A cable twisting device for a wind turbine generator

Abstract

The application discloses a cable twisting device for a wind turbine, and belongs to the technical field of cable twisting, which comprises a mounting seat, a twisting motor and a limiting sliding rod are fixedly arranged in the mounting seat, a plurality of threading holes are arranged on the bottom surface of the mounting seat, and a mounting shaft is fixedly arranged at one end of the output shaft of the twisting motor; in the application, the twisting mechanism is arranged in a matched mode, through the design, the installation of each main cable can be quickly completed, different cables are separated from each other, damage caused by mutual contact and twisting of the cables is avoided, the adjustable cable transmission assembly is arranged, the protection effect of the cables can be effectively achieved when the cables are twisted, damage is avoided, and the cables can be longitudinally positioned to a certain extent after the twisting, the subsequent twisting of the cables is avoided, and the practical application effect of the whole device is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of cable twisting technology, and particularly relates to a cable twisting device for wind turbine generators. Background Technology

[0002] A wind turbine, also known as a wind power unit or wind turbine, is a device that converts the kinetic energy of wind into mechanical energy, and then into electrical energy. The working principle of a wind turbine is based on the conversion of wind energy. When wind blows across the rotor, the rotor captures the kinetic energy of the wind and begins to rotate. The rotation of the rotor is transmitted to the generator through a transmission system, and the generator converts the mechanical energy into electrical energy. Finally, the electrical energy is transmitted to the power grid through cables for people to use. Cable twisting devices, also commonly known as cable protection devices, are devices specifically used to secure and protect cables, especially important in equipment such as wind turbines that require frequent rotation and yaw.

[0003] Chinese Patent (CN103647245A) discloses a cable twisting device for wind turbine generators, comprising a twisting rotor, a twisting guide rail, and a connecting bracket. The twisting guide rail is an annular guide rail, connected to the wind turbine tower via the connecting bracket. The twisting rotor rotates within the annular twisting guide rail. The twisting rotor has a circular hole matching the size of the main cable, and the cable and bundled signal / data cables are placed within this hole. The circular hole and the main cable or bundled signal / data cables are in clearance fit. This device reduces wear between cables and between cables and the annular guide rail by placing the main cable and signal / data cables within the circular hole, and by allowing the entire twisting rotor to rotate freely within the open annular guide rail. While current cable twisting devices can perform cable twisting, they still present some problems in use. The cable assembly process is cumbersome, and during twisting after assembly, the cable slides within the cable hole because its length remains constant. If the coefficient of friction between the cable and the cable hole is high, twisting can easily cause wear and tear on the cable, failing to protect it and even damaging it. Therefore, their practical application is ineffective. To address these issues, there is an urgent need for a cable twisting device for wind turbine units. Summary of the Invention

[0004] The purpose of this invention is to address the problems that exist in current cable twisting devices, which, while capable of twisting cables, still have issues during use. These include cumbersome cable assembly procedures, and the fact that the cable, due to its constant length, slides within the cable hole during twisting. If the coefficient of friction between the cable and the cable hole is high, twisting can easily cause wear and tear on the cable, failing to protect it and even damaging it, resulting in poor practical application. Therefore, this invention proposes a cable twisting device for wind turbine generators.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a cable twisting device for wind turbine generators, comprising a mounting base, wherein a cable twisting motor and a limiting slide rod are fixedly installed inside the mounting base, and a plurality of wire-passing holes are provided on the bottom surface of the mounting base, and a mounting shaft is fixedly installed at one end of the output shaft of the cable twisting motor;

[0006] A cable twisting mechanism and an oil guiding assembly are fixedly installed on the outside of the mounting shaft. The cable twisting mechanism is used for the stable twisting of the main cable, and the oil guiding assembly is used for the lubrication and protection of the cable exterior. A top stud is fixedly installed at the top of the mounting shaft, and a moving wire splitting mechanism is movably installed on the outside of the top stud. The moving wire splitting mechanism is used for auxiliary wire splitting during the cable twisting process of the main cable.

[0007] Furthermore, by adopting the above-mentioned solution, not only can the installation of each main cable be completed quickly, but different cables can also be separated from each other to avoid damage caused by twisting when the cables come into contact with each other. At the same time, the adjustable cable conduction component can effectively protect the cable during twisting to avoid damage. In addition, after twisting, the cable can be longitudinally positioned to a certain extent to prevent further twisting, which greatly improves the actual application effect of the overall device.

[0008] As a further description of the above technical solution:

[0009] The cable twisting mechanism includes a cable twisting disc, the inside of which is provided with multiple cable holes. The sidewalls of the cable holes are provided with mounting grooves, and a cable conduction assembly is movably installed inside the mounting grooves.

[0010] As a further description of the above technical solution:

[0011] The cable conduction assembly includes a mounting plate, which is slidably installed inside the mounting groove. A side top spring and a control motor are fixedly installed on one outer wall of the mounting plate.

[0012] As a further description of the above technical solution:

[0013] One end of the side top spring is fixedly connected to the inner side wall of the mounting groove. One end of the output shaft of the control motor is fixedly mounted with a side plate. Two roller frames are fixedly mounted on one outer side of the side plate. A positioning guide roller is rotatably mounted between the two roller frames via a rotating shaft.

[0014] As a further description of the above technical solution:

[0015] The motion splitter mechanism includes a mounting cover, on the inner side of which multiple cable separators are fixedly mounted. A threaded cylinder is fixedly mounted at one end of each cable separator, and the top stud and the threaded cylinder are threadedly connected to each other.

[0016] As a further description of the above technical solution:

[0017] The cable separator has mounting grooves on both outer walls, and the mounting cover is slidably connected to the limiting slide rod through the sliding holes inside.

[0018] As a further description of the above technical solution:

[0019] A guide rail is fixedly installed on the inner wall of the mounting side groove, and a protective wire splitter assembly is slidably installed on the guide rail. The protective wire splitter assembly includes two moving sliders, which are slidably installed on the guide rail through sliding grooves provided at both ends.

[0020] As a further description of the above technical solution:

[0021] Multiple connecting springs are fixedly installed on one side of the outer wall of the motion slider. One end of the multiple connecting springs is fixedly connected to one side of the inner wall of the mounting side groove. A protective dividing elastic plate is fixedly installed between the two motion sliders. The diameter of the mounting cover is larger than the diameter of the cable twisting disc.

[0022] Furthermore, by adopting the above scheme, while the cable twisting disc is twisting the cable, the protective branching elastic plate can be used to branch the twisted cable, which can further improve the elimination effect and efficiency of cable twisting. At the same time, since the protective branching elastic plate has a certain elasticity, it will not make hard contact with the cable, which can protect the cable to a certain extent and further improve the application effect of the equipment.

[0023] As a further description of the above technical solution:

[0024] The oil guiding assembly includes an oil reservoir, which is fixedly installed on the top surface of the cable twisting disc. The oil reservoir is installed on the outside of the mounting shaft through a through hole located in its middle position.

[0025] As a further description of the above technical solution:

[0026] The top surface of the oil reservoir is provided with multiple oil injection nozzles, and the outer surface of the oil reservoir is provided with multiple oil spray nozzles.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. In this invention, a cable twisting mechanism is provided to guide the generator main cable through the moving branching mechanism, then through the cable hole and the cable twisting disc, and finally through the cable threading hole of the mounting base. At this time, the cable can contact multiple positioning guide rollers in the cable hole. When the cable twists, the cable twisting motor is activated, and the mounting shaft is rotated in the opposite direction of the cable twisting. The mounting shaft drives the cable twisting disc to rotate. At this time, the control motor is activated, driving the side disc to rotate, thereby controlling the positioning guide rollers to be in a horizontal position. When the cable twisting disc rotates, it can twist the cable, gradually eliminating the cable twisting. When the cable is twisted, since the cable is in direct contact with the positioning guide rollers, when the cable shakes or moves during twisting, the positioning guide rollers can automatically rotate. The device moves without causing significant friction with the cable, providing excellent protection. After twisting, the cable twisting is largely eliminated. The control motor then rotates the positioning roller vertically, fixing the cable's longitudinal position. This design not only allows for rapid installation of all main cables but also separates different cables, preventing damage from twisting. The adjustable cable conduction assembly effectively protects the cable during twisting, preventing damage, and provides longitudinal positioning after twisting to prevent further twisting, significantly improving the overall effectiveness of the device.

[0029] 2. In this invention, a moving cable-splitting mechanism is provided. When the cable is twisted, the mounting shaft can synchronously drive the top stud to rotate. When the top stud rotates, the moving cable-splitting mechanism can be synchronously displaced. During the displacement of the moving cable-splitting mechanism, since each main cable entering the cable hole is separated between different cable separators, the different cable separators and multiple protective cable-splitting components can also move synchronously. The multiple protective cable-splitting components can contact different cables and squeeze them, ultimately achieving gradual separation of the twisted cable. The device is equipped with a protective branching spring plate with a connecting spring. This protective branching spring plate can effectively apply a certain pressure to the cable, and together with the cable twisting reel, it can eliminate cable twisting. Through this design, while the cable twisting reel is twisting the cable, the protective branching spring plate can separate the twisted cable, which can further improve the elimination effect and efficiency of cable twisting. At the same time, because the protective branching spring plate has a certain elasticity, it will not make hard contact with the cable, which can protect the cable to a certain extent and further improve the application effect of the equipment.

[0030] 3. In this invention, by setting up an oil guiding component, when the cable is twisted, the rotation of the twisting mechanism can drive the oil guiding component on it to rotate synchronously. As the equipment continues to work, the centrifugal force due to the rotation in the oil guiding component will be concentrated at each oil nozzle, and finally discharged to the outer cable through the oil nozzle, thereby achieving lubrication and maintenance of the cable exterior. This can further reduce the friction of the cable exterior and provide further protection for the cable during twisting. Moreover, no manual management is required, and the practical application effect is good. Attached Figure Description

[0031] Figure 1 This is a three-dimensional structural diagram of a cable twisting device for wind turbine units.

[0032] Figure 2 This is a three-dimensional structural diagram of a cable twisting device for wind turbine units from another angle.

[0033] Figure 3 This is a three-dimensional structural diagram of the moving wire splitting mechanism and the cable twisting mechanism in a cable twisting device for wind turbine units, taken from another angle.

[0034] Figure 4 This is an exploded three-dimensional structural diagram of the moving wire-splitting mechanism and the cable-twisting mechanism in a cable twisting device for wind turbine units.

[0035] Figure 5 This is an exploded three-dimensional structural diagram of the cable twisting mechanism in a cable twisting device for wind turbine units.

[0036] Figure 6 This is an exploded three-dimensional structural diagram of a moving wire-splitting mechanism in a cable twisting device for wind turbine units.

[0037] Figure 7 This is a three-dimensional structural diagram of a protective branching component in a cable twisting device for wind turbine generators.

[0038] Figure 8 This is a three-dimensional structural diagram of a cable conduction component in a cable twisting device for wind turbine generators.

[0039] Figure 9 A cable twisting device for wind turbine generators Figure 4 A magnified structural diagram of point A in the middle.

[0040] Legend:

[0041] 1. Top stud; 2. Limiting slide bar; 3. Cable threading hole; 4. Motion cable distribution mechanism; 41. Protective cable distribution assembly; 411. Slide groove; 412. Protective cable distribution elastic plate; 413. Motion slider; 414. Connecting spring; 42. Slide hole; 43. Mounting cover; 44. Cable separator plate; 45. Mounting side groove; 46. Threaded cylinder; 5. Cable twisting mechanism; 51. Cable hole; 52. Mounting inner groove; 53. Cable twisting disc; 54. Cable conduction assembly; 541. Side top spring; 542. Mounting plate; 543. Side disc; 544. Positioning conduction roller; 545. Roller frame; 546. Control motor; 6. Mounting shaft; 7. Mounting base; 8. Cable twisting motor; 9. Oil guide assembly; 91. Oil reservoir; 92. Oil injector; 93. Oil spray nozzle. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Please see Figures 1-9 The present invention provides a technical solution: a cable twisting device for wind turbine generators, including a mounting base 7, wherein a cable twisting motor 8 and a limiting slide rod 2 are fixedly installed inside the mounting base 7, and a plurality of wire through holes 3 are provided on the bottom surface of the mounting base 7, and a mounting shaft 6 is fixedly installed at one end of the output shaft of the cable twisting motor 8.

[0044] The cable twisting mechanism 5 and the oil guiding component 9 are fixedly installed on the outside of the mounting shaft 6. The cable twisting mechanism 5 is used for the stable twisting of the main cable, and the oil guiding component 9 is used for the lubrication and protection of the cable. The top of the mounting shaft 6 is fixedly installed with a top stud 1, and a moving wire splitting mechanism 4 is movably installed on the outside of the top stud 1. The moving wire splitting mechanism 4 is used for auxiliary wire splitting during the cable twisting process of the main cable.

[0045] The cable twisting mechanism 5 includes a cable twisting disc 53, which has multiple cable holes 51 inside. The sidewall of each cable hole 51 has an inner mounting groove 52, and a cable conduction assembly 54 is movably installed inside the inner mounting groove 52.

[0046] The cable conduction assembly 54 includes a mounting plate 542, which is slidably installed inside the mounting inner groove 52. A side top spring 541 and a control motor 546 are fixedly installed on one outer wall of the mounting plate 542. One end of the side top spring 541 is fixedly connected to the inner side wall of the mounting inner groove 52. A side plate 543 is fixedly installed on one end of the output shaft of the control motor 546. Two roller frames 545 are fixedly installed on one outer wall of the side plate 543. A positioning conduction roller 544 is rotatably installed between the two roller frames 545 through a rotating shaft.

[0047] The specific implementation method is as follows: The generator main cable first passes through the motion distribution mechanism 4, then through the cable hole 51 and the cable twisting disc 53, and finally through the cable threading hole 3 of the mounting base 7. At this time, the cable can contact the multiple positioning guide rollers 544 in the cable hole 51. When the cable twists, the cable twisting motor 8 is turned on, and the mounting shaft 6 is rotated in the opposite direction of the cable twisting. The mounting shaft 6 can drive the cable twisting disc 53 on it to rotate. At this time, the control motor 546 is turned on, driving the side disc 543 to rotate, thereby controlling the positioning guide rollers 544 to be in a horizontal position. When the cable twisting disc 53 rotates, it can twist the cable, gradually eliminating the twisting. During the cable twisting, since the cable is in direct contact with the positioning guide roller 544, the positioning guide roller 544 can rotate automatically when the cable shakes or moves during twisting, without generating much friction with the cable, thus providing good protection for the cable. After the twisting is completed, the twisting of the cable is basically eliminated. At this time, the control motor 546 drives the positioning guide roller 544 to rotate to the vertical direction, which can fix the longitudinal position of the cable.

[0048] This design not only enables the rapid installation of various main cables but also isolates different cables from each other, preventing damage caused by twisting when cables come into contact. Furthermore, the adjustable cable conduction component 54 effectively protects the cables during twisting, preventing damage. It also provides longitudinal positioning of the cables after twisting, preventing further twisting and significantly improving the overall practical application effect of the device.

[0049] The motion splitting mechanism 4 includes a mounting cover 43, on the inner side of which multiple cable separator plates 44 are fixedly mounted. A threaded cylinder 46 is fixedly mounted at one end of each cable separator plate 44. The top stud 1 and the threaded cylinder 46 are threadedly connected to each other. The outer walls on both sides of the cable separator plate 44 are provided with mounting side grooves 45. The mounting cover 43 is slidably connected to the limiting slide rod 2 through the sliding hole 42 provided inside it.

[0050] A guide rail is fixedly installed on the inner wall of the mounting side groove 45, and a protective cable splitter assembly 41 is slidably installed on the guide rail. The protective cable splitter assembly 41 includes two moving sliders 413. The moving sliders 413 are slidably installed on the guide rail through the sliding grooves 411 provided at both ends. A plurality of connecting springs 414 are fixedly installed on one outer wall of the moving sliders 413. One end of the plurality of connecting springs 414 is fixedly connected to one inner wall of the mounting side groove 45. A protective cable splitter elastic plate 412 is fixedly installed between the two moving sliders 413. The diameter of the mounting cover 43 is larger than the diameter of the cable twisting disc 53.

[0051] The specific implementation method is as follows: When twisting the cable, the mounting shaft 6 can synchronously drive the top stud 1 to rotate. When the top stud 1 rotates, it can control the synchronous displacement of the moving branching mechanism 4. When the moving branching mechanism 4 is displaced, since each main cable entering the cable hole 51 is separated between different cable separator plates 44, the different cable separator plates 44 and multiple protective branching components 41 can also be displaced synchronously. Multiple protective branching components 41 can contact different cables and squeeze them, ultimately realizing the gradual branching of the twisted cable. Since the protective branching component 41 is equipped with a protective branching elastic plate 412 with a connecting spring 414, the protective branching elastic plate 412 can effectively apply a certain pressure to the cable, which, together with the twisting disc 53, can eliminate the cable twisting.

[0052] This design allows the cable twisting disc 53 to twist the cable while the protective branching elastic plate 412 branches the twisted cable, further improving the elimination effect and efficiency of cable twisting. At the same time, since the protective branching elastic plate 412 has a certain elasticity, it will not make hard contact with the cable, thus protecting the cable to a certain extent and further improving the application effect of the equipment.

[0053] The oil guiding assembly 9 includes an oil storage box 91, which is fixedly installed on the top surface of the cable twisting disc 53. The oil storage box 91 is installed on the outside of the mounting shaft 6 through a through hole located in its middle position. Multiple oil injection nozzles 92 are provided on the top surface of the oil storage box 91, and multiple oil spray nozzles 93 are provided on the outer surface of the oil storage box 91.

[0054] The specific implementation method is as follows: When twisting the cable, the twisting mechanism 5 rotates, which drives the oil guiding component 9 on it to rotate synchronously. As the equipment continues to work, the centrifugal force due to the rotation in the oil guiding component 9 will be concentrated at each oil nozzle 93. Finally, it can be led out to the outside of the cable through the oil nozzle 93 to achieve lubrication and maintenance of the cable exterior. It can further reduce the friction of the cable exterior and provide further protection for the cable when twisting it. Moreover, it does not require manual management and has good practical application effect.

[0055] Working principle: The generator main cable first passes through the motion distribution mechanism 4, then through the cable hole 51 and the cable twisting disc 53, and finally through the cable threading hole 3 of the mounting base 7. At this time, the cable can contact the multiple positioning guide rollers 544 in the cable hole 51. When the cable twists, the cable twisting motor 8 is turned on, and the mounting shaft 6 is rotated in the opposite direction of the cable twisting. The mounting shaft 6 can drive the cable twisting disc 53 on it to rotate. At this time, the control motor 546 is turned on, driving the side disc 543 to rotate, thereby controlling the positioning guide rollers 544 to be in a horizontal position. When the cable twisting disc 53 rotates, it can twist the cable, gradually eliminating the twisting of the cable. When twisting the cable, since the cable is in direct contact with the positioning guide roller 544, when the cable shakes or moves during twisting, the positioning guide roller 544 can rotate automatically without generating much friction with the cable, thus providing good protection for the cable. After twisting is completed, the twisting of the cable is basically eliminated. At this time, the control motor 546 drives the positioning guide roller 544 to rotate to the vertical direction, which can fix the longitudinal orientation of the cable.

[0056] When twisting the cable, the mounting shaft 6 can synchronously drive the top stud 1 to rotate. When the top stud 1 rotates, it can control the synchronous displacement of the moving branching mechanism 4. When the moving branching mechanism 4 is displaced, since each main cable entering the cable hole 51 is separated between different cable separator plates 44, the different cable separator plates 44 and multiple protective branching components 41 can also be displaced synchronously. Multiple protective branching components 41 can contact different cables and squeeze them, ultimately realizing the gradual separation of the twisted cable. Since the protective branching component 41 is equipped with a protective branching elastic plate 412 with a connecting spring 414, the protective branching elastic plate 412 can effectively apply a certain pressure to the cable, which, together with the twisting disc 53, can eliminate the cable twisting.

[0057] When twisting the cable, the twisting mechanism 5 rotates, which drives the oil guiding component 9 on it to rotate synchronously. As the equipment continues to work, the centrifugal force due to the rotation in the oil guiding component 9 will be concentrated at each oil nozzle 93. Finally, it can be led out to the outside of the cable through the oil nozzle 93 to achieve lubrication and maintenance of the cable exterior. This can further reduce the friction of the cable exterior and provide further protection for the cable when twisting it.

[0058] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A cable twisting device for wind turbine generators, comprising a mounting base (7), characterized in that: The mounting base (7) is fixedly installed with a cable twisting motor (8) and a limiting slide rod (2). Multiple wire holes (3) are provided on the bottom surface of the mounting base (7). One end of the output shaft of the cable twisting motor (8) is fixedly installed with a mounting shaft (6). The cable twisting mechanism (5) and the oil guiding assembly (9) are fixedly installed on the outside of the mounting shaft (6). The cable twisting mechanism (5) is used for the stable twisting of the main cable, and the oil guiding assembly (9) is used for the lubrication and protection of the cable. A top stud (1) is fixedly installed on the top of the mounting shaft (6). A moving wire splitting mechanism (4) is movably installed on the outside of the top stud (1). The moving wire splitting mechanism (4) is used for auxiliary wire splitting during the cable twisting process of the main cable. The cable twisting mechanism (5) includes a cable twisting disc (53). The inside of the cable twisting disc (53) is provided with multiple cable holes (51). The side wall of the cable holes (51) is provided with an inner mounting groove (52). The inner mounting groove (52) is movable inside. A cable conduction assembly (54) is dynamically installed. The cable conduction assembly (54) includes a mounting plate (542). The mounting plate (542) is slidably installed inside the mounting inner groove (52). A side top spring (541) and a control motor (546) are fixedly installed on one side outer wall of the mounting plate (542). One end of the side top spring (541) is fixedly connected to the inner side wall of the mounting inner groove (52). A side plate (543) is fixedly installed on one end of the output shaft of the control motor (546). Two roller frames (545) are fixedly installed on one side outer wall of the side plate (543). A positioning conduction roller (544) is rotatably installed between the two roller frames (545) through a rotating shaft.

2. The cable twisting device for wind turbine generators according to claim 1, characterized in that, The motion splitting mechanism (4) includes a mounting cover (43), on the inner side of the mounting cover (43) a plurality of cable separators (44) are fixedly installed, and a threaded cylinder (46) is fixedly installed at one end of the plurality of cable separators (44), and the top stud (1) and the threaded cylinder (46) are threadedly connected to each other.

3. A cable twisting device for wind turbine units according to claim 2, characterized in that, The cable separator (44) has mounting side grooves (45) on both outer walls, and the mounting cover (43) is slidably connected to the limiting slide rod (2) through the sliding hole (42) inside it.

4. A cable twisting device for wind turbine generators according to claim 3, characterized in that, A guide rail is fixedly installed on the inner wall of the mounting side groove (45), and a protective branch assembly (41) is slidably installed on the guide rail.

5. A cable twisting device for wind turbine generators according to claim 4, characterized in that, The protection branch assembly (41) includes two motion sliders (413), which are slidably mounted on the guide rail via grooves (411) provided at both ends.

6. A cable twisting device for wind turbine generators according to claim 5, characterized in that, Multiple connecting springs (414) are fixedly installed on one side of the outer wall of the motion slider (413). One end of the multiple connecting springs (414) is fixedly connected to one side of the inner wall of the mounting side groove (45). A protective dividing elastic plate (412) is fixedly installed between the two motion sliders (413). The diameter of the mounting cover (43) is larger than the diameter of the cable twisting disc (53).

7. A cable twisting device for wind turbine units according to claim 6, characterized in that, The oil guiding assembly (9) includes an oil storage box (91), which is fixedly installed on the top surface of the cable twisting disc (53). The oil storage box (91) is installed on the outside of the mounting shaft (6) through a through hole located in its middle position.

8. A cable twisting device for wind turbine generators according to claim 7, characterized in that, Multiple oil injection nozzles (92) are provided on the top surface of the oil storage box (91), and multiple oil spray nozzles (93) are provided on the outer surface of the oil storage box (91).

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