on the motor shaft 1 (not directly marked, but its position and function can be understood in combination with the description). This design shortens the axial dimension and improves the compactness of the system. The three primary planetary gears 3 are all engaged with the primary sun gear and are connected to the primary planet carrier 6 through the primary planet carrier pin 4 and the shaft elastic retaining ring 5. A secondary sun gear is designed on the primary planet carrier 6 (also not directly marked). Such a design simplifies the system structure and improves the transmission efficiency.

[0029] The primary inner gear ring 7 is fixed in the motor housing 2 and meshes with the primary planetary gear 3 to form a primary planetary transmission. There are three secondary planetary gears 11, all of which mesh with the secondary sun gear and are connected to the secondary planetary carrier 14 through the secondary planetary carrier pin 9, the hole elastic retaining ring 8, the secondary planetary gear upper washer 10 and the secondary planetary gear lower washer 13. The secondary inner gear ring 12 is fixed in the motor housing 2 and meshes with the secondary planetary gear 11 to form a secondary planetary transmission.

[0030] The ball nut 21 is connected to the secondary planet carrier 14, and the ball screw 22 cooperates with the ball nut 21. When the motor is driven, the ball nut 21 rotates, and the axial movement is achieved through the spiral structure of the ball screw 22. The primary planet carrier 6 and the secondary planet carrier 14 are connected through a hole with a wire retaining ring 19 for axial limitation, which not only limits the axial displacement between the two, but also allows them to rotate relative to each other.

[0031] The secondary planet carrier 14 is fixed in the motor housing 2 through the deep groove ball bearing 18, ensuring the stability and reliability of the system. The axial force generated by the ball screw 22 during braking is transmitted to the frame of the motor housing 2 through the ball nut 21, the secondary planet carrier 14, the deep groove ball bearing 18 at the right end and the primary inner gear ring 7, realizing the braking function.

[0032] The hollow design inside the planetary reducer and the motor shaft 1 allows the ball screw 22 to pass smoothly, further optimizing the compactness of the brake component. The bearing seat 17 is installed at one end of the motor housing 2 by means of the first screw 15 and the second screw 16, and is used to support the deep groove ball bearing 18 and fix the primary inner gear ring 7 and the secondary inner gear ring 12.

[0033] The secondary planet carrier 14 is connected to the ball nut 21 via the third screw 20, ensuring a firm connection and stable transmission between the two.

[0034] When braking is required, the motor drives the ball nut 21 to rotate, and the ball screw 22 moves axially therewith, axially clamping the wheel hub of the subway to achieve the braking function. When the motor rotates in the reverse direction, the ball screw 22 releases the brake and resumes the driving state.

[0035] In this embodiment, since the braking time is extremely short, the first and second stage planetary gears and the pin shaft adopt a sliding structure design, so that the response time of the braking time is shortened to 0.0035 seconds, achieving timely and efficient braking response.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An electric planetary brake system, characterized in that: It includes a motor housing, a motor shaft, a primary planetary gear, a primary planetary carrier, a primary inner gear ring, a secondary planetary gear, a secondary planetary carrier, a secondary inner gear ring, a ball nut and a ball screw; The motor housing is used to accommodate and fix various transmission and braking components. A primary sun gear is integrated on the motor shaft. There are three primary planetary gears, all of which are meshed with the primary sun gear. The first-stage planet carrier is connected to three first-stage planetary gears through the first-stage planet carrier pin and the shaft with an elastic retaining ring, and a second-stage sun gear is designed on the first-stage planet carrier; the first-stage inner gear ring is fixed in the motor housing and meshes with the first-stage planetary gear; there are three second-stage planetary gears, all of which mesh with the second-stage sun gear; The secondary planet carrier is connected to the three secondary planetary gears through the secondary planet carrier pin, the elastic retaining ring for the hole, the secondary planetary gear upper washer, and the secondary planetary gear lower washer; the secondary inner gear ring is fixed in the motor housing and meshes with the secondary planetary gear; The ball nut is connected to the secondary planet carrier; the ball screw cooperates with the ball nut, and axial movement is achieved through the rotation of the ball nut.

2. An electric planetary brake system according to claim 1, characterized in that: The primary planet carrier and the secondary planet carrier are connected through holes with a wire retaining ring for axial limitation, which limits the axial displacement between the two and allows relative rotation.

3. The electric planetary brake system according to claim 1, characterized in that: The secondary planet carrier is fixed in the motor housing through a deep groove ball bearing; the axial force generated by the ball screw brake during braking is transmitted to the frame of the motor housing through the ball nut, the secondary planet carrier, the deep groove ball bearing at the right end and the primary inner gear ring.

4. The electric planetary brake system according to claim 1, characterized in that: The planetary reducer and the motor shaft are hollow inside to allow the ball screw to pass through, making the entire brake component compact.

5. The electric planetary brake system according to claim 3, characterized in that: The bearing seat is installed at one end of the motor housing through a first screw and a second screw, and is used to support the deep groove ball bearing and fix the primary inner gear ring and the secondary inner gear ring.

6. The electric planetary brake system according to claim 1, characterized in that: The axial movement of the ball screw is used to axially clamp the wheel hub of the subway to achieve the braking function; when the motor rotates in the reverse direction, the ball screw releases the brake.

7. The electric planetary brake system according to claim 1, characterized in that: The response time of the brake is 0.0035 seconds, ensuring timely brake response.

8. The electric planetary brake system according to claim 1, characterized in that: The secondary planet carrier is connected with the ball nut through the third screw.

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