Water gate opening and closing device

Abstract

To provide a water gate opening / closing device capable of reducing the size of a speed reduction mechanism including an electric motor, improving the arrangement balance, suppressing an increase in size, and being inexpensive.SOLUTION: A water gate opening / closing device 1 comprises an electric motor 11 arranged on a speed reducer case 10 for raising and lowering a door body, and a worm gear 21 which is provided in the speed reducer case 10 and receives rotation from the electric motor 11 for raising and lowering the door body. The worm gear 21 has a self-locking function. As a result, in the water gate opening / closing device 1, the parts of the reduction mechanism (speed reducer case 10) including the electric motor 11 can be made compact, the arrangement balance can be improved, the size increase can be suppressed, and the cost can be reduced.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a floodgate opening and closing device that raises and lowers or winds a rack bar, a chain, or a wire rope connected to a door body for opening and closing a floodgate, and raises and lowers the door body to open and close the floodgate.

Background Art

[0002] Normally, when opening and closing a floodgate, the door body is raised and lowered by rotationally driving the rotating shaft of an electric motor provided in the floodgate opening and closing device in the opening and closing direction. As a conventional floodgate opening and closing device, there is one in which an electric motor, a speed reducer, and a braking device are integrated. Further, in a conventional floodgate opening and closing device, the main rotating shaft in the speed reducer case extends in the horizontal direction, the electric motor is disposed on the side thereof with respect to the speed reducer case, and the rotating shaft from the electric motor also extends in the horizontal direction (see Patent Documents 1 and 2).

[0003] In such a conventional floodgate opening and closing device, a plurality of gear sets are arranged in the speed reducer case in order to obtain a high reduction ratio, the number of parts increases, and a large planar arrangement space is also required. As a result, the constituent members such as the electric motor and the gears are arranged so as to expand planarly, and the arrangement is unbalanced with respect to the support points of the opening and closing device. Further, in the strength design of a conventional floodgate opening and closing device, the strength design is such that it is safe with respect to the rated torque and the maximum generated torque of the electric motor. That is, in a conventional floodgate opening and closing device, as an overload prevention device, a device that detects an increase in torque in the power transmission path by a limit switch or the like and stops the electric motor is standardly provided, but since the connection to the electric motor is not mechanically interrupted, from the viewpoints of safety and reliability, with respect to the maximum generated torque of the electric motor, a large number of constituent members related to the power transmission path are designed to have sufficient strength to perform their functions.

[0004] Specifically, the maximum generated torque of the electric motor is large, exceeding usually 300% of the rated torque. Due to the necessity in terms of strength, it is necessary to increase the dimensions of a number of components or use expensive materials, which has become a factor in cost increase. Furthermore, generally, for a sluice gate opening and closing device, in case of power loss such as a power failure, it is required to raise and lower the door body manually. However, it was necessary to use an expensive differential gear in order to provide a manual handle for manual operation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] And the present invention has been made in view of such points. It aims to provide an inexpensive sluice gate opening and closing device by making the part of the speed reduction mechanism including the electric motor compact, improving its layout balance, and suppressing the increase in size due to the characteristics of the electric motor.

Means for Solving the Problems

[0007] As means for solving the above problems, the invention according to the sluice gate opening and closing device of claim 1 is a sluice gate opening and closing device for raising and lowering a door body to open and close a sluice gate, comprising: an electric motor disposed on a speed reduction case for raising and lowering the door body; and a worm gear provided in the speed reduction case, to which rotation from the electric motor is transmitted for raising and lowering the door body, the worm gear having a self-locking function. A bevel gear is provided on the worm shaft having the worm gear, and a bevel gear meshing with the bevel gear of the worm shaft is provided at the tip of the rotary slide shaft to which the rotation from the manual handle is transmitted. The rotary slide shaft is configured to be movable along the axial direction so that the bevel gear of the worm shaft and the bevel gear of the rotary slide shaft can mesh and disengage from each other. It is characterized by this. In the invention of claim 1, by arranging the electric motor on the speed reducer case, the planar occupied space can be reduced, and the electric motor can be stably arranged. That is, when the electric motor is arranged on the speed reducer case, the planar occupied space can be reduced as compared with the conventional arrangement where the electric motor is arranged on the side of the speed reducer case. Moreover, since the electric motor is not projected laterally from the speed reducer case and is arranged within the support area of the speed reducer case in a planar manner, the electric motor can be stably arranged. Also, by using a worm gear as the speed reduction mechanism, a higher reduction ratio can be obtained as compared with a spur gear. As a result, it is possible to miniaturize without requiring a plurality of gear sets. Further, since the worm gear has a self-locking function, it is not necessary to provide a braking device for suppressing the fall of the door body, the number of constituent members can be reduced, and cost reduction can be achieved. Note that a geared motor incorporating a reduction gear may be employed for the electric motor. When the door body is raised and lowered by the electric motor, the rotary slide shaft is moved in one direction along the axial direction so that the rotary slide shaft does not rotate, and the meshing between the bevel gear of the rotary slide shaft and the bevel gear of the worm shaft is released. On the other hand, when the door body is raised and lowered by the manual handle, the rotary slide shaft is moved in the other direction along the axial direction so that the bevel gear of the rotary slide shaft and the bevel gear of the worm shaft are in a meshed state. Then, by rotating the manual handle, the door body can be raised and lowered via the worm shaft. As a result, a manual operation function can be ensured without using an expensive differential gear.

[0008] The invention according to the gate opening / closing device of claim 2 is, in the invention of claim 1, The worm shaft extends in the vertical direction, and when the door body is lifted and lowered, the axial load transmitted to the worm shaft is transmitted to a bearing that rotatably supports the lower end portion of the worm shaft. In the invention of claim 2, the load in the downward direction of the door body (the self-weight of the door body), which is the dominant axial load acting on the worm shaft, is transmitted to a bearing that rotatably supports the lower end portion of the worm shaft, which is advantageous for lubrication in an oil bath state, for example, within the speed reducer case. Therefore, this axial load can be safely supported.

[0009] The invention according to the gate opening / closing device of claim 3 is, in the invention of claim 2, characterized in that the rotating shaft from the electric motor and the worm shaft are arranged concentrically with each other. In the invention according to claim 3, the rotating shaft from the electric motor is arranged along the vertical direction, the worm shaft and the rotating shaft are arranged concentrically, and they can be connected in a non-rotatable relative manner without passing through other transmission gears. As a result, it is not necessary to arrange transmission gears or the like in the power transmission path from the rotating shaft to the worm gear, and the number of constituent members such as transmission gears can be reduced, so that the size can be reduced, which also leads to cost reduction.

[0010] The invention according to claim 4 regarding the water gate opening and closing device is characterized in that, in the invention according to claim 2 or 3, between the rotating shaft from the electric motor and the worm shaft, when the difference in rotational torque between them reaches a predetermined value, a mechanical torque limiter is provided to mechanically cut off the power transmission from the rotating shaft of the electric motor to the worm shaft. In the invention according to claim 4, by means of the mechanical torque limiter, when the difference in rotational torque between the rotating shaft from the electric motor and the worm shaft reaches a predetermined value, the power transmission (torque transmission) from the rotating shaft of the electric motor to the worm shaft can be mechanically cut off. As a result, it is not necessary to design the strength of a large number of constituent members on the downstream side related to the power transmission path based on the excessive maximum generated torque of the electric motor, and it is only necessary to design based on a rotational torque slightly larger than the rotational torque from the electric motor during normal operation, and further miniaturization and cost reduction of the device can be achieved. In addition, even when the power transmission from the electric motor is cut off by the mechanical torque limiter, the door body in the suspended state will not fall due to the self-locking function of the worm gear.

Effects of the Invention

[0013] According to the water gate opening and closing device according to the present invention, the part of the speed reduction mechanism including the electric motor can be made compact, and its layout balance can be improved. By providing a mechanical torque limiter for reliable overload prevention, the increase in size due to the characteristics of the electric motor can be suppressed, and the cost can be reduced.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS. 1 to 5. The sluice gate opening / closing devices 1A and 1B according to the first and second embodiments of the present invention are for opening and closing a sluice gate (not shown), and support a door body (not shown) between a pair of left and right gate posts (not shown) constituting the sluice gate so as to be movable up and down. First, the sluice gate opening / closing device 1A according to the first embodiment will be described in detail with reference to FIGS. 1 to 4. As shown in FIG. 1, the sluice gate opening / closing device 1A according to the first embodiment raises and lowers a pair of left and right rack bars 4, 4 extending along the vertical direction to raise and lower the door body, but can be similarly applied to a sluice gate opening / closing device that raises and lowers the door body using a chain or a wire rope. As shown in FIG. 1, by the sluice gate opening / closing device 1A according to the first embodiment, a pair of left and right rack bars 4, 4 are respectively supported so as to be movable up and down, and a door body is respectively suspended from the lower parts of the pair of left and right rack bars 4, 4. A machine base 6 is arranged so as to span between the pair of left and right rack bars 4, 4.

[0016] As shown in FIGS. 1 and 2, the floodgate opening / closing device 1A according to the first embodiment includes a speed reduction case 10 that houses a worm shaft 20 and a worm wheel 34 as a speed reduction mechanism therein, an electric motor 11 disposed on the speed reduction case 10, a pair of interlocking shafts 12, 12 that extend from the speed reduction case 10 toward a pair of left and right rack bars 4, 4 and transmit the rotation from the electric motor 11 via the worm shaft 20 and the worm wheel 34 respectively, a pair of pin gear mechanisms 13, 13 that transmit the rotation from the pair of interlocking shafts 12, 12 respectively and raise and lower the pair of rack bars 4, 4, and a manual operation transmission mechanism 14 that transmits the rotation by the manual operation of an operator to the worm shaft 20 and the worm wheel 34 in the speed reduction case 10.

[0017] The speed reduction case 10 is disposed at substantially the center in the longitudinal direction of the machine base 6 and on its upper surface. The speed reduction case 10 is formed in a rectangular parallelepiped shape having an internal space. The longitudinal direction of the speed reduction case 10 coincides with the width direction (short side direction) of the machine base 6. A worm shaft 20 and a worm wheel 34 are disposed inside the speed reduction case 10 as a speed reduction mechanism. The electric motor 11 is above the speed reduction case 10 and disposed near one end in the width direction of the machine base 6. Near one end in the longitudinal direction of the speed reduction case 10, a rectangular tube-shaped cover member 18 projects upward from its upper surface. The electric motor 11 is disposed on the upper surface of this rectangular tube-shaped cover member 18. In this embodiment, a geared motor with a built-in reduction gear is adopted for the electric motor 11. The rotation of the rotation shaft 11A of the geared motor is reduced by the built-in reduction gear, and the rotation speed is set to about 100 to 200 rpm.

[0018] As shown in Fig. 2, in the speed reducer case 10, the worm shaft 20 is arranged along the vertical direction. A worm gear 21 is provided at the lower part of the worm shaft 20. The worm shaft 20 is rotatably supported in the speed reducer case 10. Specifically, for the worm shaft 20, the part near its upper end is rotatably supported by a pair of upper bearings 24, 24 arranged vertically, and its lower end is rotatably supported by a pair of lower bearings 26, 26 arranged vertically. The upper bearings 24, 24 mainly receive radial loads, and grease is enclosed in each of the upper bearings 24, 24. On the other hand, the lower bearings 26, 26 receive radial and axial loads. The downward movement of the worm shaft 20 is restricted by a pair of lower bearings 26, 26 arranged vertically at the lower side. Incidentally, the upward movement of the lower bearings 26, 26 relative to the speed reducer case 10 is also restricted by, for example, a bearing retainer or the like. The upper end of the worm shaft 20 protrudes into the square tube-shaped cover member 18 from the upper surface of the speed reducer case 10. The rotating shaft 11A from the electric motor 11 extends in the vertical direction. The tip of the rotating shaft 11A from the electric motor 11 is arranged in the square tube-shaped cover member 18. The rotating shaft 11A from the electric motor 11 and the worm shaft 20 are arranged concentrically. The rotating shaft 11A from the electric motor 11 and the worm shaft 20 are connected by a mechanical torque limiter 29 in the square tube-shaped cover member 18.

[0019] The rotating shaft 11A from the electric motor 11 and the worm shaft 20 are connected in a non-rotatable relative manner to each other by a mechanical torque limiter 29 as long as the rotational torque difference between them is within a predetermined range. On the other hand, when the rotational torque difference between the rotating shaft 11A from the electric motor 11 and the worm shaft 20 reaches a predetermined value, the balls or rollers in the mechanical torque limiter 29 move out of the groove against the pressing force of the spring, so that the rotating shaft 11A from the electric motor 11 and the worm shaft 20 rotate idly (relatively rotate) with respect to each other. In short, when the rotational torque difference between the rotating shaft 11A from the electric motor 11 and the worm shaft 20 reaches a predetermined value, the mechanical torque limiter 29 mechanically cuts off the transmission of power (rotational torque) from the rotating shaft 11A of the electric motor 11 to the worm shaft 20. The mechanical torque limiter 29 is protected by a rectangular tubular cover member 18. Referring to FIG. 1, the rectangular tubular cover member 18 is provided with an inspection window 23 of sufficient size (also refer to FIG. 1). Through this inspection window 23, the mechanical torque limiter 29 can be visually inspected, and it can operate stably for a long time.

[0020] When the rotational torque difference between the rotary shaft 11A from the electric motor 11 and the worm shaft 20 reaches a predetermined value, the load from the worm shaft 20 is also disconnected from the brake of the electric motor 11 by the mechanical torque limiter 29. Therefore, if no braking device is provided on the downstream side of the mechanical torque limiter 29 in the power transmission path, the door body will drop. However, in the sluice opening / closing device 1A according to the first embodiment, the self-locking function (described later) of the worm gear 21 and the worm wheel 34 acts as a braking device, so that the dropping of the door body can be prevented. Further, the sluice opening / closing device 1A according to the first embodiment is provided with a limit switch 32 for detecting the power transmission interruption operation of the mechanical torque limiter 29, that is, the power transmission interruption operation of the mechanical torque limiter 29 that occurs when the rotational torque difference between the rotary shaft 11A from the electric motor 11 and the worm shaft 20 reaches a predetermined value. The limit switch 32 is electrically connected to a control device (not shown) that controls the drive of the electric motor 11. In the control device, when the power transmission interruption operation of the mechanical torque limiter 29 is detected by the limit switch 32, the control device controls to stop the drive of the electric motor 11 (interlock circuit).

[0021] As shown in FIGS. 2 and 3, a worm wheel 34 meshes with a worm gear 21 of a worm shaft 20. The worm wheel 34 is disposed within a speed reducer case 10. The axial direction of the worm wheel 34 extends in the horizontal direction. The worm wheel 34 is rotatably supported by the speed reducer case 10 such that its axial direction coincides with the longitudinal direction of the machine base 6. Thereby, the load in the downward direction of the door body (the self-weight of the door body) becomes a gear combination (the gear combination of the worm gear 21 and the worm wheel 34) that is transmitted downward in the axial direction of the worm shaft 20. Note that the worm gear 21 and the worm wheel 34 are provided with a self-locking function that does not rotate due to a load (load) from the door body side. Specifically, considering the friction coefficient between the worm gear 21 and the worm wheel 34, which is determined by the material, machining accuracy, and lubricating oil used for the worm gear 21 and the worm wheel 34, the tooth profile and lead angle of the worm gear 21 are appropriately designed so that the worm gear 21 does not rotate along the downward direction of the door body (self-locking function) due to the load in the downward direction of the door body.

[0022] An bevel gear 36 is non-rotatably connected to the worm shaft 20 at a position above the worm gear 21. Then, the rotation from the manual operation transmission mechanism 14 is transmitted to the worm shaft 20 via the bevel gear 36. As shown in FIGS. 2 and 4, the manual operation transmission mechanism 14 includes a manual handle 40, a first spur gear 41 to which the rotation from the manual handle 40 is transmitted, a second spur gear 43 that meshes with the first spur gear 41, and a second rotating shaft 44 whose rotation is transmitted to the second spur gear 43 and that allows relative movement in the axial direction. A first rotating shaft 42 is non-rotatably connected to the first spur gear 41 at the central portion in the radial direction thereof. The first rotating shaft 42 extends in the horizontal direction. The first rotating shaft 42 extends in a direction away from the worm shaft 20. The first rotating shaft 42 is rotatably supported by a plurality of bearings 48, 48 with respect to the manual operation housing 46. The first rotating shaft 42 protrudes externally from the manual operation housing 46 along the longitudinal direction of the speed reducer case 10. The manual handle 40 is integrally connected to the end of the first rotating shaft 42 that protrudes externally from the manual operation housing 46.

[0023] The second spur gear 43 meshes with the first spur gear 41. The second spur gear 43 is rotatably supported by the manual operation housing 46 via a plurality of bearings 49, 49. A second rotating shaft 44 is non-rotatably connected to the central portion in the radial direction of the second spur gear 43. A bevel gear 52 is non-rotatably connected to the end portion of the second rotating shaft 44 on the side close to the worm shaft 20. The second rotating shaft 44 extends along the horizontal direction. The rotation of the second rotating shaft 44 is transmitted to the second spur gear 43, while relative movement along its axial direction is allowed. The second rotating shaft 44 is connected to an insertion hole provided at the radial center of the second spur gear 43 by spline engagement or keyway engagement. The second rotating shaft 44 is rotatably supported by the manual operation housing 46 via a bearing 54 and is movable along the axial direction. The second rotating shaft 44 corresponds to a rotating slide shaft. A bearing 55 is disposed on the outer peripheral surface of the end portion of the second rotating shaft 44 on the side away from the worm shaft 20. An adapter shaft portion 57 is disposed on the outer periphery of the bearing 55.

[0024] Specifically, the adapter shaft portion 57 extends in the horizontal direction. The adapter shaft portion 57 is arranged concentrically with the second rotating shaft 44. The adapter shaft portion 57 includes an adapter large-diameter shaft portion 59 formed on the worm shaft 20 side and an adapter small-diameter shaft portion 60 that extends continuously from the adapter large-diameter shaft portion 59 in a direction away from the worm shaft 20. A housing recess 62 is formed on the end face of the adapter large-diameter shaft portion 59 close to the worm shaft 20. The bearing 55 is disposed between an engagement groove portion provided on the inner peripheral surface of the housing recess 62 and the outer peripheral surface of the second rotating shaft 44. A retaining ring 63 is disposed on the second rotating shaft 44 on the side away from the worm shaft 20 with the bearing 55 as a boundary, and a stepped portion 64 is formed on the side of the bearing 55 close to the worm shaft 20.

[0025] As a result, the end of the second rotating shaft 44 on the side spaced apart from the worm shaft 20 is rotatably supported with respect to the adapter shaft portion 57 via the bearing 55. Further, the second rotating shaft 44 can move along the axial direction so as to follow the movement along the axial direction of the adapter shaft portion 57 by the bearing 55. The outer peripheral surface of the adapter large-diameter shaft portion 59 of the adapter shaft portion 57 is screwed with the inner peripheral surface of the opposing manual operation housing 46. The adapter small-diameter shaft portion 60 of the adapter shaft portion 57 is rotatably supported by the manual operation housing 46 via the bearing 56. The tip end portion of the adapter small-diameter shaft portion 60 is formed to be further smaller in diameter and protrudes outside the manual operation housing 46. Then, an operator can move the second rotating shaft 44 along its axial direction by rotating the adapter shaft portion 57 axially.

[0026] At this time, when the operator rotates the adapter shaft portion 57 in the forward direction, the second rotating shaft 44 advances along the axial direction, so that the bevel gear 52 provided at the tip of the second rotating shaft 44 meshes with the bevel gear 36 provided on the worm shaft 20. After that, by rotating the manual handle 40, the rotation is transmitted to the worm shaft 20 via the first rotating shaft 42, the first spur gear 41, the second spur gear 43, the second rotating shaft 44, the bevel gear 52 of the second rotating shaft 44, and the bevel gear 36 of the worm shaft 20. On the other hand, when the operator rotates the adapter shaft portion 57 in the reverse direction, the second rotating shaft 44 retreats along the axial direction, so that the meshing between the bevel gear 52 provided at the tip of the second rotating shaft 44 and the bevel gear 36 provided on the worm shaft 20 is released.

[0027] As shown in FIGS. 2 and 4, an annular striker member 67 projects radially outward on the outer peripheral surface of the second rotating shaft 44 on the side away from the worm shaft 20 with respect to the bevel gear 52. The striker member 67 has a larger diameter than the outer diameter of the bevel gear 52. A limit switch 70 is disposed on the side of the worm shaft 20 with respect to the striker member 67. The limit switch 70 detects contact with the striker member 67 when the manual handle 40 is rotated in the forward direction and the second rotating shaft 44 advances to a predetermined position. This limit switch 70 is electrically connected to a control device that controls the drive of the electric motor 11. In the control device, when contact with the striker member 67 is detected by the limit switch 70, the drive of the electric motor 11 is controlled to stop (interlock circuit).

[0028] As shown in FIGS. 2 and 3, an output shaft 72 is non-rotatably connected to the center in the radial direction of the worm wheel 34. The output shaft 72 is rotatably supported by the reduction gear case 10 via a plurality of bearings 73, 73. The output shaft 72 extends horizontally along the longitudinal direction of the machine base 6. Referring also to FIG. 2, lubricating oil is stored in the reduction gear case 10 such that the oil level is located at a substantially upper end portion in the meshing range of the worm gear 21 and the worm wheel 34, in other words, such that the oil level is located near the upper end of the output shaft 72. As a result, the meshing range of the worm gear 21 and the worm wheel 34 and the pair of upper and lower lower bearings 26, 26 that rotatably support the lower portion of the worm shaft 20 are in an oil bath state constantly lubricated by the lubricating oil. Referring to FIGS. 1 and 3, the output shaft 72 projects outward from the reduction gear case 10, and a pair of interlocking shafts 12, 12 are non-rotatably connected to both ends thereof via respective couplings 74, 74 (only one is shown in FIGS. 1 and 3). The interlocking shaft 12 extends horizontally along the longitudinal direction of the machine base 6. The interlocking shaft 12 is non-rotatably connected to the third rotating shaft 79 of the pin gear mechanism 13 via a coupling 75.

[0029] As shown in FIG. 3, the pin gear mechanism 13 includes a third spur gear 78 having a third rotating shaft 79, a fourth spur gear 80 meshing with the third spur gear 78, and a pin gear 82 to which the rotation of the fourth spur gear 80 is transmitted. The third rotating shaft 79 extends in the horizontal direction. The third rotating shaft 79 extends along the longitudinal direction of the machine base 6 from the third spur gear 78 toward the speed reducer case 10. The third rotating shaft 79 is rotatably supported by a plurality of bearings 87, 87 in a pin gear housing 85. The third rotating shaft 79 is non-rotatably connected to the interlocking shaft 12 via a coupling 75. The third spur gear 78 is integrally provided on the side of the third rotating shaft 79 away from the speed reducer case 10. The fourth spur gear 80 meshes with the third spur gear 78.

[0030] A fourth rotating shaft 81 is non-rotatably connected to the radially central portion of the fourth spur gear 80. The fourth rotating shaft 81 extends along the longitudinal direction of the machine base 6 in a direction opposite to the speed reducer case 10 side. The fourth rotating shaft 81 extends in the horizontal direction. A pin gear 82 is integrally provided on the outer peripheral surface of the end portion of the fourth rotating shaft 81 on the side opposite to the speed reducer case 10 side. The fourth rotating shaft 81 is rotatably supported by a plurality of bearings 88, 88 in the pin gear housing 85. The rack bar 4 is engaged with the pin gear 82, and the rotation of the pin gear 82 accompanying the rotation of the fourth rotating shaft 81 causes the rack bar 4 to move up and down.

[0031] In the gate opening / closing device 1A according to the first embodiment, the interlocking shaft 12 is non-rotatably connected to the third rotating shaft 79 of the pin gear mechanism 13 via the coupling 75, and the rotation of the third rotating shaft 79 is transmitted to the pin gear 82 via the third spur gear 78 and the fourth spur gear 80. The third spur gear 78 and the fourth spur gear 80 reduce the load on the interlocking shaft 12 and the coupling 75, suppress the interlocking shaft 12 and the coupling 75 from becoming excessively large (large-sized), and reduce costs. However, the configuration may be such that the rotation of the interlocking shaft 12 is directly transmitted to the pin gear 82 (fourth rotating shaft 81) via the coupling 75 without including the third spur gear 78 and the fourth spur gear 80.

[0032] Then, in the floodgate opening / closing device 1A according to the first embodiment, when raising and lowering the door body by driving the electric motor 11, first, an operator rotates the adapter shaft portion 57 of the manual operation transmission mechanism 14 in the reverse direction and retracts the second rotating shaft 44 along the axial direction from the worm shaft 20 in the speed reducer case 10, thereby releasing the engagement between the bevel gear 52 provided at the tip of the second rotating shaft 44 and the bevel gear 36 provided on the worm shaft 20.

[0033] Next, the electric motor 11 (gear motor) is operated. Then, the rotating shaft 11A of the electric motor 11 is decelerated by the built-in reduction gear, and rotates at a rotational speed of about 100 to 200 rpm. Along with the rotation of the rotating shaft 11A, the worm shaft 20 rotates via the mechanical torque limiter 29. Along with the rotation of the worm shaft 20, the worm wheel 34 rotates at a high reduction ratio via the worm gear 21. When the worm wheel 34 rotates along with the rotation of the worm shaft 20, deceleration of about 1 / 40 to 1 / 80 is possible, and the necessary deceleration can be achieved without using other reduction gears.

[0034] Along with the rotation of the worm wheel 34, the output shaft 72 and the interlocking shaft 12 rotate. Along with the rotation of the interlocking shaft 12, the fourth rotating shaft 81 rotates at a predetermined reduction ratio via the third spur gear 78 and the fourth spur gear 80. Then, along with the rotation of the fourth rotating shaft 81, the pin gear 82 rotates, and along with the rotation of the pin gear 82, the rack bar 4 moves up and down and the door body moves up and down. In the floodgate opening / closing device 1A according to the first embodiment, the necessary rotational speed of the pin gear 82 of the pin gear mechanism 13 can be obtained at about 0.3 to 1.0 rpm.

[0035] Therefore, when the worm shaft 20 rotates via the mechanical torque limiter 29 along with the rotation of the rotating shaft 11A from the electric motor 11, when the rotational torque difference between the rotating shaft 11A and the worm shaft 20 reaches a predetermined value, the mechanical torque limiter 29 mechanically cuts off the transmission of power (rotational torque) from the rotating shaft 11A of the electric motor 11 to the worm shaft 20. Further, when the limit switch 32 detects the operation of the mechanical torque limiter 29, the drive of the electric motor 11 is stopped.

[0036] At this time, since the worm gear 21 and the worm wheel 34 have a self-locking function that does not rotate due to the load from the door body side, even if the mechanical torque limiter 29 operates, the self-locking function can prevent the door body from falling. Also, when the door body moves up and down, the load in the lowering direction of the door body (the self-weight of the door body), which is the dominant axial load acting on the worm shaft 20, is directed axially downward with respect to the worm shaft 20. This axially downward load can be safely supported by a pair of upper and lower lower bearings 26, 26 (receiving radial and axial loads) in an oil bath state that rotatably supports the lower part of the worm shaft 20.

[0037] Next, in the water gate opening and closing device 1A according to the first embodiment, when raising and lowering the door body with the manual handle 40, the operator rotates the adapter shaft portion 57 of the manual operation transmission mechanism 14 in the positive direction and advances the second rotating shaft 44 along the axial direction toward the worm shaft 20 in the speed reducer case 10, so that the bevel gear 52 provided at the tip of the second rotating shaft 44 and the bevel gear 36 provided on the worm shaft 20 are in a meshed state. At this time, the limit switch 70 detects the contact with the striker member 67, and based on the detection signal, the control device controls to stop the drive of the electric motor 11.

[0038] Next, the operator rotates the manual handle 40. Then, as the first rotating shaft 42 rotates, the first spur gear 41 rotates. As the first spur gear 41 rotates, the second spur gear 43 rotates. As the second spur gear 43 rotates, the second rotating shaft 44 rotates, and the worm shaft 20 rotates due to the meshing between the bevel gear 52 provided at the tip of the second rotating shaft 44 and the bevel gear 36 provided on the worm shaft 20. And the rotation from the worm shaft 20 is transmitted to the pin gear 82 via the worm wheel 34, the output shaft 72, the interlocking shaft 12, the third rotating shaft 79 of the pin gear mechanism 13, the third spur gear 78, the fourth spur gear 80, and the fourth rotating shaft 81. As the pin gear 82 rotates, the rack bar 4 moves up and down to raise and lower the door body. Note that when the operator manually operates, the brake attached to the electric motor 11 is manually released.

[0039] As described above, in the sluice gate opening / closing device 1A according to the first embodiment, there are provided an electric motor 11 which is arranged on the speed reducer case 10 and raises and lowers the door body, and a worm gear 21 as a speed reduction mechanism which is provided in the speed reducer case 10 and to which the rotation from the electric motor 11 is transmitted to raise and lower the door body. The worm gear 21 has a self-locking function. Thereby, compared with the conventional case where the electric motor 11 is arranged on the side of the speed reducer case 10, the planar occupied space can be reduced. Moreover, since the electric motor 11 does not protrude to the side of the speed reducer case 20, the electric motor 11 is arranged within the support area of the speed reducer case 10 in a planar manner, so that the electric motor 11 can be stably arranged. Thus, in the sluice gate opening / closing device 1A according to the first embodiment, the part of the speed reduction mechanism (speed reducer case 10) including the electric motor 11 can be made compact, and the arrangement balance thereof can be improved.

[0040] In addition, by using the worm gear 21 and the worm wheel 34 as the speed reduction mechanism, a higher speed reduction ratio can be obtained compared to spur gears. As a result, miniaturization can be achieved without the need for a plurality of spur gear sets. Further, since the worm gear 21 and the worm wheel 34 are provided with a self-locking function, there is no need to provide a braking device for suppressing the fall of the door body, the number of constituent members can be reduced, and cost reduction can be achieved.

[0041] In addition, in the sluice gate opening / closing device 1A according to the first embodiment, the worm shaft 20 having the worm gear 21 extends in the vertical direction, and the load in the descending direction of the door body (the self-weight of the door body) is transmitted as a gear combination that is transmitted downward in the axial direction of the worm shaft 20. Therefore, the load in the descending direction of the door body, which is the dominant axial load acting on the worm shaft 20, can be configured to be transmitted downward with respect to the worm shaft 20. Further, the axial load transmitted to the worm shaft 20 when raising and lowering the door body is transmitted to the lower bearings 26, 26 that rotatably support the lower end portion of the worm shaft 20. Moreover, lubricating oil is stored in the lower part of the speed reduction case 10, and the meshing range between the worm gear 21 and the worm wheel 34 and the pair of lower bearings 26, 26 that rotatably support the lower end portion of the worm shaft 20 are in an oil bath state by the lubricating oil. Thereby, the pair of lower bearings 26, 26 that rotatably support the worm shaft 20 and are advantageous for lubrication in the oil bath state can safely support the downward axial load acting on the worm shaft 20.

[0042] In this embodiment, the dominant axial load transmitted to the worm shaft 20 is configured to be downward with respect to the worm shaft 20. However, for example, by restricting the upward movement of the pair of lower bearings 26, 26 with respect to the speed reduction case 10 by a bearing retainer or the like, regardless of the axial load, the pair of lower bearings 26, 26 in the oil bath state can safely support the axial load on the worm shaft 20.

[0043] Furthermore, in the floodgate opening / closing device 1A according to the first embodiment, the rotating shaft 11A from the electric motor 11 and the worm shaft 20 are connected to each other in a concentric and non-rotatable relative manner. As a result, it is not necessary to arrange transmission gears or the like in the power transmission path from the rotating shaft 11A of the electric motor 11 to the worm gear 21, and the number of component members such as transmission gears can be reduced, so that the device can be miniaturized and the cost can be reduced.

[0044] Furthermore, in the floodgate opening / closing device 1A according to the first embodiment, a mechanical torque limiter 29 is provided between the rotating shaft 11A from the electric motor 11 and the worm shaft 20. And when the rotational torque difference between the rotating shaft 11A from the electric motor 11 and the worm shaft 20 reaches a predetermined value by the mechanical torque limiter 29, the power transmission from the rotating shaft 11A of the electric motor 11 to the worm shaft 20 can be mechanically interrupted. As a result, it is not necessary to design the strength of a large number of component members on the downstream side related to the power transmission path based on the maximum generated torque of the electric motor 11 that is excessive. It is only necessary to design the strength based on a rotational torque slightly larger than the rotational torque from the electric motor 11 during normal operation, and further miniaturization and cost reduction of the opening / closing device 1A can be achieved.

[0045] It should be noted that conventionally, an overload protection device that detects over-torque with a limit switch and electrically operates an electromagnetic contactor to cut off the power supply of the electric motor 11 has been adopted. However, since there is also a possibility of failure of electrical components such as electromagnetic contactors, relay contacts, and limit switches, as described above, considering the possibility that excessive torque may act on the opening / closing device, even if this situation occurs, strength verification has been carried out at the maximum generated torque of the electric motor 11 so as not to be destroyed. However, if the mechanical torque limiter 29 is used, the transmission of rotational torque is mechanically interrupted, so there is no worry about the maximum generated torque of the electric motor 11 acting.

[0046] In addition, in the electric motor 11 (geared motor) according to the present embodiment, the rotational speed of the rotating shaft 11A is sufficiently reduced to 100 to 200 rpm, and it is considered that an unstable phenomenon in which the attachment and detachment of balls or rollers to the groove occur at high speed and continuously in a short time due to high-speed rotation does not occur in the mechanical torque limiter 29. In accordance with this, the sluice gate opening / closing device 1A according to the first embodiment is provided with a limit switch 32 for detecting the operation of the mechanical torque limiter 29, and after the operation of the mechanical torque limiter 29, the electric motor 11 is controlled to stop without delay, and the safety and reliability can be further improved.

[0047] Furthermore, in the sluice gate opening / closing device 1A according to the first embodiment, a bevel gear 52 that mates with the bevel gear 36 of the worm shaft 20 is connected to the tip of a second rotating shaft 44 (rotating slide shaft) to which rotation from the manual handle 40 is transmitted so as not to be relatively rotatable, and the second rotating shaft 44 is configured to be movable along the axial direction so that the bevel gear 36 of the worm shaft 20 and the bevel gear 52 of the second rotating shaft 44 can be engaged and disengaged. Thereby, when the door body is raised and lowered by the electric motor 11, the second rotating shaft 44 is retracted from the worm shaft 20 in the speed reducer case 20 along the axial direction, so that the bevel gear 52 of the second rotating shaft 44 and the bevel gear 36 of the worm shaft 20 are disengaged.

[0048] On the other hand, when the door body is raised and lowered by the manual handle 40, the second rotating shaft 44 is advanced along the axial direction toward the worm shaft 20 in the speed reducer case 10, so that the bevel gear 52 of the second rotating shaft 44 and the bevel gear 36 of the worm shaft 20 are engaged, and the operator can rotate the manual handle 40 to raise and lower the door body. As a result, a manual operation function can be ensured without using an expensive differential gear, contributing to further cost reduction.

[0049] Next, the sluice gate opening / closing device 1B according to the second embodiment will be described in detail with reference to FIG. 5 and appropriately also referring to FIG. 4 and the like. When describing the sluice gate opening / closing device 1B according to the second embodiment, only the differences from the sluice gate opening / closing device 1A according to the first embodiment will be described.

[0050] In the floodgate opening / closing device 1B according to the second embodiment, the square tube-shaped cover member 18 is not provided, and the electric motor 11 is directly disposed on the upper surface of the speed reducer case 10. Inside the speed reducer case 10, a vertical rotating shaft 100 extends in the vertical direction. The tip of the rotating shaft 11A from the electric motor 11 is disposed inside the speed reducer case 10. The rotating shaft 11A from the electric motor 11 and the vertical rotating shaft 100 are arranged concentrically with each other. A mechanical torque limiter 29 is disposed between the rotating shaft 11A from the electric motor 11 and the vertical rotating shaft 100. The mechanical torque limiter 29 is disposed inside the speed reducer case 10. The lower end of the vertical rotating shaft 100 is rotatably supported via a pair of bearings 105, 105 on a support base 101 disposed on the bottom surface of the speed reducer case 10. Near the lower end of the vertical rotating shaft 100, a bevel gear 110 is connected non-rotatably relative to the vertical rotating shaft 100. Inside the speed reducer case 10, a worm shaft 20 is disposed at the bottom thereof, in other words, near the lower end of the vertical rotating shaft 100.

[0051] The worm shaft 20 extends horizontally inside the speed reducer case 10. The worm shaft 20 extends along the longitudinal direction (width direction of the machine base 6) of the speed reducer case 10. At the bottom inside the speed reducer case 10, a pair of support bases 101, 102 are disposed at intervals along the longitudinal direction thereof. The worm shaft 20 is rotatably supported on each of the pair of support bases 101, 102 via a plurality of bearings 106, 106. A worm gear 21 is provided at substantially the central portion in the longitudinal direction of the worm shaft 20. At the end of the worm shaft 20 on the side of the vertical rotating shaft 100, a bevel gear 111 is connected non-rotatably relative to the worm shaft 20. The bevel gear 110 provided on the vertical rotating shaft 100 and the bevel gear 111 provided on the worm shaft 20 are meshed with each other. A worm wheel 34 is meshed with the worm gear 21 of the worm shaft 20. The worm wheel 34 is disposed inside the speed reducer case 10.

[0052] The worm wheel 34 is rotatably supported such that its axial direction coincides with the longitudinal direction of the machine base 6. An output shaft 72 is non-rotatably connected to the center in the radial direction of the worm wheel 34. In the speed reducer case 10, lubricating oil is stored so as to immerse the meshing range of the worm gear 21 and the worm wheel 34. As a result, in the speed reducer case 10, a plurality of bearings 105 and 106 including the meshing range of the worm gear 21 and the worm wheel 34 are in an oil bath state. In the sluice gate opening / closing device 1B according to the second embodiment, the amount of lubricating oil in the speed reducer case 10 can be made less than that in the sluice gate opening / closing device 1A according to the first embodiment.

[0053] Note that the sluice gate opening / closing device 1B according to the second embodiment also includes a manual operation transmission mechanism 14 (see FIG. 4) which is the same configuration as that of the sluice gate opening / closing device 1A according to the first embodiment (not shown in FIG. 5). On the other hand, a bevel gear (not shown in FIG. 5) is non-rotatably connected to the vertical rotating shaft 100. Then, by meshing the bevel gear 52 (see FIG. 4) of the second rotating shaft 44 provided in the manual operation transmission mechanism 14 with the bevel gear of the vertical rotating shaft 100, an operator can operate the manual operation transmission mechanism 14 to raise and lower the door body.

[0054] When the electric motor 11 is operated in the sluice gate opening / closing device 1B according to the second embodiment, as the rotating shaft 11A of the electric motor 11 rotates, the vertical rotating shaft 100 rotates via the mechanical torque limiter 29. As the vertical rotating shaft 100 rotates, the worm shaft 20 rotates via the bevel gears 110 and 111, and the worm wheel 34 rotates. As the worm wheel 34 rotates, the output shaft 72, the interlocking shaft 12, the third rotating shaft 79, the third spur gear 78, the fourth spur gear 80, the fourth rotating shaft 81, and the pin gear 82 of the pin gear mechanism 13 rotate. As the pin gear 82 rotates, the rack bar 4 moves up and down to raise and lower the door body.

[0055] Also, in the gate opening / closing device 1B according to the second embodiment described above, in terms of the points that the electric motor 11 is arranged on the speed reducer case 10, the mechanical torque limiter 29 is provided, the worm gear 21 and the worm wheel 34 having a self-locking function are adopted as the speed reduction mechanism, and the manual operation transmission mechanism 14 is provided, the same operational effects as those of the gate opening / closing device 1A according to the first embodiment can be achieved.

[0056] Further, in the gate opening / closing device 1B according to the second embodiment, since the worm shaft 20 having the worm gear 21 extends along the bottom in the horizontal direction within the speed reducer case 10, the amount of lubricating oil in the speed reducer case 10 can be made less than the amount of lubricating oil in the speed reducer case 10 adopted in the gate opening / closing device 1A according to the first embodiment.

Explanation of Reference Numerals

[0057] 1A, 1B Gate opening / closing device, 10 Speed reducer case, 11 Electric motor, 11A Rotating shaft, 20 Worm shaft, 21 Worm gear, 26 Lower bearing, 29 Mechanical torque limiter, 44 Second rotating shaft (rotating slide shaft), 36 Bevel gear, 52 Bevel gear

Claims

1. A water gate opening and closing device for raising and lowering a door body to open and close a water gate, comprising: an electric motor disposed on a speed reducer case for raising and lowering the door body; a worm gear provided in the speed reducer case and having rotation transmitted from the electric motor for raising and lowering the door body; and the worm gear has a self-locking function; a bevel gear is provided on a worm shaft having the worm gear; a bevel gear meshing with the bevel gear of the worm shaft is provided at the tip of a rotary slide shaft to which rotation from a manual handle is transmitted; and the rotary slide shaft is configured to be movable along an axial direction such that the bevel gear of the worm shaft and the bevel gear of the rotary slide shaft can be engaged and disengaged with each other. The water gate opening and closing device is characterized by this.

2. The worm shaft extends in the vertical direction, and when raising and lowering the door body, the axial load transmitted to the worm shaft is transmitted to a bearing that rotatably supports the lower end portion of the worm shaft. The water gate opening and closing device according to claim 1 is characterized by this.

3. The rotary shaft from the electric motor and the worm shaft are arranged concentrically with each other. The water gate opening and closing device according to claim 2 is characterized by this.

4. A mechanical torque limiter is provided between the rotary shaft from the electric motor and the worm shaft to mechanically cut off the transmission of power from the rotary shaft of the electric motor to the worm shaft when the difference in rotational torque between them reaches a predetermined value. The water gate opening and closing device according to claim 2 or 3 is characterized by this.

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