A drum type park executive

Abstract

The utility model discloses a kind of drum type line control parking actuators, including electric actuator and drum brake, the electric actuator is driven drum brake by cable and brake and release brake, the electric actuator includes motor, screw nut transmission mechanism and dust cover;Its characterized in that, the screw nut in the screw nut transmission mechanism is supported on the lower shell of the electric actuator by self-lubricating bushing slidingly.The utility model does not need additional lubrication system, reduces cost.

Description

Technical Field

[0001] This utility model relates to the field of parking actuator technology, and in particular to a drum-type wire-controlled parking actuator. Background Technology

[0002] Drum brakes were the earliest form of automobile brakes, and they were widely used in various types of automobiles before disc brakes even appeared.

[0003] Current drum-type wire actuators have the following problems:

[0004] 1. See Figure 1 The lead screw nut 1 is slidably supported on the upper housing 3 of the electric actuator by a deep groove ball bearing 2. This method requires an additional lubrication system, which increases costs. In addition, it is not resistant to dust, mud and impurities, which can easily cause wear and jamming of the deep groove ball bearing 2 due to grease contamination. Furthermore, due to the rolling element friction, the deep groove ball bearing 2 has high noise and vibration during operation, and its service life is unstable under low-speed heavy load or impact load.

[0005] 2. See Figure 2 The existing lead screw is a split-type lead screw 4, and it lacks a limit device (hardware protection). The lead screw nut can break through the upper housing due to excessive stroke. Furthermore, the lead screw nut is prone to radial and axial movement during operation, resulting in insufficient material continuity, torsional resistance, and bending rigidity of the overall structure, making it susceptible to deformation under heavy loads or operation. The split-type lead screw has a long assembly process, and improper assembly can easily lead to errors. Additionally, stress concentration is prone to occur at the connection points of the split-type lead screw, making it susceptible to loosening or fatigue damage under impact loads. Moreover, the split-type lead screw has connection gaps, increasing transmission energy, resulting in greater energy loss and low transmission efficiency.

[0006] 3. See also Figure 3 The existing dust cover 5 of the drum-type wired actuator has poor guiding properties and is prone to lateral sway. The inside of the dust cover 5 is prone to wear and rigid tension with the lead screw, which causes slight deviation of the lead screw during operation. It can also easily cause the dust cover 5 to be torn, wrinkled or loose at the connection. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide an improved drum-type drive-by-wire parking actuator to address the aforementioned technical problems of existing drum-type drive-by-wire actuators.

[0008] The technical problem to be solved by this utility model can be achieved through the following technical solution:

[0009] A drum-type wire-controlled parking actuator includes an electric actuator and a drum brake. The electric actuator drives the drum brake to brake and release the brake via a cable. The electric actuator includes a motor, a lead screw and nut transmission mechanism, and a dust cover. The characteristic feature is that the lead screw and nut transmission mechanism has a lead screw nut that is slidably supported on the lower housing of the electric actuator by a self-lubricating bushing.

[0010] In a preferred embodiment of this utility model, the lead screw is an integral lead screw.

[0011] In a preferred embodiment of this utility model, a limiting structure is added to the tail of the lead screw to restrict the movement of the lead screw nut.

[0012] In a preferred embodiment of the present invention, the limiting structure consists of several blocking points disposed in several grooves at the tail of the lead screw.

[0013] In a preferred embodiment of this utility model, the dust cover covers the head of the lead screw, and the bottom of the dust cover is installed on the upper housing of the electric actuator; the inner diameter of the dust cover is 8.5-15mm larger than the outer diameter of the lead screw, the axial direction of the dust cover is wavy, and a number of reinforcing ribs are circumferentially spaced within the troughs of the wavy shape.

[0014] Due to the adoption of the above technical solution, this utility model has the following advantages:

[0015] 1. The lead screw nut, which is slidably supported on the lower housing of the electric actuator via a self-lubricating bushing, replaces the lead screw nut with a deep groove ball bearing for sliding support on the lower housing of the electric actuator. This has the following advantages:

[0016] 1. Cost and maintenance advantages: No additional lubrication system is required, reducing costs.

[0017] 2. Advantages in adaptability to working conditions: It can withstand harsh environments such as dust, mud, and small amounts of impurities, avoiding wear and jamming of deep groove ball bearings caused by grease contamination.

[0018] 3. Operational stability advantages: With no rolling element friction, there is less noise and vibration during operation, and the service life is more stable under low-speed heavy load or impact load.

[0019] II. The use of an integral lead screw with a limiting device has the following advantages:

[0020] 1. An integral lead screw is adopted and a limit switch is added (hardware protection to prevent the upper housing from being broken due to excessive stroke).

[0021] 2. Improved precision and rigidity: Reduces radial runout and axial movement during operation; enhances the material continuity of the overall structure; improves torsional and bending rigidity; and prevents deformation under heavy loads or during operation.

[0022] 3. Assembly and maintenance optimization: Reduce assembly processes, shorten working hours, and avoid errors caused by improper assembly.

[0023] 4. Reliability and extended lifespan: The connection point of a split lead screw is prone to stress concentration, and impact loads can cause loosening or fatigue damage. An integrated lead screw eliminates this weak point and can withstand more complex working conditions.

[0024] 5. Efficiency and cost optimization: Clearance-free transmission reduces energy loss, improves transmission efficiency, and saves costs and labor time.

[0025] Third, increasing the size of the dust cover and adding supporting ribs to it has the following advantages:

[0026] 1. Improved guidance during compression, preventing lateral sway and wear between the dust cover and the lead screw.

[0027] 2. Avoid rigid tension: It can accommodate slight deviations that may occur in the lead screw during operation, preventing the dust cover from tearing, wrinkling, or loosening at the connection.

[0028] 3. Reduce friction loss: Increase the inner diameter of the dust cover to reduce wear between the inside of the dust cover and the lead screw.

[0029] 4. Ensure sealing and dustproof effect: Adding support ribs makes the dust cover less prone to deformation, maintaining the sealing and dustproof effect.

[0030] 5. Improve structural reliability and adaptability to complex working conditions: In complex working conditions such as vibration, impact and low temperature, the design of the support ribs can disperse the stress on the dust cover when the actuator moves, avoid stress concentration damage to the dust cover, and improve the deformation resistance of the overall structure. Attached Figure Description

[0031] Figure 1 This is one of the schematic diagrams of the electric actuator part of an existing drum-type wire-controlled parking actuator.

[0032] Figure 2 This is an exploded view of the lead screw in the electric actuator of an existing drum-type wire-controlled parking actuator.

[0033] Figure 3 This is a schematic diagram of the dust cover for an existing drum-type wire-controlled parking actuator.

[0034] Figure 4 This is a schematic diagram of the electric actuator structure of the drum-type wire-controlled parking actuator of this utility model.

[0035] Figure 5 This is a schematic diagram of the lead screw structure in the electric actuator of the drum-type wire-controlled parking actuator of this utility model.

[0036] Figure 6 This is a schematic diagram of the dust cover for an existing drum-type wire-controlled parking actuator. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] See Figures 4 to 6 The drum-type drive-by-wire parking actuator shown in the figure includes an electric actuator 100 and a drum brake (not shown in the figure). The electric actuator 100 drives the drum brake to brake and release the brake via a cable.

[0039] The electric actuator 100 includes an electric motor (not shown), a lead screw and nut transmission mechanism 110, and a dust cover 120.

[0040] The feature of this utility model is that a self-lubricating bushing 111 is used to replace the deep groove ball bearing in the prior art, and the screw nut 112 in the screw nut transmission mechanism 110 is slidably supported on the upper housing 130 of the electric actuator 100 through the self-lubricating bushing 111.

[0041] The lead screw 113 is a one-piece lead screw. A limiting structure is added to the tail of the lead screw 113 to restrict the movement of the lead screw nut. The limiting structure consists of several stop points 113b provided in several grooves 113a at the tail of the lead screw 113.

[0042] The dust cover 120 covers the head of the lead screw 113, and the bottom of the dust cover 120 is installed on the upper housing 130 of the electric actuator 100. The inner diameter of the dust cover 120 is 8.5-15mm larger than the outer diameter of the lead screw 113. The axial direction of the dust cover 120 is wavy, and several reinforcing ribs 121a are arranged circumferentially at intervals in the troughs 121 of the wavy shape.

Claims

1. A drum-type drive-by-wire parking actuator, comprising an electric actuator and a drum brake, wherein the electric actuator drives the drum brake via a cable for braking and releasing, and the electric actuator includes a motor, a lead screw and nut transmission mechanism, and a dust cover; characterized in that, In the lead screw and nut transmission mechanism, the lead screw nut is slidably supported on the lower housing of the electric actuator by a self-lubricating bushing.

2. The drum-type wire-controlled parking actuator according to claim 1, characterized in that, The lead screw is a one-piece lead screw.

3. A drum-type drive-by-wire parking actuator according to claim 2, characterized in that, A limiting structure is added to the tail of the lead screw to restrict the movement of the lead screw nut.

4. A drum-type drive-by-wire parking actuator according to claim 3, characterized in that, The limiting structure consists of several stopping points set in several grooves at the tail of the lead screw.

5. A drum-type drive-by-wire parking actuator according to any one of claims 1 to 4, characterized in that, The dust cover covers the head of the lead screw, and the bottom of the dust cover is installed on the upper housing of the electric actuator; the inner diameter of the dust cover is 8.5-15mm larger than the outer diameter of the lead screw, the axial direction of the dust cover is wavy, and several reinforcing ribs are circumferentially spaced in the trough of the wavy shape.

Images