CN110254130B

CN110254130B - Universal caster

Info

Publication number: CN110254130B
Application number: CN201910606710.1A
Authority: CN
Inventors: 张文龙; 叶庆奇; 许智勇
Original assignee: Zhejiang Best Locomotive Parts Co Ltd
Current assignee: Zhejiang best locomotive parts Co., Ltd
Priority date: 2019-07-06
Filing date: 2019-07-06
Publication date: 2020-11-17
Anticipated expiration: 2039-07-06
Also published as: CN110254130A

Abstract

The invention relates to the technical field of casters, in particular to a universal caster which comprises a sleeve, a rotating structure, a rolling structure, a lifting structure, a limiting structure, clamping teeth, a lubricating structure, a connecting structure and a circulating structure, wherein the rotating structure is arranged on the sleeve; lubricating oil that lubricating structure leaked can be collected by circulating structure, thereby can prevent that lubricating oil leakage of lubricating structure from causing the waste, and circulating structure's power comes from elevation structure, collect the lubricating oil of retrieving promptly through elevation structure's rising, elevation structure's decline is carried out the reinjection lubricating structure of retrieving lubricating oil, through lubricating structure, circulating structure and elevation structure's linkage, not only can carry out abundant lubrication to rolling structure, make rolling structure's frictional force reduce, thereby prolong the life of universal wheel, can also retrieve leaking lubricating oil and recycle, thereby can save lubricating oil.

Description

Universal caster

Technical Field

The invention relates to the technical field of casters, in particular to a universal caster.

Background

In daily life, people move used articles on the ground conveniently by mounting universal casters, namely, movable casters, below various articles, wherein the universal casters are constructed to allow 360-degree horizontal rotation. The caster is a general term and comprises a movable caster and a fixed caster. In some heavy mechanical devices, universal wheels are also mounted at the bottom end of the heavy mechanical devices to facilitate movement of the devices.

However, the universal wheels at the bottom ends of some heavy mechanical equipment have heavy weight, and the pressure borne by the universal wheels is large, so that the friction of the universal wheels in the working process is increased, and the universal wheels are easily damaged.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the universal caster, lubricating oil leaked from a lubricating structure can be collected by a circulating structure, so that the waste caused by the leakage of the lubricating oil of the lubricating structure can be prevented, the power of the circulating structure is from a lifting structure, namely the recovered lubricating oil is collected by the lifting structure, the descending of the lifting structure is used for injecting the recovered lubricating oil into the lubricating structure again, and through the linkage of the lubricating structure, the circulating structure and the lifting structure, not only can the rolling structure be fully lubricated, but also the friction force of the rolling structure is reduced, so that the service life of the universal wheel is prolonged, the leaked lubricating oil can be recovered and reused, and the lubricating oil can be saved; be equipped with the space that can hold down rolling structure at sleeve inside, through the elevation structure of connecting in sleeve one end, can control the lift of rolling structure in sleeve inside, thereby realize taking in and stretching out of rotating-structure, take in into telescopic inside back at rolling structure, the sleeve will play fixed effect with ground contact, the area of contact with ground has been increased, increase frictional force, thereby it is better to make fixed effect, it distributes to have a plurality of latches to be annular array in telescopic bottom, the land fertility of grabbing on sleeve and ground has been increased, thereby it is better to make fixed effect, and the limiting displacement through limiting structure, can carry out spacing fixed to elevation structure, thereby reach and carry out spacing effect to rolling structure.

The technical scheme adopted by the invention for solving the technical problems is as follows: a universal caster comprises a sleeve, a rotating structure, a rolling structure, a lifting structure, a limiting structure, a latch, a lubricating structure, a connecting structure and a circulating structure, wherein the lubricating structure for lubricating a rotating point of a wheel is connected to the inside of the sleeve for accommodating the wheel in a sliding manner; the bottom end of the lubricating structure is rotatably connected with the rotating structure used for rotating the wheels, and the bottom end of the rotating structure is provided with the rolling structure used for moving; one end of the sleeve is connected with the lifting structure used for lifting the rolling structure, and the limiting structure used for limiting and fixing the lifting structure is connected in the lifting structure in a sliding manner; the limiting structure and be connected with between the lubricating structure and be used for driving the lubricating structure carries out the oscilaltion elevation structure the telescopic bottom is equipped with and is used for increasing the sleeve grabs the land fertility the latch, telescopic inside is equipped with can be right lubricating structure's lubricating oil is collected and is recycled circulation structure.

Specifically, elevation structure includes a fixed cylinder, a bottom plate, a hexagonal pole, a first gear, a second gear and a lead screw, telescopic one end welding a fixed cylinder, just the diameter of a fixed cylinder is less than telescopic diameter, the bottom mounting of a fixed cylinder the bottom plate, a gear rotate connect in the inside of bottom plate, the central point of a gear puts fixedly the hexagonal pole, just the hexagonal pole with the bottom plate rotates to be connected, the inside bottom of a fixed cylinder rotates to be connected with the second gear, a gear with the meshing of second gear, just the outside diameter of a gear is less than the outside diameter of second gear, the central point of second gear puts fixedly the lead screw, just the lead screw with a fixed cylinder rotates to be connected.

Specifically, limit structure includes limiting plate, pull rod and spacing tooth, the bottom sliding connection of a fixed section of thick bamboo has the rectangle the limiting plate, the limiting plate is close to the one end of second gear is equipped with spacing tooth, spacing tooth with the meshing of second gear, the limiting plate deviates from the one end rotation of spacing tooth is connected with curved the pull rod.

Specifically, connection structure includes spout, connecting block and commentaries on classics cover, the spout is located the solid fixed cylinder with between the sleeve, the outside of lead screw is rotated and is connected with change the cover, change the fixed rectangle in outside of cover the connecting block, the connecting block is in the inside slip of spout, just the width of connecting block with the width of spout is the same.

Specifically, lubricating structure includes sliding tray, inlet port, oil storehouse and oil outlet, telescopic inside sliding connection has inside hollow and the cross-section is for falling "concave" shape structure the sliding tray, the top of sliding tray is equipped with the inlet port, the inside of sliding tray is equipped with the oil storehouse, the bottom of sliding tray is equipped with a plurality ofly the oil outlet, and a plurality of the oil outlet is funnel shaped structure.

Specifically, revolution mechanic includes bearing, fixed cover, slide bar and spring, the bottom mounting of sliding tray the bearing, the inside of bearing is fixed cover, fixed cover passes through the bearing with the sliding tray rotates to be connected, the inside of fixed cover is equipped with the spring the inside sliding connection of fixed cover has "T" shape structure the slide bar, just the terminal surface of slide bar is the square structure.

Specifically, the rolling structure includes stop collar, pin and gyro wheel, the bottom mounting of slide bar the stop collar, centre gripping between the stop collar the gyro wheel, the gyro wheel passes through the pin with the stop collar rotates to be connected.

Specifically, the circulating structure comprises a mandril, a fixed barrel, a piston, a collecting sleeve, a first oil pipe, a first one-way valve, a second oil pipe and a second one-way valve, the fixed barrel which is hollow inside and has a cylindrical structure with one open end is fixed inside the sleeve, one end of the connecting block is fixed with the ejector rod, one end of the ejector rod, which is far away from the sleeve, is fixed with the piston, the piston is connected with the fixed barrel in a sliding way, the center lines of the ejector rod, the fixed barrel and the piston are consistent, one end of the sliding disc, which is far away from the oil bin, is fixed with the collecting sleeve, the fixed barrel is connected with the collecting sleeve through the first oil pipe, the fixed barrel is connected with the oil bin through the second oil pipe, the first check valve is connected to the outside of the first oil pipe, and the second check valve is arranged on the outside of the second oil pipe.

The invention has the beneficial effects that:

(1) according to the universal caster wheel, lubricating oil leaked from the lubricating structure can be collected by the circulating structure, so that waste caused by the lubricating oil leakage of the lubricating structure can be prevented, power of the circulating structure is from the lifting structure, namely the recovered lubricating oil is collected by the lifting structure, the lubricating structure is filled again by the descending of the lifting structure, and through the linkage of the lubricating structure, the circulating structure and the lifting structure, not only can the rolling structure be sufficiently lubricated, but also the friction force of the rolling structure is reduced, so that the service life of the universal wheel is prolonged, the leaked lubricating oil can be recovered and reused, and the lubricating oil can be saved.

(2) The universal caster wheel has the advantages that the space capable of accommodating the lower rolling structure is arranged in the sleeve, the lifting structure connected to one end of the sleeve can control the rolling structure to lift in the sleeve, so that the rotating structure can be accommodated and extended, after the rolling structure is accommodated in the sleeve, the sleeve can be in contact with the ground to play a role in fixing, the contact area with the ground is increased, the friction force is increased, the fixing effect is better, the clamping teeth are distributed at the bottom end of the sleeve in an annular array mode, the ground grabbing force of the sleeve and the ground is increased, the fixing effect is better, the lifting structure can be limited and fixed through the limiting effect of the limiting structure, the rolling structure is limited, and meanwhile, the oil in the oil bin can be squeezed into the ball in the descending process in the ascending process, the lubrication can be realized in the motion process, and the phenomenon that the inside is rusted and blocked when the device is placed for a long time is reduced.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic structural diagram of the overall structure of a preferred embodiment of the caster of the present invention;

FIG. 2 is an enlarged view of part A of FIG. 1

FIG. 3 is a schematic view of a coupling structure of the rotating structure and the lubricating structure shown in FIG. 1;

FIG. 4 is an enlarged view of the portion B shown in FIG. 3;

fig. 5 is a schematic view of a connection structure between the lifting structure and the limiting structure shown in fig. 1.

In the figure: 1. the oil cylinder comprises a sleeve, 2, a rotating structure, 21, a bearing, 22, a fixed sleeve, 23, a sliding rod, 24, a spring, 3, a rolling structure, 31, a limiting sleeve, 32, a pin, 33, a roller, 4, a lifting structure, 41, a fixed cylinder, 42, a bottom plate, 43, a hexagonal rod, 44, a first gear, 45, a second gear, 46, a screw rod, 5, a limiting structure, 51, a limiting plate, 52, a pull rod, 53, a limiting tooth, 6, a latch, 7, a lubricating structure, 71, a sliding disc, 72, an oil inlet, 73, an oil bin, 74, an oil outlet, 8, a connecting structure, 81, a sliding groove, 82, a connecting block, 83, a rotating sleeve, 9, a circulating structure, 91, a push rod, 92, a fixed barrel, 93, a piston, 94, a collecting sleeve, 95, a first oil pipe, 96, a first one-way valve, 97, a second oil pipe, 98 and a second one-way valve.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 5, the universal caster according to the present invention comprises a sleeve 1, a rotating structure 2, a rolling structure 3, a lifting structure 4, a limiting structure 5, a latch 6, a lubricating structure 7, a connecting structure 8 and a circulating structure 9, wherein the lubricating structure 7 for lubricating a rotating point of a wheel is slidably connected inside the sleeve 1 for accommodating the wheel; the bottom end of the lubricating structure 7 is rotatably connected with the rotating structure 2 used for rotating wheels, and the rolling structure 3 used for moving is arranged at the bottom end of the rotating structure 2; one end of the sleeve 1 is connected with the lifting structure 4 for lifting the rolling structure 3, and the limiting structure 5 for limiting and fixing the lifting structure 4 is connected in the lifting structure 4 in a sliding manner; limiting structure 5 with be connected with between the lubricating structure 7 and be used for driving lubricating structure 7 carries out the oscilaltion elevation structure 4 the bottom of sleeve 1 is equipped with and is used for increasing sleeve 1 grabs the land fertility latch 6, the inside of sleeve 1 is equipped with can be right lubricating structure 7's lubricating oil is collected and is recycled circulation structure 9.

Specifically, the lifting structure 4 includes a fixed cylinder 41, a bottom plate 42, a hexagonal rod 43, a first gear 44, a second gear 45 and a lead screw 46, one end of the sleeve 1 is welded to the fixed cylinder 41, the diameter of the fixed cylinder 41 is smaller than that of the sleeve 1, the bottom end of the fixed cylinder 41 is fixed to the bottom plate 42, the first gear 44 is rotatably connected to the inside of the bottom plate 42, the center position of the first gear 44 is fixed to the hexagonal rod 43, the hexagonal rod 43 is rotatably connected to the bottom plate 42, the bottom end of the inside of the fixed cylinder 41 is rotatably connected to the second gear 45, the first gear 44 is engaged with the second gear 45, the outer diameter of the first gear 44 is smaller than that of the second gear 45, the center position of the second gear 45 is fixed to the lead screw 46, and the lead screw 46 is rotatably connected to the fixed cylinder 41, by the fact that the outer diameter of the first gear 44 is smaller than that of the second gear 45, the principle that the pinion drives the bull gear to save labor is utilized, and the effect of saving labor can be achieved when the hexagonal rod 43 is rotated.

Specifically, limit structure 5 includes limiting plate 51, pull rod 52 and spacing tooth 53, the bottom sliding connection of solid fixed cylinder 41 has the rectangle limiting plate 51, limiting plate 51 is close to the one end of second gear 45 is equipped with spacing tooth 53, spacing tooth 53 with second gear 45 meshes, limiting plate 51 deviates from the one end rotation of spacing tooth 53 is connected with the arc pull rod 52, through spacing tooth 53 with second gear 45 meshes, can with second gear 45 meshes fixedly, prevents when supporting, gyro wheel 33 is accomodate into sleeve 1's inside.

Specifically, connection structure 8 includes spout 81, connecting block 82 and commentaries on classics cover 83, spout 81 is located gu fixed cylinder 41 with between the sleeve 1, the outside of lead screw 46 is rotated and is connected with change cover 83, change the fixed rectangle in outside of cover 83 connecting block 82, connecting block 82 is in the inside of spout 81 slides, just the width of connecting block 82 with spout 81's width is the same, through change cover 83 with the cooperation of connecting block 82 is used, can utilize the rotation of lead screw 46 is realized the lift of sliding plate 71.

Specifically, lubricating structure 7 includes sliding tray 71, inlet port 72, oil sump 73 and oil outlet 74, the inside sliding connection of sleeve 1 has inside hollow and the cross-section is for falling "concave" shape structure sliding tray 71, sliding tray 71's top is equipped with inlet port 72, sliding tray 71's inside is equipped with oil sump 73, sliding tray 71's bottom is equipped with a plurality ofly oil outlet 74, and a plurality of oil outlet 74 is funnel shaped structure, through oil sump 73 is with a plurality of oil outlet 74's setting can be right bearing 21 carries out abundant lubrication, avoids bearing 21 blocks dead phenomenon.

Specifically, revolution mechanic 2 includes bearing 21, fixed cover 22, slide bar 23 and spring 24, the bottom mounting of sliding tray 71 bearing 21, the inside of bearing 21 is fixed cover 22, fixed cover 22 pass through bearing 21 with sliding tray 71 rotates and connects, the inside of fixed cover 22 is equipped with spring 24 the inside sliding connection of fixed cover 22 has "T" shape structure slide bar 23, just the terminal surface of slide bar 23 is the square structure, through spring 24 with the cooperation of slide bar 23 is used, can play absorbing effect.

Specifically, rolling structure 3 includes stop collar 31, pin 32 and gyro wheel 33, the bottom mounting of slide bar 23 stop collar 31, centre gripping between the stop collar 31 gyro wheel 33, gyro wheel 33 passes through pin 32 with stop collar 31 rotates to be connected, in order to guarantee to realize the removal function.

Specifically, the circulating structure 9 includes a top rod 91, a fixed barrel 92, a piston 93, a collecting sleeve 94, a first oil pipe 95, a first check valve 96, a second oil pipe 97 and a second check valve 98, the fixed barrel 92 of a cylindrical structure with a hollow interior and an open end is fixed inside the sleeve 1, one end of the connecting block 82 is fixed to the top rod 91, one end of the top rod 91, which is away from the sleeve 1, is fixed to the piston 93, the piston 93 is slidably connected to the fixed barrel 92, center lines of the top rod 91, the fixed barrel 92 and the piston 93 are consistent, one end of the sliding disk 71, which is away from the oil bin 73, is fixed to the collecting sleeve 94, the fixed barrel 92 and the collecting sleeve 94 are connected through the first oil pipe 95, the fixed barrel 92 and the oil bin 73 are connected through the second oil pipe 97, the first check valve 96 is connected to the exterior of the first oil pipe 95, the second check valve 98 is disposed outside the second oil pipe 97, when the bearing 21 is lubricated by the internal lubricating oil in the oil bin 73, the redundant lubricating oil flows into the collecting sleeve 94 from the bearing 21, so that the leaked lubricating oil can be collected conveniently, the lubricating oil in the collecting sleeve 94 can be pumped into the fixed barrel 92, the connecting block 82 drives the ejector rod 91 to inject the lubricating oil in the fixed barrel into the oil bin 73 again through the second oil pipe 97, and the lubricating oil can be reused and circulated in sequence, and the first check valve 96 and the second check valve 98 are used in cooperation, so that the pumping-in and the discharging of the fixed barrel 92 are not influenced by each other.

When an object needs to be fixed, only a wrench is needed to screw the hexagonal rod 43, the first gear 44 is rotatably connected inside the bottom plate 42, the hexagonal rod 43 is fixed with the first gear 44, namely, the rotation of the first gear 44 can be realized by rotating the hexagonal rod 43, the second gear 45 is rotatably connected at the bottom end inside the fixed cylinder 41, the first gear 44 is meshed with the second gear 45, the lead screw 46 is fixed inside the second gear 45, the rotation of the lead screw 46 can be realized by the rotation of the second gear 45, the sliding disc 71 is connected with the lead screw 46 through the connecting block 82 and the rotating sleeve 83, namely, the sliding disc 71 can rotate the hexagonal rod 43 to realize the up-and-down lifting, the fixed sleeve 22 at the bottom end of the sliding disc 71 is rotatably connected with the sliding disc 71 through the bearing 21, the rotation of the roller 33 can be realized by the rotary connection of the sliding disc 71 and the fixed sleeve 22, so that the 360-degree rotation of the roller 33 can be realized, and the universal function can, the spring 24 is arranged in the fixed sleeve 22, the roller 33 can play a role of shock absorption in the working process through the elastic force effect of the spring 24, the T-shaped sliding rod 23 is connected in the fixed sleeve 22 in a sliding manner, the limiting effect can be achieved, the sliding rod 23 is prevented from completely sliding out of the fixed sleeve 22, the cross section of the sliding rod 23 is of a square structure, the sliding rod 23 can be prevented from rotating, after the hexagonal rod 43 is rotated until the roller 33 is completely accommodated in the sleeve 1, the sleeve 1 can be in contact with the ground, the contact area with the ground is increased, the friction force is increased, the fixing effect is better, the plurality of latch teeth 6 are distributed at the bottom end of the sleeve 1 in an annular array manner, the ground gripping force between the sleeve 1 and the ground is increased, the fixing effect is better, when the bearing 21 is lubricated by the lubricating oil in the oil bin 73, redundant lubricating oil can flow into the collecting sleeve 94 from the bearing 21, when the connecting block 82 rises, that is, when the roller 33 is accommodated in the sleeve 1, the ram 91 drives the piston 93 to move upward in the fixed barrel 92, the fixed barrel 92 and the collecting sleeve 94 are connected by the first oil pipe 95, when the piston 93 moves, the lubricating oil in the collecting sleeve 94 is pumped into the fixed barrel 92, at this time, the roller 33 is retracted, the collected lubricating oil is stored by the fixed barrel 92, when the roller 33 needs to be used, that is, the roller 33 extends out of the sleeve 1, the connecting block 82 drives the ram 91 to inject the lubricating oil in the fixed barrel into the oil bin 73 again through the second oil pipe 97, so that the lubricating oil can be used again, and the lubricating oil is circulated in sequence through the cooperation of the first check valve 96 and the second check valve 98, it can be ensured that the suction and discharge of the fixed tub 92 do not affect each other.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the embodiments and descriptions given above are only illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A universal caster, characterized in that: the wheel-mounted rolling device comprises a sleeve (1), a rotating structure (2), a rolling structure (3), a lifting structure (4), a limiting structure (5), a clamping tooth (6), a lubricating structure (7), a connecting structure (8) and a circulating structure (9), wherein the lubricating structure (7) for lubricating a rotating point of a wheel is connected to the inside of the sleeve (1) for accommodating the wheel in a sliding manner; the bottom end of the lubricating structure (7) is rotatably connected with the rotating structure (2) used for rotating wheels, and the rolling structure (3) used for moving is arranged at the bottom end of the rotating structure (2); one end of the sleeve (1) is connected with the lifting structure (4) used for lifting the rolling structure (3), and the limiting structure (5) used for limiting and fixing the lifting structure (4) is connected in the lifting structure (4) in a sliding manner; the lifting structure (4) used for driving the lubricating structure (7) to lift up and down is connected between the limiting structure (5) and the lubricating structure (7), the clamping teeth (6) used for increasing the ground gripping force of the sleeve (1) are arranged at the bottom end of the sleeve (1), and the circulating structure (9) capable of collecting and recycling lubricating oil of the lubricating structure (7) is arranged in the sleeve (1);

the lifting structure (4) comprises a fixed cylinder (41), a bottom plate (42), a hexagonal rod (43), a first gear (44), a second gear (45) and a screw rod (46), one end of the sleeve (1) is welded to the fixed cylinder (41), the diameter of the fixed cylinder (41) is smaller than that of the sleeve (1), the bottom end of the fixed cylinder (41) is fixed to the bottom plate (42), the first gear (44) is rotatably connected to the inside of the bottom plate (42), the hexagonal rod (43) is fixed to the center position of the first gear (44), the hexagonal rod (43) is rotatably connected with the bottom plate (42), the bottom end of the inside of the fixed cylinder (41) is rotatably connected with the second gear (45), the first gear (44) is meshed with the second gear (45), and the outer diameter of the first gear (44) is smaller than that of the second gear (45), the center position of the second gear (45) fixes the screw rod (46), and the screw rod (46) is rotationally connected with the fixed cylinder (41);

the limiting structure (5) comprises a limiting plate (51), a pull rod (52) and limiting teeth (53), the rectangular limiting plate (51) is connected to the bottom end of the fixed cylinder (41) in a sliding mode, the limiting teeth (53) are arranged at one end, close to the second gear (45), of the limiting plate (51), the limiting teeth (53) are meshed with the second gear (44), and the arc-shaped pull rod (52) is rotatably connected to one end, away from the limiting teeth (53), of the limiting plate (51);

the connecting structure (8) comprises a sliding groove (81), a connecting block (82) and a rotating sleeve (83), the sliding groove (81) is arranged between the fixed cylinder (41) and the sleeve (1), the rotating sleeve (83) is rotatably connected to the outer portion of the screw rod (46), the rectangular connecting block (82) is fixed to the outer portion of the rotating sleeve (83), the connecting block (82) slides in the sliding groove (81), and the width of the connecting block (82) is the same as that of the sliding groove (81);

the lubricating structure (7) comprises a sliding disc (71), an oil inlet hole (72), an oil bin (73) and oil outlet holes (74), the sliding disc (71) which is hollow inside and has an inverted concave-shaped cross section is connected to the inside of the sleeve (1) in a sliding mode, the oil inlet hole (72) is formed in the top end of the sliding disc (71), the oil bin (73) is formed in the inside of the sliding disc (71), the oil outlet holes (74) are formed in the bottom end of the sliding disc (71), and the oil outlet holes (74) are of a funnel-shaped structure;

the rotating structure (2) comprises a bearing (21), a fixed sleeve (22), a sliding rod (23) and a spring (24), the bearing (21) is fixed at the bottom end of the sliding disc (71), the fixed sleeve (22) is fixed inside the bearing (21), the fixed sleeve (22) is rotatably connected with the sliding disc (71) through the bearing (21), the spring (24) is arranged inside the fixed sleeve (22), the sliding rod (23) with a T-shaped structure is slidably connected inside the fixed sleeve (22), and the end face of the sliding rod (23) is of a square structure;

the rolling structure (3) comprises limiting sleeves (31), pins (32) and rollers (33), the limiting sleeves (31) are fixed at the bottom ends of the sliding rods (23), the rollers (33) are clamped between the limiting sleeves (31), and the rollers (33) are rotatably connected with the limiting sleeves (31) through the pins (32);

the circulating structure (9) comprises a push rod (91), a fixed barrel (92), a piston (93), a collecting sleeve (94), a first oil pipe (95), a first one-way valve (96), a second oil pipe (97) and a second one-way valve (98), the fixed barrel (92) which is hollow inside and has a cylindrical structure with one open end is fixed inside the sleeve (1), the push rod (91) is fixed at one end of the connecting block (82), the piston (93) is fixed at one end of the push rod (91) departing from the sleeve (1), the piston (93) is connected with the fixed barrel (92) in a sliding mode, the center lines of the push rod (91), the fixed barrel (92) and the piston (93) are consistent, the collecting sleeve (94) is fixed at one end of the sliding disc (71) departing from the oil bin (73), and the fixed barrel (92) and the collecting sleeve (94) are connected through the first oil pipe (95), the fixed barrel (92) is connected with the oil bin (73) through the second oil pipe (97), the first check valve (96) is connected to the outside of the first oil pipe (95), and the second check valve (98) is arranged on the outside of the second oil pipe (97).