A reducer safety device and a reducer having the same

Abstract

The invention discloses a reducer safety device and a reducer with the device. A plurality of brackets are arranged at intervals on the axial surface of the roller of the reducer; a cylinder is arranged below the worm gear reducer of the reducer, and the cylinder is connected to the gas storage tank through an air guide pipe, and a solenoid valve is connected in series in the air guide pipe; an encoder is installed on the output shaft of the reducer, and when the encoder exceeds the set value, the encoder transmits the signal of the roller stalling to the upper computer, and the upper computer gives an instruction to the solenoid valve, and the solenoid valve is quickly opened to input the high-pressure gas in the gas storage tank into the cylinder, and push the piston rod of the cylinder to move outward and press against the bracket of the roller, thereby achieving the purpose of preventing the roller from rotating. The function of the invention is that the reducer can effectively prevent the instantaneous fall of heavy objects when the transmission device fails.

Description

Technical Field

[0001] The invention relates to the field of reducers, and in particular to a reducer safety device. Background Art

[0002] The worm gear reducer has the advantages of compact structure, large transmission ratio, large number of meshing tooth pairs, large overlap, smooth transmission, low noise, and self-locking when the lead angle of the worm is less than the equivalent friction angle of the meshing tooth surface. Therefore, worm gear transmission has been widely used in various sports and power transmission devices.

[0003] However, worm gear transmission also has disadvantages: the tooth surface sliding speed is high during transmission, friction and wear are serious, and the transmission efficiency is low. When the transmission is self-locking, the efficiency is less than 0.5, so it is not suitable for high-power transmission. If the worm gear is not lubricated well, it will accelerate the wear of its tooth surface and reduce its service life.

[0004] Worm-gear transmission, with the worm gear as the output end, once there is a problem with the worm gear, the entire deceleration will stall, leading to an accident. Most of the current reducers have a braking device added to the motor output end. However, for some occasions with higher requirements, such as the cover of a nuclear power plant, a loading crane, a manned cable car and a hoist, end braking, also called low-speed shaft braking, is required. At present, the low-speed shaft braking device is mainly a hydraulic caliper brake, and there is a small amount of hydraulic belt brake. However, the brake devices of these two are relatively large in size, and if the vehicle does not have other hydraulic devices, a hydraulic pump station is also required.

[0005] The reaction time of hydraulic pressure is relatively long. From detection to feedback to execution, it takes several seconds for the hydraulic system to build up enough pressure. When the heavy object is in a free fall under the condition of stall, it drops about 5 meters per second. Before the pressure is built up, the hoisted heavy object falls to the ground. This is not suitable for working conditions with a relatively short lifting distance. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a reducer safety device, which mainly solves the problem of rapid braking of a low-speed shaft in a limited space (especially a vehicle-mounted gantry crane or the like) without an external hydraulic pump station.

[0007] The present invention is implemented according to the following technical solutions:

[0008] A speed reducer safety device comprises a plurality of brackets arranged at intervals on the axial surface of the roller of the speed reducer; a cylinder is arranged under the worm gear reducer of the speed reducer, and the cylinder is connected to the gas storage tank through an air guide pipe, and an electromagnetic valve is connected in series in the air guide pipe; an encoder is installed on the output shaft of the speed reducer, when the encoder exceeds the set value, the encoder transmits the signal of the roller stalling to the upper computer, the upper computer gives an instruction to the electromagnetic valve, the electromagnetic valve opens quickly, and the high-pressure gas in the gas storage tank is input into the cylinder, pushing the piston rod of the cylinder to move outward and press against the bracket of the roller, thereby achieving the purpose of preventing the roller from rotating.

[0009] Furthermore, the number of the cylinders is at least two, and each cylinder is connected to the gas storage tank through an air guide pipe, and a solenoid valve is serially connected in each air guide pipe.

[0010] Furthermore, the cylinder includes a cylinder barrel, a piston rod I and a piston rod II; an end cover is provided on each of the two axial surfaces of the cylinder barrel, the piston rod I and the piston rod II are installed in the cylinder barrel, and the piston rod I and the piston rod II can both pass through the end cover; an air inlet joint is provided in the middle of the cylinder barrel, and when the piston rod I and the piston rod II are not working, a predetermined space is left between the two to facilitate the smooth entry of high-pressure gas into the cylinder; a boss extends from the end of the piston rod I and the piston rod II to abut against the end cover to prevent them from popping out of the cylinder barrel.

[0011] Furthermore, a circle of grooves is provided on the bosses of the piston rods I and II, and a sealing ring is provided in the grooves.

[0012] Furthermore, the end cover is provided with a plurality of exhaust holes to reduce exhaust resistance and increase the movement speed of the piston rod.

[0013] Furthermore, a piston rod baffle is provided on the end cover. The piston rod baffle is made of brittle material and is instantly destroyed under the push of the piston rod.

[0014] Furthermore, each end cover is provided with two piston rod baffles, and the two piston rod baffles are distributed at 180 degrees.

[0015] Furthermore, the bracket on the roller is set to be an arc shape slightly larger than the diameter of the piston rod, so that when the two are in contact, the contact stress is much smaller than the contact stress between the cylinder and the plane.

[0016] Furthermore, it also includes a battery, which is connected to the pneumatic circuit through a passive switch. When the power is off, the passive switch is automatically closed and the battery starts to supply power; the host computer is powered by a UPS power supply. When the power is off, the host computer can still send a signal to the solenoid valve to achieve connectivity of the gas circuit.

[0017] A reducer includes a worm gear reducer and two double-small-tooth-difference reducers, and also includes the above-mentioned reducer safety device, which can effectively prevent heavy objects from falling instantly when the transmission device of the reducer fails.

[0018] Beneficial effects of the invention: The invention can effectively prevent the instantaneous fall of heavy objects when the transmission device fails. The speed from detection to feedback to execution is fast; the space occupied is small; the pipeline routing is flexible and will not affect other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the reducer safety device of the present invention;

[0020] Figure 2 This is the gas control principle diagram of the present invention;

[0021] Figure 3 It is a cross-sectional view of a cylinder of the present invention;

[0022] Figure 4 A side view of a cylinder of the present invention;

[0023] Figure 5 It is a structural diagram of the drum of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0025] like Figure 1As shown, the present invention is mainly based on the dual-output rope reducer composed of a worm gear reducer and two small-tooth difference reducers (planetary reducers), and a set of safety devices is added. When the worm gear fails, the driving force becomes the sum of the deadweight of the heavy object and its inertia force. At this time, the heavy object is similar to free fall. The speed of the drum 4 is increased and transmitted to the output shaft of the original worm gear through a certain acceleration transmission ratio. The encoder 8 on the output shaft detects that its speed exceeds the set value, and it will send an alarm command to the upper computer. After receiving the command, the upper computer quickly sends a command to the solenoid valve on the air path. The solenoid valve opens instantly, releasing the high-pressure gas in the gas tank 7 to the cylinder 5, pushing the piston rod to move outward, thereby achieving the purpose of preventing the drum 4 from rotating. The specific implementation plan is as follows:

[0026] A plurality of brackets 3 are arranged at intervals on the axial surface of the roller 4 of the reducer; a cylinder 5 is arranged under the worm gear reducer 2 of the reducer, and the cylinder 5 is connected to the gas storage tank 7 through an air duct 6, and an electromagnetic valve is connected in series in the air duct 6; an encoder 8 is installed on the output shaft of the reducer, and when the encoder 8 exceeds the set value, the encoder 8 transmits the signal of the roller 4 stalling to the upper computer, and the upper computer gives an instruction to the electromagnetic valve, and the electromagnetic valve opens quickly, inputs the high-pressure gas in the gas storage tank 7 into the cylinder 5, and pushes the piston rod of the cylinder 5 to move outward and press against the bracket 3 of the roller 4, thereby achieving the purpose of preventing the roller 4 from rotating.

[0027] like Figure 2 As shown, considering that the piston rod of one cylinder may directly hit the bracket 3 of the roller 4 during the action process, thereby losing the function of preventing the roller 4 from rotating, two sets of cylinders are connected in parallel (i.e. Figure 2 In the cylinder Ⅰ and cylinder Ⅱ, when the drum 4 stalls, there must be a group of cylinder 5 piston rods that can stop the rotation of the drum 4, thereby effectively preventing the hoisted object from falling. Each cylinder 5 is connected to a solenoid valve, which controls the on and off of the air path to achieve the extension and retraction of the cylinder 5.

[0028] It should be noted that the cylinder 5 is a single-acting cylinder. It is only when it stalls that the gas pushes the piston rod to move to both sides. In this way, there is no need to worry about the airtightness of the cylinder.

[0029] A preferred embodiment of the above cylinder is given below:

[0030] like Figure 3 , Figure 4As shown, the cylinder 5 comprises a cylinder barrel 5.1, a piston rod I 5.2 and a piston rod II 5.4; an end cover 5.5 is respectively provided on the two axial surfaces of the cylinder barrel 5.1, and the piston rod I 5.2 and the piston rod II 5.4 are installed in the cylinder barrel 5.1, and the piston rod I 5.2 and the piston rod II 5.4 can both pass through the end cover 5.5; an air inlet joint 5.7 is provided in the middle of the cylinder barrel 5.1, and when the piston rod I 5.2 and the piston rod II 5.4 are not working, a predetermined space is left between the two to facilitate the smooth entry of high-pressure gas into the cylinder 5; a boss extends from the end of the piston rod I 5.2 and the piston rod II 5.4 to abut against the end cover 5.5 to prevent them from popping out of the cylinder barrel 5.1.

[0031] It should be noted that the end cover 5.5 is fixed to the cylinder barrel 5.1 by a plurality of end cover screws 5.6.

[0032] The end cover 5.5 is provided with a plurality of exhaust holes 5.10 to reduce exhaust resistance and increase the movement speed of the piston rod.

[0033] A circle of groove is arranged on the boss of piston rod I 5.2 and piston rod II 5.4, and a sealing ring 5.3 is arranged in the groove.

[0034] The end cover 5.5 is provided with a piston rod baffle 5.8, which is fixed to the end cover 5.5 by a piston rod baffle screw 5.9. The piston rod baffle 5.8 is made of brittle material and is instantly destroyed under the push of the piston rod.

[0035] Further solution: two piston rod baffles 5.8 are provided on each end cover 5.5, and the two piston rod baffles 5.8 are distributed at 180 degrees.

[0036] like Figure 5 As shown, in order to improve the local stress of the structure and prevent the drum 4 from suffering secondary damage due to its own insufficient strength when it stalls, the bracket 3 of the drum 4 is made into an arc shape slightly larger than the diameter of the cylinder piston rod, so that when the two are in contact, the contact stress is much smaller than the contact stress between the cylinder and the plane.

[0037] Further preferred embodiments of the above embodiment are given below:

[0038] In order to prevent the entire electric control system from being powered off when the worm gear fails, a battery is added to the pneumatic control circuit. The battery is equipped with an undervoltage protection device. It will self-check when powered on. If the voltage is too low, the system power supply system will be responsible for charging it. In addition, a passive switch is set in the entire pneumatic circuit. When the power is off, the passive switch automatically closes and the battery starts to supply power. The host computer is powered by a UPS power supply. In the event of a power outage, the host computer can still send a signal to the solenoid valve to achieve the connection of the gas circuit. At the same time, to ensure the reliability of the gas circuit, two solenoid control valves are equipped and connected in parallel in the pipeline to ensure that at least one of the solenoid control valves can be opened when powered on. Similarly, two encoders are also set, one of which is also designed as a safety redundancy.

[0039] In summary, when the worm gear is damaged, you can hold the output shaft or the roller to stop it. The advantage of holding the output shaft directly is that the torque is small, but directly stopping the roller is the most direct. Holding the output shaft has an electromagnetic brake, but it occupies a large space, so it cannot meet the space requirements.

[0040] Commonly used actuators include electric, hydraulic, and pneumatic. The main assessment of this technical solution is the speed of response and execution. Therefore, this technical solution comprehensively considers the choice of pneumatic. Electric and hydraulic actions are not fast enough. In order to improve the stability of the medium, we choose inert gas such as nitrogen. At the same time, we also consider that pneumatics take up less space, have flexible pipeline routing, and will not affect other components.

[0041] This technical solution also has many protection measures, such as: system power failure, piston rod popping out and hitting the roller bracket, solenoid valve not opening at a critical time, encoder failure, etc. Backups are made in the system.

[0042] The present invention also provides a reducer, including a worm gear reducer 2 and two double-small-tooth difference reducers 1 installed on a support 9, and also includes the above-mentioned reducer safety device, which can effectively prevent the instantaneous fall of heavy objects when the transmission device of the reducer fails.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A reducer safety device, characterized in that: A plurality of brackets are arranged at intervals on the axial surface of the reducer drum; A cylinder is arranged below the worm gear reducer of the reducer, and the cylinder is connected to the air storage tank through an air guide pipe, and an electromagnetic valve is connected in series in the air guide pipe; An encoder is installed on the output shaft of the reducer. When the encoder exceeds the set value, the encoder transmits the signal of the drum stalling to the upper computer. The upper computer gives instructions to the solenoid valve, and the solenoid valve opens quickly to input the high-pressure gas in the gas tank into the cylinder, pushing the piston rod of the cylinder to move outward and press against the bracket of the drum, thereby achieving the purpose of preventing the drum from rotating. The number of cylinders is at least two, and each cylinder is connected to the gas storage tank through an air guide pipe, and a solenoid valve is serially connected in each air guide pipe; The cylinder comprises a cylinder barrel, a piston rod I and a piston rod II; An end cover is respectively provided on the two axial surfaces of the cylinder barrel, and the piston rod I and the piston rod II are installed in the cylinder barrel, and the piston rod I and the piston rod II can both pass through the end cover; An air inlet joint is provided in the middle of the cylinder barrel, and when the piston rod I and the piston rod II are not in operation, a predetermined space is left between the two to facilitate the smooth entry of high-pressure gas into the cylinder; A boss extends out from the end of the piston rod I and the piston rod II to abut against the end cover to prevent them from popping out of the cylinder barrel; A circle of groove is provided on the boss of the piston rod I and the piston rod II, and a sealing ring is provided in the groove; The end cover is provided with a plurality of exhaust holes to reduce exhaust resistance and increase the movement speed of the piston rod; The end cover is provided with a piston rod baffle, which is made of brittle material and is instantly destroyed under the push of the piston rod; Each end cover is provided with two piston rod baffles, and the two piston rod baffles are distributed at 180 degrees; The bracket on the roller is set to be an arc shape slightly larger than the diameter of the piston rod, so that when the two are in contact, the contact stress is much smaller than the contact stress between the cylinder and the plane; It also includes a battery, which is connected to the pneumatic circuit through a passive switch. When the power is off, the passive switch is automatically closed and the battery starts to supply power; The host computer is powered by a UPS power supply. In the event of a power outage, the host computer can still send a signal to the solenoid valve to achieve connectivity of the gas path.

2. A reducer, comprising a worm gear reducer and two double-small-tooth-difference reducers, characterized in that: It also includes the reducer safety device as described in claim 1, which can effectively prevent the heavy object from falling instantly when the transmission device of the reducer fails.

Images