Actuating device for disc brake and disc brake

Abstract

The utility model provides an actuating device for a disc brake and the disc brake, the actuating device comprises a driving mechanism and a transmission mechanism which is connected with the driving mechanism and driven by the driving mechanism, the transmission mechanism is a ball screw mechanism and comprises a variable-lead screw, a nut and a transmission ball, the screw is connected with a brake pad of the disc brake, and the nut is connected with the transmission ball. The nut is connected with a driving mechanism.

Description

Technical Field

[0001] The present application relates to disc brakes, and more particularly, to an actuating device for a disc brake. Background Art

[0002] With the advancement of automotive electronic technology, people have higher and higher requirements on vehicle braking performance and the structure and function of vehicle braking systems. On the premise of ensuring vehicle braking stability and reliability, how to improve braking response speed and accurately control braking force has become an urgent need for vehicle development.

[0003] In the electronic mechanical brake system (EMB for short), the rotational motion of the rotor of the motor is converted into the linear motion of the screw (nut) in the ball screw pair by using a ball screw pair, so that the brake pad connected to the screw (nut) is moved to contact the brake disc through the screw (nut) to achieve the purpose of braking the vehicle. During this process, the speed of the linear motion of the screw (nut) depends on the rotation speed of the rotor of the motor, that is, the moving speed of the brake pad depends on the rotation speed of the motor. In the relevant design, in order to make the brake pad contact the brake disc faster, the rotation speed of the motor must be increased. However, this will inevitably cause the brake pad to hit the brake disc at a higher speed, thereby bringing a larger reaction impact force to the screw (nut), resulting in a shortened service life of the screw (nut). Therefore, in practical applications, it is necessary to enable the brake pad to contact the brake disc at a variable speed without changing the rotation speed of the motor to achieve braking.

[0004] Therefore, there is an urgent need for a disc brake that can achieve a desired braking effect in a simple manner. Utility Model Content

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] One aspect of the present application provides an actuating device for a disc brake, which may include a driving mechanism and a transmission mechanism connected to the driving mechanism and driven by the driving mechanism. The transmission mechanism may be a ball screw mechanism and may include a variable lead screw, a nut and a transmission ball. The screw may be connected to the brake pad of the disc brake, and the nut may be connected to the driving mechanism.

[0007] By using the actuating device for a disc brake provided by the present application, when the speed of the motor rotor is constant, the screw rod can push the brake pad to contact the brake disc at a variable speed, thereby providing the driver with a desired braking effect.

[0008] In some exemplary embodiments, the screw may include a first end for connecting to the brake pad and a second end formed as a free end, and the lead of the screw may gradually increase from the first end toward the second end. In this case, when the rotation speed of the driving mechanism remains constant, the transmission ball travels a longer distance on the screw per unit time. Therefore, the axial travel speed of the screw increases, so that the screw can push the brake pad to abut the brake disc in a shorter time, thereby achieving rapid braking of the disc brake.

[0009] In some exemplary embodiments, the screw may include a first end for connecting to the brake pad and a second end formed as a free end, and the lead of the screw may gradually decrease from the first end toward the second end. In this case, when the rotation speed of the drive mechanism remains constant, the transmission ball travels a shorter distance on the screw per unit time. Therefore, the axial travel speed of the screw is reduced, so that the screw can push the brake pad to abut the brake disc with less force, thereby providing a more gentle braking and providing a good braking experience for the driver.

[0010] In some exemplary embodiments, the screw may include a first end for connecting to the brake pad and a second end formed as a free end, and the lead of the screw may increase from the first end toward the central portion of the screw and then decrease from the central portion toward the second end. In this case, on the one hand, at the beginning of the movement, the transmission ball travels a larger distance on the screw per unit time, so that the screw can obtain a larger axial travel speed; on the other hand, at the end of the movement, the transmission ball travels a shorter distance on the screw per unit time, so that the screw can obtain a smaller axial travel speed, so that the screw can push the brake pad against the brake disc with less force, thereby providing a gentler braking. In this way, the screw can not only travel axially at a larger speed at the beginning of the movement, but also provide a gentle braking at the end of the movement, thereby providing a good braking experience for the driver.

[0011] In some exemplary embodiments, the nut may include a recessed portion located at the inner circumferential surface of the nut, and a transmission ball may be placed in the recessed portion. When the nut rotates, the transmission ball rolls in the recessed portion along the thread of the screw, i.e., along the groove of the screw, thereby converting the rotational motion of the nut into the axial motion of the screw.

[0012] In some exemplary embodiments, the transmission mechanism may further include at least one retaining ball for maintaining a gap between the screw and the nut.

[0013] In some exemplary embodiments, the nut may also include at least one retaining groove, which is arranged on the inner circumferential surface of the nut along the axial direction. A retaining ball may be placed in the retaining groove. When the screw moves along the axial direction, the retaining ball may reciprocate in the retaining groove, thereby ensuring that the transmission ball is not stuck between the nut and the screw when rolling along the thread of the screw.

[0014] In some exemplary embodiments, the nut may further include at least one hole required for forming the recessed portion, and the hole may be disposed opposite to the recessed portion in a radial direction.

[0015] In some exemplary embodiments, the actuating device may be provided with a bearing for connecting the actuating device with a caliper body of the disc brake.

[0016] In some exemplary embodiments, the nut may further include a bearing mounting portion, which may protrude in the axial direction from one of the axial ends of the nut; the bearing is mounted on the outer circumferential surface of the bearing mounting portion and is flush with one axial end of the bearing mounting portion.

[0017] In some exemplary embodiments, an aperture may be provided on the bearing mount.

[0018] In some exemplary embodiments, the caliper body of the disc brake may be formed with a receiving portion for receiving the nut and the bearing, the receiving portion may include a large diameter chamber and a small diameter chamber, the nut may be located in the small diameter chamber and a gap is formed between the outer circumference of the nut and the inner circumference of the small diameter chamber; the bearing may be located in the large diameter chamber, one side of the outer ring of the bearing abuts against the stepped surface formed between the large diameter chamber and the small diameter chamber, the other side of the outer ring of the bearing abuts against the pressure plate, and the pressure plate is connected to the inner wall of the large diameter chamber by an interference fit. In this way, the bearing is fixed in the axial direction of the screw, thereby preventing the nut from moving in the axial direction.

[0019] In some exemplary embodiments, the first end of the screw rod may include a flat portion, the first end portion passes through a through hole formed in a side wall of a caliper body of the disc brake and is connected to the brake pad, the through hole includes a coupling portion having a flat plane, and when the first end portion is installed in the through hole, the flat portion of the first end portion contacts the coupling portion of the through hole to prevent rotational movement of the screw rod.

[0020] In some exemplary embodiments, the actuating device may further include a gear mechanism, and the driving mechanism may be connected to the transmission mechanism via the gear mechanism.

[0021] In some exemplary embodiments, the nut may include a toothed portion, and the toothed portion may mesh with the gear mechanism.

[0022] Another aspect of the present application provides a disc brake, which may include a brake pad, a brake disc, a caliper body, and the actuating device provided by the above aspect, and the actuating device may be installed on the caliper body and connected to the brake pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present application, the drawings required for the specific implementation methods will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1a is a schematic diagram of a disc brake according to the present application;

[0025] Figure 1b is another schematic diagram of a disc brake according to the present application;

[0026] Figure 2 is a perspective view of a transmission mechanism of an actuating device for a disc brake according to the present application;

[0027] Figure 3 is an exploded perspective view of a transmission mechanism of an actuating device for a disc brake according to the present application;

[0028] Figure 4 is a perspective view of a nut of an actuating device for a disc brake according to the present application;

[0029] Figure 5 is another perspective view of a nut of an actuating device for a disc brake according to the present application;

[0030] Figure 6 is a side view of an actuating device for a disc brake according to the present application;

[0031] Figure 7 It is along Figure 6 A cross-sectional view taken along line AA in FIG.

[0032] List of reference numerals:

[0033] 1-actuating device; 10-screw; 11-groove; 12-first end; 13-second end; 14-flat portion; 20-bearing; 30-nut; 31-bearing mounting portion; 32-retaining groove; 33-orifice; 34-tooth portion; 35-recessed portion; 40-driving mechanism; 45-gear mechanism; 50-brake pad; 60-brake disc; 70-caliper body; 71-large diameter chamber; 72-small diameter chamber; 73-through hole; 80-transmission ball; 90-retaining ball; 100-pressure plate. DETAILED DESCRIPTION

[0034] The present application will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the exemplary embodiments of the present application are intended to enable those of ordinary skill in the art to easily implement the present application, and should not be construed as being limited to the embodiments described in the present application. The various embodiments of the present application can be implemented in many different forms. Accordingly, the following detailed description of the present application is only for illustrative purposes and is by no means a limitation of the present application. In addition, the same reference numerals are used in the various drawings to represent the same components. In addition, the terms "first", "second", etc. are only for the purpose of convenience of description and are not to be understood as indicating or implying relative importance or relative order.

[0035] It should also be noted that, for the sake of clarity, not all features of the actual specific implementation are described and shown in the specification and drawings, and in order to avoid unnecessary details obscuring the technical solution that the present application focuses on, only the device structure closely related to the technical solution of the present application is described and shown in the drawings and the specification, while other details that are not closely related to the technical content of the present application and are known to those skilled in the art are omitted.

[0036] It should be understood that the terms "inside", "outside", "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0037] One aspect of the present application provides an actuating device 1 for a disc brake. Figure 1a As shown, the actuator 1 may include a driving mechanism 40 and a transmission mechanism connected to the driving mechanism 40 and driven by the driving mechanism 40. The disc brake may include a brake pad 50, a brake disc 60 and a caliper body 70. In the present application, the transmission mechanism is a ball screw mechanism. Figure 3 As shown, the transmission mechanism may include a variable lead screw 10, a nut 30 and a transmission ball 80. The screw 10 is connected to the brake pad 50 of the disc brake. Figure 1a As shown, the nut 30 is connected to the driving mechanism 40. In some examples, the driving mechanism 40 can be a motor. In the present application, the screw 10 is a single-start screw. It can be understood by those skilled in the art that a single-start screw refers to a screw having a screw body with a spiral groove thread.

[0038] like Figure 1a and Figure 3As shown, the actuator 1 may further include a gear mechanism 45, and the drive mechanism 40 is connected to the transmission mechanism through the gear mechanism 45. In some examples, the gear mechanism 45 may be a spur gear, a helical gear, a bevel gear, etc. However, the embodiment is not limited thereto, as long as the gear mechanism can transmit the rotational motion of the drive mechanism to the nut so that the nut rotates. In addition, the nut 30 may include a tooth portion 34, and the tooth portion 34 may mesh with the gear mechanism 45.

[0039] Figure 2 and Figure 3 1 and 2 respectively show a perspective view and an exploded perspective view of a transmission mechanism of an actuating device 1 for a disc brake according to the present application. Figure 3 As shown, the screw rod 10 may include a first end 12 for connecting to a brake pad 50 of a disc brake and a second end 13 formed as a free end. Figure 3 In the illustrated embodiment, the lead of the screw 10 can gradually increase from the first end 12 toward the second end 13. It can be understood by those skilled in the art that the distance between two adjacent spiral grooves is called the pitch, and the pitch is equal to the axial distance between two corresponding points on the mid-diameter line of adjacent teeth. The distance advanced along the spiral groove for one rotation is called the lead. In the case of a single-start screw, the pitch is equal to the lead.

[0040] according to Figures 1a to 3 In the actuator 1 shown, a drive mechanism 40, such as a motor, is connected to a nut 30, so that the rotation of the drive mechanism 40 is transmitted to the nut 30, thereby causing the nut 30 to rotate. The rotation of the nut 30 is transmitted to the screw 10 through the transmission ball 80, so that the screw 10 moves in the axial direction. The screw 10 pushes the brake pad 50 to abut against the brake disc 60, thereby achieving the braking effect of the vehicle wheel. Figure 2 and Figure 3 In the illustrated embodiment, the lead of the screw 10 gradually increases from the first end 12 toward the second end 13. In this case, when the rotation speed of the driving mechanism 40, such as a motor, remains constant, the transmission ball 80 travels a longer distance on the screw per unit time. Therefore, the axial travel speed of the screw 10 increases, so that the screw 10 can push the brake pad 50 to abut against the brake disc 60 in a shorter time, thereby achieving rapid braking of the disc brake.

[0041] Optionally, in some embodiments not shown, the lead of the screw 10 may also gradually decrease from the first end 12 toward the second end 13. In this case, when the rotation speed of the driving mechanism 40, such as a motor, remains constant, the transmission ball 80 travels a shorter distance on the screw 10 per unit time. Therefore, the axial travel speed of the screw 10 is reduced, so that the screw 10 can push the brake pad 50 to abut against the brake disc 60 with less force, thereby providing a more moderate braking and providing a good braking experience for the driver.

[0042] Alternatively, in some other embodiments not shown, the lead of the screw 10 may increase from the first end 12 toward the central portion of the screw 10 and then decrease from the central portion toward the second end 13. In this case, on the one hand, at the initial stage of movement, the transmission ball 80 travels a larger distance on the screw 10 per unit time, so that the screw 10 can obtain a larger axial travel speed, thereby enabling the screw 10 to push the brake pad 50 to abut against the brake disc 60 more quickly; on the other hand, at the later stage of movement, the transmission ball 80 travels a shorter distance on the screw 10 per unit time, so that the screw 10 can obtain a smaller axial travel speed, thereby enabling the screw 10 to push the brake pad 50 to abut against the brake disc 60 with a smaller force, thereby providing a more gentle braking. In this way, the screw 10 can not only push the brake pad 50 to abut against the brake disc 60 in a shorter time at the initial stage of movement, but also provide a gentle braking at the later stage of movement, thereby providing a good braking experience for the driver.

[0043] Also like Figure 5 As shown, the nut 30 may include a recessed portion 35 located at the inner circumferential surface of the nut 30, and the transmission ball 80 is placed in the recessed portion 35. When the nut 30 rotates, the transmission ball 80 rolls along the thread of the screw 10 in the recessed portion 35. Figure 3 In the illustrated embodiment, the threads of the screw 10 are represented by grooves 11 formed in a spiral shape on the outer peripheral surface of the screw 10. When the nut 30 rotates, the driving balls 80 roll along the grooves 11 of the screw 10 in the recessed portion 35, thereby converting the rotational motion of the nut 30 into the axial motion of the screw 10.

[0044] like Figure 4 As shown, the transmission mechanism may further include at least one retaining ball 90 for maintaining a gap between the screw 10 and the nut 30. The nut 30 may further include at least one retaining groove 32, which is arranged at the inner peripheral surface of the nut 30 along the axial direction. Figure 4 and Figure 7As shown, the retaining balls 90 are placed in the retaining grooves 32. When the driving balls 80 roll along the threads of the screw 10 to make the screw 10 move in the axial direction, the retaining balls 90 reciprocate in the retaining grooves 32, thereby ensuring that the driving balls 80 are not stuck between the nut 30 and the screw 10 when rolling along the threads of the screw 10. As can be understood by those skilled in the art, the number of retaining balls is equal to the number of retaining grooves.

[0045] exist Figure 4 and Figure 5 In the illustrated embodiment, the retaining ball 90 and the retaining groove 32 are respectively provided as one. In this case, preferably, the retaining groove 32 is provided to be opposite to the recessed portion 35 in the radial direction of the nut 30. However, the embodiment is not limited thereto, and the retaining groove 32 may also be provided to be adjacent to the recessed portion 35, as long as the retaining ball 90 can be placed in the retaining groove 32 to maintain the distance between the nut 30 and the screw 10, thereby ensuring that the transmission ball 80 is not stuck between the screw 10 and the nut 30 when rolling along the thread of the screw 10.

[0046] In some embodiments not shown, the retaining groove 32 may be provided in plurality. A plurality of retaining grooves may be provided at equal intervals on the inner circumferential surface of the nut 30. For example, the retaining groove 32 may be provided in four portions, and the four retaining grooves may be provided on the inner circumferential surface of the nut 30 at an angle of 90 degrees to each other relative to the rotation axis of the nut.

[0047] like Figure 3 As shown, the nut 30 may further include at least one orifice 33 required for forming the recessed portion 35. Specifically, the recessed portion 35 may be formed by mechanical drilling. A drill bit may be inserted into the interior of the nut 30 through the orifice 33 to process the inner surface of the nut 30, thereby forming the recessed portion 35. It will be understood by those skilled in the art that the number of orifices 33 is the same as the number of recessed portions 35 and is opposite to the recessed portions 35 in the radial direction.

[0048] During the pre-assembly of the actuating device for a disc brake of the present application, first, the transmission ball 80 is placed in the recessed portion 35; then, the screw 10 is passed through the nut 30 and the transmission ball 80 is positioned in the groove 11 of the screw 10; then, the retaining ball 90 is placed adjacent to one end of the retaining groove 32, while aligning the retaining ball 90 with the groove 11 of the screw 10, and at this time, the screw 10 is rotated so that the retaining ball 90 enters the retaining groove 32. It can be understood by those skilled in the art that the retaining ball 90 can be configured so that the retaining ball 90 reciprocates in the retaining groove 32 in a portion where the orifice 33 is not provided.

[0049] Also like Figure 2and Figure 3 As shown, the actuator 1 may be provided with a bearing 20 for connecting the actuator 1 to the caliper body 70 of the disc brake. The nut 30 may further include a bearing mounting portion 31 that protrudes in the axial direction from one of the axial ends of the nut 30. The bearing 20 may be mounted on the outer circumferential surface of the bearing mounting portion 31 and flush with one axial end of the bearing mounting portion 31. In this way, the bearing 20 may prevent the retaining ball 90 from falling out of the retaining groove 32 during the reciprocating motion in the retaining groove 32.

[0050] Preferably, if Figure 5 As shown, the aperture 33 may be provided on the bearing mounting portion 31 , and the aperture 33 may be provided adjacent to one axial end of the retaining groove 32 .

[0051] like Figure 1b As shown, the caliper body 70 of the disc brake is formed with an accommodating portion for accommodating the nut 30 and the bearing 20, and the accommodating portion includes a large diameter chamber 71 and a small diameter chamber 72. The nut 30 is located in the small diameter chamber 72 and a gap is formed between the outer peripheral surface of the nut 30 and the inner peripheral surface of the small diameter chamber 71. The bearing 20 is located in the large diameter chamber 71, and one side of the outer ring of the bearing 20 abuts against the step surface formed between the large diameter chamber 71 and the small diameter chamber 72, and the other side of the outer ring of the bearing 20 abuts against the pressure plate 100. More specifically, one side portion of the outer ring of the bearing 20 in the axial direction abuts against the step surface, and the other side portion of the outer ring of the bearing 20 in the axial direction abuts against the pressure plate 100. The pressure plate 100 is connected to the inner wall of the large diameter chamber 71 by an interference fit. In order to clearly show the structure of the accommodating portion, Figure 1b In the embodiment, there is a gap between the pressing plate 100 and the large diameter chamber 71, but in fact the two are connected by an interference fit. In this way, the bearing 20 is fixed in the axial direction of the screw rod 10, thereby preventing the nut 30 from moving in the axial direction.

[0052] like Figure 1a , Figure 1b and Figure 3 As shown, the first end 12 of the screw rod 10 may include a flat portion 14, which extends in the axial direction of the screw rod 10 and is in the form of a plane. In addition, two flat portions may be formed at the first end 12 of the screw rod 10, and the two flat portions are respectively formed at opposite sides of the first end 12. The first end 12 is connected to the brake pad 50 through a through hole 73 formed in the side wall of the caliper body 70 of the disc brake, and the through hole 73 includes a coupling portion in the form of a flat plane. When the first end 12 is installed in the through hole 73, the flat portion 14 of the first end 12 contacts the coupling portion of the through hole 73 to prevent the screw rod 10 from rotating.

[0053] Another aspect of the present application provides a disc brake, which includes a brake pad 50, a brake disc 60, a caliper body 70 and the above-mentioned actuating device 1. The actuating device 1 is mounted on the caliper body 70 and connected to the brake pad 50. The screw 10 of the actuating device 1 is connected to the brake pad 50.

[0054] Although the present application has been described with reference to exemplary embodiments, it should be understood that the present application is not limited to the specific embodiments described and shown in detail herein. Various changes may be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of the present application.

[0055] The features mentioned and / or shown in the above description of the exemplary embodiments of the present application may be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or substituted for the corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present application.

Claims

1. An actuating device (1) for a disc brake, characterized in that The actuating device (1) comprises a driving mechanism (40) and a transmission mechanism connected to the driving mechanism (40) and driven by the driving mechanism (40). The transmission mechanism is a ball screw mechanism and comprises a variable-lead screw (10), a nut (30) and a transmission ball (80); the screw (10) is connected to a brake pad (50) of the disc brake, and the nut (30) is connected to the drive mechanism (40).

2. The actuating device (1) according to claim 1, characterized in that The screw rod (10) comprises a first end (12) for connecting to the brake pad (50) and a second end (13) formed as a free end, and the lead of the screw rod (10) gradually increases from the first end (12) toward the second end (13).

3. The actuating device (1) according to claim 1, characterized in that The screw rod (10) comprises a first end (12) for connecting to the brake pad (50) and a second end (13) formed as a free end, and the lead of the screw rod (10) gradually decreases from the first end (12) toward the second end (13).

4. The actuating device (1) according to claim 1, characterized in that The screw (10) includes a first end (12) for connecting to the brake pad (50) and a second end (13) formed as a free end, and the lead of the screw (10) increases from the first end (12) toward the central part of the screw (10) and then decreases from the central part toward the second end (13).

5. The actuating device (1) according to any one of claims 1 to 4, characterized in that The nut (30) includes a recessed portion (35) located at the inner peripheral surface of the nut (30), and the transmission ball (80) is placed in the recessed portion (35). When the screw (10) moves in the axial direction, the transmission ball (80) rolls in the recessed portion (35) along the thread of the screw (10).

6. The actuating device (1) according to claim 5, characterized in that The transmission mechanism further comprises at least one retaining ball (90) for maintaining a gap between the screw rod (10) and the nut (30).

7. The actuating device (1) according to claim 6, characterized in that The nut (30) further comprises at least one retaining groove (32), which is arranged on the inner peripheral surface of the nut (30) along the axial direction, and the retaining ball (90) is placed in the retaining groove (32). When the screw (10) moves along the axial direction, the retaining ball (90) reciprocates in the retaining groove (32).

8. The actuating device (1) according to claim 7, characterized in that The nut (30) further comprises at least one hole (33) required for forming the recessed portion (35), wherein the hole (33) is arranged to be opposite to the recessed portion (35) in a radial direction.

9. The actuating device (1) according to claim 8, characterized in that The actuating device (1) is provided with a bearing (20) for connecting the actuating device (1) to a caliper body (70) of the disc brake.

10. The actuating device (1) according to claim 9, characterized in that The nut (30) further comprises a bearing mounting portion (31), wherein the bearing mounting portion (31) protrudes from one of the axial ends of the nut (30) along the axial direction; The bearing (20) is mounted on the outer peripheral surface of the bearing mounting portion (31) and is flush with one axial end of the bearing mounting portion (31).

11. The actuating device (1) according to claim 10, characterized in that The orifice (33) is arranged on the bearing mounting portion (31).

12. The actuating device (1) according to claim 9, characterized in that The caliper body (70) of the disc brake is formed with a receiving portion for receiving the nut (30) and the bearing (20), wherein the receiving portion includes a large-diameter chamber (71) and a small-diameter chamber (72). The nut (30) is located in the small-diameter chamber (72) and a gap is formed between the outer circumferential surface of the nut (30) and the inner circumferential surface of the small-diameter chamber (72). The bearing (20) is located in the large diameter chamber (71), one side of the outer ring of the bearing (20) abuts against a stepped surface formed between the large diameter chamber (71) and the small diameter chamber (72), and the other side of the outer ring of the bearing (20) abuts against a pressure plate (100), and the pressure plate (100) is connected to the inner wall of the large diameter chamber (71) by an interference fit.

13. Actuating device (1) according to any one of claims 2 to 4, characterized in that The first end portion (12) of the screw rod (10) includes a flat portion (14), the first end portion (12) is connected to the brake pad (50) through a through hole (73) formed in a side wall of a caliper body (70) of the disc brake, the through hole (73) includes a coupling portion in a flat plane, and when the first end portion (12) is installed in the through hole (73), the flat portion (14) of the first end portion (12) contacts the coupling portion of the through hole (73) to prevent the screw rod (10) from rotating.

14. Actuating device (1) according to any one of claims 1 to 4, characterized in that The actuating device (1) further comprises a gear mechanism (45), and the driving mechanism (40) is connected to the transmission mechanism via the gear mechanism (45).

15. Actuating device (1) according to claim 14, characterized in that The nut (30) includes a toothed portion (34) which meshes with the gear mechanism (45).

16. A disc brake, characterized in that: The disc brake comprises a brake pad (50), a brake disc (60), a caliper body (70), and an actuating device (1) according to any one of claims 1 to 15; the actuating device (1) is mounted on the caliper body (70) and connected to the brake pad (50).

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