A power-off brake device

Abstract

The present invention discloses a power-off brake device, which includes a main electromagnet, a base, a cross arm, friction plates, a compression spring, and a limiting device. The cross arm is installed on the base through a rotating shaft. One side of the rotating shaft of the cross arm is connected to the limiting device, and the other side of the rotating shaft of the cross arm is connected to the upper end of the compression spring. The lower end of the compression spring is connected to the base. The friction plates are fixedly installed on the upper end surface of the cross arm on the other side of the rotating shaft. The main electromagnet is arranged on the base on the other side of the rotating shaft. When the cross arm is in a horizontal state, there is a gap between the upper end surface of the main electromagnet and the lower end surface of the cross arm. The limiting device includes a vertical rod, a roller, and a rotation driving mechanism capable of driving the vertical rod to rotate. The roller is installed at the upper end of the vertical rod, the lower end of the vertical rod is rotatably installed on the base, and the rod body of the vertical rod is connected to the rotation driving mechanism. The device of the present invention has a simple and reliable structure and is easy to control in a motion state, and is especially suitable for the braking requirements of heavy-duty and large-inertia turntables.

Description

Technical Field

[0001] The present invention relates to the field of electromechanical technology, and particularly to a power-off brake device. The power-off brake device has a simple and reliable structure and is easy to control in its working state. It can be used in cooperation with multiple devices, and is particularly suitable for device fields with large turntable braking requirements such as astronomical telescopes. Background Art

[0002] When a large ground-based astronomical telescope observes, it tracks celestial bodies through the movement of the tracking axis system. For safety considerations, the tracking axis system needs to be equipped with a power-off brake for braking. In actual work, due to the large diameter of the turntable of a large astronomical telescope, it is very difficult to brake the entire turntable. Traditional power-off brakes are of a relatively complex disc type, and their complex structure determines that their size cannot be made to brake the entire turntable. Therefore, they are not suitable for application in the braking field of large astronomical telescopes. So, it is necessary to design a power-off brake with a simple and reliable structure that can be applied to large astronomical telescopes. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention proposes a power-off braking device with a simple structure and easy control of its working state. The power-off brake device has a simple and reliable structure and is easy to control in its motion state, and is particularly suitable for the braking requirements of heavy and large-inertia turntables.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A power-off brake device includes a main electromagnet, a base, a cross arm, a friction plate, a compression spring, and a limiting device. The cross arm is installed on the base through a rotating shaft. One side of the cross arm on the rotating shaft is connected to the limiting device, and the other side of the cross arm on the rotating shaft is connected to the upper end of the compression spring. The lower end of the compression spring is connected to the base. A friction plate is fixedly installed on the upper end surface of the cross arm on the other side of the rotating shaft. The main electromagnet is arranged on the base on the other side of the rotating shaft. When the cross arm is in a horizontal state, there is a gap between the upper end surface of the main electromagnet and the lower end surface of the cross arm. The limiting device includes a vertical rod, a roller, and a rotation driving mechanism capable of driving the vertical rod to rotate. The roller is installed at the upper end of the vertical rod, the lower end of the vertical rod is rotatably installed on the base, and the rod body of the vertical rod is connected to the rotation driving mechanism.

[0006] Further, the compression spring is used to provide the upward force of the cross arm after the main electromagnet loses power. The upward torque of the compression spring is greater than the torque formed by the gravity of the cross arm and the friction plate. When the main electromagnet is energized, the sum of the torque formed by the gravity of the cross arm and the friction plate and the electromagnetic torque is greater than the upward torque of the compression spring.

[0007] Further, the rotation driving mechanism includes a secondary electromagnet, a return spring, and a movable iron core. The secondary electromagnet is horizontally installed on the base. One end of the movable iron core is hinged to the vertical rod, and the other end is connected to the secondary electromagnet through the return spring. The rotation driving mechanism is used to keep the cross arm stationary in a rotating state when the main electromagnet is energized or when the main electromagnet is at low power or even de-energized.

[0008] Further, a slope with a predetermined angle is provided at the position where the end of the cross arm contacts the roller. The roller contacts the cross arm and the interaction pressure between the two is along the normal direction of the slope. The angle of the slope satisfies: when the secondary electromagnet is energized, the moments of the three forces, namely, the pressure of the cross arm on the roller, the pulling force generated by the push-pull electromagnet, and the static friction force generated by the roller, on the vertical rod are balanced, so that the cross arm remains stationary; when the secondary electromagnet is de-energized, the vertical rod rotates under the action of the pressure of the cross arm, the thrust of the return spring, and the rolling friction force.

[0009] Further, a stop block is provided at the end of the cross arm, and the stop block is used to limit the rotation angle of the vertical rod and the roller.

[0010] Further, the power-off brake device is located below the turntable. When the main electromagnet is energized, the cross arm drives the friction plate to rotate downward, and at this time, the highest point of the friction plate is lower than the lower surface of the turntable.

[0011] Further, the material of the cross arm is steel or the cross arm has magnetic material at the position where it contacts the electromagnet.

[0012] Further, a bottom plate is also included. The bottom plate is installed below the base. The magnetic field of the main electromagnet is closed through the bottom plate at the lower end surface of the base, and the magnetic field of the main electromagnet is closed through the cross arm at the upper end surface of the base.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] Compared with the traditional power-off brake scheme, the structure of the present invention is simple, the processing difficulty is low, and multiple devices can be used together during use, which is more suitable for large turntable devices.

[0015] Compared with the traditional disc-type power-off brake scheme, the present invention has a fast response and high motion reliability.

[0016] Compared with the traditional disc-type power-off brake scheme, the present invention is easy to realize serialization and standardization.

[0017] Generally speaking, the power-off brake device of the present invention has a simple and reliable structure and is especially suitable for precision instrument fields such as large astronomical telescopes. Description of the Drawings

[0018] Figure 1Schematic diagram of the power-off state of the power-off brake (the cross arm is in the horizontal state).

[0019] Figure 2 Schematic diagram of the powered-on state of the power-off brake (the cross arm is in the rotating state).

[0020] Figure 3 Schematic diagram of the working position of the power-off brake.

[0021] Markings in the figure: 1. Friction plate; 2. Compression spring; 3. Cross arm; 4. Rotating shaft; 5. Base; 6. Socket head cap screw; 7. Flat washer; 8. Spring washer; 9. Bottom plate; 10. Main electromagnet; 11. Lead wire; 12. Roller; 13. Stop block; 14. Vertical rod; 15. Mounting seat; 16. Sub-electromagnet; 17. Return spring; 18. Rotating seat; 19. Movable iron core. Specific implementation mode

[0022] The present invention will be further described in detail below with reference to the accompanying drawings.

[0023] This embodiment provides a power-off brake device as Figure 1 shown. The power-off brake device includes a friction plate 1, a compression spring 2, a cross arm 3, a rotating shaft 4, a base 5, a socket head cap screw 6, a flat washer 7, a spring washer 8, a bottom plate 9, a main electromagnet 10, a lead wire 11, a roller 12, a stop block 13, a vertical rod 14, a mounting seat 15, a sub-electromagnet 16, a return spring 17, a rotating seat 18, and a movable iron core 19.

[0024] For the convenience of description, the direction is defined as follows: the position of the base 5 is downward, and the position of the cross arm 2 is upward.

[0025] The lower and upper parts of the base 5 in this embodiment are an integral body. The base 5 and the bottom plate 9 are fixed by socket head cap screws 6, flat washers 7, and spring washers 8. The base 5 has mounting holes for installing the compression spring 2 and the electromagnet, and a rotating seat 18 for the vertical rod 14 to rotate is installed on the base 5, as Figure 1 shown. The base 5 is provided with a mounting groove. The main electromagnet 10 is installed on the base 5. The main electromagnet 10 is provided with a lead wire 11. The main electromagnet 10 is arranged between the base 5 and the cross arm 3. When the main electromagnet is powered on, the magnetic force generated by it acts on the cross arm, causing the cross arm to rotate downward. At this time, the power-off braking device does not produce a braking effect. The mounting groove allows the magnetic field of the main electromagnet 10 to pass through the two end faces of the base 5. The magnetic field closes through the bottom plate 9 at the lower end face of the base 5, and the magnetic field closes through the cross arm 3 at the upper end face of the base 5.

[0026] The compression spring 2 in this embodiment is a cylindrical helical compression spring with a circular cross-section. The lower end of the compression spring 2 is connected to the base 5, and the upper end is connected to the cross arm 3. The compression spring 2 is arranged between the base 5 and the cross arm 3 and is used to provide elastic force for the cross arm and the friction plate after the main electromagnet loses power, so that the friction plate presses against the turntable to produce a braking effect.

[0027] The friction plate 1 in this embodiment is fixed to the cross arm 3 by welding or threaded connection. The pressing force provided by the compression spring 2 acts on the friction plate 1, and friction is generated when the friction plate contacts the turntable, providing the required braking torque for braking.

[0028] The cross arm 3 and the base 5 in this embodiment are connected by a rotating shaft 4. The cross arm 3 can rotate around the rotating shaft 4, thereby controlling the relative position relationship between the friction plate and the turntable, and further controlling the braking effect of the brake. Moreover, since the distance between the cross arm 3 and the main electromagnet 10 is small, the cross arm 3 only needs to rotate a small angle to perform braking control. The electromagnetic force generated by the main electromagnet can provide sufficient electromagnetic force to make the cross arm rotate downward in a small action range. The material of the cross arm is steel or there is a magnetic material at the position where the cross arm contacts the electromagnet, so that the cross arm can move under the action of the magnetic field.

[0029] The auxiliary electromagnet 16 in this embodiment is horizontally installed on the mounting seat 15. The mounting seat 15 is fixed to the base 5 by bolts. The auxiliary electromagnet 16, the return spring 17 and the movable iron core 19 together form a push-pull electromagnet. The return spring provides the elastic force for the upward rotation of the cross arm and the friction plate after losing power and provides the resistance to resist the downward rotation of the return spring. When the auxiliary electromagnet 16 is energized, its pulling force can make the vertical rod and the roller rotate to the vertical state. At this time, the roller contacts the cross arm and provides pressure to keep the cross arm in the rotating state. When the auxiliary electromagnet loses power, the return spring provides a thrust to make the vertical rod rotate and not contact the cross arm. Under the pulling force of the push-pull electromagnet, the acting force of the vertical rod and the roller on the cross arm can keep the cross arm rotating. When this acting force is large enough, the main electromagnet can keep the cross arm rotating under low power or even power-off conditions. At this time, the power-off braking device does not produce a braking effect. When the push-pull electromagnet is energized, due to the action of the pulling force of the push-pull electromagnet, the power consumption of the main electromagnet can be reduced or the main electromagnet can be powered off, thereby reducing the power generation of the main electromagnet.

[0030] The roller 12 in this embodiment is fixed to the vertical rod 14. The device composed of the vertical rod and the roller is placed on the other side of the main electromagnet and the compression spring. The two are connected to the rotating seat 18 by a rotating pair. The vertical rod and the roller can rotate around the rotating shaft under the action of the push-pull electromagnet. The vertical rod is also connected to the movable iron core 19. When the power-off brake does not brake and the cross arm rotates, the force generated by the vertical rod and the roller on the cross arm under the action of the push-pull electromagnet can make the cross arm resist the elastic force of the compression spring and maintain the force balance in the rotating state.

[0031] In this embodiment, a slope formed at a certain angle is provided at the position where the end of the cross arm 3 contacts the roller 12. The roller contacts the cross arm, and the interaction pressure between the two is along the normal direction of the slope. The angle range of this slope is mainly determined by the rolling friction of the roller. According to the design requirements, the slope angle must satisfy that when the push-pull electromagnet is energized, the moment balance of the three forces, namely, the pressure of the cross arm on the roller, the pulling force generated by the push-pull electromagnet, and the static friction force generated by the roller, on the vertical rod, so that the cross arm remains stationary. In addition, the slope angle must enable the vertical rod to rotate under the action of the pressure of the cross arm, the thrust of the return spring, and the rolling friction force when the push-pull electromagnet loses power. This design can enable the roller to provide sufficient pressure on the cross arm when the push-pull electromagnet is energized, and at the same time enable the roller and the vertical rod to rotate away from the cross arm under the action of the pressure of the cross arm and the thrust of the push-pull electromagnet when the push-pull electromagnet loses power.

[0032] The stopper 13 in this embodiment is fixed to the end of the cross arm 3, and this stopper plays a role in restricting the rotation angle of the vertical rod 14 and the roller 12. When the main electromagnet and the push-pull electromagnet lose power, the vertical rod rotates away from the cross arm, and at this time, the stopper plays a limiting role on the vertical rod.

[0033] The compression spring 2 in this embodiment provides the upward force for the cross arm 3 to the friction plate 1 after losing power. The upward moment of the compression spring 2 is greater than the moment formed by the gravity of the cross arm 3 and the friction plate 1. When the main electromagnet 10 is energized, the sum of the moment formed by the gravity of the cross arm 3 and the friction plate 1 and the electromagnetic moment is greater than the upward moment of the compression spring 4.

[0034] As Figure 3 shown, in this embodiment, a power-off brake device is provided at each symmetric position of the turntable ( Figure 3 shown by the dotted line).

[0035] The working principle of the power-off brake of the present invention is that when the main electromagnet is energized, the magnetic force generated by the energization of its coil winding is greater than the spring force, causing the cross arm to rotate towards the base. At this time, the cross arm can rotate freely. At this time, when the push-pull electromagnet is energized, it drives the vertical rod to rotate, so that the pulley above the vertical rod contacts the cross arm. At this time, the cross arm remains in a balanced state under the action of the compression spring, the main electromagnet, and the roller; when the coil winding of the main electromagnet loses power, the main electromagnet does not generate magnetic force, and the cross arm is pushed towards the brake disc by the compression spring. At this time, the push-pull electromagnet loses power, and the vertical rod rotates away from the cross arm under the action of the pressure of the cross arm and the thrust of the return spring. At this time, the brake disc is pressed against the turntable by the compression spring, and the two generate frictional force through the friction plate to prevent the turntable from rotating, thus playing a braking role.

[0036] As Figure 2As shown in the figure, when the power-off brake device of this embodiment is in the standby state with the electromagnet energized, the magnetic force moment exerted by the main electromagnet 10 on the cross arm 3 is greater than the elastic force moment of the compression spring 2. The main electromagnet 10 drives the cross arm 3 and the friction plate 1 to rotate towards the base. The highest point of the friction plate 1 is lower than the lower surface of the turntable (as shown by the dashed line in Figure 2 ), at this time, the friction plate 1 does not contact the turntable, and the brake device does not produce a braking effect. At the same time, the auxiliary electromagnet 16 is energized, driving the vertical rod 14 and the roller 12 to rotate. At this time, the roller 12 contacts the cross arm 3 and provides pressure. The pulling force moment generated by the auxiliary electromagnet 16, the pressure moment of the cross arm 3 on the vertical rod 14, and the moment generated by the surface friction of the roller 12 are balanced. At this time, the acting force of the roller on the cross arm keeps the cross arm in a rotating state, preventing the cross arm 3 from rotating upward to maintain the non-braking effect;

[0037] As shown in Figure 1 , when the power-off brake device of this embodiment is braking with the electromagnet powered off, the electromagnet does not exert a force on the cross arm 3. At this time, the cross arm 3 only receives the elastic force of the compression spring 2. The cross arm 3 and the friction plate 1 move away from the base 5 under the action of the compression spring 2. At this time, the friction plate 1 contacts the turntable and is pressed tightly by the two under the action of the spring force, thereby producing a braking effect. At the same time, the auxiliary electromagnet 16 is powered off, and the vertical rod 14 and the roller 12 rotate away from the cross arm and do not contact the cross arm.

[0038] In summary, the power-off brake of the present invention includes a main electromagnet, a base, a cross arm, a friction plate, a stop block, a compression spring, and a limiting device. The limiting device includes components such as a push-pull electromagnet, a vertical rod, a pulley, and a rotating seat. The push-pull electromagnet is mainly composed of an auxiliary electromagnet, a return spring, and a movable iron core. Among them, the friction plate is fixedly connected to the cross arm. When the main electromagnet is energized, the cross arm is subjected to the electromagnetic force of the main electromagnet to overcome the elastic force of the spring, causing the cross arm to rotate towards the base along with the rear armature, and at the same time driving the friction plate fixedly connected to the cross arm to rotate downward. The friction plate and the turntable do not come into contact. At this time, the auxiliary electromagnet is energized, and the auxiliary electromagnet drives the vertical rod to rotate, so that the pulley above the vertical rod remains in a balanced state under the action of forces such as the pressure of the cross arm and the pulling force of the push-pull electromagnet. At this time, the device can be made not to produce a braking effect when the main electromagnet is at low power or powered off; when the main electromagnet is powered off, the electromagnet no longer generates magnetic force, and the cross arm is subjected to the elastic force of the compression spring, driving the friction plate to rotate towards the turntable. At this time, the auxiliary electromagnet is powered off, and the vertical rod rotates under the elastic force of the return spring. The stop block at the end of the cross arm limits the vertical rod. At this time, the friction plate is pressed tightly against the turntable under the action of the compression spring, thereby generating frictional force to brake the turntable. The device of the present invention has a simple and reliable structure and is easy to control in the working state. Multiple such power-off brakes can be used together for braking, and it is especially suitable for devices with large turntables such as large astronomical telescopes.

[0039] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electropneumatic fail-safe brake device, characterized in that, It includes a main electromagnet, a base, a cross arm, a friction plate, a compression spring and a limiting device. The cross arm is installed on the base through a rotating shaft. One side of the cross arm on the rotating shaft is connected to the limiting device, and the other side of the cross arm on the rotating shaft is connected to the upper end of the compression spring. The lower end of the compression spring is connected to the base. The friction plate is fixedly installed on the upper end surface of the cross arm on the other side of the rotating shaft. The main electromagnet is arranged on the base on the other side of the rotating shaft. When the cross arm is in a horizontal state, there is a gap between the upper end surface of the main electromagnet and the lower end surface of the cross arm. The limiting device includes a vertical rod, a roller and a rotation driving mechanism capable of driving the vertical rod to rotate. The roller is installed at the upper end of the vertical rod, and the lower end of the vertical rod is rotatably installed on the base. The rod body of the vertical rod is connected to the rotation driving mechanism. The rotation driving mechanism includes a secondary electromagnet, a return spring and a movable iron core. The secondary electromagnet is horizontally installed on the base. One end of the movable iron core is hinged to the vertical rod, and the other end is connected to the secondary electromagnet through the return spring. The rotation driving mechanism is used to keep the cross arm stationary in a rotating state when the main electromagnet is powered on or when the main electromagnet is at low power or even powered off. A slope with a predetermined angle is provided at the position where the end of the cross arm contacts the roller. The roller contacts the cross arm and the mutual acting pressure between the two is along the normal direction of the slope. The angle of the slope satisfies that when the secondary electromagnet is powered on, the moment of the pressure of the cross arm on the roller, the pulling force generated by the push-pull electromagnet and the static friction force generated by the roller on the vertical rod are balanced, so that the cross arm remains stationary; when the secondary electromagnet loses power, the vertical rod rotates under the action of the pressure of the cross arm, the pushing force of the return spring and the rolling friction force.

2. The power-off brake device according to claim 1, characterized in that, The compression spring is used to provide the upward force of the cross arm after the main electromagnet loses power. The upward moment of the compression spring is greater than the moment formed by the gravity of the cross arm and the friction plate. When the main electromagnet is powered on, the sum of the moment formed by the gravity of the cross arm and the friction plate and the electromagnetic moment is greater than the upward moment of the compression spring.

3. The power-off brake device according to claim 1, wherein, A stop block is arranged at the end of the cross arm, and the stop block is used to limit the rotation angle of the vertical rod and the roller.

4. The power-off brake device according to claim 1, characterized in that, The power-off brake device is located below the turntable. When the main electromagnet is powered on, the cross arm drives the friction plate to rotate downward. At this time, the highest point of the friction plate is lower than the lower surface of the turntable.

5. The power-off brake device according to claim 1, characterized in that, The material of the cross arm is steel or there is a magnetic material at the position where the cross arm contacts the electromagnet.

6. The power-off brake device according to claim 1, characterized in that, It also includes a bottom plate. The bottom plate is installed below the base. The magnetic field of the main electromagnet is closed through the bottom plate at the lower end surface of the base, and the magnetic field of the main electromagnet is closed through the cross arm at the upper end surface of the base.

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