Electric push rod with braking function

Abstract

The utility model belongs to the technical field of electric push rods, and particularly relates to an electric push rod with a braking function, which comprises a push rod assembly, a transmission assembly and a motor assembly, the motor assembly comprises a rotating shaft, a brake pad is sleeved on the outer side of the rotating shaft, and a first friction plate is arranged on one axial side of the brake pad. An air inlet pipe or a liquid inlet pipe is arranged on one axial side of the first friction plate, a piston is arranged in the air inlet pipe or the liquid inlet pipe, the piston and the air inlet pipe or the liquid inlet pipe are in dynamic seal, and the piston moves towards the first friction plate under the action of air pressure or hydraulic pressure and pushes the first friction plate to make contact with the brake pad. The motor is in a braking state; a magnetic induction coil is further arranged on one axial side of the first friction plate, and when the motor is powered on, the first friction plate moves towards the magnetic induction coil so that braking of the motor can be relieved. The magnetic force of the magnetic induction coil is larger than the thrust of the piston to the first friction plate. The utility model has the advantage of higher safety.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric push rods, and in particular relates to an electric push rod with a braking function. Background Art

[0002] At present, the brakes of electric push rods usually adopt electromagnetic brakes. For example, Chinese patent with application number 201920233451.8 discloses an electric push rod with braking function. When the brake assembly in the patent is energized, the electromagnetic coil will suck the movable block downward and make the movable block compress the compression spring, so that the brake pad between the movable block and the fixed block is free in the up and down directions and can rotate with the extension shaft. When the brake assembly is powered off, the electromagnetic coil loses its magnetic force. Under the action of the compression spring, the movable block is pushed upward, squeezing the brake pad between the movable block and the fixed block, so that the extension shaft stops rotating.

[0003] Electric push rods are used as driving mechanisms for some electric doors, such as the doors of some buses. When such electric doors fail, they need to be opened manually. However, when the electric push rods of the above scheme are powered off, the compression spring always acts on the movable block, making the motor of the electric push rod always in the brake state, making it difficult to open the electric door and causing accidents. Utility Model Content

[0004] The utility model aims to provide an electric push rod with a braking function and higher safety.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an electric push rod with a braking function, comprising a push rod assembly, a transmission assembly and a motor assembly, wherein the push rod assembly realizes transmission with the motor assembly through the transmission assembly, and the motor assembly comprises a rotating shaft, a brake pad rotating with the rotating shaft is sleeved on the outer side of the rotating shaft, a first friction plate is provided on the axial side of the brake pad, an air intake pipe or a liquid intake pipe is provided on the axial side of the first friction plate, a piston is provided in the air intake pipe or the liquid intake pipe, a dynamic seal is formed between the piston and the air intake pipe or the liquid intake pipe, and the piston moves toward the first friction plate side under the action of air pressure or hydraulic pressure and pushes the first friction plate to contact the brake plate, so that the motor is in a braking state; a magnetic induction coil is also provided on the axial side of the first friction plate, and when the motor is powered on, the first friction plate moves toward the magnetic induction coil side to release the brake of the motor; the magnetic force of the magnetic induction coil is greater than the thrust of the piston on the first friction plate.

[0006] The electric push rod of this solution is always in a ventilated or liquid-permeable state when in use, so that the piston is always pushed by air pressure or hydraulic pressure, and the piston pushes the first friction plate, so that the first friction plate contacts the brake pad, so that the electric push rod is always in a braking state when not powered on. When the motor push rod is powered on, the magnetic induction coil will generate a magnetic field, and the first friction plate will be attracted by the magnetic field. The magnetic force of the magnetic field is greater than the thrust of the piston, so the first friction plate will be away from the brake pad, so that the motor shaft can rotate smoothly. When a fault occurs, the motor can no longer be powered on, and the device no longer takes in air or liquid at this time, so there is no friction between the brake pad and the first friction plate, or the friction is small, so that the motor can rotate, and the operator can directly open the electric door, thereby avoiding accidents and improving safety.

[0007] The air intake pipe or the liquid intake pipe is connected to the electric push rod through a pipeline so as to achieve air intake or liquid intake.

[0008] Preferably, an intake pipe is provided on one axial side of the first friction plate.

[0009] Compared with the liquid inlet pipe, the air intake system is simpler to install and is more convenient to replace after damage.

[0010] Preferably, the air intake pipe and the magnetic induction coil are arranged on the same mounting block, the mounting block is provided with an annular chamber for accommodating the magnetic induction coil, the air intake pipe axially penetrates the mounting block and is coaxially arranged with the annular chamber.

[0011] The air intake pipe is coaxially arranged with the annular chamber, so that when the first friction plate is subjected to thrust and magnetic force, the force is more evenly applied and no deviation occurs.

[0012] Preferably, the first friction plate comprises a moving block and a friction plate body, wherein the friction plate body is fixed on the moving block, and the moving block has magnetic conductivity and is adsorbed by the magnetic induction coil after being energized.

[0013] Usually, the magnetic conductivity of the friction plate body is relatively weak, so the first friction plate includes a moving block and a friction plate body. The moving block has relatively good magnetic conductivity so that the moving block can be adsorbed, thereby achieving adsorption of the first friction plate.

[0014] Preferably, the first friction plate is provided with a plurality of guide holes which penetrate axially and are arranged in annular intervals, and an axially extending guide member passes through the guide holes, and the first friction plate is slidably matched with the guide member.

[0015] The first friction plate is guided by providing a guide member so that the first friction plate will not deviate when moving.

[0016] Preferably, the motor assembly includes an end cover, the brake pad is located between the end cover and the first friction plate, an elastic member is provided between the end cover and the first friction plate, the first friction plate has a tendency to move away from the brake pad under the action of the elastic member, and the elastic force applied by the elastic member to the first friction plate is smaller than the thrust applied by the piston to the first friction plate.

[0017] By arranging an elastic member, contact between the first friction plate and the brake plate can be avoided when the electric push rod fails, thereby facilitating the operator to open the electric door; at the same time, the elastic force applied by the elastic member to the first friction plate is smaller than the thrust applied by the piston to the first friction plate, thereby ensuring that the motor brakes when the piston pushes the first friction plate.

[0018] Preferably, a second friction plate is provided on the other axial side of the brake pad, and the second friction plate is directly or indirectly fixed to the end cover of the motor assembly. The brake pad is located between the first friction plate and the second friction plate, and the brake pad has space for axial movement; the first friction plate can squeeze the brake pad toward the second friction plate, so that the brake pad is in contact with the first friction plate and the second friction plate.

[0019] By providing the second friction plate, the friction force is further increased, thereby improving the braking effect of the electric push rod.

[0020] Preferably, a linkage block is sleeved on the outer side of the rotor shaft, the linkage block is tightly fitted with the rotor shaft and rotates synchronously, the brake pad is sleeved on the outer side of the linkage block, and a linkage structure is provided between the brake pad and the linkage block to realize synchronous rotation of the brake pad and the linkage block, and the brake pad can move in the axial direction on the linkage block.

[0021] The linkage block is tightly matched with the rotor shaft so that the linkage block will not move axially. The brake pad is sleeved on the linkage block so that the brake pad can move axially, thereby making the brake pad contact with the first friction block and the second friction block; wherein the linkage structure can be a spline and a spline groove. wherein the axial movement space of the brake pad is limited by the first friction block and the second friction block.

[0022] Preferably, a ring groove is provided on the circumferential outer wall of the piston, and a sealing ring is embedded in the ring groove.

[0023] A sealing ring is provided to achieve dynamic sealing between the piston and the air inlet pipe or the liquid inlet pipe.

[0024] The utility model has the advantage of higher safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the utility model.

[0026] Figure 2A cross-sectional view of the motor assembly.

[0027] Figure 3 This is a cross-sectional view of the brake pad.

[0028] Figure 4 This is an enlarged view of the brake pad.

[0029] Figure 5 This is an enlarged view of the brake pad.

[0030] Figure 6 A schematic diagram of the internal structure of the motor assembly.

[0031] Figure numbers: 1. Motor assembly; 11. Motor housing; 12. End cover; 121. Cover plate; 122. Fixing hole; 13. Rotor shaft; 2. Transmission assembly; 3. Push rod assembly; 4. Intake head; 41. Intake pipe; 42. Piston; 43. Annular groove; 5. Mounting block; 51. Annular chamber; 511. Wiring; 6. Moving block; 61. Friction plate body; 62. Elastic member; 63. Guide sleeve; 7. Second friction plate; 8. Brake pad; 81. Linkage block; 9. Guide member; 91. Screw. DETAILED DESCRIPTION

[0032] The utility model is further described below based on the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, this embodiment discloses an electric push rod with a braking function, including a motor assembly 1, a transmission assembly 2 and a push rod assembly 3, and the push rod assembly 3 realizes transmission with the motor assembly 1 through the transmission assembly 2. The transmission assembly 2 and the push rod assembly 3 can be any existing transmission assembly and push rod assembly of an electric push rod, for example, a reduction box is a transmission assembly, and the push rod assembly is a combination of a lead screw, a lead screw nut, a guide tube, and a jack pipe.

[0034] like Figures 1 to 3 As shown, the motor assembly 1 includes a motor housing 11, an end cover 12 is provided at one axial end of the motor housing 11, and a rotor shaft 13 is rotatably connected in the motor housing 11. A mounting block 5 is provided on one axial side of the rotor shaft 13 and the end cover 12, and an annular chamber 51 is provided in the mounting block 5, and a magnetic induction coil (not shown in the figure) is provided in the annular chamber 51, and a wiring 511 is connected to the magnetic induction coil from the outside to the inside. An axially extending air intake pipe 41 is also provided in the mounting block 5, and the air intake pipe 41 is located on the inner side of the annular chamber 51 and is coaxially arranged with the annular chamber 51; an air intake head 4 connected to the air intake pipe 41 is provided on the upper housing of the motor assembly. A piston 42 is provided in the air intake pipe 41, and the piston 42 is provided with a circle of annular grooves 43, and a sealing ring (not shown in the figure) is provided in the annular grooves 43, and the piston 42 is dynamically sealed with the air intake pipe 41. When the air intake pipe 41 is inlet, the piston 42 will move toward the rotor shaft 13 side in the air intake pipe 41.

[0035] like Figures 3 to 5 As shown, a first friction plate is provided between the rotor shaft 13 and the mounting block 5. The first friction plate includes a moving block 6 and a friction plate body 61. The moving block 6 has magnetic conductivity. When the magnetic induction coil in the mounting block 5 is energized, the moving block 6 will be adsorbed and move toward the mounting block 5. The moving block 6 can also be pushed by the piston 42 and move toward the rotor shaft 13. A linkage block 81 is sleeved on the outer side of the rotor shaft 13. The linkage block 81 is tightly matched with the rotor shaft 13 and the linkage block 81 and the rotor shaft 13 rotate synchronously. A brake pad 8 is sleeved on the outer side of the linkage block 81. The brake pad 8 and the linkage block 81 are connected by a linkage structure of splines and spline grooves to achieve synchronous rotation. The brake pad 8 can move axially on the linkage block 81. A second friction plate 7 is provided on the axial side of the brake pad 8 that deviates from the first friction plate. The second friction plate 7 is fixed on the cover plate 121. The brake pad 8 is confined between the second friction plate 7 and the first friction plate. When the piston 42 pushes the first friction plate, the first friction plate pushes the brake plate 8, and the brake plate 8 moves toward the second friction plate 7 so that the axial sides of the brake plate 8 contact the second friction plate 7 and the first friction plate respectively, thereby achieving braking of the motor assembly.

[0036] A plurality of elastic members 62 are provided between the cover plate 121 and the first friction plate. The moving block 6 of the first friction plate is provided with an axially open receiving groove. A guide sleeve 63 is provided in the receiving groove. The elastic member 62 is arranged in the guide sleeve 63. The elastic member 62 is a compression spring that can push the first friction plate toward the mounting block 5. The elastic force of the elastic member 62 is smaller than the thrust of the piston 42, and the thrust of the piston 42 is smaller than the magnetic force of the magnetic induction coil.

[0037] like Figure 5 to Figure 6 As shown, the moving block 6 is provided with at least two axially penetrating guide holes, and an axially extending guide member 9 is provided in the guide hole. The guide member 9 is hollow, and an axially open threaded hole is provided on the mounting block 5. The screw 91 passes through the cover plate 121 and the guide member 9 and is threadedly matched with the threaded hole of the mounting block 5. The cover plate 121 is provided with a plurality of fixing holes 122, which are fixed to the end cover 12 by bolts (not shown in the figure).

[0038] During actual use, the air intake pipe 41 is always taking in air, so that the piston 42 moves and drags the first friction plate, and the first friction plate moves toward the brake pad 8 and pushes the brake pad 8 to move, so that the axial sides of the brake pad 8 are respectively in contact with the first friction plate and the second friction plate 7, and the electric push rod is in a brake state. When the motor assembly is powered on, the magnetic induction coil will generate magnetic force and adsorb the moving block 6 of the first friction plate. Since the magnetic force is greater than the thrust of the piston 42, the moving block 6 moves toward the mounting block 5, and the brake pad 8 is not pressed. At this time, the rotor shaft 13 of the motor assembly can rotate, and the electric push rod can be extended or retracted. When a fault occurs, the electric push rod is no longer ventilated and powered. At this time, the elastic member 62 will push the moving block 6 to move toward the mounting block 5, so that the brake pad 8 is not pressed, and the operator can pull the electric door.

Claims

1. An electric push rod with a braking function, comprising a push rod assembly, a transmission assembly and a motor assembly, wherein the push rod assembly realizes transmission with the motor assembly through the transmission assembly, the motor assembly comprises a rotating shaft, and a brake pad rotating together with the rotating shaft is sleeved on the outer side of the rotating shaft, characterized in that: A first friction plate is provided on one axial side of the brake pad, an air intake pipe or a liquid intake pipe is provided on one axial side of the first friction plate, a piston is provided in the air intake pipe or the liquid intake pipe, a dynamic seal is provided between the piston and the air intake pipe or the liquid intake pipe, and the piston moves toward the first friction plate under the action of air pressure or hydraulic pressure and pushes the first friction plate to contact the brake pad, so that the motor is in a braking state; a magnetic induction coil is also provided on one axial side of the first friction plate, and when the motor is powered on, the first friction plate moves toward the magnetic induction coil to release the brake of the motor; the magnetic force of the magnetic induction coil is greater than the thrust of the piston on the first friction plate.

2. The electric push rod with brake function according to claim 1, characterized in that: An intake pipe is provided on one axial side of the first friction plate.

3. The electric push rod with brake function according to claim 2, characterized in that: The air intake pipe and the magnetic induction coil are arranged on the same mounting block. The mounting block is provided with an annular annular chamber for accommodating the magnetic induction coil. The air intake pipe axially penetrates the mounting block and is coaxially arranged with the annular chamber.

4. The electric push rod with brake function according to claim 1, characterized in that: The first friction plate comprises a moving block and a friction plate body, wherein the friction plate body is fixed on the moving block, and the moving block has magnetic conductivity and is adsorbed by the magnetic induction coil after being energized.

5. The electric push rod with brake function according to any one of claims 1 to 4, characterized in that: The first friction plate is provided with a plurality of guide holes which penetrate axially and are arranged at annular intervals. A guide member extending axially passes through the guide holes. The first friction plate is slidably matched with the guide member.

6. The electric push rod with brake function according to any one of claims 1 to 4, characterized in that: The motor assembly includes an end cover, the brake pad is located between the end cover and the first friction plate, an elastic member is provided between the end cover and the first friction plate, the first friction plate has a tendency to move away from the brake pad under the action of the elastic member, and the elastic force applied by the elastic member to the first friction plate is smaller than the thrust applied by the piston to the first friction plate.

7. The electric push rod with brake function according to claim 6, characterized in that: A second friction plate is provided on the other axial side of the brake pad, and the second friction plate is directly or indirectly fixed to the end cover of the motor assembly. The brake pad is located between the first friction plate and the second friction plate, and the brake pad has space for axial movement; the first friction plate can squeeze the brake pad toward the second friction plate, so that the brake pad is in contact with the first friction plate and the second friction plate.

8. The electric push rod with brake function according to claim 7, characterized in that: A linkage block is sleeved on the outer side of the rotating shaft, and the linkage block is tightly fitted with the rotating shaft and rotates synchronously. The brake pad is sleeved on the outer side of the linkage block, and a linkage structure is provided between the brake pad and the linkage block to realize synchronous rotation of the brake pad and the linkage block. The brake pad can move in the axial direction on the linkage block.

9. The electric push rod with brake function according to any one of claims 1 to 4, characterized in that: A circle of annular groove is arranged on the circumferential outer wall of the piston, and a sealing ring is embedded in the annular groove.

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