Positioning tool for mounting aircraft wings

Abstract

The invention discloses a positioning tool for aircraft wing installation, and belongs to the technical field of aircraft wing installation, the positioning tool comprises three hydraulic telescopic cylinders and a supporting mechanism for installing and supporting the hydraulic telescopic cylinders; the three hydraulic telescopic cylinders are distributed on the supporting mechanism in a triangular shape. The output end of the hydraulic telescopic cylinder is provided with a rotary adjusting supporting assembly used for supporting wing installation. The rotary adjusting and supporting assembly comprises a supporting rod fixedly connected to the output end of the hydraulic telescopic cylinder; the rotating sleeve is rotationally connected to the upper end part of the supporting rod; the supporting rod rotatably supports the rotating sleeve; the bottom bracket is fixedly connected to the rotating sleeve; and the top bracket is mounted on the bottom bracket. According to the positioning tool, the wing is lifted through the whole positioning tool, and it is ensured that the position shape of the root of the wing meets the position requirement of the opening in the fuselage, so that the wing is more stable and accurate in the installation process, and the installation efficiency and the installation effect are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft wing installation, and particularly relates to a positioning tooling for aircraft wing installation. Background Art

[0002] The wing is one of the important components of an aircraft. It is installed on the fuselage. Its main function is to generate lift and, together with the tail wing, form good stability and maneuverability. Additionally, ammunition, equipment, and fuel tanks can be loaded inside the wing, and landing gears, engines, suspended missiles, auxiliary fuel tanks, and other external hanging devices can be installed on the wing.

[0003] As one of the important components of an aircraft, the wing is constructed by connecting multiple levels of webs, crossbeams, and skins, and is supported by accessories such as upper and lower chord horizontal supports, purlins, bracing bars, and tie rods. Various hydraulic and electrical operating devices are interspersed during this process; After the wings on the left and right sides of the aircraft are respectively assembled, they will be bolted to the connection center block on the fuselage. Before docking, it is necessary to adjust the overall attitude of the wing to accurately cut the root of the wing into the opening on the fuselage and fit it with the connection center block. Since the overall volume of the wing is large and heavy after assembly and there is no lifting ring on the wing, it is impossible to lift the wing by hoisting, so it is very difficult to cut the root of the wing into the fuselage, which affects the work efficiency and work quality during wing installation. Therefore, a positioning tooling for aircraft wing installation is proposed to solve the above problems. Summary of the Invention

[0004] (I) Object of the Invention To solve the technical problems in the background art, the present invention proposes a positioning tooling for aircraft wing installation. The rotation adjustment support assembly at the output end of the hydraulic telescopic cylinder can be telescoped and rotationally adjusted to closely fit and support according to the wing specifications, with advantages such as improving installation efficiency and installation effect.

[0005] (II) Technical Solution The present invention provides a positioning tooling for aircraft wing installation, including: Three hydraulic telescopic cylinders and a support mechanism for installing and supporting the hydraulic telescopic cylinders; the three hydraulic telescopic cylinders are distributed in a triangular shape on the support mechanism; A rotation adjustment support assembly for supporting the wing installation is provided at the output end of the hydraulic telescopic cylinder; The rotation adjustment support assembly includes: A support rod, fixedly connected to the output end of the hydraulic telescopic cylinder; a rotating sleeve, rotatably connected to the upper end of the support rod; the support rod rotatably supports the rotating sleeve; Bottom bracket, fixedly connected to the rotating sleeve; top bracket, mounted on the bottom bracket; control shaft, rotatably connected to the connection between the bottom bracket and the top bracket, and the bottom bracket and the top bracket are rotatably connected through the control shaft; support plate, fixedly connected to the top bracket; the bottom bracket cooperates with the control shaft to rotatably support the top bracket; Two groups of adjusting brackets, respectively mounted on the bottom bracket and the top bracket; two connecting shafts, respectively rotatably connected between the two groups of adjusting brackets; lifting screw, rotatably connected to the top connecting shaft and passing through the bottom connecting shaft; the rotating and adjusting lifting screw pushes the top adjusting bracket to drive the top bracket and the support plate to rotate and adjust.

[0006] Preferably, a limiting ring located inside the rotating sleeve is fixedly connected to the upper end of the support rod, and an annular limiting groove for the limiting ring to rotate is provided on the inner wall of the rotating sleeve.

[0007] Preferably, an adjusting knob is fixedly connected to the end of the lifting screw away from the connecting shaft, and an anti-slip rubber pad is fixedly connected to the upper surface of the support plate.

[0008] Preferably, a first threaded hole is provided in the middle of the top connecting shaft, and the thread on the outer side of the first threaded hole is matched with the thread on the outer side of the lifting screw.

[0009] Preferably, the support mechanism includes: vertical plate; Two rotating frames, hinged to one side of the vertical plate; a connecting frame is fixedly connected to one side of the vertical plate and is located between the two rotating frames; an adjusting plate, slidably connected to the other side of the vertical plate; an adjusting screw, rotatably connected to the vertical plate and the connecting frame and passing through the adjusting plate; a driving block, threadedly connected to the adjusting screw; a hinged rod, hinged between the two rotating frames and one driving block; Limit members for supporting and limiting the rotation of the rotating frame are provided on the rotating frame and the vertical plate.

[0010] Preferably, second threaded holes are provided in the middle of the driving block and the adjusting plate, and the thread on the outer side of the second threaded hole is matched with the thread on the outer side of the adjusting screw. The thread on the outer side of the adjusting screw is in two sections, and the two sections of the thread are symmetrically distributed.

[0011] Preferably, a cross bar passing through the adjusting plate at one end is fixedly connected to the side of the vertical plate away from the rotating frame, and the rotating frame is U-shaped.

[0012] Preferably, the limiting member includes: Two support rings, symmetrically fixed on the vertical plate, and the support rings are distributed centered on the hinge point of the rotating frame and the vertical plate; two limit columns, respectively fixedly connected to the two rotating frames and passing through the support rings; a limit sleeve, threadedly connected to the upper end of the limit column; Annular hole, opened on the support ring for the limit post to rotate circularly; The inner peripheral wall of the limit sleeve is provided with internal threads, and the outer surface of the upper end of the limit post is provided with external threads, and the internal threads are adapted to the external threads.

[0013] Preferably, moving wheels are installed on the lower surfaces of the connecting frame, the adjusting plate and the rotating frame, and the moving wheels on the adjusting plate and the rotating frame are symmetrically distributed in pairs of two. Handrails are fixedly connected to both of the rotating frames.

[0014] Compared with the prior art, the above technical solution of the present invention has the following beneficial technical effects: 1. The positioning tooling for aircraft wing installation holds the wing through the whole positioning tooling, ensuring that the shape of the wing root position conforms to the position requirements of the opening on the fuselage, so that the wing is more stable and accurate during the installation process, thereby improving the installation efficiency and installation effect.

[0015] 2. The positioning tooling for aircraft wing installation adjusts the length of the output end of the hydraulic telescopic cylinder and the position of the rotating and adjusting support assembly, so that the support plates of the three rotating and adjusting support assemblies are closely attached to the lower surface of the wing, so as to improve the stability of the whole positioning tooling for holding the wing.

[0016] 3. The whole support mechanism adjusts the orientation of the rotating frame and the adjusting plate by rotating the adjusting screw rod during the process of supporting the hydraulic telescopic cylinder, and can adjust the orientation of the three hydraulic telescopic cylinders, so that the support plates of the rotating and adjusting support assembly can be adapted to wings of different specifications for assembly, improving the adaptability of the whole positioning work.

[0017] 4. After the whole support mechanism is extended and adjusted, by rotating the limit sleeve onto the limit post and abutting against the support ring to support and stabilize the rotating frame, the stability of the whole support mechanism after extension and adjustment can be provided. Description of the Drawings

[0018] Figure 1 Is a three-dimensional view of the overall structure of the present invention; Figure 2 Is a schematic structural diagram of the rotating and adjusting support assembly of the present invention; Figure 3 Is a sectional view of the connection structure of the support rod and the rotating sleeve of the present invention; Figure 4 Is a bottom view sectional view of the support mechanism structure of the present invention; Figure 5 Is a schematic connection diagram of the limiting member structure of the present invention.

[0019] Reference numerals: 1, support mechanism; 11, vertical plate; 12, connecting frame; 13, adjusting screw; 14, driving block; 15, hinge rod; 16, limiting member; 161, support ring; 162, annular hole; 163, limiting column; 164, limiting sleeve; 17, adjusting plate; 18, rotating frame; 19, cross bar; 2, hydraulic telescopic cylinder; 3, rotary adjusting support assembly; 31, support rod; 32, rotating sleeve; 33, bottom bracket; 34, control shaft; 35, top bracket; 36, support plate; 37, adjusting bracket; 38, connecting shaft; 39, lifting screw; 310, adjusting knob; 311, limiting ring; 4, moving wheel; 5, handrail. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the detailed implementation manners and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. are based on the orientation or positional relationships shown in the drawings. These 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, and thus should not be construed as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, such as welding, riveting, bonding, etc., or a detachable connection, such as screw connection, key connection, pin connection, etc., or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] As Figures 1-5 shown, a positioning tooling for aircraft wing installation proposed by the present invention includes: Three hydraulic telescopic cylinders 2 and a support mechanism 1 for installing and supporting the hydraulic telescopic cylinders 2; the three hydraulic telescopic cylinders 2 are distributed in a triangular shape on the support mechanism 1; The output end of the hydraulic telescopic cylinder 2 is provided with a rotary adjustment support assembly 3 for supporting the wing installation.

[0024] In the present invention, the docking end and the end far from the fuselage of the wing are stably supported by the hydraulically telescopic cylinders 2 distributed in a triangular shape and the rotary adjustment support assembly 3 at the output end of the hydraulically telescopic cylinder 2, and the orientation can also be adjusted during the wing docking process to improve the accuracy of the wing docking and installation.

[0025] In an alternative embodiment, the rotary adjustment support assembly 3 includes: A support rod 31, fixedly connected to the output end of the hydraulic telescopic cylinder 2; a rotating sleeve 32, rotatably connected to the upper end of the support rod 31; the support rod 31 rotatably supports the rotating sleeve 32. A bottom bracket 33, fixedly connected to the rotating sleeve 32; a top bracket 35, mounted on the bottom bracket 33; a control shaft 34, rotatably connected to the connection between the bottom bracket 33 and the top bracket 35, and the bottom bracket 33 and the top bracket 35 are rotatably connected through the control shaft 34; a support plate 36, fixedly connected to the top bracket 35, and an anti-slip rubber pad is fixedly connected to the upper surface of the support plate 36 to increase the friction force after the support plate 36 fits the wing; the bottom bracket 33 cooperates with the control shaft 34 to rotatably support the top bracket 35. Two groups of adjustment brackets 37, respectively mounted on the bottom bracket 33 and the top bracket 35; two connecting shafts 38, respectively rotatably connected between the two groups of adjustment brackets 37; a lifting screw 39, rotatably connected to the top connecting shaft 38 and passing through the bottom connecting shaft 38, and an adjustment knob 310 is fixedly connected to the end of the lifting screw 39 far from the connecting shaft 38 to facilitate the operator to rotate the lifting screw 39; the rotating and adjusting lifting screw 39 pushes the top adjustment bracket 37 to drive the top bracket 35 and the support plate 36 to rotate and adjust.

[0026] In this embodiment, by adjusting the length of the output end of the hydraulic telescopic cylinder 2 and the position of the rotary adjustment support assembly 3, the support plates 36 of the three rotary adjustment support assemblies 3 are perfectly fitted with the lower surface of the wing to improve the stability of the entire positioning tooling for lifting the wing.

[0027] It should be noted that a limit ring 311 located inside the rotating sleeve 32 is fixedly connected to the upper end of the support rod 31, and an annular limit groove for the limit ring 311 to rotate is provided on the inner wall of the rotating sleeve 32, so that the rotating sleeve 32 is limited by the cooperation of the limit ring 311 and the annular limit groove and can stably rotate at the upper end of the support rod 31 to drive the support plate 36 to rotate and adjust in the horizontal plane orientation.

[0028] Among them, a first threaded hole is provided in the middle of the top connecting shaft 38, and the first threaded hole is matched with the thread on the outer side of the lifting screw 39. Since the two connecting shafts 38 can rotate on the two groups of adjusting brackets 37 respectively, and the support plate 36 rotates on the control shaft 34 through the top bracket 35, by rotating the lifting screw 39 to lift or pull the top connecting shaft 38 and the top adjusting bracket 37 to rotate around the control shaft 34, the support plate 36 can be driven to rotate and adjust around the control shaft 34.

[0029] In an alternative embodiment, the support mechanism 1 includes: a vertical plate 11; Two rotating frames 18 are hinged to one side of the vertical plate 11; a connecting frame 12 is fixedly connected to one side of the vertical plate 11 and is located between the two rotating frames 18; an adjusting plate 17 is slidably connected to the other side of the vertical plate 11; an adjusting screw 13 is rotatably connected to the vertical plate 11 and the connecting frame 12 and penetrates through the adjusting plate 17; a driving block 14 is threadedly connected to the adjusting screw 13; a hinge rod 15 is hinged between the two rotating frames 18 and a driving block 14; A limiting member 16 for supporting and limiting the rotating frame 18 is provided on the rotating frame 18 and the vertical plate 11.

[0030] In this embodiment, during the process of the entire support mechanism 1 supporting the hydraulic telescopic cylinder 2, by rotating the adjusting screw 13 to extend and adjust the orientations of the rotating frame 18 and the adjusting plate 17, the orientations of the three hydraulic telescopic cylinders 2 can be adjusted, so that the support plate 36 of the rotary adjusting support assembly 3 can be adapted to wings of different specifications for assembly, improving the adaptability of the entire positioning work.

[0031] It should be noted that second threaded holes are provided in the middle of both the driving block 14 and the adjusting plate 17, and the second threaded holes are matched with the thread on the outer side of the adjusting screw 13. The thread on the outer side of the adjusting screw 13 is in two sections, and the two sections of the thread are symmetrically distributed, so that the rotating adjusting screw 13 can drive the driving block 14 and the adjusting plate 17 to move and adjust towards or away from one side of the vertical plate 11.

[0032] Among them, a cross bar 19 fixedly connected to one side of the vertical plate 11 away from the rotating frame 18 penetrates through the adjusting plate 17. By means of the cross bar 19 penetrating through the adjusting plate 17, the stability of the adjusting plate 17 during the adjustment process is improved. The rotating frame 18 is U-shaped, and the hinge rod 15 is located inside the rotating frame 18.

[0033] In an alternative embodiment, the limiting member 16 includes: Two support rings 161 are symmetrically fixed on the vertical plate 11 and are distributed around the hinge joint between the rotating frame 18 and the vertical plate 11; two limit posts 163 are respectively fixedly connected to the two rotating frames 18 and penetrate through the support rings 161; a limit sleeve 164 is threadedly connected to the upper end of the limit post 163; anti-slip rubber blocks are fixedly provided on the upper surface of the support ring 161 and the lower end of the limit sleeve 164. An annular hole 162 is formed in the support ring 161 for the limit post 163 to rotate circularly. Internal threads are provided on the inner peripheral wall of the limit sleeve 164, and external threads are provided on the outer surface of the upper end of the limit post 163, and the internal threads and the external threads are adapted to each other, so that the limit sleeve 164 screwed on the limit post 163 can move and adjust toward the side close to or away from the support ring 161.

[0034] In this embodiment, after the entire support mechanism 1 is extended and adjusted, by rotating the limit sleeve 164 to abut against the support ring 161, after the rotating frame 18 is stably supported, the stability of the entire support mechanism 1 after the extension and adjustment can be provided.

[0035] It should be noted that moving wheels 4 are installed on the lower surfaces of the connecting frame 12, the adjusting plate 17 and the rotating frame 18, and the moving wheels 4 on the adjusting plate 17 and the rotating frame 18 are symmetrically distributed in pairs of two. The connecting frame 12, the adjusting plate 17 and the rotating frame 18 are slidably supported by the five moving wheels 4. At the same time, the adjusting plate 17 and the rotating frame 18 for rotational adjustment are not affected. Handrails 5 are fixedly connected to the two rotating frames 18, which is convenient for the operator to push the rotating frame 18 through the handrails 5 to drive the entire tooling to move.

[0036] The control method of the present invention is automatically controlled by a controller. The control circuit of the controller can be realized by simple programming of those skilled in the art and belongs to the common knowledge in the art. Since the present invention mainly protects the mechanical structure, the control method and circuit connection and other technical means of the present invention will not be described in detail.

[0037] The working principle of the above embodiment is as follows: Since the support rod 31 can rotatably support the rotating sleeve 32 through the limit ring 311, during the process of the support plate 36 supporting the wing, the operator can hold the adjustment knob 310 on the lifting screw rod 39 and rotate it along the horizontal plane, and then rotate the lifting screw rod 39 to lift or pull the top connecting shaft 38 and the top adjustment bracket 37 to rotate around the control shaft 34, and then the support plate 36 can be driven to rotate and adjust around the control shaft 34 to adjust the support orientation of the side of the lower surface of the support plate 36 close to the ground of the wing. At the same time, after the heights of the three support plates 36 are adjusted by the three hydraulic cylinders 2, the three support plates 36 can be closely attached to the lower surface of the wing to stably support the wing. After the standby wing support is stable, the entire tooling and the wing can be pushed to the fuselage through the armrest 5 by the moving wheels 4 for butt-joint installation of the wing and the fuselage. During the butt-joint installation process, the telescopic hydraulic cylinder 2 can also be controlled to extend and retract, and the three support plates 36 can be respectively controlled to rise and fall. The butt-joint angle of the wing during the butt-joint process can also be adjusted to enable the wing to be accurately butt-jointed. During the process of the entire support mechanism 1 supporting the telescopic hydraulic cylinder 2, after rotating the adjusting screw 13 to drive the driving block 14 and the adjusting plate 17 to move and adjust towards the side away from the vertical plate 11, the orientation of the rotating adjusting bracket 18 and the adjusting plate 17 can be extended and adjusted to adjust the distribution orientation of the three telescopic hydraulic cylinders 2, so that the support plates 36 of the rotating adjusting support assembly 3 can be adapted to wings of different specifications for assembly. During the adjustment process of the rotating bracket 18, the limit post 163 on the rotating bracket 18 can rotate together with the rotating bracket 18 in the annular hole 162 of the support ring 161. After the rotating bracket 18 is adjusted, by rotating the limit sleeve 164 onto the limit post 163 and abutting against the support ring 161, after the rotating bracket 18 is supported and stabilized, the stability of the entire support mechanism 1 after extension and adjustment can be provided.

[0038] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A positioning tool for aircraft wing installation, characterized in that, Including: Three hydraulic telescopic cylinders (2) and a support mechanism (1) for mounting and supporting the hydraulic telescopic cylinders (2); the three hydraulic telescopic cylinders (2) are distributed in a triangular shape on the support mechanism (1); The output end of the hydraulic telescopic cylinder (2) is provided with a rotary adjustment support assembly (3) for supporting the wing installation; The rotary adjustment support assembly (3) includes: A support rod (31), fixedly connected to the output end of the hydraulic telescopic cylinder (2); a rotating sleeve (32), rotatably connected to the upper end of the support rod (31); the support rod (31) rotatably supports the rotating sleeve (32); A bottom bracket (33), fixedly connected to the rotating sleeve (32); a top bracket (35), installed on the bottom bracket (33); a control shaft (34), rotatably connected to the connection between the bottom bracket (33) and the top bracket (35), and the bottom bracket (33) and the top bracket (35) are rotatably connected through the control shaft (34); A support plate (36), fixedly connected to the top bracket (35); the bottom bracket (33) cooperates with the control shaft (34) to rotatably support the top bracket (35); Two groups of adjustment brackets (37), respectively installed on the bottom bracket (33) and the top bracket (35); two connecting shafts (38), respectively rotatably connected between the two groups of adjustment brackets (37); a lifting screw (39), rotatably connected to the top connecting shaft (38) and passing through the bottom connecting shaft (38); the rotating and adjusting lifting screw (39) pushes the top adjustment bracket (37) to drive the top bracket (35) and the support plate (36) to rotate and adjust.

2. The positioning tooling for aircraft wing installation according to claim 1, characterized in that, The upper end of the support rod (31) is fixedly connected with a limit ring (311) located inside the rotating sleeve (32), and the inner wall of the rotating sleeve (32) is provided with an annular limit groove for the limit ring (311) to rotate.

3. A positioning tool for aircraft wing installation according to claim 1, characterized in that, One end of the lifting screw (39) away from the connecting shaft (38) is fixedly connected with an adjustment knob (310), and the upper surface of the support plate (36) is fixedly connected with an anti-slip rubber pad.

4. A positioning tool for aircraft wing installation according to claim 1, characterized in that, The middle part of the top connecting shaft (38) is provided with a first threaded hole, and the first threaded hole matches the thread on the outer side of the lifting screw (39).

5. A positioning tool for aircraft wing installation according to claim 1, characterized in that, The support mechanism (1) includes: a vertical plate (11); Two rotating frames (18), hinged to one side of the vertical plate (11); a connecting frame (12) is fixedly connected to one side of the vertical plate (11) and is located between the two rotating frames (18); an adjustment plate (17), slidably connected to the other side of the vertical plate (11); an adjustment screw (13), rotatably connected to the vertical plate (11) and the connecting frame (12) and passing through the adjustment plate (17); a driving block (14), threadedly connected to the adjustment screw (13); a hinged rod (15), hinged between the two rotating frames (18) and a driving block (14); The rotating frame (18) and the vertical plate (11) are provided with a limiting member (16) for supporting and limiting the rotating frame (18).

6. A positioning tool for aircraft wing installation according to claim 5, characterized in that, Both the driving block (14) and the middle part of the adjusting plate (17) are provided with second threaded holes, and the second threaded holes are matched with the threads on the outer side of the adjusting screw (13). The threads on the outer side of the adjusting screw (13) are in two sections, and the two sections of threads are symmetrically distributed.

7. A positioning tool for aircraft wing installation according to claim 5, characterized in that, One side of the vertical plate (11) far from the rotating frame (18) is fixedly connected with a cross bar (19) whose one end penetrates through the adjusting plate (17). The rotating frame (18) is U-shaped.

8. A positioning tool for aircraft wing installation according to claim 5, characterized in that, The limiting member (16) includes: Two support rings (161) symmetrically fixed on the vertical plate (11), and the support rings (161) are distributed with the hinge point of the rotating frame (18) and the vertical plate (11) as the center; two limiting columns (163) respectively fixedly connected to the two rotating frames (18) and penetrating through the support rings (161); a limiting sleeve (164) threadedly connected to the upper end of the limiting column (163); An annular hole (162) is opened on the support ring (161) for the limiting column (163) to rotate circularly; The inner peripheral wall of the limiting sleeve (164) is provided with internal threads, and the outer surface of the upper end of the limiting column (163) is provided with external threads, and the internal threads are adapted to the external threads.

9. A positioning tool for aircraft wing installation according to claim 5, characterized in that, Moving wheels (4) are installed on the lower surfaces of the connecting frame (12), the adjusting plate (17) and the rotating frame (18), and the moving wheels (4) on the adjusting plate (17) and the rotating frame (18) are symmetrically distributed in pairs of two. Handrails (5) are fixedly connected to both of the two rotating frames (18).

Images