A gravity energy storage system suitable for ultra-deep shafts

Abstract

The utility model discloses a kind of suitable for super-deep vertical shaft gravity energy storage system, at least including two subsections and modularization setting bottom transport unit and top transport unit;Still include the connecting platform of setting between bottom transport unit and top transport unit and the independent power source equipment located in bottom transport unit one side, and with its transmission connection;Wherein, bottom transport unit and top transport unit are chain transmission, and all be provided with multiple fork arms with chain transmission axial connection.The utility model can solve the stable, unpowered transmission connection problem between heavy object in lifting or lowering process in adjacent transport unit between upper and lower.

Description

Technical Field

[0001] This utility model relates to the field of gravity energy storage technology for abandoned mines, specifically a gravity energy storage system suitable for ultra-deep vertical shafts. Background Technology

[0002] Gravity energy storage in abandoned mines is an energy storage system that utilizes gravitational potential energy to store and release electrical energy. Its basic principle is similar to pumped-storage hydroelectricity, using a solid weight as the energy storage medium. Potential energy is stored and electrical energy is released by raising or lowering the weight. When there is excess electricity, the motor driving the hoisting system lifts the weight to a higher position, storing it as potential energy. When electricity is needed, the weight is lowered back down, converting its potential energy into kinetic energy to drive a generator to produce electricity.

[0003] Against the backdrop of a global emphasis on the development of renewable energy and energy storage technologies, gravity storage has garnered significant attention due to its advantages such as simple technical principles, relatively low construction barriers, environmental friendliness, long lifespan, and high efficiency. Currently, the coal industry has shut down over 10,000 mines as part of capacity reduction efforts, leaving behind a total capacity of approximately 9 billion cubic meters. 3 The vast underground space in mines urgently needs to be developed and utilized. Therefore, developing new gravity energy storage by utilizing the abundant space above and below ground in closed mines, as well as convenient production service facilities, is an urgent requirement for building a new power system based on new energy sources, an important support for ensuring the safe and stable operation of the power system, and an important guarantee for the large-scale development of renewable energy.

[0004] The depth difference of nearly 1,000 meters is a significant advantage for gravity energy storage. However, the vertical shaft transportation requirements for gravity energy storage in abandoned mines are extremely high, including: simultaneous carrying capacity exceeding 1,000 tons, high stability requirements with maximum fluctuation not exceeding 5%, precise positioning—positioning of tens of tons of weight with millimeter-level accuracy, and stringent safety and stability requirements—relative deformation ≤0.1% over a 30-year operation and maintenance period, among other major challenges. Existing vertical transportation methods are mostly suspended cable transport, which generally suffers from low unit transport capacity, poor stability due to intermittent transport, high energy consumption from frequent start-stop operations, and severe wear and tear on open-type cables, severely restricting the efficiency of deep-earth development and the synergistic effect of grid peak shaving.

[0005] Existing gravity energy storage systems often utilize the sloping structure of mine shafts, which results in significant energy loss due to friction. Current vertical gravity energy storage facilities employ cable-stayed hoists to lift and lower a single load for energy conversion. To achieve higher power output using this method, it is necessary to either increase the mass of the load or accelerate the operating speed. Utility Model Content

[0006] The technical problem to be solved by this utility model is that the traditional suspended lifting system has frequent start-stop and no-load return intervals, which leads to large power fluctuations, discontinuous transportation process, and affects the stability and efficiency of power generation.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0008] A gravity energy storage system suitable for ultra-deep vertical shafts includes at least two segmented and modularly arranged bottom transport unit 10 and top transport unit 20; it also includes a connecting platform 30 disposed between the bottom transport unit 10 and the top transport unit 20 and an independent power source device 40 located on one side of the bottom transport unit 10 and connected to it in a drive; wherein the bottom transport unit 10 and the top transport unit 20 are both chain driven and are each provided with multiple forks 123 axially connected to the chain drive.

[0009] In this embodiment, both the bottom transport unit 10 and the top transport unit 20 are provided with a first bearing frame 121, a first transmission chain 122 and a first electric / generator integrated machine; the first bearing frame 121 is fixed to the well wall; the first transmission chain 122 and the first electric / generator integrated machine are disposed inside the first bearing frame 121; and the first transmission chain 122 is chain driven to the power output end of the first electric / generator integrated machine.

[0010] In this embodiment, the bottom transport unit 10 and the top transport unit 20 are equipped with conveyor roller devices; the two conveyor roller devices have the same structure.

[0011] In this embodiment, the conveying roller device includes a first fixed frame 124 and a first conveying roller 125 disposed on the first fixed frame 124;

[0012] The first fixed frame 124 is not completely closed and has a notch; and at the notch, only one end of the plurality of first conveying rollers 125 is connected to the first fixed frame 124; the fork arm 123 passes through the first conveying rollers 125 at the notch of the first fixed frame 124.

[0013] In this embodiment, the independent power source device 40 is provided with a second electric / generator integrated machine and a second transmission chain 41; the second electric / generator integrated machine is connected to the first electric / generator integrated machine at the top of the bottom transport unit 10 through a coupling; and the second transmission chain 41 is connected to the output end of the second electric / generator integrated machine by chain drive.

[0014] In this embodiment, multiple fork arms 123 are evenly arranged on the drive chain; each fork arm 123 includes a connector 12, a connecting bearing 13, a connecting plate 14, and a bearing 15;

[0015] At the location where the fork arm 123 is set in the transmission chain, at the hinge point of two adjacent links 21 on the transmission chain, the hinge is set as a long shaft, so that the hinge protrudes from the link 21 and is fixed to the connector 12.

[0016] The connecting bearing 13 is fixedly located inside the connecting member 12, with one end extending out of the connecting member 12; one end of the connecting plate 14 is movably connected to the connecting bearing 13 extending out of the connecting member 12; the bearing member 15 is fixedly connected to the other end of the connecting plate 14.

[0017] In this embodiment, the support member 15 is mainly formed by fixing multiple tripods 151 to the connecting plate 14 at intervals and evenly; wherein, when the support member 15 intersects with the conveying roller device, the arrangement of the multiple tripods 151 is staggered with the multiple first conveying rollers 125 located at the gap.

[0018] In this embodiment, the connecting platform 30 includes a second fixed frame 31 and a third fixed frame 32 with the same structure, and also includes a second conveying roller 33;

[0019] The "L"-shaped second fixing frame 31 and the third fixing frame 32 form a rectangle with a diagonal notch; the second conveying roller 33, located at the diagonal notch, is fixedly connected to the second fixing frame 31 or the third fixing frame 32 at only one end.

[0020] During operation, the forks 123 on the bottom transport unit 10 and the top transport unit 20 pass through the second conveyor roller 33 through the diagonal notches.

[0021] In this embodiment, during operation, when the carrier 15 and the connecting platform 30 intersect, the arrangement of multiple tripods 151 and the multiple second conveying rollers 33 located at the gap are staggered.

[0022] In this embodiment, both the bottom transport unit 10 and the top transport unit 20 are equipped with chain sensors and hydraulic servo cylinders; the chain drive is equipped with a driven wheel and a tension wheel that mesh with the first transmission chain 122; the chain sensor is located at the driven wheel to monitor the tension of the first transmission chain 122, and the extension section of the hydraulic servo cylinder is connected to the tension wheel.

[0023] Compared with the prior art, the beneficial effects of this utility model are:

[0024] Improved efficiency: The chain drive combined with the forklift enables continuous closed-loop operation, completely eliminating frequent starts and stops and no-load return intervals, allowing more heavy objects to be transported per unit time. Simultaneously, it avoids drastic power fluctuations in the power grid caused by intermittent operation, providing the grid with a more stable and reliable gravitational potential energy-to-electrical energy conversion output.

[0025] Energy saving: The constant speed continuous transportation mode avoids the huge energy consumption of frequent start-up acceleration of the electric / generator integrated machine, especially eliminating the high peak current during startup.

[0026] The simplified process and ease of operation: The segmented and modular design enables a smooth, seamless, and low-impact transition of heavy objects between different transport unit tracks. The connecting platform, combined with the forklift loading and unloading design, greatly simplifies the connection operation and saves the complex synchronization and power intervention processes required by traditional systems. The seamless connection itself reduces waiting and adjustment time. It solves the problem of smooth, non-powered (or low-power intervention) transfer of heavy objects between adjacent transport units during lifting or lowering, ensuring smooth, unimpeded, and impact-free transition of heavy objects between different units and maintaining transport continuity.

[0027] Raw material savings and reduced wear: The segmented and modular design, combined with independent power source equipment, significantly reduces the wear rate of key components such as chains, gears, bearings, and tracks. Simultaneously, uniform speed operation eliminates the severe mechanical shocks caused by start-stop cycles, effectively extending equipment lifespan and reducing raw material consumption and maintenance costs associated with replacing worn parts. Through a load-distribution mechanism, the burden on the upper chain is significantly reduced, successfully preventing plastic deformation, stress overload, or even breakage caused by excessive load capacity in a single chain. The modular design and independent force transmission of the bottom transport unit avoid the need for oversized, heavy-duty single-chain systems to meet ultra-long distances and ultra-high loads, while also preventing component replacement due to overload damage.

[0028] The emergence of useful performance features: It overcomes the core load-bearing bottleneck of continuous long-distance, ultra-large tonnage (over 1000 tons) transportation in ultra-deep vertical shaft environments. The modular load-distribution solution makes it possible to continuously transport over 1000 tons of heavy objects in vertical shafts >500 meters deep, a new performance that traditional suspension systems cannot achieve. It also enables truly continuous operation during the lifting or lowering process, a key useful performance feature compared to traditional intermittent transportation modes. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a gravity energy storage system suitable for ultra-deep vertical shafts, according to an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the fork arm according to an embodiment of the present utility model.

[0031] Figure 3 This is a schematic diagram of the conveyor roller device according to an embodiment of the present invention.

[0032] Figure 4 This is a partial enlarged view of the connection platform according to an embodiment of the present utility model.

[0033] Figure 5 This is a schematic diagram of an independent power source device according to an embodiment of the present utility model. Detailed Implementation

[0034] To facilitate understanding of the technical solution of this utility model by those skilled in the art, the technical solution of this utility model will now be further described in conjunction with the accompanying drawings.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] Please see Figure 1 As shown, this utility model provides a gravity energy storage system suitable for ultra-deep vertical shafts, comprising at least two segmented and modularly arranged bottom transport unit 10 and top transport unit 20, and further including a connecting platform 30 disposed between the bottom transport unit 10 and the top transport unit 20, and an independent power source device 40 located on one side of the bottom transport unit 10 and driven thereto. Both the bottom transport unit 10 and the top transport unit 20 are chain-driven and each is provided with multiple forks 123 axially connected to the chain drive.

[0037] In this embodiment, it should be noted that, depending on the shaft depth, multiple intermediate transport units can be set between the bottom transport unit 10 and the top transport unit 20. These intermediate transport units are identical to the bottom transport unit 10 except that they do not require a conveyor roller device. Correspondingly, an independent power source device 40 connected to its transmission can be set on one side of each intermediate transport unit. Specifically, each intermediate transport unit can be equipped with an independent power source device 40, or one can be selected from multiple transport units to be equipped with an independent power source device 40. Undoubtedly, connecting platforms 30 are provided between the ends of the multiple transport units, between the bottom transport unit 10 and the transport units above it, and between the top transport unit 20 and the transport units below it, for transferring heavy objects. Furthermore, in this embodiment, the ultra-deep shaft is a kilometer-deep shaft with a depth greater than 500 meters.

[0038] Please see Figures 1 to 4 As shown in this embodiment, both the bottom transport unit 10 and the top transport unit 20 are provided with a first support frame 121, a first transmission chain 122, and a first electric / generator integrated machine (not shown in the figure). The first support frame 121 is fixed to the well wall, and the first transmission chain 122 and the first electric / generator integrated machine are disposed inside the first support frame 121, and the first transmission chain 122 is chain-driven with the power output end of the first electric / generator integrated machine.

[0039] In this embodiment, the first load-bearing frame 121 serves as the system's basic support structure, bearing the load of a thousand-ton load and the static / dynamic stress of the transmission components. It provides a rigid installation benchmark for the chain track and the integrated electric / generator, ensuring the spatial positioning accuracy of each unit. The first transmission chain 122 replaces intermittent lifting with continuous closed-loop operation, completely eliminating the no-load return and start-stop intervals. It carries heavy loads and transmits power to the power generation system, realizing the direct conversion of gravitational potential energy into electrical energy. More specifically, both the bottom transport unit 10 and the top transport unit 20 are equipped with chain sensors and hydraulic servo cylinders. The chain drive includes a driven wheel and a tensioning wheel that mesh with the first transmission chain 122. The chain sensor is located at the driven wheel to monitor the tension of the first transmission chain 122, and the extension section of the hydraulic servo cylinder is connected to the tensioning wheel. The chain sensor and the hydraulic servo cylinder are connected to the PLC system, which controls the tension difference on both sides of the first transmission chain 122 to avoid uneven tension.

[0040] In this embodiment, multiple fork arms 123 are evenly arranged on the transmission chain, which refers to the first transmission chain 122 in the bottom transport unit 10 and the top transport unit 20. Each fork arm 123 includes a connector 12, a connecting bearing 13, a connecting plate 14, and a carrier 15. At the position of the fork arm 123 on the transmission chain, at the hinge point of two adjacent links 21, the hinge is set as a long shaft, so that the hinge protrudes from the link 21 and is fixed to the connector 12. Specifically, the hinge can be a pin. The connecting bearing 13 is fixedly located inside the connector 12, and one end extends out of the connector 12. One end of the connecting plate 14 is movably connected to the connecting bearing 13 extending out of the connector 12. The carrier 15 is fixedly connected to the other end of the connecting plate 14. The carrier 15 is mainly formed by multiple tripods 151 that are spaced apart and evenly fixed to the connecting plate 14. Specifically, the connecting plate 14 is also triangular.

[0041] In this embodiment, the fork arm 123 uses a connecting bearing 13 to form a movable connection node. This design allows the fork arm 123 to rotate flexibly. Utilizing the principle of gravity self-balancing, the rotational characteristics ensure that the main body bearing the heavy load maintains a horizontal posture during operation, guaranteeing load stability. The triangular load-bearing component 15 and the triangular connecting plate 14 follow the principle of triangle stability in mechanics, effectively strengthening the structural strength and significantly improving the overall load-bearing capacity of the fork arm 123. This makes it suitable for industrial handling, mechanical loading and unloading, and other scenarios, meeting the needs for load support and posture control, and optimizing the mechanical performance and work efficiency of the equipment during operation.

[0042] In one embodiment of this utility model, a conveyor roller device is provided in the bottom transport unit 10 and the top transport unit 20. The two conveyor roller devices have the same structure. The conveyor roller device includes a first fixed frame 124 and a first conveyor roller 125 disposed on the first fixed frame 124. The first fixed frame 124 is not completely closed and has a notch, and at the notch, only one end of the plurality of first conveyor rollers 125 is connected to the first fixed frame 124. During operation, the fork arm 123 passes through the first conveyor roller 125 through the notch of the first fixed frame 124.

[0043] In this embodiment, the connecting platform 30 includes a second fixed frame 31 and a third fixed frame 32 with identical structures, and also includes a second conveyor roller 33. The "L"-shaped second fixed frame 31 and third fixed frame 32 form a rectangle with a diagonal notch. The second conveyor roller 33, located at the diagonal notch, is fixedly connected to the second fixed frame 31 or the third fixed frame 32 at only one end. During operation, the forks 123 on the bottom transport unit 10 and the top transport unit 20 pass through the second conveyor roller 33 through the diagonal notch, respectively.

[0044] In this embodiment, during operation, when the carrier 15 intersects with the conveyor roller device, the arrangement of multiple tripods 151 is staggered with the multiple first conveyor rollers 125 located at the gap; when the carrier 15 intersects with the connecting platform 30, the arrangement of multiple tripods 151 is staggered with the multiple second conveyor rollers 33 located at the gap.

[0045] Furthermore, one end of the connecting platform 30 is raised, with the raised end facing the top transport unit 20. During energy storage, when the bottom transport unit 10 lifts the heavy object onto the connecting platform 30, the motor power of the second conveyor roller 33 transfers the heavy object to the end near the top transport unit 20, i.e., the raised end of the connecting platform 30, where the fork arm 123 on the top transport unit 20 removes it. During power generation, the heavy object at the raised end of the connecting platform 30 does not require motor drive from the second conveyor roller 33; under its own weight, it slides to the end of the connecting platform 30 near the bottom transport unit 10 and is removed by the fork arm 123 on the bottom transport unit 10.

[0046] Please see Figures 1 to 5 As shown, in one embodiment of this utility model, the independent power source device 40 is provided with a second electric / generator integrated machine (not shown in the figure) and a second transmission chain 41. The second electric / generator integrated machine is connected to the first electric / generator integrated machine located at the top of the bottom transport unit 10 via a coupling. Furthermore, the second transmission chain 41 is chain-driven to the output end of the second electric / generator integrated machine.

[0047] In this embodiment, it should be noted that the first and second integrated electric / generator units are identical components; they are both integrated electric / generator units, and the designation "first" and "second" is used only for distinction. The integrated electric / generator unit is a device that integrates the functions of a motor and a generator to achieve bidirectional conversion between electrical and mechanical energy. It can drive the motor for transportation and lifting during energy storage, and it can also act as a generator during energy release to further convert the mechanical energy derived from the potential energy of heavy objects into electrical energy for storage or feedback to the grid.

[0048] Please see Figures 1 to 5 As shown, in this embodiment, the gravity energy storage system performs gravity energy storage as follows: using off-peak electricity or new energy power to start the motor of the electric / generator integrated machine, driving the first transmission chain 122 and the second transmission chain 41 to drive the conveyor roller device of the bottom transport unit 10 to transfer the heavy objects stored in the abandoned mine tunnel to the fork arm 123, then to the connecting platform 30, and then to the fork arm 123 of the top transport unit 20 through the connecting platform 30, and finally to the conveyor roller device of the top transport unit 20, so that the heavy objects are lifted from bottom to top to the ground, and then stored in the ground storage center through the ground horizontal transport system, thus realizing the storage of energy.

[0049] Please see Figures 1 to 5 As shown, in this embodiment, the gravity energy storage system performs gravity energy release and power generation as follows: the ground horizontal transportation system and the conveyor roller device of the top transportation unit 20 transport the heavy objects from the ground storage center to the well shaft. The fork arm 123 of the top transportation unit 20 transfers them to the connecting platform 30, and then through the connecting platform 30 they are transferred to the fork arm 123 of the bottom transportation unit 10. Under the action of their own gravity, these heavy objects drive the first transmission chain 122 to move. The first transmission chain 122 then drives the generator of the electric / generator integrated machine to convert kinetic energy into electrical energy, realizing the conversion process of potential energy of solid heavy objects into electrical energy.

[0050] In this embodiment, during both the energy storage and power generation processes, each fork arm 123 is equipped with a heavy object. The first transmission chain 122 moves in a uniform, continuous, closed-loop manner, completely eliminating frequent start-stop cycles and no-load return intervals, thus transporting more heavy objects per unit time. Simultaneously, it avoids drastic fluctuations in grid power caused by intermittent operation, providing the grid with a more stable and reliable gravitational potential energy-to-electrical energy conversion output. The uniform, continuous transport mode avoids the enormous energy consumption associated with frequent starts and accelerations of the integrated electric / generator unit, particularly eliminating the high peak current during startup.

[0051] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0052] The above-described embodiments are merely examples of implementation methods of the utility model. The scope of protection of this utility model is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and these all fall within the scope of protection of this utility model.

Claims

1. A gravity energy storage system suitable for ultra-deep vertical shafts, characterized in that, It includes at least two segmented and modularly configured bottom transport unit (10) and top transport unit (20); it also includes a connecting platform (30) between the bottom transport unit (10) and the top transport unit (20) and an independent power source device (40) located on one side of the bottom transport unit (10) and connected to it in a drive; wherein the bottom transport unit (10) and the top transport unit (20) are both chain driven and are each provided with multiple forks (123) axially connected to the chain drive.

2. The gravity energy storage system for ultra-deep vertical shafts according to claim 1, characterized in that, Both the bottom transport unit (10) and the top transport unit (20) are provided with a first bearing frame (121), a first transmission chain (122) and a first electric / generator integrated machine; the first bearing frame (121) is fixed on the well wall; the first transmission chain (122) and the first electric / generator integrated machine are located inside the first bearing frame (121); and the first transmission chain (122) is chain driven to the power output end of the first electric / generator integrated machine.

3. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 1, characterized in that, The bottom transport unit (10) and the top transport unit (20) are equipped with conveyor roller devices; the two conveyor roller devices have the same structure.

4. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 3, characterized in that, The conveying roller device includes a first fixed frame (124) and a first conveying roller (125) disposed on the first fixed frame (124); The first fixed frame (124) is not completely closed and has a gap; and at the gap, a plurality of first conveying rollers (125) are connected to the first fixed frame (124) at only one end; the fork arm (123) passes through the first conveying roller (125) at the gap of the first fixed frame (124).

5. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 2, characterized in that, The independent power source device (40) is equipped with a second electric / generator and a second transmission chain (41); the second electric / generator is connected to the first electric / generator at the top of the bottom transport unit (10) via a coupling; and the second transmission chain (41) is chain driven to the output end of the second electric / generator.

6. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 1, characterized in that, Multiple fork arms (123) are evenly arranged on the drive chain; each fork arm (123) includes a connector (12), a connecting bearing (13), a connecting plate (14), and a load-bearing component (15); At the location where the fork arm (123) is set in the transmission chain, at the hinge of the corresponding two adjacent links (21) on the transmission chain, the hinge is set as a long shaft, so that the hinge protrudes from the link (21) and is fixed to the connector (12). The connecting bearing (13) is fixedly located inside the connecting member (12), and one end extends out of the connecting member (12); one end of the connecting plate (14) is movably connected to the connecting bearing (13) extending out of the connecting member (12); the bearing (15) is fixedly connected to the other end of the connecting plate (14).

7. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 6, characterized in that, The carrier (15) is mainly formed by fixing multiple tripods (151) to the connecting plate (14) at intervals and evenly; wherein, when the carrier (15) intersects with the conveyor roller device, the arrangement of multiple tripods (151) is interspersed with multiple first conveyor rollers (125) at the gap.

8. The gravity energy storage system suitable for ultra-deep vertical shafts according to claim 7, characterized in that, The connecting platform (30) includes a second fixed frame (31) and a third fixed frame (32) with the same structure, and also includes a second conveying roller (33); The "L"-shaped second fixing frame (31) and the third fixing frame (32) form a rectangle with a diagonal notch; the second conveying roller (33) located at the diagonal notch is fixedly connected to the second fixing frame (31) or the third fixing frame (32) at only one end; During operation, the forks (123) on the bottom transport unit (10) and the top transport unit (20) pass through the second conveyor roller (33) through the diagonal notch.

9. The gravity energy storage system for ultra-deep vertical shafts according to claim 8, characterized in that, During operation, when the carrier (15) and the connecting platform (30) intersect, the arrangement of multiple tripods (151) and multiple second conveyor rollers (33) at the gap are intersected.

10. The gravity energy storage system for ultra-deep vertical shafts according to claim 2, characterized in that, Both the bottom transport unit (10) and the top transport unit (20) are equipped with chain sensors and hydraulic servo cylinders; the chain drive is equipped with a driven wheel and a tension wheel that mesh with the first transmission chain (122); the chain sensor is set at the driven wheel to monitor the tension of the first transmission chain (122), and the extension section of the hydraulic servo cylinder is connected to the tension wheel.

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