Motion conversion mechanism with circular-truncated-cone-shaped roller structure

Abstract

The utility model provides a motion conversion mechanism with a circular-truncated-cone-shaped roller structure. The motion conversion mechanism comprises a driving disc, a driven disc and a circular-truncated-cone-shaped roller. The driving disc is provided with a driving slope ramp; the driven disc is provided with a driven slope ramp; the circular truncated cone roller is located between the driving disc and the driven disc, and the circular truncated cone side face of the circular truncated cone roller is attached to the driving slope ramp and the driven slope ramp. The rolling bearing has the beneficial effects that the rolling body adopts a circular truncated cone-shaped roller structure, and the roller is in linear contact with the raceway, so that compared with a ball ramp scheme, the rolling bearing can bear larger load; the rolling body is of a circular-truncated-cone-shaped structure, and compared with a cylindrical roller ramp scheme, less sliding friction is generated, and higher efficiency and longer service life are achieved.

Description

Technical Field

[0001] This utility model relates to a motion conversion mechanism technology, specifically a motion conversion mechanism with a frustum-shaped roller structure. Background Technology

[0002] Electromechanical braking (EMB) has replaced electrohydraulic braking (EHB) and has become the mainstream solution for the next stage of braking systems. However, there are currently many different EMB configurations with varying structures and functions. An EMB actuator includes five main modules: service brake mechanism, parking brake mechanism, brake clearance compensation mechanism, quick return mechanism, and sensors. As the basic module of the actuator, the service brake mechanism mainly consists of a motor, a reduction and force amplification mechanism, a motion conversion mechanism, and a pressing component. Based on the different reduction and force amplification mechanisms and motion conversion mechanisms, EMBs are currently mainly divided into four basic configurations: ball screw, wedge self-energizing, ball ramp, and cam. Among these, ball screw and ball ramp configurations are most commonly used in commercial vehicle electromechanical braking systems.

[0003] The ball bearing ramp configuration utilizes balls and an inclined guide ramp to achieve rotational-translational motion conversion, driving a piston to move and achieve braking clamping. To make this rotational-translational motion conversion non-linear, the guide ramp is designed to vary in depth. However, due to the limitations of the circumferential track path, in order to achieve the non-linear change, some sections of the ramp are very shallow, making it easy for the balls to disengage from the mechanism, thus compromising its safety and reliability. Specifically, a detailed description of a ball bearing motion conversion mechanism can be found in Chinese invention patent application number 202410403288.0.

[0004] However, in the existing ball bearing ramp designs described above, the rolling elements are generally balls or cylindrical rollers. Ball bearings have point contact with the raceway; under heavy loads, the contact surface deforms and fails, making them generally suitable for light loads. Cylindrical rollers have line contact with the raceway; however, due to the difference in linear velocity at both ends, the rollers slip on the raceway. At higher speeds, this can easily lead to lateral movement, tilting, or even jamming. These designs are generally suitable for low-speed applications, and the slippage of the rollers reduces efficiency and service life. Utility Model Content

[0005] To address the aforementioned issues, this application proposes a novel type of roller structure for motion conversion mechanisms, which offers higher efficiency and longer service life, making it suitable for heavy-duty applications.

[0006] To address the problems existing in the above-mentioned technologies, this utility model provides a technology that can increase the output load of the motion conversion mechanism.

[0007] This utility model provides a motion conversion mechanism with a frustum-shaped roller structure, including a driving disc, a driven disc, and a frustum-shaped roller;

[0008] The active disc has an active ramp;

[0009] The driven disc has a driven ramp;

[0010] The frustum roller is located between the driving disc and the driven disc, and the frustum side of the frustum roller is in contact with the driving ramp and the driven ramp; the vertical distance between the frustum side of the frustum roller and the central axis of the frustum roller increases linearly from the inside to the outside.

[0011] The thickness of the slope line in contact with the frustum roller of the active ramp and / or driven ramp gradually decreases from the inside to the outside, so that the central axis of the frustum roller is perpendicular to the central axis of the active disc and / or driven disc, that is, so that the frustum roller is kept horizontal.

[0012] Preferably, it further includes a cage on which the frustum roller is rotatably disposed, the cage being located between the driving disc and the driven disc.

[0013] Preferably, the cage has a notch or groove for holding a rotatable frustum roller.

[0014] Preferably, the number of active ramps, driven ramps, and frustum rollers are all three sets.

[0015] Preferably, the driving disc and the driven disc have a ramp start point and a ramp end point;

[0016] The motion conversion mechanism has a starting state and an ending state in the combined state. In the starting state, the driven plate is closest to the driving plate, and at this time the truncated roller contacts the starting position of the ramp.

[0017] At the end point, the driven disc is furthest from the driving disc, and at this point, the truncated roller contacts the end point of the ramp.

[0018] Preferably, the side surface of the frustum roller is an inclined straight line, and its extension forms an included angle α, which is set in the range of 1° to 12°.

[0019] Preferably, α is no greater than 2×arctan(0.5×D / R).

[0020] Preferably, the outer periphery of the active disk has teeth for receiving rotational power.

[0021] The beneficial effects of this utility model are as follows:

[0022] 1. The rolling elements adopt a frustum-shaped roller structure, and the roller and raceway are in line contact, which can withstand a greater load compared with the ball bearing ramp design.

[0023] 2. The rolling elements have a frustum-shaped structure, which generates less sliding friction compared to cylindrical roller ramp designs, resulting in higher efficiency and longer lifespan. Attached Figure Description

[0024] Figure 1 This is a structural diagram showing the exploded structure of a motion conversion mechanism with a frustum-shaped roller structure according to this utility model.

[0025] Figure 2 This is a schematic diagram of the starting position of the motion conversion mechanism with a frustum-shaped roller structure according to this utility model.

[0026] Figure 3 This is a schematic diagram of the motion conversion mechanism with a frustum-shaped roller structure according to the present invention, showing the end point position of the frustum roller's motion.

[0027] Figure 4 This is a schematic diagram of the driven disc of a motion conversion mechanism with a frustum-shaped roller structure according to this utility model;

[0028] Figure 5 This is a structural schematic diagram of the cross-sectional view of the center of the frustum roller of a motion conversion mechanism with a frustum roller structure according to the present invention;

[0029] Figure 6 This is a schematic diagram of the force analysis of the frustum roller in a motion conversion mechanism with a frustum roller structure according to this utility model.

[0030] Figure 7 This is a partially enlarged schematic diagram of the force analysis of the frustum roller in the motion conversion mechanism with a frustum roller structure according to this utility model.

[0031] Figure 8 This is a schematic diagram of a preferred structure of a motion conversion mechanism with a frustum-shaped roller structure according to the present invention;

[0032] Explanation of reference numerals in the attached figures:

[0033] 10-Driving disc; 11-Driving ramp; 12-Ramp start point; 13-Ramp end point; 14-Gear; 20-Driven disc; 21-Driven ramp; 30-Frustum roller; 31-Frustum side; 40-Cage; 41-Notch groove. Detailed Implementation

[0034] First embodiment:

[0035] This embodiment provides a motion conversion mechanism with a frustum-shaped roller structure, such as... Figure 1 As shown, it includes a driving disc 10, a driven disc 20, and a frustum roller 30;

[0036] The active disc 10 has an active ramp 11;

[0037] The driven plate 20 has a driven ramp 21;

[0038] The frustum roller 30 is located between the driving disc 10 and the driven disc 20. The frustum side 31 of the frustum roller 30 is in contact with the driving ramp 11 and the driven ramp 21. The vertical distance between the frustum side 31 of the frustum roller 30 and the central axis H of the frustum roller 30 increases linearly from the inside to the outside.

[0039] In practical applications, the three components are assembled together and used in the vehicle braking system. The active disc 10 receives rotational power, and during the rotation, the changing active ramp 11 forces the frustum roller 30 to move axially, which in turn pushes the driven disc 20 to move axially. In this way, the rotational power is converted into axial thrust through this structure, and the axial thrust can be used to contact the wheel hub for braking. Since the contact between the frustum roller 30 and the ramp is a line contact, the contact area is increased, the force is more stable, and the load-bearing capacity is improved.

[0040] The thickness of the ramp lines where the active ramp 11 and the driven ramp 21 contact the frustum roller 30 gradually decreases from the inside out, so that the central axis of the frustum roller (30) is perpendicular to the central axis of the active disc (10) and / or the driven disc (20), thus keeping the frustum roller 30 horizontal. Because the frustum roller 30 has inclined sides, the thickness of the active ramp 11 and the driven ramp 21 varies to maintain the frustum roller 30 in a horizontally balanced state. Figure 4 As shown, the arrow d1 extends outward from the center, that is, from the inside to the outside. The wall is thicker near the center and thinner on the outside. The bottom of the frustum roller 30 is placed on the outside, while the pointed head is near the center. In this way, when the frustum roller 30 is in contact with the ramp wall of the active ramp 11 and the driven ramp 21, it can be stably kept in a horizontal state without tilting.

[0041] Preferably, the device further includes a retainer 40, on which the frustum roller 30 is rotatably mounted. The retainer 40 is located between the driving disc 10 and the driven disc 20. The retainer 40 ensures more stable placement of the frustum roller 30, reducing the likelihood of positional deviation. In practical applications, during the rotation of the driving disc 10, different positions of the driving ramp 11 contact the frustum roller 30, causing it to rotate and move axially due to varying contact thicknesses with the driving ramp 11.

[0042] The retainer 40 has a notch 41 for placing a rotatable frustum roller 30. The frustum roller 30 is rotatably arranged in the notch 41 to stabilize its movement.

[0043] The active ramp 11, the driven ramp 21, and the frustum rollers 30 are all in three sets. The multiple sets of evenly distributed structures make the overall stress distribution more uniform, further increasing the load-bearing capacity.

[0044] Second embodiment:

[0045] like Figure 2-4 As shown, the driving disk 10 and the driven disk 20 have a ramp start point 12 and a ramp end point 13;

[0046] The motion conversion mechanism has a starting state and an ending state in the combined state. In the starting state, the driven disk 20 is closest to the driving disk 10, and at this time the frustum roller 30 contacts the starting position 12 of the ramp.

[0047] At the end point, the driven disc 20 is furthest from the driving disc 10, and at this time the truncated roller 30 contacts the end point 13 of the ramp.

[0048] like Figure 5 As shown, the frustum side surface 31 of the frustum roller 30 is an inclined straight line, that is, the vertical distance between the frustum side surface 31 and the central axis H of the frustum roller 30 increases linearly from the inside to the outside. The frustum side surface 31 can be extended from the outside to the inside and intersect at the vertex of the cone. The vertex forms an angle α on the cross section of the frustum roller 30 through the central axis H. The overall length of the frustum roller 30 is L, and the width diameter D (at position ab) is at the middle position. The roller runs along the center line cd, and the two sides intersect the center line at points m and n, respectively.

[0049] When the active ramp 11 and the driven ramp 21 contact the frustum side 31 of the frustum roller 30, that is, when the raceway (active ramp 11 and driven ramp 21) applies an axial thrust F to the roller, the component of this force along the inclined surface (direction of the frustum side 31) of the frustum roller 30 needs to be less than the frictional force between the inclined surface and the raceway to prevent the roller from being pushed out of the raceway radially (i.e., in the direction extending from the center of the active disc to the edge profile). That is, F×cos(0.5×α)×μ≥F×sin(0.5×α), μ≥tan(0.5×α). Considering that the friction coefficient μ of the actual material is between 0.01 and 0.1, the included angle α is set in the range of 1° to 12°.

[0050] When points c and d are the same, a conical structure is formed, tan(0.5×α)=0.5×D / R, that is, the included angle α=2×arctan(0.5×D / R). At this time, the angular velocities at both ends of the roller are the same, and the motion between the frustum-shaped roller and the raceway is pure rolling friction, which has the highest efficiency. Since the included angle α is too large, the component of the force exerted by the raceway on the roller along the inclined plane is large, which will make the roller easily pushed out radially. Therefore, the actual included angle α should not be greater than 2×arctan(0.5×D / R).

[0051] Roller thrust and component forces:

[0052] like Figure 6 , 7 The diagram shown illustrates the force analysis of the roller. Roller 30 is subjected to an axial thrust F from the raceway. 10 =F 20 =F T F 10 For the thrust of the 10 pairs of rollers on the drive disc, F 20 For the thrust of the driven disc 20 on the roller 30, F T This is the output force of the motion conversion mechanism.

[0053] The thrust F of the 10-pair rollers on the drive disc is 30mm. 10 The component of force F along the inclined plane of the vertical roller 30 N =F 10 ×cos(α / 2), the component of the force F along the parallel inclined plane. S =F 10 ×sin(α / 2). The thrust F of the driven disc 20 on the roller 30. 20 Referring to the analysis of the driving disc 10; that is, the thrust F of the driven disc 20 on the rollers. 20 It is also divided into forces perpendicular to the roller 30 direction and forces parallel to the inclined plane.

[0054] The tapered rollers used in this application generate less sliding friction compared to cylindrical rollers (which do not form an inclined surface). The principle is explained below:

[0055] When the motion conversion mechanism is working, the roller 30 rotates along the axis cd. The roller 30 is in line contact with the raceway, and the angular velocity ω is the same at any point on the contact line, while the linear velocity υ=ω×(D / 2), where D is the width diameter of the roller 30 at that point.

[0056] When using cylindrical rollers, the D value is the same at any point on the contact line, so the linear velocity is also the same. However, when the roller rotates along the axis, the outer end travels a greater displacement than the inner end, which requires a greater linear velocity. Therefore, relative sliding is necessary to maintain the same angular velocity.

[0057] When using tapered rollers, the linear velocity of the inner end near the axis is smaller than that of the outer end, so the slippage is smaller when the angular velocity is kept the same.

[0058] like Figure 8 As shown, preferably, the outer periphery of the active disk 10 has teeth 14 for receiving rotational power.

Claims

1. A motion conversion mechanism having a circular-truncated-cone roller structure, characterized by, The motion conversion mechanism comprises: a driving disc (10) having a driving ramp (11); a driven disc (20) having a driven ramp (21); a circular cone roller (30) located between the driving disc (10) and the driven disc (20), a circular cone side (31) of the circular cone roller (30) abutting the driving ramp (11) and the driven ramp (21); a vertical distance between the circular cone side (31) of the circular cone roller (30) and a central axis of the circular cone roller (30) linearly increasing from inside to outside; a slope line thickness of the driving ramp (11) and / or the driven ramp (21) contacting the circular cone roller (30) gradually decreasing from inside to outside, so that the central axis of the circular cone roller (30) is perpendicular to a central axis of the driving disc (10) and / or the driven disc (20).

2. The motion converting mechanism with a frustoconical roller structure according to claim 1, characterized in that Further comprising a retainer (40), the circular cone roller (30) being rotatably arranged on the retainer (40), the retainer (40) being located between the driving disc (10) and the driven disc (20).

3. The motion conversion mechanism with a frustoconical roller structure according to claim 2, characterized in that The retainer (40) has a notch groove (41) for placing the rotatable circular cone roller (30) therein.

4. The motion converting mechanism with a frustoconical roller structure according to claim 1, characterized in that The driving ramp (11), the driven ramp (21) and the circular cone roller (30) are all in three groups.

5. The motion converting mechanism with a frustoconical roller structure according to claim 1, characterized in that, The driving disc (10) and the driven disc (20) have a ramp starting point (12) and a ramp ending point (13).

6. The motion converting mechanism with a frustoconical roller structure according to claim 5, characterized in that The motion conversion mechanism has a starting point state and an ending point state in a combined state, in the starting point state, the driven disc (20) is closest to the driving disc (10), at this time, the circular cone roller (30) contacts a position of the ramp starting point (12); in the ending point state, the driven disc (20) is farthest from the driving disc (10), at this time, the circular cone roller (30) contacts a position of the ramp ending point (13).

7. The motion converting mechanism with a frustoconical roller structure according to claim 1, characterized in that The circular cone side (31) of the circular cone roller (30) extends from outside to inside to form an included angle α, the included angle α being in a range of 1° to 12°.

8. The motion converting mechanism with a frustoconical roller structure according to claim 7, characterized in that α is not greater than 2×arctan(0.5×D / R).

9. Motion conversion mechanism with a frustum of cone roller structure according to one of claims 1 to 8, characterized in that The driving disc (10) has a tooth portion (14) on an outer periphery thereof, the tooth portion (14) being used for receiving a rotating power.

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