Centrifugal brake and electric cylinder

Abstract

The invention belongs to the technical field of electric cylinders, and particularly relates to a centrifugal brake and an electric cylinder. The device comprises a rotating disc, the rotating disc can be assembled along with rotation, and at least two sliding grooves are evenly formed in the rotating disc in the circumferential direction; the centrifugal block is arranged in the sliding groove and connected with the inner wall of the sliding groove through an elastic piece, and a first inclined face is arranged on the side face of the centrifugal block. The brake disc is fixedly arranged and is opposite to the first inclined surface of the centrifugal block, a second inclined surface is arranged on one side, opposite to the centrifugal block, of the brake disc, and the first inclined surface is parallel to the second inclined surface; when the turntable is static, the first inclined surface is far away from the second inclined surface; when the centrifugal force borne by the centrifugal blocks is larger than the elastic force of the elastic pieces, the centrifugal blocks move outwards in the radial direction of the sliding grooves, the first inclined faces make contact with the second inclined faces to generate braking torque, and the brake device is large in braking area, high in braking efficiency and convenient to disassemble and assemble.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric cylinders, and in particular relates to a centrifugal brake and an electric cylinder. Background Art

[0002] The electric cylinder uses a motor to drive the screw to rotate, and the screw nut converts the rotational motion into linear motion of the piston rod. The motor can accurately control the operating speed, position and thrust of the electric cylinder to achieve high-precision linear motion.

[0003] Conventional electric cylinders lack speed limits. In construction machinery with lifting functions, such as aerial work platforms, cranes, and pump trucks, after the piston rod of the lifting cylinder extends, the motor is controlled to provide reverse torque to retract the piston rod, thereby lowering the lifting device. However, this method cannot retract the piston rod or recover potential energy if the motor is powered off, resulting in significant energy waste and safety hazards. During emergency evacuation of aerial work platforms, cranes, pump trucks, and other mainframes, the electric cylinder's descent speed must be controlled within a certain range. If the lifting device accelerates its descent under its own weight, the back EMF current generated by the motor's reverse rotation could damage electronic components at best, or even endanger the lives of on-site workers.

[0004] In the prior art, overspeed clutches are generally installed in the opposite direction of the motor, on either side of the gearbox. This increases the axial dimension of the entire electric cylinder, which has a certain impact on customer installation and use. In addition, the brake pads rub against the housing, resulting in a small braking area and low braking efficiency. Patent publication number CN217633566U discloses a centrifugal brake and lifting electric cylinder. The centrifugal brake is placed inside the gearbox, solving the technical problems of the long axial dimension of the entire electric cylinder and the small braking area and low braking efficiency caused by the elastic parts of the centrifugal brake occupying circumferential space. However, the brake pads rub against the inner hole of the housing. Since the centrifugal brake housing is integrated with the gearbox body, long-term operation will inevitably cause wear on the inner hole of the housing, making replacement of the housing complex and costly. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the present invention provides a centrifugal brake and an electric cylinder, which can solve the problem of inconvenient disassembly or installation after wear and tear while providing a larger braking area.

[0006] To achieve the above object, the technical solution provided by the present invention is as follows:

[0007] In a first aspect, the present application provides a centrifugal brake, comprising:

[0008] A turntable, which can be assembled as it rotates, and has at least two sliding grooves evenly arranged along the circumference of the turntable;

[0009] The centrifugal block is arranged in the chute and connected to the inner wall of the chute via an elastic member. A first inclined surface is provided on the side surface of the centrifugal block;

[0010] The brake disc is fixedly arranged, the brake disc is opposite to the first inclined surface of the centrifugal block, a second inclined surface is arranged on the side of the brake disc opposite to the centrifugal block, and the first inclined surface is parallel to the second inclined surface;

[0011] When the turntable is stationary, the first inclined surface and the second inclined surface are far away from each other; when the turntable rotates, when the centrifugal force on the centrifugal block is greater than the elastic force of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

[0012] Optionally, the first inclined surface of the centrifugal block and the bottom surface of the centrifugal block form an acute angle.

[0013] Optionally, the turntable includes an inner ring, a slide groove is arranged on the outside of the inner ring, one end of the elastic member is connected to the outer wall of the inner ring, and the other end is connected to the centrifugal block. When the centrifugal force applied to the centrifugal block is greater than the pulling force of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

[0014] Optionally, the turntable includes an inner ring and an outer ring, a slide groove is arranged between the inner ring and the outer ring, one end of the elastic member is connected to the inner side wall of the outer ring, and the other end is connected to the centrifugal block. When the centrifugal force applied to the centrifugal block is greater than the pressure of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

[0015] Optionally, an inner hole is provided on the brake disc, the rotating disc includes an inner ring, the brake disc is sleeved on the outside of the inner ring through the inner hole and does not contact the inner ring, a shoulder is provided on the side wall of the inner ring away from the brake disc, and the groove wall is provided on the shoulder.

[0016] Optionally, the second inclined surface is arranged in a ring shape, and the second inclined surface corresponds to the centrifugal block.

[0017] In a second aspect, the present application further provides an electric cylinder, comprising:

[0018] Motor;

[0019] A telescopic cylinder comprising a cylinder barrel and a piston rod, wherein the piston rod is slidably assembled in the cylinder barrel;

[0020] a screw assembly, the screw assembly extending into the interior of the piston rod, the motor driving the screw assembly to move, and the piston rod moving along the cylinder barrel under the drive of the screw assembly;

[0021] The centrifugal brake described in the first aspect is used to limit the rotational speed of the motor.

[0022] Optionally, the motor drives the screw assembly through a gear box, and the gear box includes an outer box body, in which an input gear and an output gear are assembled, and the input gear and the output gear are in transmission cooperation, and the input gear and the turntable are both connected to the output shaft of the motor for rotation, and the brake disc is mounted on the outer box body of the gear box, and the output gear is connected to the screw assembly for transmission.

[0023] Optionally, a flat key is installed on the output shaft of the motor, and a keyway is correspondingly provided on the turntable. The flat key and the keyway are connected for radial positioning of the turntable, and the axial ends of the turntable are axially positioned by the shoulders and spacers of the input gear respectively.

[0024] Optionally, the piston rod is connected to a connecting earring through an anti-biased load structure, and the anti-biased load structure includes a first nut and a second nut, and the first nut and the second nut are arranged in sequence at the ends of the connecting earring from the inside to the outside. The inner hole of the first nut is smooth and has a clearance fit with the connecting earring, and the second nut is threadedly connected to the connecting earring through an internal thread. The inner diameter of the first nut is larger than the inner diameter of the second nut and smaller than the outer diameter of the second nut, and the first nut is connected to the internal thread of the piston rod through an external thread.

[0025] Compared with the prior art, this application has at least the following beneficial effects:

[0026] The present invention uses a brake disc arranged on the side of the centrifugal block to perform friction braking with the centrifugal block through the first inclined surface and the second inclined surface, so the braking area is large and the braking efficiency is high. The brake disc is directly fixed on the outer box body and is not connected to the turntable, which is convenient for disassembly and installation, and reduces maintenance costs. By arranging a centrifugal brake on the electric cylinder, the piston rod can be retracted when the motor stops supplying power, and the descending speed of the electric cylinder can be controlled to avoid energy waste and safety hazards. The connecting earring in the present invention can rotate within a certain range to maintain the normal operation and high working accuracy of the electric cylinder, and can eliminate the unbalanced load caused by the large deviation in parallelism between the electric cylinder earring and the cylinder bottom. It also has the advantages of simple and compact structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 This is a structural schematic diagram of a centrifugal brake in an embodiment of the present application;

[0029] Figure 2This is a cross-sectional schematic diagram of a centrifugal brake in an embodiment of the present application;

[0030] Figure 3 This is a schematic structural diagram of an electric cylinder in an embodiment of the present application;

[0031] Description of reference numerals:

[0032] 1. Turntable; 11. Slide; 12. Inner ring; 121. Shoulder; 13. Outer ring; 2. Centrifugal block; 21. First inclined surface; 3. Elastic member; 4. Brake disc; 41. Second inclined surface; 42. Inner hole; 5. Motor; 51. Motor output shaft; 6. Cylinder; 7. Piston rod; 71. Connecting earring; 72. First nut; 73. Second nut; 8. Gearbox; 81. Input gear; 82. Output gear; 9. Centrifugal brake; 10. Flat key. DETAILED DESCRIPTION

[0033] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only some embodiments of the present application, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application, its application, or use.

[0034] Example 1

[0035] like Figure 1 and Figure 2 As shown, a centrifugal brake comprises:

[0036] The turntable 1 can be assembled with the turntable 1, and at least two chutes 11 are evenly opened along the circumferential direction on the turntable 1; the number of the chutes 11 can be two, three, four, etc., and in this embodiment, there are three chutes 11;

[0037] The centrifugal block 2 is in the shape of a circular ring segment and is disposed in the chute 11. It is connected to the inner wall of the chute 11 through an elastic member 3. A first inclined surface 21 is provided on the side of the centrifugal block 2. The elastic member 3 can be a spring, an elastic block, etc., and a spring is used in this embodiment.

[0038] The brake disc 4 is fixedly arranged. The brake disc 4 is generally fixedly arranged on the outer box body. During the rotation of the turntable 1, the brake disc 4 does not rotate with it. The brake disc 4 is opposite to the first inclined surface 21 of the centrifugal block 2. A second inclined surface 41 is provided on the side of the brake disc 4 opposite to the centrifugal block 2. The first inclined surface 21 is parallel to the second inclined surface 41.

[0039] When the turntable 1 is stationary, the first inclined surface 21 does not contact the second inclined surface; when the turntable 1 rotates, when the centrifugal force acting on the centrifugal mass 2 is less than the elastic force of the elastic member 3, the first inclined surface 21 will not contact the second inclined surface 41. As the speed increases, when the centrifugal force acting on the centrifugal mass 2 is greater than the elastic force of the elastic member 3, the centrifugal mass 2 moves radially outward along the slide groove 11, and the first inclined surface 21 contacts the second inclined surface 41 to generate friction, thereby generating a braking torque. The friction between the first inclined surface 21 and the second inclined surface 41 is used for braking, resulting in a large braking area and high braking efficiency.

[0040] Example 2

[0041] The difference between this embodiment and the embodiment is that: Figure 1 As shown, the turntable 1 includes an inner ring 12 and an outer ring 13, with a chute 11 disposed between the inner ring 12 and the outer ring 13. One end of the elastic member 3 is connected to the inner sidewall of the outer ring 13, and the other end is connected to the centrifugal mass 2. When the centrifugal force applied to the centrifugal mass 2 exceeds the pressure of the elastic member 3, the centrifugal mass 2 moves radially outward along the chute 11, and the first inclined surface 21 contacts the second inclined surface 41 to generate a braking torque. Through the above design, when the centrifugal mass 2 is subjected to a force and undergoes radial movement, it moves toward the connection between the spring and the outer ring 13, limiting the movement direction of the centrifugal mass 2 and improving the accuracy of braking.

[0042] The first inclined surface 21 of the centrifugal block 2 forms an acute angle with the bottom surface of the centrifugal block 2 . The second inclined surface 41 is arranged in a ring shape. The second inclined surface 41 corresponds to the centrifugal block 2 , so that the centrifugal block 2 can contact the second inclined surface 41 when moving radially outward.

[0043] An inner hole 42 is provided on the brake disc 4, and the turntable 1 includes an inner ring 12. The brake disc 4 is sleeved on the outside of the inner ring 12 through the inner hole 42 and does not contact the inner ring 12. A shoulder 121 is provided on the side wall of the inner ring 12 away from the brake disc 4, and the groove wall of the slide groove 11 is provided on the shoulder 121. The structural setting of the shoulder 121 can ensure that there is a certain distance between the first inclined surface 21 and the second inclined surface 41 when there is no movement.

[0044] Example 3

[0045] The difference between this embodiment and embodiment 2 is that: the turntable 1 includes an inner ring 12 (excluding the outer ring 13), the slide groove 11 is arranged on the outside of the inner ring 12, one end of the elastic member 3 is connected to the outer wall of the inner ring 12, and the other end is connected to the centrifugal block 2, and the centrifugal block 2 is slidingly connected to the inner wall of the slide groove 11. When the centrifugal force applied to the centrifugal block 2 is greater than the pulling force of the elastic member 3, the centrifugal block 2 moves radially outward along the slide groove 11, and the first inclined surface 21 contacts the second inclined surface 41 to generate a braking torque.

[0046] Example 4

[0047] like Figure 3As shown, an electric cylinder includes: a motor 5; a telescopic cylinder including a cylinder barrel 6 and a piston rod 7, which is slidably mounted within the cylinder barrel 6; a screw assembly extending into the interior of the piston rod 7, which is driven by the motor 5 to move the screw assembly, thereby moving the piston rod 7 along the cylinder barrel 6; and a centrifugal brake 9 according to Example 2, which is used to limit the rotation speed of the motor 5. By providing the centrifugal brake 9 on the electric cylinder, the piston rod 7 can be retracted when the motor 5 stops supplying power, and the descent speed of the electric cylinder can be controlled, thereby avoiding energy waste and safety hazards.

[0048] In this embodiment, the motor 5 drives the screw assembly to work through the gear box 8. The gear box 8 includes an outer box body, and the outer box body is equipped with an input gear 81 and an output gear 82. The input gear 81 and the output gear 82 are in transmission cooperation. A number of intermediate gears can be set between the input gear 81 and the output gear 82. The input gear 81 and the turntable 1 are both connected to the output shaft of the motor 5 for rotation. The brake disc 4 is installed on the outer box body of the gear box 8, and the output gear 82 is connected to the screw assembly for transmission.

[0049] A flat key 10 is installed on the output shaft of the motor 5, and a keyway is correspondingly provided on the turntable 1. The flat key 10 and the keyway are connected for radial positioning of the turntable 1. The axial ends of the turntable 1 are axially positioned by the shoulders 121 of the input gear 81 and the spacer sleeve respectively.

[0050] The turntable 1 rotates synchronously with the output shaft of the motor 5, while the brake disc 4 and the gear box 8 casing are fixed. When the speed of the output shaft of the motor 5 is low, the centrifugal force exerted on the centrifugal weight 2 is less than the compression force of the spring, and the centrifugal weight 2 does not contact the brake disc 4; when the speed of the output shaft of the motor 5 continues to increase and the centrifugal force exerted on the centrifugal weight 2 is greater than the compression force of the spring, the centrifugal weight 2 slides along the slide groove 11 of the turntable 1 in the centrifugal direction and contacts with the second inclined surface 41 of the brake disc 4 to generate friction, thereby generating a braking torque on the output shaft of the motor 5, the retraction of the piston rod 7 is blocked, and the speed is controlled.

[0051] Existing electric lifting cylinders on the market are generally hinged at both ends. The mainframe installation requires high parallelism between the earrings and the cylinder bottom axis. If the parallelism deviation is large, it will cause eccentric loading during installation, making it difficult for the piston rod 7 to extend during operation. This not only accelerates the wear of the piston guide, but also causes the piston rod 7 to retract and retract at a reduced speed or even fail to reach the specified speed. This situation not only affects the operating efficiency of the electric cylinder, but may also cause unstable operation of the equipment and even damage it. Some electric cylinder products solve the problem of eccentric loading through ball joint structures or external support plates, but this structure is generally applied to outrigger products and is limited by the connection method to the mainframe.

[0052] like Figure 3As shown, in order to solve the problem of overloading of the connecting earring 71 of the electric cylinder, the piston rod 7 in this embodiment is connected to the connecting earring 71 through an anti-overloading structure. The anti-overloading structure includes a first nut 72 and a second nut 73. The first nut 72 and the second nut 73 are arranged in sequence from the inside to the outside at the ends of the connecting earring 71. The first end is a circular ring with a shoulder. The inner hole 42 of the first nut 72 is smooth and has a clearance fit with the connecting earring 71. The second nut 73 is threadedly connected to the connecting earring 71 through an internal thread. The inner diameter of the first nut 72 is larger than the inner diameter of the second nut 73 and smaller than the outer diameter of the second nut 73. The first nut 72 is connected to the internal thread of the piston rod 7 through an external thread.

[0053] The connecting earring 71 can pass through the inner hole 42 of the first nut 72. First install the first nut 72, then install the second nut 73, and then install the first nut 72 on the piston rod 7. After the thread is tightened, the earring can rotate relatively freely around the axis of the piston rod 7, and automatically fit the installation pin of the main machine, eliminating the eccentric load caused by the large deviation in parallelism between the connecting earring 71 of the electric cylinder and the cylinder bottom, thereby maintaining the normal operation and high working precision of the electric cylinder.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0055] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A centrifugal brake, characterized in that: include: A rotating disk, which can be assembled as it rotates, and at least two sliding grooves are evenly opened along the circumferential direction on the rotating disk; A centrifugal block is arranged in the slide groove and connected to the inner wall of the slide groove through an elastic member, and a first inclined surface is arranged on the side surface of the centrifugal block; The brake disc is fixedly arranged, the brake disc is opposite to the first inclined surface of the centrifugal block, a second inclined surface is arranged on the side of the brake disc opposite to the centrifugal block, and the first inclined surface is parallel to the second inclined surface; When the turntable is stationary, the first inclined surface is far away from the second inclined surface; when the turntable rotates, when the centrifugal force on the centrifugal block is greater than the elastic force of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

2. The centrifugal brake according to claim 1, characterized in that: The first inclined surface of the centrifugal block and the bottom surface of the centrifugal block form an acute angle.

3. The centrifugal brake according to claim 1, characterized in that: The turntable includes an inner ring, a slide groove is arranged on the outer side of the inner ring, one end of the elastic member is connected to the outer side wall of the inner ring, and the other end is connected to the centrifugal block. When the centrifugal force applied to the centrifugal block is greater than the pulling force of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

4. The centrifugal brake according to claim 1, characterized in that: The turntable includes an inner ring and an outer ring, a slide groove is arranged between the inner ring and the outer ring, one end of the elastic member is connected to the inner side wall of the outer ring, and the other end is connected to the centrifugal block. When the centrifugal force applied to the centrifugal block is greater than the pressure of the elastic member, the centrifugal block moves radially outward along the slide groove, and the first inclined surface contacts the second inclined surface to generate a braking torque.

5. The centrifugal brake according to claim 1, characterized in that: The brake disc is provided with an inner hole, the rotating disc includes an inner ring, the brake disc is sleeved outside the inner ring through the inner hole and does not contact the inner ring, a shoulder is provided on the side wall of the inner ring away from the brake disc, and the groove wall is provided on the shoulder.

6. The centrifugal brake according to claim 1, characterized in that: The second inclined surface is arranged in a ring shape, and the second inclined surface corresponds to the centrifugal block.

7. An electric cylinder, characterized in that: include: Motor; A telescopic cylinder, the telescopic cylinder comprising a cylinder barrel and a piston rod, the piston rod being slidably assembled in the cylinder barrel; A screw assembly, the screw assembly extends into the interior of the piston rod, the motor drives the screw assembly to move, and the piston rod moves along the cylinder barrel driven by the screw assembly; The centrifugal brake according to any one of claims 1 to 6, wherein the centrifugal brake is used to limit the rotational speed of the motor.

8. The electric cylinder according to claim 7, characterized in that: The motor drives the screw assembly to work through a gear box. The gear box includes an outer box body, and an input gear and an output gear are assembled in the outer box body. The input gear and the output gear are in transmission cooperation with each other. The input gear and the turntable are both rotatably connected with the output shaft of the motor. The brake disc is mounted on the outer box body of the gear box, and the output gear is transmission connected with the screw assembly.

9. The electric cylinder according to claim 8, characterized in that: A flat key is installed on the output shaft of the motor, and a keyway is correspondingly arranged on the turntable. The flat key and the keyway are connected for radial positioning of the turntable, and the axial ends of the turntable are axially positioned by the shoulders and spacers of the input gear respectively.

10. The electric cylinder according to claim 8, characterized in that: The piston rod is connected to a connecting earring through an anti-eccentric load structure, and the anti-eccentric load structure includes a first nut and a second nut, which are arranged at the ends of the connecting earring in sequence from the inside to the outside. The inner hole of the first nut is smooth and has a clearance fit with the connecting earring. The second nut is threadedly connected to the connecting earring through an internal thread. The inner diameter of the first nut is larger than the inner diameter of the second nut and smaller than the outer diameter of the second nut. The first nut is connected to the internal thread of the piston rod through an external thread.

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