A safe hydraulic spring device used in a ship lift and a load transfer method thereof

Abstract

A safety gas-liquid spring device used in a ship lift comprises a bracket, a measuring shaft, a lower flange, a guide sleeve, a self-lubricating bearing, a gas-liquid spring cylinder, a pull rod, an upper flange, a self-lubricating sliding sleeve, an air bag accumulator and an oil pipe; the lower end of the bracket is fixedly mounted on a ship-bearing structure, and a support hinge shaft in the middle of the gas-liquid spring cylinder is supported on the bracket through a self-lubricating bearing; the end of the upper piston rod is connected to the upper flange through a thread, and the lower end of the lower piston rod of the gas-liquid spring cylinder is assembled with a clearance fit through the guide sleeve and the mounting hole of the lower flange, and the lower end of the measuring shaft and the bottom beam of a gear bracket mechanism form an articulated structure; the upper end of the pull rod is sleeved on the inner hole of a self-lubricating sleeve with a flange and the top is positioned with a nut, the lower end of the pull rod is hinged to the bottom beam of the gear bracket mechanism through the measuring shaft at the bottom, and the air bag accumulator is communicated with the rodless cavity through the oil pipe; the function of smoothly transitioning the vertical support of the ship compartment from the pinion and rack to the rotating screw and nut column of the safety mechanism is realized, thereby improving safety.

Description

Technical Field

[0001] The present invention relates to a hydraulic spring device, and more specifically to a safety hydraulic spring device and a load transfer method thereof, which is suitable for a rack and pinion climbing vertical ship lift, and which realizes the transfer of bidirectional accident loads in the ship compartment from the rack and pinion of a driving mechanism to a safety mechanism through the movement of double piston rods and corresponding displacement-load mechanical characteristics when an unbalance accident occurs in the ship compartment. Background Art

[0002] As a navigation facility, vertical ship lifts are increasingly widely used in water conservancy hubs because of their short ship passing time and suitability for high dam navigation. The fully balanced rack and pinion vertical ship lift is used in water conservancy hubs for large ships to pass through dams due to its high safety, such as the 3000t rack and pinion climbing vertical ship lift in the Three Gorges Water Conservancy Hub and the 1000t rack and pinion climbing vertical ship lift in the Xiangjiaba Hydropower Station. These two ship lifts are the largest in terms of the scale of ship lifts built and under construction in my country, and the Three Gorges ship lift is currently the largest ship lift in the world. The total design weight of the fully balanced vertical ship lift cabin is equal to the total weight of the suspended counterweight, so the driving of the cabin only needs to overcome the loads such as the mis-loaded water weight caused by the depth of the cabin, the friction resistance of the pulley bearing, the rigid resistance of the wire rope, and the inertia force. One of the most important features of the fully balanced gear climbing ship lift is that the lifting and lowering operation of the ship compartment is driven by an open gear and a rack meshing, wherein the open gear is installed on the ship compartment and the rack is installed within the operating height of the tower column; at the same time, a safety mechanism is provided to provide support for the ship compartment in the event of an unbalanced accident, so it is a very safe ship lift. The safety mechanism is connected to the drive mechanism through a mechanical shaft transmission system, so that the linear speed of the open gear of the drive mechanism is the same as the lifting speed of the rotating screw of the safety mechanism; however, the open gear of the drive mechanism of the gear rack fully balanced vertical ship lift in the prior art often suffers from a large accident load when an unbalanced accident occurs in the ship compartment, resulting in gear damage. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the open gears of the drive mechanism of the rack and pinion fully balanced vertical ship lift in the prior art often bear a large accident load and cause gear damage when an unbalance accident occurs in the ship compartment.

[0004] The technical solution adopted by the present invention is: a safe liquid-gas spring device used in a ship lift, comprising a bracket, a measuring shaft, a lower flange, a guide sleeve, a self-lubricating bearing, a liquid-gas spring cylinder, a pull rod, an upper flange, a self-lubricating sliding sleeve, an airbag accumulator and an oil pipe;

[0005] The lower end of the bracket is fixedly installed on the ship-bearing box structure, the gas spring cylinder adopts a double piston rod type, and the support hinge shaft in the middle of the gas spring cylinder is supported on the bracket through a self-lubricating bearing; the upper piston rod end of the gas spring cylinder is connected to the upper flange through a thread, and the lower end of the lower piston rod of the gas spring cylinder is assembled with the mounting hole of the lower flange through a guide sleeve with a clearance fit, the measuring shaft is fixedly installed at the lower end of the lower flange, and its lower end forms a hinged structure with the bottom beam of the gear bracket mechanism; the upper and lower flanges are connected by a pull rod, and a flanged self-lubricating sliding sleeve is installed on the upper flange pull rod mounting hole of the upper flange, the upper end of the pull rod is sleeved on the inner hole of the flanged self-lubricating sliding sleeve and the top is positioned with a nut, and the lower end of the pull rod is fixed to the lower flange through a nut; the measuring shaft at the bottom is hinged with the bottom beam of the gear bracket mechanism, thereby forming a force transmission system with the pinion bracket to transmit the unbalanced load of the ship-bearing box under the lifting condition of the ship lift to the tower column; the airbag accumulator is connected to the rodless cavity of the gas spring cylinder through an oil pipe;

[0006] The gas-liquid spring cylinder is connected to the bladder accumulator of the external hydraulic pump station. The preload of the gas-liquid spring is determined by the oil pressure of the bladder accumulator and can be adjusted as needed. The gas-liquid spring composed of the cylinder and the bladder accumulator has the displacement load characteristics of a pre-compressed nonlinear spring: when the gear load is less than the preload determined by the oil pressure of the bladder accumulator, the pistons at both ends of the gas-liquid spring cylinder are pressed against the two ends of the gas-liquid spring cylinder body by the oil pressure, and the pistons at both ends of the gas-liquid spring cylinder maintain their initial positions, thereby maintaining the normal load-bearing and operation of the gear and rack meshing of the drive mechanism; when the gear load exceeds the preload, the oil pressure in the rodless chamber of the double-piston-rod gas-liquid spring cylinder exceeds the initial value, and compresses the gas in the airbag of the bladder accumulator to make the gas volume The oil in the rodless chamber enters the airbag accumulator, causing the compressed piston of the gas spring cylinder to produce axial displacement; thereby, the connection hinge between the lower part of the measuring shaft and the bottom beam of the pinion bracket and the rotation of the gas spring cylinder around the support hinge connected to the ship-bearing box cause the movement of the pinion bracket, which reduces the clearance between the thread pair of the rotating screw of the safety mechanism and the nut column until the clearance of the thread pair of the safety mechanism disappears, and finally forms the geometric contact condition for the safety mechanism to bear the unbalanced load of the ship-bearing box; when the ship-bearing box of the rack and pinion climbing ship lift is unbalanced, the upper piston rod and the lower piston rod of the gas spring cylinder move axially, causing the hinge between the measuring shaft and the bottom beam of the pinion bracket at the bottom of the gas spring to move up and down.

[0007] Furthermore, the bottom measuring shaft is hinged to the bottom beam of the gear bracket mechanism through a self-aligning rolling bearing assembled in the shaft hole of the lower flange and a support hinge hole at the end of the bottom beam, and is axially positioned by an shaft end baffle and connecting screws installed at the end of the bottom beam.

[0008] Furthermore, the bracket includes a base plate, a vertical plate and a reinforcing triangular plate. The base plate is connected to the ship-bearing box structure through base plate bolts. The vertical plate is vertically installed on the upper end surface of the base plate. The two sides of the reinforcing triangular plate for reinforcement are respectively fixedly installed on the base plate and the vertical plate.

[0009] The load transfer method of the safety type hydraulic spring device used in the ship lift comprises the following steps:

[0010] Step 1: Set the stroke of the gas spring cylinder. The stroke of the gas spring cylinder is a more important parameter of the gas spring device. The stroke of the cylinder must ensure that the gas spring cylinder still retains a certain amount of surplus stroke after the thread gap of the safety mechanism disappears, so as to avoid the accident that the safety mechanism cannot provide support when the thread gap of the safety mechanism has not disappeared and the cylinder stroke has been exhausted; for this reason, the thread gap should be considered as large as possible, that is, the larger gap value when the upper and lower thread gaps are not equal and biased to one side, and the displacement difference of the bearing compartment structure where the safety mechanism and the drive mechanism are located when the bearing compartment is unbalanced should be considered; the stroke of the gas spring cylinder is calculated as follows:

[0011] f s =2(2d sb +d f +d m -5mm)

[0012] Where, fs is the stroke of the hydraulic spring cylinder; d sb is the theoretical thread clearance of the safety mechanism (i.e. the thread clearance value when the clearances of the upper and lower thread pairs are equal); d f is the displacement difference of the ship compartment structure where the safety mechanism and the driving mechanism are located when an unbalance accident occurs in the ship compartment; d m is the margin of the cylinder stroke; in the above formula, 2d sb -5mm represents the maximum thread gap on one side caused by the imbalance of the upper and lower thread pairs due to various reasons;

[0013] Step 2: Set the initial pressure p0 and initial volume V0 of the bladder accumulator after inflation;

[0014] Step 3: In the actual operation of the ship lift, when the docking process between the ship lift's ship compartment and the upper and lower gates is completed and the central control station issues a "ship compartment lifting and lowering operation" command, the external hydraulic system is started to inject pressurized oil into the bladder accumulator to make its initial pressure p0, so that the pinion bracket of the driving mechanism forms a supporting structure for the ship compartment during the lifting process;

[0015] When the gas-liquid spring device is subjected to the vertical downward load transmitted by the bottom beam of the pinion bracket at the measuring shaft, the load is transmitted to the upper piston rod through the lower flange, the threaded tie rod and the upper flange, forming the pressure of the upper piston on the rodless chamber of the gas-liquid spring oil cylinder; when the downward load is less than the initial oil pressure of the oil in the rodless chamber of the gas-liquid spring oil cylinder set by the bladder accumulator on the upper piston rod, the upper piston rod remains stationary; when the downward load is greater than the initial setting value of the oil in the rodless chamber of the gas-liquid spring oil cylinder, the oil in the rodless chamber generated compresses the air in the bladder accumulator, thereby moving the upper piston rod downward, so that the gas-liquid spring device is subjected to the vertical downward load transmitted by the bottom beam of the pinion bracket at the measuring shaft, the load is transmitted to the upper piston rod through the lower flange, the threaded tie rod and the upper flange, forming the pressure of the upper piston on the rodless chamber of the gas-liquid spring oil cylinder; when the downward load is less than the initial oil pressure of the oil in the rodless chamber of the gas-liquid spring oil cylinder set by the bladder accumulator, the upper piston rod remains stationary; when the downward load is greater than the initial setting value of the oil in the rodless chamber of the gas-liquid spring oil cylinder, the oil in the rodless chamber generated compresses the air in the bladder accumulator, thereby moving the upper piston rod downward, thereby causing the gas-liquid spring device to be subjected to the vertical downward load transmitted by the bottom beam of the pinion bracket The volume of the rodless chamber of the spring oil cylinder is reduced, further compressing the gas of the airbag accumulator, so that the pressure of the rodless chamber of the gas spring oil cylinder is increased; at the same time, the lower flange is also displaced downward under the downward external load, and the guide sleeve threadedly connected to the bottom end of the lower piston rod slides relative to the inner hole of the lower flange, so that the lower piston rod is not affected by the external load and remains stationary relative to the cylinder body of the gas spring oil cylinder; the downward movement of the lower flange and its measuring axis can trigger the corresponding movement of the pinion bracket mechanism, so that the ship bearing chamber is displaced downward, resulting in a reduction in the lower thread clearance of the rotating screw and the nut column of the safety mechanism;

[0016] When the gas-liquid spring device is subjected to the vertical upward load transmitted by the bottom beam of the pinion bracket at the measuring shaft, the load is transmitted to the lower piston rod through the guide sleeve, forming the pressure of the lower piston on the rodless chamber of the gas-liquid spring oil cylinder; when the upward load is less than the initial oil pressure of the oil in the rodless chamber of the gas-liquid spring oil cylinder set by the air bag accumulator on the lower piston rod, the lower piston rod remains stationary; when the upward load is greater than the initial setting value of the oil in the rodless chamber of the gas-liquid spring oil cylinder, the oil in the rod chamber generated compresses the air in the air bag accumulator, thereby moving the lower piston rod upward, thereby reducing the volume of the rodless chamber of the gas-liquid spring oil cylinder. The pressure in the rodless chamber of the gas spring cylinder increases; the lower flange moves upward under the action of the upward external load; at this time, the tie rod threaded with the lower flange also moves upward; because the upper end of the tie rod is hollowly sleeved in the inner hole of the self-lubricating sleeve with flange, the tie rod will not generate force on the upper flange when it moves upward, and the upper flange and its upper piston rod remain stationary relative to the cylinder body of the gas spring cylinder; the movement of the lower flange and its measuring axis can trigger the corresponding movement of the pinion bracket, thereby causing the upward displacement of the ship bearing compartment structure, resulting in a reduction in the upper thread clearance between the rotating screw of the safety mechanism and the nut column;

[0017] Step 4: When the ship lift completes and ends the current lifting operation, after the central control station issues the "ship compartment docking" command, after confirming that the ship lift docking lock has formed support for the ship compartment, the pressure of the hydraulic spring accumulator is released to a value close to zero, and the pressure value is determined according to the weight of the gear shaft, so that the drive mechanism pinion bracket only supports the weight of the open pinion to keep the mechanism configuration, but does not have the ability to withstand external loads. The ship compartment is locked by the docking locking mechanism, and the open pinion of the drive mechanism is in an unloaded state, so that the open pinion is protected from external loads during the docking process between the ship compartment and the upper and lower gates, avoiding the load-carrying sliding of the pinion along the width direction caused by the relative horizontal movement of the ship compartment and the tower column.

[0018] Furthermore, the initial pressure P0 is set according to the shutdown load of the ship lift driving mechanism:

[0019]

[0020] The initial volume V0 is determined by the following formula:

[0021]

[0022] Where:

[0023] F ds Set the load for the drive mechanism overload stop pinion;

[0024] p0 is the initial pressure of the bladder accumulator after inflation; p1 is the pressure of the bladder accumulator at the initial moment when the hydro-gas spring starts to act;

[0025] V1 is the volume of the bladder accumulator at that moment; p2 is the pressure of the bladder accumulator at the end of the action of the hydro-gas spring, and V2 is the volume of the bladder accumulator at that moment;

[0026] D i is the inner diameter of the gas spring cylinder;

[0027] λ is the lever ratio of the pinion-carrier mechanism, L1 and L2 are the distances from the bottom hinge seat of the pinion bracket to the support hinge seat of the hydraulic spring cylinder and from the bottom hinge seat to the pinion respectively;

[0028] F sp is the gear load at the initial moment of deformation of the hydro-pneumatic spring, F lim is the gear limit load;

[0029] Vw is the effective volume of the bladder accumulator,

[0030] The beneficial effects and features of the present invention are:

[0031] The gas-liquid spring composed of the oil cylinder and the accumulator has the displacement-load mechanical characteristics of a bidirectional pre-compressed nonlinear spring. Therefore, when the gear rack climbing ship lift has an unbalanced cabin, the axial movement of the double piston rods of the gas-liquid spring oil cylinder causes the connecting support hinge shaft between the bottom of the mechanism and the pinion bracket to move up and down, thereby realizing the smooth transition of the vertical support of the cabin from the pinion and rack to the rotating screw and nut column of the safety mechanism, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional structural diagram of a liquid-gas spring mechanism of a preferred embodiment of the present invention;

[0033] Figure 2 for Figure 1 The side view of the structure;

[0034] Figure 3 This is a structural schematic diagram of a double piston rod hydraulic spring cylinder according to a preferred embodiment of the present invention;

[0035] Figure 4 This is a partial structural diagram of the connection between the lower flange, the lower piston rod and the self-lubricating sliding sleeve in a preferred embodiment of the present invention;

[0036] Figure 5 The preferred embodiment of the present invention is an upper flange, a self-lubricating sleeve and a tie rod connection structure;

[0037] Figure 6 This is a schematic diagram of the working principle of the liquid-gas spring in a preferred embodiment of the present invention;

[0038] Figure 7 Schematic diagram of the connection between the hydraulic and pinion bracket of a preferred embodiment of the present invention.

[0039] The numbers in the figure represent: 1-bracket, 1-1-bottom plate, 1-2-vertical plate, 1-3-reinforced triangle plate, 2-measuring shaft, 3-lower flange, 4-guide sleeve, 5-self-lubricating bearing, 6-hydraulic spring cylinder, 6-1-upper piston rod, 6-2-lower piston rod, 6-3-support hinge shaft, 6-4-rodless chamber, 7-pull rod, 8-upper flange, 9-self-lubricating sliding sleeve, 10-airbag accumulator, 11-oil pipe, 12-self-aligning rolling bearing, 13-hydraulic oil pipe, 15-bolt, 16-bottom beam of pinion bracket, 17-pinion bracket, 18-carriage structure. 19-open pinion, 20-rack. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings:

[0041] Please refer to Figure 1 to Figure 4, a safety type liquid-gas spring device used in a ship lift, installed at the tail of a pinion bracket mechanism, comprising a bracket 1, a measuring shaft 2 (the measuring shaft has the same appearance as an ordinary shaft, has a force transmission function, and is equipped with a detection device), a lower flange 3, a guide sleeve 4, a self-lubricating bearing 5, a liquid-gas spring cylinder 6, a pull rod 7, an upper flange 8, a self-lubricating sliding sleeve 9, and its bearing and other parts and accumulator hydraulic pipelines and valve parts and other parts; the liquid-gas spring cylinder 6 adopts a double piston rod type, and the support hinge shaft in the middle of the liquid-gas spring cylinder 6 is supported on the bracket 1 through the self-lubricating bearing 5, and the bottom of the bracket 1 is connected to the ship compartment structure 18 through bolts 15, and the bracket 1 includes a bottom plate 1-1, a vertical plate 1-2 and a reinforcing triangle plate 1-3, the bottom plate 1-1 is connected to the ship compartment structure 18 through the bottom plate bolts 15, the vertical plate 1-2 is vertically installed on the upper end surface of the bottom plate 1-1, and the two sides of the reinforcing triangle plate 1-3 for reinforcing are respectively fixedly installed on the bottom plate 1-1 and the vertical plate 1-2;

[0042] The piston rod end of the upper part of the hydraulic spring oil cylinder 6 is connected to the upper flange 8 by thread, and the piston rod of the lower part of the oil cylinder is assembled with the installation hole of the lower flange 3 through the guide sleeve 4 with clearance fit; the upper and lower flanges are connected by the tie rod 7, and the self-lubricating sleeve with flange is installed in the installation hole of the tie rod of the upper flange. The upper end of the tie rod (7) is hollowly sleeved in the inner hole of the self-lubricating sleeve with flange, and the top is positioned by a nut, and the lower end of the tie rod 7 is fixed to the lower flange 3 by upper and lower nuts. The bottom measuring shaft 2 is assembled in the self-aligning rolling bearing 12 in the shaft hole of the lower flange 3 and the support hinge hole at the end of the bottom beam, and is axially fixed by the shaft end baffle and connecting screws installed at the end of the bottom beam.

[0043] Please refer to Figure 5 , Figure 6 The gas spring cylinder 6 is connected to the bladder accumulator 10 of the external hydraulic pump station. The preload of the gas spring is determined by the oil pressure of the bladder accumulator and can be adjusted as needed. The gas spring composed of the cylinder and the bladder accumulator has the displacement load characteristics of a pre-compressed nonlinear spring: when the gear load is less than the preload determined by the oil pressure of the bladder accumulator, the pistons at both ends of the gas spring cylinder 6 are pressed against the two ends of the cylinder body of the gas spring cylinder 6 by the oil pressure, and the gas spring maintains the initial position. When the gear load exceeds the preload, the oil pressure of the rodless chamber 15 of the double-piston-rod gas spring cylinder exceeds the initial value, and compresses the gas in the bladder accumulator to reduce the gas volume. The oil in the cylinder enters the bladder accumulator, causing the compressed piston of the gas spring cylinder to produce axial displacement.

[0044] According to the structural type of the tie rod and the piston rod head, when the gas spring device is subjected to the vertical downward load transmitted by the pinion bracket bottom beam 16 at the measuring shaft position, the load is transmitted to the upper piston rod 6-1 through the lower flange 3, the threaded tie rod 7, and the upper flange, forming pressure from the upper piston to the rodless chamber of the gas spring cylinder. When the load is less than the initial oil pressure of the oil in the rodless chamber 15 of the gas spring cylinder set by the air bag accumulator on the upper piston rod, the upper piston rod 6-1 remains stationary; when the load is greater than the initial setting value of the oil in the rodless chamber 15 of the gas spring cylinder, the oil in the rodless chamber 15 generated compresses the air in the air bag accumulator 10, thereby moving the upper piston rod downward, thereby reducing the volume of the rodless chamber 15 of the gas spring cylinder, further compressing the gas in the air bag accumulator 10, and increasing the pressure in the rodless chamber of the gas spring cylinder; at the same time, the lower flange 3 also moves downward under the action of the downward external load. At this time, the guide sleeve 4 threadedly connected to the bottom end of the lower piston rod slides relative to the inner hole of the lower flange, so that the lower piston rod 6-2 is not affected by the external load and remains stationary relative to the cylinder body of the gas spring cylinder 6. The downward movement of the lower flange 3 and its measuring shaft 2 can trigger the corresponding movement of the pinion bracket 16 mechanism, thereby causing the ship carrier to move downward, resulting in a reduction in the lower thread clearance of the safety mechanism rotating screw and the nut column.

[0045] When the gas-liquid spring device is subjected to the vertical upward load transmitted by the bottom beam of the pinion bracket 16 at the measuring shaft 2, the load is transmitted to the lower piston rod through the guide sleeve 4, forming the pressure of the lower piston on the rodless chamber 15 of the gas-liquid spring oil cylinder. When the load is less than the initial oil pressure of the oil in the rodless chamber 15 of the gas-liquid spring oil cylinder set by the airbag accumulator 10 on the lower piston rod, the lower piston rod remains stationary; when the load is greater than the initial setting value of the oil in the rodless chamber 15 of the gas-liquid spring oil cylinder, the oil in the rod chamber 15 generated compresses the air of the airbag accumulator, thereby moving the lower piston rod 6-2 upward, thereby reducing the volume of the rodless chamber 15 of the gas-liquid spring oil cylinder, further compressing the gas in the airbag accumulator 10, and increasing the pressure of the rodless chamber 15 of the gas-liquid spring oil cylinder. The lower flange moves upward under the upward external load. At this time, the tie rod threaded to the lower flange also moves upward. Since the upper end of the tie rod is hollowly sleeved in the inner hole of the self-lubricating sleeve 9 with flange, the tie rod 7 will not generate force on the upper flange 8 when it moves upward, and the upper flange 8 and its upper piston rod 6-1 remain stationary relative to the cylinder body of the gas spring oil cylinder. The upward movement of the lower flange 3 and its measuring shaft 2 can trigger the corresponding movement of the pinion bracket 17, thereby causing the ship bearing box structure 18 to produce an upward displacement, resulting in a reduction in the upper thread clearance of the rotating screw and the nut column of the safety mechanism.

[0046] (2) Calculation of basic parameters and mechanical properties of hydraulic spring cylinder

[0047] 1) Determination of the stroke of the hydraulic spring cylinder

[0048] The stroke of the gas spring cylinder is a relatively important parameter of the gas spring device. The stroke of the cylinder must ensure that the gas spring cylinder still retains a certain amount of surplus stroke after the thread gap of the safety mechanism disappears, so as to avoid the safety mechanism being unable to provide support when the thread gap of the safety mechanism has not disappeared but the cylinder stroke has been exhausted. For this reason, the thread gap should be considered as large as possible, that is, the larger gap value when the upper and lower thread gaps are not equal and biased to one side. At the same time, the displacement difference of the ship compartment structure where the safety mechanism and the drive mechanism are located should be considered when an unbalanced accident occurs in the ship compartment. For large and medium-sized rack and pinion climbing ship lifts, the stroke of the gas spring cylinder can be calculated according to the following formula:

[0049] f s =2(2d sb +d f +d m -5mm) (1)

[0050] In the formula, f s is the stroke of the hydraulic spring cylinder; d sb is the theoretical thread clearance of the safety mechanism (i.e. the thread clearance value when the clearances of the upper and lower thread pairs are equal); d f is the displacement difference of the ship compartment structure where the safety mechanism and the driving mechanism are located when an unbalance accident occurs in the ship compartment; d m is the margin of the cylinder stroke. sb -5mm represents the maximum thread gap on one side caused by the imbalance of the upper and lower thread pairs due to various reasons.

[0051] 2) Calculation of the total volume of the bladder accumulator

[0052] The pressure p and volume V of the gas in the bladder accumulator satisfy Boyle's law

[0053] pV n =C (2)

[0054] Where n is an index and C is a constant. For isothermal thermodynamic processes, n = 1; for adiabatic thermodynamic processes, n = 1.4. The unbalance accident of the ship compartment during the lifting operation of the ship lift is generally caused by water leakage in the ship compartment. Field tests of the Three Gorges Ship Lift and the Xiangjiaba Ship Lift show that the action of the liquid-gas spring caused by the leakage of the ship compartment is relatively slow. Therefore, the design of the liquid-gas spring airbag accumulator can be considered as an isothermal process. Therefore, the basic equation for the design of the liquid-gas spring airbag accumulator is

[0055] p0V0=p1V1=p2V2=C (3)

[0056] Where p0 is the initial pressure of the bladder accumulator after inflation, V0 is the initial volume, that is, the total volume of the bladder accumulator; p1 is the accumulator pressure at the initial moment when the gas spring starts to move, V1 is the volume of the bladder accumulator at that moment; p2 is the bladder accumulator pressure at the end of the action of the gas spring, V2 is the volume of the bladder accumulator at that moment.

[0057]

[0058]

[0059] (4) and (5) where D i is the inner diameter of the gas spring cylinder, and λ is the lever ratio of the pinion carrier mechanism:

[0060]

[0061] L1 and L2 are the distances from the bottom hinge seat of the pinion bracket to the support hinge seat of the hydraulic spring cylinder and from the bottom hinge seat to the pinion respectively. Figure 6 shown.

[0062] F sp is the gear load at the initial moment of deformation of the hydro-pneumatic spring, F lim is the gear limit load, and the effective volume of the bladder accumulator is the volume of hydraulic oil discharged by the full stroke movement of the gas spring cylinder piston:

[0063]

[0064] According to equations (3) and (6), the total volume of the bladder accumulator can be obtained as

[0065]

[0066] It should be pointed out that since the isothermal process is an ideal thermodynamic process, the system temperature will inevitably change during the operation of the gas spring. In particular, when the pinion load increases rapidly due to the blocking of the carrier during the lifting process or the large amount of water leakage in the carrier, the actual thermodynamic process of the bladder accumulator will have a certain deviation from the isothermal process. The calculation based on the isothermal process will make the total volume of the bladder accumulator smaller. Therefore, the total volume of the bladder accumulator calculated by formula (7) should be regarded as the minimum value. When determining the design value of the total volume of the bladder accumulator, a moderate margin should be considered.

[0067] 3) Elastic coefficient function and mechanical characteristic function of hydraulic spring

[0068] During the action of the gas spring, the volume corresponding to the displacement x of the gas spring piston rod is

[0069] V(x)=V1-Sx (8)

[0070] In the above formula, S = πD i 2 / 4 is the rodless chamber area of ​​the gas spring cylinder.

[0071] According to Boyle's law of isothermal process

[0072] pV(x)=C (9)

[0073] Differentiating both sides of equation (8), we get

[0074] dpV(x)+pdV(x)=0 (10)

[0075] Substituting equations (8) and (9) into equation (10)

[0076]

[0077] Substituting C = p1V1 and Fsp = Sp1 / λ into equation (11), we obtain

[0078]

[0079] The axial load during the operation of the gas spring cylinder is

[0080] F(x)=p(x)S (13)

[0081] Substituting equation (13) into equation (12), we get the elastic coefficient function of the hydro-pneumatic spring:

[0082]

[0083] It can be seen from (14) that the elastic coefficient function of the hydro-pneumatic spring is a positive nonlinear function of displacement.

[0084] By integrating (14), the mechanical characteristic curve of the hydraulic spring can be obtained. (14) can be written as follows:

[0085]

[0086] Integrate both sides of (15)

[0087]

[0088] The precise expression of the mechanical characteristic curve of the hydraulic spring is:

[0089]

[0090] Let F0 = F sp / λ, x0=V1 / S, (17) can be written as

[0091]

[0092] To facilitate the dynamic analysis and control of the ship lift system, equation (18) can also be written as a polynomial series as follows:

[0093]

[0094] Since x / x0<<1, the series is convergent, so we can ignore the terms with n>3 and get

[0095]

[0096] Obviously, the gas spring is a pre-compressed nonlinear spring with an initial load of F0 and a pre-compression amount of x0. It should be noted that equations (18) and (20) correspond to the case where both F(x) and x are positive numbers, that is, the case corresponding to the first quadrant of the xF(x) coordinate plane. Since the gas spring can withstand bidirectional loads, the mechanical characteristic curves corresponding to equations (18) and (20) are antisymmetric relative to the xF(x) coordinate origin.

[0097] Load transfer implementation process:

[0098] 1. Press Figures 1 to 5 Install the gear bracket mechanism and press Figure 7 Connected to the pinion bracket mechanism. The hydraulic spring mechanism and the air bag accumulator are connected. Figure 6 For configuration, the hydraulic spring cylinder is determined according to formula (1).

[0099] 2. Set the initial pressure p0 and initial volume V0 of the bladder accumulator, where the initial pressure is set according to the shutdown load of the ship lift drive mechanism:

[0100]

[0101] In the formula, F ds Set the load for the overload stop pinion of the drive mechanism. The initial volume is determined according to formula (7).

[0102] 3. In the actual operation of the ship lift, when the docking process between the ship lift's cabin and the upper and lower gates is completed and the central control station issues a "ship cabin lifting and lowering operation" command, the hydraulic system injects pressurized oil into the bladder accumulator 10 to make its initial pressure p0, so that the drive mechanism pinion bracket 17 forms a supporting structure for the cabin during the lifting process, and performs the functions of transferring the liquid-gas spring load and transferring it to the safety mechanism according to the principles described in the "Claims" and "Summary of the Invention".

[0103] 4. When the ship lift completes and ends the current lifting operation, after the central control station issues the "ship compartment docking" command, after confirming that the ship lift docking lock has formed support for the ship compartment, the pressure of the airbag accumulator 10 is released to a value close to zero, and the pressure value is determined according to the weight of the gear shaft, so that the drive mechanism pinion bracket only supports the weight of the open pinion 19 to maintain the mechanism configuration, but does not have the ability to withstand external loads. The ship compartment is locked by the docking locking mechanism, and the drive mechanism open pinion 19 is in an unloaded state, so that the open pinion 19 is protected from external loads during the docking process between the ship compartment and the upper and lower gates, avoiding the load-carrying sliding of the pinion along the width direction caused by the relative horizontal movement of the ship compartment and the tower column.

[0104] When the gear load is less than the initial load of the spring deformation determined by the oil pressure of the bladder accumulator, the two pistons are pressed against the two ends of the cylinder by the oil pressure of the rodless chamber of the cylinder between them, and the gas-liquid spring maintains the initial position, thereby maintaining the normal load-bearing and operation of the gear and rack meshing of the drive mechanism; when the gear load exceeds the initial load of the spring deformation, the drive mechanism overload signal is sent through the structural measurement shaft, and the drive system shuts down; at the same time, the oil pressure between the two pistons formed by the overload of the cylinder reduces the volume of the rod chamber of the cylinder, and the pressure of the hydraulic oil compresses the gas volume of the bladder accumulator, and causes the compressed piston at one end to displace, thereby generating the up and down movement of the connection hinge between the lower part of the mechanism and the pinion bracket and the rotation of the gas-liquid spring cylinder around the hinge connected to the ship carriage, thereby triggering the movement of the pinion bracket mechanism, reducing the clearance between the thread pair of the rotating screw of the safety mechanism and the nut column until the clearance of the thread pair of the safety mechanism disappears, and finally forming the geometric contact condition for the safety mechanism to bear the unbalanced load of the ship carriage.

[0105] The safety type gas spring device is a component of the support system of the open gear on the ship-carrying box in the normal lifting and lowering operation of the ship lift, and participates in the load transmission of the unbalanced load of the ship-carrying box to the tower column structure; in the case of an unbalanced accident of the ship-carrying box, the compression of the accumulator air generated by the overload of the gas spring device and the movement of the piston rods at both ends of the double piston rod oil cylinder caused by the overload of the gas spring device make the load and displacement of the double piston oil cylinder present the mechanical characteristics of the spring; the mechanism of the device is set up so that the two pistons of the double piston oil cylinder each move unidirectionally, resulting in the up and down movement of the support hinge shaft connected to the bottom beam of the pinion bracket on the lower flange of the device, so that the gap of the safety mechanism disappears slowly. The mechanism design of the gas spring device makes each piston rod of the double piston rod gas spring oil cylinder only bear unidirectional axial load, and the movement of the piston rod of each gas spring oil cylinder when the driving mechanism is overloaded causes the upward or downward movement of the hinge point connecting the device with the bottom beam of the pinion bracket along the axis of the gas spring oil cylinder and the rotation of the gas spring oil cylinder around the support hinge shaft, so that the thread contact pair formed by the disappearance of the thread gap corresponds to the direction of the unbalanced load of the ship-carrying box.

[0106] The unidirectional axial movement of the two pistons of the double-piston cylinder causes the up and down movement of the support hinge shaft connected to the bottom beam of the pinion bracket on the lower flange of the device, thereby slowly eliminating the gap of the safety mechanism. Each piston rod of the double-piston rod gas spring cylinder only bears a unidirectional axial load, and the movement of the piston rod of each gas spring cylinder when the driving mechanism is overloaded causes the upward or downward movement of the hinge point connecting the device and the bottom beam of the pinion bracket along the axis of the gas spring cylinder and the rotation of the gas spring cylinder around the support hinge shaft, thereby making the threaded contact pair formed by the disappearance of the thread gap correspond to the direction of the unbalanced load of the ship bearing compartment, thereby realizing safe and smooth load transfer.

[0107] Under normal working conditions, the unbalanced force, friction force and inertia force of the ship-carrying box of the rack and pinion fully balanced vertical ship lift are transmitted to the tower column through the driving mechanism liquid-gas spring, gear bracket, pinion and rack, and the motor, reducer and universal joint provide power to the open gear to overcome the load of the driving mechanism and drive the ship-carrying box to move up and down. The open gear is supported on the side wing structure platform of the ship-carrying box through the gear bracket and the liquid-gas spring device, and is horizontally positioned relative to the rack through the gear bracket mechanism. The horizontal relative displacement and angular displacement of the tower column and the ship-carrying box are adapted by the gear bracket. The bottom of the liquid-gas spring cylinder mechanism is hinged with the bottom beam of the gear bracket through the measuring shaft and bearing. Under normal lifting conditions of the ship-carrying box, the liquid-gas spring cylinder is one of the force transmission components that transmit the unbalanced force of the ship-carrying box to the tower column. It neither rotates as a whole due to the gear bracket mechanism adapting to the relative displacement of the tower column and the ship-carrying box, nor does it cause the axial displacement of the piston caused by the axial load. When the ship-carrying compartment is unbalanced due to water leakage or other reasons, causing the drive mechanism to be overloaded, the gas-liquid spring device triggers the movement of the gear bracket mechanism through the compression of the gas in the airbag accumulator and the axial movement of the double-acting oil cylinder piston, so that the thread gap between the rotating screw of the safety mechanism and the nut column on one side disappears smoothly and slowly, thereby providing the necessary conditions for the safety mechanism to bear the accident load of the ship-carrying compartment unbalance. After the thread gap between the rotating screw of the safety mechanism and the nut column disappears and contacts each other, the additional unbalanced force generated by the unbalanced accident of the ship-carrying compartment is transmitted to the nut column and the tower column structure through the thread pair of the safety mechanism, and the load on the open gear of the drive mechanism no longer increases, thereby preventing the drive mechanism from bearing a large accident load.

[0108] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "lateral", "parallel", "vertical", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0109] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the structural relationship and principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A load transfer method for a safety type hydraulic spring device used in a ship lift, characterized in that: The steps include: Step 1: Set the stroke of the gas spring cylinder. The stroke of the cylinder must ensure that the gas spring cylinder still has a certain amount of surplus stroke after the thread gap of the safety mechanism disappears, so as to avoid the accident that the safety mechanism cannot provide support when the thread gap of the safety mechanism has not disappeared and the cylinder stroke has been exhausted; for this reason, the thread gap should be considered as large as possible, that is, the larger gap value when the upper and lower thread gaps are not equal and biased to one side, and the displacement difference of the bearing compartment structure where the safety mechanism and the drive mechanism are located when the bearing compartment is unbalanced should be considered; the stroke of the gas spring cylinder is calculated as follows: f s =2(2d sb +d f +d m -5mm) In the formula, f s is the stroke of the hydraulic spring cylinder; d sb is the theoretical thread clearance of the safety mechanism, that is, the thread clearance value when the clearances of the upper and lower thread pairs are equal; d f is the displacement difference of the ship compartment structure where the safety mechanism and the driving mechanism are located when an unbalance accident occurs in the ship compartment; d m is the margin of the cylinder stroke; in the above formula, 2d sb -5mm represents the maximum thread gap on one side caused by the imbalance of the upper and lower thread pairs due to various reasons; Step 2: Set the initial pressure p0 and initial volume V0 of the accumulator after inflation; Step 3: During the actual operation of the ship lift, when the docking process between the ship lift's ship compartment and the upper and lower gates is completed and the central control station issues a "ship compartment lifting and lowering operation" command, the external hydraulic system is started to inject pressurized oil into the bladder accumulator (10) to make its initial pressure p0, so that the drive mechanism pinion bracket (17) forms a supporting structure for the ship compartment during the lifting process; When the gas spring device is subjected to a vertical downward load transmitted by the pinion bracket bottom beam (16) at the measuring shaft position, the load is transmitted to the upper piston rod (6-1) through the lower flange (3), the threaded tie rod (7) and the upper flange, forming a pressure of the upper piston on the rodless chamber (6-4) of the gas spring oil cylinder; when the downward load is less than the initial oil pressure of the oil in the rodless chamber (6-4) of the gas spring oil cylinder set by the accumulator on the upper piston rod, the upper piston rod (6-1) remains stationary; when the downward load is greater than the initial setting value of the oil in the rodless chamber (6-4) of the gas spring oil cylinder, the air in the airbag accumulator (10) in the rodless chamber (6-4) is generated, thereby causing the upper piston rod to move downward, thereby The volume of the rodless chamber (6-4) of the gas spring oil cylinder is reduced, and the gas in the airbag accumulator (10) is further compressed, so that the pressure of the rodless chamber of the gas spring oil cylinder is increased; at the same time, the lower flange (3) is also displaced downward under the downward external load, and the guide sleeve (4) threadedly connected to the bottom end of the lower piston rod slides relative to the inner hole of the lower flange, so that the lower piston rod (6-2) is not affected by the external load and remains stationary relative to the cylinder body of the gas spring oil cylinder (6); the downward movement of the lower flange (3) and its measuring shaft (2) can trigger the corresponding movement of the pinion bracket mechanism, so that the ship bearing chamber is displaced downward, resulting in a reduction in the lower thread clearance between the rotating screw of the safety mechanism and the nut column; When the gas-liquid spring device is subjected to a vertical upward load transmitted by the pinion bracket bottom beam (16) at the measuring shaft (2), the load is transmitted to the lower piston rod through the guide sleeve (4), forming a pressure of the lower piston on the rodless chamber (6-4) of the gas-liquid spring oil cylinder; when the upward load is less than the initial oil pressure of the oil in the rodless chamber (6-4) of the gas-liquid spring oil cylinder on the lower piston rod set by the airbag accumulator (10), the lower piston rod remains stationary; when the upward load is greater than the initial setting value of the oil in the rodless chamber of the gas-liquid spring oil cylinder, the oil in the rodless chamber generated compresses the air in the accumulator, thereby causing the lower piston rod (6-2) to move upward, thereby reducing the volume of the rodless chamber (6-4) of the gas-liquid spring oil cylinder, and further The gas in the airbag accumulator (10) is compressed step by step, so that the pressure of the rodless chamber (6-4) of the gas spring oil cylinder increases; the lower flange moves upward under the action of the upward external load; at this time, the pull rod threadedly connected to the lower flange also moves upward accordingly; because the upper end of the pull rod is hollowly sleeved in the inner hole of the self-lubricating sliding sleeve (9) with a flange, the pull rod (7) will not generate a force on the upper flange (8) when it moves upward, and the upper flange (8) and its upper piston rod (6-1) remain stationary relative to the cylinder body of the gas spring oil cylinder; the upward movement of the lower flange (3) and its measuring shaft (2) can trigger a corresponding movement of the pinion bracket (17), thereby causing the ship bearing compartment structure (18) to produce an upward displacement, resulting in a reduction in the upper thread clearance between the rotating screw and the nut column of the safety mechanism; Step 4: When the ship lift completes and ends the lifting operation, after the central control station issues a "ship compartment docking" command, after confirming that the ship lift docking lock has formed a support for the ship compartment, the pressure of the airbag accumulator (10) is released to a value close to zero, and the pressure value is determined according to the weight of the gear shaft, so that the drive mechanism pinion bracket (17) only supports the weight of the open pinion (19) to maintain the mechanism configuration, but does not have the ability to withstand external loads. The ship compartment is locked by the docking locking mechanism, and the drive mechanism open pinion (19) is in an unloaded state, so that the open pinion (19) is protected from external loads during the docking process between the ship compartment and the upper and lower gates, and the open pinion (19) is prevented from sliding with load along the width direction due to the relative horizontal movement of the ship compartment and the tower column; The initial pressure p0 is set according to the stop load of the ship lift driving mechanism: ， The initial volume V0 is determined as follows: ， Where: F ds Set the load for the drive mechanism overload stop pinion; p0 is the initial pressure of the bladder accumulator after inflation; p1 is the accumulator pressure at the initial moment when the hydro-pneumatic spring starts to act; V1 is the volume of the bladder accumulator at that moment; p2 is the pressure of the bladder accumulator at the end of the action of the hydro-gas spring, and V2 is the volume of the accumulator at that moment; D i is the inner diameter of the gas spring cylinder; λ is the lever ratio of the pinion-carrier mechanism, , L1 and L2 are the distances from the bottom hinge seat of the pinion bracket to the support hinge seat of the hydraulic spring cylinder and from the bottom hinge seat to the pinion respectively; F sp is the gear load at the initial moment of deformation of the hydro-pneumatic spring, F lim is the gear limit load; V w is the effective volume of the bladder accumulator, ; The safety type gas-liquid spring device comprises a bracket (1), a measuring shaft (2), a lower flange (3), a guide sleeve (4), a self-lubricating bearing (5), a gas-liquid spring cylinder (6), a pull rod (7), an upper flange (8), a self-lubricating sliding sleeve (9), an airbag accumulator (10) and an oil pipe (11); The lower end of the bracket (1) is fixedly mounted on the ship-bearing compartment structure (18); the gas spring cylinder (6) is of a double piston rod type; the support shaft (6-3) in the middle of the gas spring cylinder (6) is supported on the bracket (1) via a self-lubricating bearing (5); the end of the upper piston rod (6-1) of the gas spring cylinder (6) is connected to the upper flange (8) via a thread; the lower end of the lower piston rod (6-2) of the gas spring cylinder (6) is assembled with a clearance fit via a guide sleeve (4) and a mounting hole (3-1) of the lower flange (3); the measuring shaft (2) is fixedly mounted on the lower flange (3) The upper and lower flanges are connected by a tie rod (7); a self-lubricating sliding sleeve (9) with a flange is installed on the upper flange tie rod mounting hole (81) of the upper flange (8); the upper end of the tie rod (7) is sleeved in the inner hole of the self-lubricating sliding sleeve (9) with a flange and the top is positioned with a nut; the lower end of the tie rod (7) is fixed to the lower flange (3) by a nut; the measuring shaft at the bottom is hinged with the bottom beam of the gear bracket mechanism, thereby forming a force transmission system together with the pinion bracket to transmit the unbalanced load of the ship-bearing compartment under the lifting condition of the ship lift to the tower column; The airbag accumulator (10) is in communication with the rodless chamber (6-4) of the gas spring cylinder (6) through an oil pipe (11); The gas-liquid spring cylinder (6) is connected to the airbag accumulator (10) of the external hydraulic pump station. The preload of the gas-liquid spring is determined by the oil pressure of the accumulator and can be adjusted as needed. The gas-liquid spring composed of the cylinder and the accumulator has the displacement load characteristic of a pre-compressed nonlinear spring: when the gear load is less than the preload determined by the oil pressure of the accumulator, the pistons at both ends of the gas-liquid spring cylinder (6) are pressed against the two ends of the cylinder body of the gas-liquid spring cylinder (6) by the oil pressure, and the pistons at both ends of the gas-liquid spring cylinder (6) maintain their initial positions, thereby maintaining the normal load-bearing and operation of the gear and rack meshing of the driving mechanism; when the gear load exceeds the preload, the oil pressure in the rodless chamber of the double-piston-rod gas-liquid spring cylinder exceeds the initial value, and compresses the gas in the airbag (10-1) of the accumulator to reduce the gas volume, and the oil in the rodless chamber (6-4) enters the airbag accumulator (10), so that the gas-liquid spring The compressed piston of the spring oil cylinder (6) generates axial displacement; thereby, the connection hinge point between the lower part of the measuring shaft (2) and the pinion bracket bottom beam (16) moves up and down, and the hydraulic spring oil cylinder (6) rotates around the support hinge connected to the ship carriage, thereby inducing the movement of the pinion bracket (17), so that the thread pair clearance between the rotating screw of the safety mechanism and the nut column is reduced until the thread pair clearance of the safety mechanism disappears, and finally forms the geometric contact condition for the safety mechanism to bear the unbalanced load of the ship carriage; when the ship carriage of the rack and pinion climbing ship lift is unbalanced, the upper piston rod (6-1) and the lower piston rod (6-2) of the hydraulic spring oil cylinder move axially, and the hinge point between the measuring shaft (2) and the pinion bracket bottom beam (16) located at the bottom of the hydraulic spring is displaced up and down, so that the vertical support of the ship carriage is smoothly transitioned from the pinion and rack to the rotating screw and nut column of the safety mechanism.

2. The load transfer method of a safety type hydraulic spring device used in a ship lift according to claim 1, characterized in that: The measuring shaft (2) is hinged to the bottom beam of the gear bracket mechanism through a self-aligning rolling bearing (12) assembled in the shaft hole of the lower flange (3) and a hinge hole at the end of the bottom beam.

3. The load transfer method of a safety type hydraulic spring device used in a ship lift according to claim 1, characterized in that: The bracket (1) comprises a bottom plate (1-1), a vertical plate (1-2) and a reinforcing triangular plate (1-3); the bottom plate (1-1) is connected to a ship-bearing box structure (18) via bottom plate bolts (15); the vertical plate (1-2) is vertically mounted on the upper end surface of the bottom plate (1-1); and two side edges of the reinforcing triangular plate (1-3) having a reinforcing function are respectively fixedly mounted on the bottom plate (1-1) and the vertical plate (1-2).

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