Shake-off device

Abstract

To provide an improved shake-off device which can cancel inertial force acting on a reciprocating part without generating vibration in the vertical direction to inertial force of the reciprocating part with a small number of components and with a simple structure, which is small-sized and lightweight.SOLUTION: When a counter weight (44) and a reverse gear (42) perform the rotational movement of revolution around a first rotation axis (C) and rotation around a second rotation axis (E), the gravity center of a reverse part (52) including the counter weight (44) and the reverse gear (42) reciprocates along the same reciprocation axis (A) as a reciprocating part (2).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a shake-off device having a reciprocating pole and a contact part, such as a hook or pusher, configured to engage a branch, such as an olive branch, to shake the branch and thereby release, for example, olives. [Background technology]

[0002] EP 2042020 B1 discloses a shake-off device having a reciprocating pole and a hook configured to engage with branches to shake them and remove olives, for example. The shake-off device has a main rotation shaft, a driven shaft that is offset from the main rotation shaft and rotates in the opposite direction to the main rotation shaft, a first counterweight fixed to the main rotation shaft, and a second counterweight fixed to the driven shaft. The first and second counterweights are positioned in retracted positions when the pole is in the forward position.

[0003] EP 2625948 (Patent Document 2) also discloses a shake-off device having a reciprocating pole and a hook configured to engage with branches to shake them and remove olives, for example. The shake-off device includes a main rotation shaft with a first flywheel, a sleeve with a second flywheel rotatably disposed about the main rotation shaft and rotating in the opposite direction to the main rotation shaft, a first counterweight fixed to the first flywheel, and a second counterweight fixed to the second flywheel. The first and second counterweights are positioned in retracted positions when the pole is in the forward position.

[0004] In each of these shake-off devices, when the pole reaches the forward position, an impact is transmitted to the operator in a direction from the rearward side to the forward side. However, because the first and second counterweights reach the rearward position at the same time, this impact transmitted to the operator can be reduced. Similarly, when the pole reaches the rearward position, an impact is transmitted to the operator in a direction from the rearward side to the rearward side. However, because the first and second counterweights reach the forward position at the same time, this impact transmitted to the operator can be reduced.

[0005] Furthermore, when the pole reaches an intermediate position while moving from the forward position to the retracted position, the first counterweight generates, for example, a downward force, and the second counterweight generates, for example, an upward force. Similarly, when the pole reaches an opposite intermediate position while moving from the retracted position to the forward position, the first counterweight generates, for example, an upward force, and the second counterweight generates, for example, a downward force. As a result, such downward and upward forces are at least partially canceled out, and the shock transmitted to the operator caused by these upward and downward forces can be reduced. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent No. 2042020 [Patent Document 1] European Patent No. 2625948 Summary of the Invention [Problem to be solved by the invention]

[0007] In a shake-off device that has a reciprocating motion part consisting of a pole with a hook as described above (for example, a device that shakes an olive branch to drop olives is also called an olive shaker), vibration during operation remains a problem.

[0008] As a countermeasure against vibration, as disclosed in the prior art document mentioned above, it is conceivable to attach a rotating counterweight so that centrifugal force acts in the opposite direction to the inertial force acting on the reciprocating part, thereby canceling out the inertial force. However, because the counterweight performs simple rotational motion, centrifugal force also acts in a direction perpendicular to the inertial force of the reciprocating part, causing vibration in a different direction.

[0009] The shake-off devices disclosed in EP 2042020 (Patent Document 1) and EP 2625948 (Patent Document 2) are equipped with a counterweight that rotates in a first direction, and are further equipped with a counterweight that rotates in the opposite direction to the first direction to cancel out the vertical centrifugal force generated by the counterweight. This results in a large number of parts and a complex structure. Furthermore, in the shake-off device disclosed in EP 2042020 (Patent Document 1), the main rotation shaft and the driven shaft to which the counterweights are attached are offset in the vertical direction, which tends to increase the size of the shake-off device's case in the vertical direction.

[0010] In the shake-off device disclosed in EP 2625948 (Patent Document 2), the main rotating shaft and the sleeve are coaxial, resulting in a relatively small case size. However, in EP 2625948 (Patent Document 2), when the pole reaches an intermediate position, downward and upward forces may generate, for example, a counterclockwise torsional force around the pole's axis. Similarly, when the pole reaches the opposite intermediate position, upward and downward forces may generate, for example, a clockwise torsional force around the pole's axis. In other words, counterclockwise and clockwise torsional forces alternately occur. These torsional forces are transmitted to the operator via the flywheel, main rotating shaft, and case, potentially adversely affecting the operability of the shake-off device. Furthermore, these torsional forces may adversely affect the meshing relationship between the bevel pinions and bevel gears of the first and second flywheels, potentially causing unstable rotation of the first and second flywheels.

[0011] Therefore, in such a shaking-off device, if a counterweight could be created whose center of gravity does not rotate but moves linearly in the opposite direction to the reciprocating part, it is thought that the inertial force acting on the reciprocating part could be canceled out without generating vibrations perpendicular to the inertial force of the reciprocating part.

[0012] Therefore, the object of the present invention is to provide an improved, small, lightweight shake-off device that has a small number of parts, a simple structure, and can cancel out the inertial force acting on the reciprocating part without generating vibrations perpendicular to the inertial force of the reciprocating part. [Means for solving the problem]

[0013] In order to achieve the above object, the shake-off device according to the present invention is a shake-off device comprising: a crankshaft unit driven by a drive source; a connecting rod; and a reciprocating part having a contact part, the reciprocating part being reciprocated along a reciprocating axis between an advanced position and a retreated position by the crankshaft unit via the connecting rod, wherein the crankshaft unit includes a crankshaft part that engages with the connecting rod and a reverse part, and the crankshaft part includes a forward rotating member that is driven by the drive source to rotate around a first rotation axis in a first rotation direction, The reversing unit includes a reversing gear to which a counterweight is attached and which meshes with an internal gear fixed to the case, and which is driven to revolve around the first rotation axis in the first rotation direction together with the forward rotating member, while rotating around a second rotation axis offset from the first rotation axis in a second rotation direction opposite to the first rotation direction; as the counterweight and the reversing gear perform rotational motion of revolving around the first rotation axis and rotating around the second rotation axis, the center of gravity of the reversing unit including the counterweight and the reversing gear reciprocates along the same reciprocating axis as the reciprocating unit.

[0014] In one embodiment, the reference pitch diameter of the reversing gear is set to half the reference pitch diameter of the internal gear.

[0015] In another preferred embodiment, the center of gravity of the reversing portion including the counterweight and the reversing gear is located on a reference pitch circle of the reversing gear.

[0016] In another preferred embodiment, the second rotation axis and the connection axis between the forward rotation member and the connecting rod are provided on opposite sides of the first rotation axis.

[0017] In another preferred embodiment, the counterweight is positioned closer to the axis of reciprocation than the reversing gear.

[0018] In another preferred aspect, the center of gravity of the reversing unit including the counterweight and the reversing gear is positioned at the retracted position when the reciprocating unit is in the forward position, and is positioned at the forward position when the reciprocating unit is in the retracted position.

[0019] According to the present invention, the center of gravity of the reversing section, which includes the counterweight and the reversing gear, does not rotate but rather reciprocates (linearly moves) along the same reciprocating axis as the reciprocating section, thereby making it possible to provide an improved, small, lightweight shake-off device with a small number of parts and a simple structure that can cancel out the inertial force acting on the reciprocating section without generating vibrations perpendicular to the inertial force of the reciprocating section. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic front view of a shake-off device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partial perspective view of the shake-off device of FIG. 1, with the case omitted. [Figure 3] 2 is a partial cross-sectional bottom view of the shake-off device of FIG. 1. FIG. [Figure 4A]2 is a partial front view of the crankshaft unit of the shake-off device of FIG. 1 when the connecting rod is in a forward position (bevel gear: 0°). FIG. [Figure 4B] 2 is a partial front view of the crankshaft unit of the shake-off device of FIG. 1 when the connecting rod is in an intermediate position (bevel gear: 45°). FIG. [Figure 4C] 2 is a partial front view of the crankshaft unit of the shake-off device of FIG. 1 when the connecting rod is in an intermediate position (bevel gear: 90°). FIG. [Figure 4D] 2 is a partial front view of the crankshaft unit of the shake-off device of FIG. 1 when the connecting rod is in an intermediate position (bevel gear: 135°). FIG. [Figure 4E] 2 is a partial front view of the crankshaft unit of the shake-off device of FIG. 1 when the connecting rod is in a retracted position (bevel gear: 180°). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shake-off device according to an exemplary embodiment of the present invention will now be described with reference to the accompanying drawings.

[0022] As shown in FIG. 1, the shake-off device 1 includes a pole 2, a case 6 that houses the base end of the pole 2, and an engine 8 attached to the case 6. The pole 2 has a contact part 4, such as a hook or pusher, at its tip 2b, and moves linearly back and forth relative to the case 6 along a reciprocating axis A. The contact part 4 is configured to engage with a branch, such as an olive branch, to shake the branch and cause, for example, olives to fall. The case 6 has a two-part structure that is flat overall, and includes a first side wall 6a (FIG. 3) located on a first side of the reciprocating axis A (the back side not visible in FIG. 1) and a second side wall 6b located on a second side opposite the first side of the reciprocating axis A (the front side visible in FIG. 1).

[0023] 2 and 3, the shake-off device 1 also includes a drive shaft 18 driven by the engine 8 and having a bevel pinion (hereinafter sometimes simply referred to as a pinion) 20, a crankshaft unit 12 driven by the pinion 20, and a connecting rod 10. The pole 2 is driven by the pinion 20 via the crankshaft unit 12 and the connecting rod 10. The drive shaft 18, the crankshaft unit 12, and the connecting rod 10 are housed in a case 6. The drive shaft 18 preferably extends along a drive axis B aligned in a straight line with the reciprocating axis A.

[0024] 3, engine 8 is preferably an internal combustion engine, but may also be an electric or pneumatic engine. Drive shaft 18 is coupled to an output shaft (not shown) of engine 8 via, for example, a centrifugal clutch (not shown). Drive shaft 18 is therefore configured to be rotated by engine 8 about drive axis B.

[0025] 2 and 3, the crankshaft unit 12 includes a crankshaft portion 50 that engages with the connecting rod 10 and a reverse portion 52, which will be described later. The crankshaft portion 50 includes a bevel gear 22 as a forward gear (forward member) driven by the pinion 20, a first crankshaft 24, and a second crankshaft 26.

[0026] The bevel gear 22 meshes with a bevel pinion 20 at the tip of the drive shaft 18, which transmits the rotation of the engine 8, and reduces the rotation speed of the drive shaft 18. The bevel gear 22 is driven by the pinion 20 and configured to rotate (spin on its own axis) around a rotation axis C in a first or normal rotation direction R1 (see FIGS. 4A to 4E). The bevel gear 22 has a first opening 22a into which a first crankshaft 24 (a first crankpin 24a) is press-fitted from the side of the bevel gear 22 facing the reciprocating axis A of the pole 2, a second opening 22b into which a second crankshaft 26 (a second crankpin 26a) is press-fitted from the side of the bevel gear 22 opposite to the side facing the reciprocating axis A of the pole 2, and a plurality of (four substantially sector-shaped in the illustrated example) holes 22c arranged in the circumferential direction. The first opening 22a and the second opening 22b are offset from the rotation axis C and provided on opposite sides of the rotation axis C. In other words, the first crankshaft 24 (the first crankpin 24a) press-fitted into the first opening 22a and the second crankshaft 26 (the second crankpin 26a) press-fitted into the second opening 22b are out of phase with each other by 180°. In other words, the bevel gear 22 has an annular portion 22C on the side of the bevel gear 22 facing the reciprocating axis A of the pole 2, on which a gear that meshes with the pinion 20 is formed, and a first bridging portion 22A and a second bridging portion 22B that intersect at the center of the bevel gear 22 (on the rotation axis C). One of the first bridging portion 22A and the second bridging portion 22B (in the illustrated example, the first bridging portion 22A) is offset from the rotation axis C and has a first opening 22a and a second opening 22b on either side of the rotation axis C (on the opposite side), and approximately fan-shaped holes 22c are formed (at four locations) between the first bridging portion 22A and the second bridging portion 22B.

[0027] The bevel gear 22 is disposed (housed) in a space sealed by the first side wall 6a and the second side wall 6b. A first crank pin 24a of a first crankshaft 24, which is press-fit into the first opening 22a, extends from (the first opening 22a of) the bevel gear 22 toward the first side wall 6a along an offset axis D (parallel to and offset from the rotation axis C). A first main shaft 24b of the first crankshaft 24 extends from the first crank pin 24a toward the first side wall 6a along the rotation axis C and is rotatably supported about the rotation axis C by a first bearing 30 attached to (the recess 6c of) the first side wall 6a. The second crank pin 26a of the second crankshaft 26, which is press-fitted into the second opening 22b, extends from (the second opening 22b of) the bevel gear 22 toward the second side wall 6b along an offset axis E (parallel to and offset from the rotation axis C). The second main shaft 26b of the second crankshaft 26 extends from the second crank pin 26a toward the second side wall 6b along the rotation axis C, and is supported rotatably about the rotation axis C by a second bearing 32 attached to (the recess 6d of) the second side wall 6b. As a result, the crankshaft portion 50 is configured to rotate in a rotational direction R1 about the rotation axis C.

[0028] As shown in Fig. 3, the connecting rod 10 has a rear end 10a pivotally connected to a first crank pin 24a of the first crankshaft 24 via a first needle bearing 34, and a front end 10b pivotally connected to a rear end 2a of the pole 2. The pole 2 is configured to be guided by a pole guide 16 fixed to the case 6 so as to linearly move the pole 2 along a reciprocating axis A. The pole 2 is configured to reciprocate between a fully extended forward position shown in Fig. 4A and a fully retracted backward position shown in Fig. 4E.

[0029] As shown in FIGS. 2 and 3 , the reversing section 52 of the crankshaft unit 12 includes a reversing gear (hereinafter sometimes simply referred to as a gear) 42 and a counterweight 44 attached to the gear 42. The counterweight 44 is disposed adjacent to the bevel gear 22 (on the surface opposite to the surface facing the reciprocating axis A). The counterweight 44 is formed flat and has a mounting portion 46 and, for example, a fan-shaped weight portion 48. The mounting portion 46 of the counterweight 44 has an opening 46a into which the second crankpin 26a of the second crankshaft 26 is rotatably inserted via the second needle bearing 36. In other words, the counterweight 44 has the mounting portion 46 pivotally attached to the second crankpin 26a of the second crankshaft 26 via the second needle bearing 36, and the weight portion 48 formed integrally with the mounting portion 46.

[0030] The gear 42 has a central opening 42a into which a cylindrical portion 46b protruding from a surface opposite to the reciprocating axis A of the opening 46a of the mounting portion 46 of the counterweight 44 is inserted. The gear 42 is attached to the counterweight 44 (on the surface opposite to the surface facing the reciprocating axis A) with two bolts 43 so as to be able to move integrally with the counterweight 44. The method of fixing the gear 42 and the counterweight 44 is not limited to bolt fixing. The gear 42 and the counterweight 44 may also be formed by integral molding. The gear 42 is configured to mesh with an internal gear 49 fixed to the case 6 (at the stepped portion 6e of the case 6). In the illustrated example, the internal gear 49 has approximately the same diameter as the bevel gear 22.

[0031] As a result, when the crankshaft portion 50 is driven by the pinion 20 to rotate in the rotational direction R1 around the rotational axis C, the reversing portion 52 rotates (revolves) together with the crankshaft portion 50 around the rotational axis C in the first or normal rotational direction R1, and is configured to rotate (spin on its own axis) around the offset axis (rotational axis) E in the second or reverse rotational direction R2 (opposite to the first or normal rotational direction R1) due to the meshing between the gear 42 and the internal gear 49.

[0032] In this embodiment, as described above, the first crankshaft 24 (the first crankpin 24a) and the second crankshaft 26 (the second crankpin 26a) are shifted in phase by 180° around the rotation axis C. In other words, the connecting axis (offset axis D) between the bevel gear 22 and the connecting rod 10 and the offset axis (rotation axis) E are provided on opposite sides of the rotation axis C (they are shifted in phase by 180°). The center of gravity of the reversing portion 52, which is the combination of the counterweight 44 and the gear 42, is adjusted to be on the reference pitch circle of the gear 42 (see FIGS. 4A to 4E). The reference pitch circle diameter (number of teeth) of the gear 42 is set to half the reference pitch circle diameter (number of teeth) of the internal gear 49.

[0033] Therefore, the center of gravity of the reversing unit 52, which is the combination of the counterweight 44 and the gear 42, is located in the retracted position (on the reciprocating axis A) as shown in FIG. 4A when the pole 2 is in the forward position, and is located in the forward position (on the reciprocating axis A) as shown in FIG. 4E when the pole 2 is in the retracted position. In this way, the center of gravity of the reversing unit 52 is located in a position opposite to the movement of the pole 2, thereby reducing vibrations that are generated in the front-to-back direction and transmitted to the operator. Also, as shown in FIGS. 4A to 4E, when the pole 2 is in an intermediate position between the forward and retracted positions, the center of gravity of the reversing unit 52 moves on the same reciprocating axis A as the pole 2, which is the reciprocating unit, in the opposite direction to the movement of the pole 2. Also, the center of gravity of the reversing unit 52 as a whole is arranged to reciprocate linearly on the reciprocating axis A. In the counterweight 44 configured in this manner, vertical centrifugal force due to rotation is not generated, as in conventional counterweights.

[0034] Furthermore, the reversing unit 52 can be constructed using only a single counterweight 44. While a rotating counterweight as in a conventional structure requires a counter-rotating counterweight to cancel out the centrifugal force, the counterweight 44 of this embodiment does not generate centrifugal force. This allows the thickness of the case 6 in the direction of the rotation axis C to be reduced. Furthermore, the counterweight 44 of the reversing unit 52 is disposed closer to the reciprocating axis A (in the direction of the rotation axis C) than the gear 42, and the distance between the reciprocating axis A and the counterweight 44 is short. Therefore, the torsional force generated by the counterweight 44 with respect to the reciprocating axis A can be made extremely small compared to a conventional configuration in which a counterweight rotates around the flywheel shaft.

[0035] The operation of the shake-off device 1 will be described with reference to FIGS. 4A to 4E.

[0036] The drive shaft 18 is rotated by the engine 8 via an output shaft (not shown) of the engine 8 and a centrifugal clutch (not shown). The bevel gear 22 is rotated by the bevel pinion 20 around the rotation axis C in a first rotation direction R1. The direction of the rotation axis C is normally the left-right direction when the direction in which the operator faces the working unit is considered to be forward.

[0037] The first crankshaft 24 is rotated together with the bevel gear 22, and the pole 2 moves linearly back and forth along the reciprocating axis A via the connecting rod 10. The reciprocating motion of the pole 2 causes the contact portion 4, which vibrates in the direction of the reciprocating axis A, to drop, for example, an olive.

[0038] The second crankshaft 26 is rotated together with the bevel gear 22, and the reversing portion 52 rotates (revolves) together with the bevel gear 22 around the rotation axis C in a first rotation direction R1. Meanwhile, since the gear 42 of the reversing portion 52 is engaged with the internal gear 49 fixed to the case 6, the reversing portion 52 rotates (spins) around the offset axis (rotation axis) E in a second rotation direction R2 opposite to the first rotation direction R1.

[0039] 4A, when the pole 2 moves toward the forward position, an impact (inertial force Fp) occurs in a direction from the rear to the front. However, the center of gravity G of the reversing part 52 simultaneously reaches the retracted position, and an inertial force Fg in a direction from the front to the rear is generated in the reversing part 52, so that the impact transmitted to the operator as described above can be reduced.

[0040] 4B, 4C, and 4D, when the pole 2 reaches an intermediate position between the forward and backward positions, the reversing part 52 performs two types of rotational motion, namely, revolution in a first rotational direction R1 about the rotation axis C and rotation in a second rotational direction R2 about the offset axis (rotational axis) E, as described above, causing the center of gravity G of the reversing part 52 to reciprocate in the opposite direction to the pole 2 (reciprocating part) on the same reciprocating axis A as the pole 2 (reciprocating part), without any vertical component. As a result, no force (impact) is generated in a direction perpendicular to the reciprocating axis A (up and down relative to the operator).

[0041] 4E, when the pole 2 moves toward the retracted position, an impact (inertial force Fp) occurs in the direction from the front to the rear. However, the center of gravity G of the reversing part 52 simultaneously reaches the forward position, and an inertial force Fg in the direction from the rear to the front is generated in the reversing part 52, so that the impact transmitted to the worker can be reduced.

[0042] Although not shown in the figures, when the pole 2 reaches an intermediate position between the retracted position and the advanced position, the center of gravity G of the reversing part 52 also reciprocates in the opposite direction to the pole 2 (reciprocating part) on the same reciprocating axis A as the pole 2 (reciprocating part), without any vertical component. As a result, no force (impact) is generated in a direction perpendicular to the reciprocating axis A (up and down relative to the operator).

[0043] As described above, the shake-off device 1 of this embodiment is a shake-off device (1) including a crankshaft unit (12) driven by a drive source (engine 8), a connecting rod (10), and a reciprocating part (pole 2) having a contact part (4), the reciprocating part (pole 2) being reciprocated along a reciprocating axis (A) between an advanced position and a retreated position by the crankshaft unit (12) via the connecting rod (10), the crankshaft unit (12) including a crankshaft part (50) engaged with the connecting rod (10) and a reversing part (52), the crankshaft part (50) including a normal rotation member (bevel gear 22) driven by the drive source (engine 8) to rotate (spin) around a first rotation axis (C) in a first rotation direction (R1), and the reversing part (5 2) includes a reversing gear (42) to which a counterweight (44) is attached and which meshes with an internal gear (49) fixed to the case (6), and which is driven to revolve around the first rotation axis (C) in the first rotation direction (R1) together with the normal rotation member (bevel gear 22) and rotate around a second rotation axis (E) offset (parallel) from the first rotation axis (C) in a second rotation direction (R2) opposite to the first rotation direction (R1). As a result of the counterweight (44) and the reversing gear (42) performing (two types of) rotational motion, namely, revolution around the first rotation axis (C) and rotation around the second rotation axis (E), the center of gravity of the reversing part (52) including the counterweight (44) and the reversing gear (42) reciprocates along the same reciprocating axis (A) as the reciprocating part (pole 2).

[0044] In addition, the reference pitch diameter (number of teeth) of the reversing gear (42) is set to half the reference pitch diameter (number of teeth) of the internal gear (49). With this configuration, the reversing gear (42) rotates once while the bevel gear (22) rotates half a rotation, so the counterweight (44) can be turned outward at the timing when the reversing gear (42) reaches the forward position and the reverse position, and the inertial force acting on the counterweight (44) can be utilized to the maximum.

[0045] Furthermore, it is preferable that the center of gravity of the reversing unit 52, including the counterweight 44 and the reversing gear 42, be located on the reference pitch circle of the reversing gear 42. With this configuration, the center of gravity of the reversing unit 52 during reciprocating motion coincides with the reciprocating axis A, thereby minimizing vertical vibration components. However, even if the center of gravity of the reversing unit 52 during reciprocating motion deviates from the reciprocating axis A and vertical vibration components are generated, the stroke perpendicular to the reciprocating axis A is sufficiently smaller than the stroke in the direction of the reciprocating axis A, so the force perpendicular to the reciprocating axis A is smaller than in a conventional configuration in which a counterweight rotates around a flywheel shaft.

[0046] Furthermore, it is preferable that the connecting axis between the forward rotating member (bevel gear 22) and the connecting rod (10) and the second rotation axis (E) are located on opposite sides of the first rotation axis (C). With this configuration, the reciprocating unit (pole 2) and the counterweight (44) move in opposite directions, and the inertial force acting on the reciprocating unit (pole 2) can be offset by the inertial force of the counterweight (44). Furthermore, by arranging the first crank pin 24a and the second crank pin 26a on either side of the rotation axis (C), the center of gravity of the crankshaft unit (12) is positioned closer to the rotation axis (C), thereby reducing unnecessary centrifugal force generated around the rotation axis (C) during operation.

[0047] In addition, it is preferable that the counterweight (44) is configured to be disposed closer to the reciprocating axis (A) (or the bevel gear 22) than the reversing gear (42). With this configuration, the center of gravity of the reversing part (52) is closer to the reciprocating axis (A) of the reciprocating part (pole 2), thereby reducing the torsional force generated by the counterweight (44) with respect to the reciprocating axis (A).

[0048] Furthermore, the center of gravity of the reversing unit (52), including the counterweight (44) and the reversing gear (42), is positioned at the retracted position when the reciprocating unit (pole 2) is in the advanced position, and is positioned at the advanced position when the reciprocating unit (pole 2) is in the advanced position. When the reciprocating unit (pole 2) moves between the advanced position and the retracted position, the center of gravity of the reversing unit (52) moves along the reciprocating axis (A) between the advanced position and the retracted position in the direction opposite to the moving direction of the reciprocating unit (pole 2).

[0049] According to this embodiment, the center of gravity of the reversing part (52) including the counterweight (44) and the reversing gear (42) does not rotate but reciprocates (linearly moves) along the same reciprocating axis (A) as the reciprocating part (pole 2). This makes it possible to provide an improved, small, lightweight shake-off device (1) with a small number of parts and a simple structure that can cancel out the inertial force acting on the reciprocating part without generating vibrations perpendicular to the inertial force of the reciprocating part.

[0050] In the above embodiment, the engine 8 is used as the drive source, but a motor may also be used. Furthermore, in the above embodiment, the bevel gear 22 is driven to rotate in the first rotation direction R1 around the rotation axis C by the bevel pinion 20, but any member other than the bevel gear 22 may be used as the forward rotating member that rotates in the first rotation direction R1 around the rotation axis C. For example, instead of rotating the drive shaft 18, it is also possible to use a structure in which a motor is connected to the first main shaft 24b of the first crankshaft 24 or the second main shaft 26b of the second crankshaft 26 to rotate the forward rotating member.

[0051] Although an example of an embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the invention. [Explanation of symbols]

[0052] 1. Shake-off device 2 Pole (reciprocating motion part) 2a rear end 2b tip 4 Contact area 6 cases 6a First side wall 6b Second side wall 8 Engine (power source) 10 Connecting rod 10a rear end 10b Front end 12 Crankshaft unit 16 Pole Guide 18 Drive shaft 20 Bevel Pinion 22 Bevel gear (forward rotating member) 22a First opening 22b Second opening 22c hole 22A First bridge section 22B Second bridge section 22C Annular section 24 First crankshaft 24a First crank pin 24b First main axis 26 Second crankshaft 26a Second crank pin 26b Second main axis 30 First Bearing 32 Second bearing 34 First needle bearing 36 Second needle bearing 42 Reverse Gear 42a center opening 43 volts 44 Counterweight 46 Mounting part 46a aperture 46b Cylindrical part 48 Weight section 49 Internal Gear 50 Crankshaft section 52 Reversal section A Reciprocating axis B Drive axis C Rotation axis (first rotation axis) D offset axis E Offset axis (second rotation axis) R1 First rotation direction R2 Second rotation direction

Claims

1. a crankshaft unit (12) driven by a drive source (8); A connecting rod (10); A shake-off device (1) comprising: a reciprocating part (2) having a contact part (4), the reciprocating part (2) being reciprocated along a reciprocating axis (A) between an advanced position and a retreated position by the crankshaft unit (12) via the connecting rod (10); The crankshaft unit (12) includes a crankshaft portion (50) that engages with the connecting rod (10) and a reverse portion (52); the crankshaft portion (50) includes a normal rotation member (22) that is driven by the drive source (8) to rotate around a first rotation axis (C) in a first rotation direction (R1); The reversing unit (52) includes a reversing gear (42) to which a counterweight (44) is attached, which meshes with an internal gear (49) fixed to the case (6), and which is driven to revolve around the first rotation axis (C) together with the normal rotation member (22) in the first rotation direction (R1) and to rotate around a second rotation axis (E) offset from the first rotation axis (C) in a second rotation direction (R2) opposite to the first rotation direction (R1), The counterweight (44) and the reversing gear (42) perform rotational motion of revolving around the first rotation axis (C) and rotating around the second rotation axis (E), so that the center of gravity of the reversing unit (52) including the counterweight (44) and the reversing gear (42) reciprocates along the same reciprocating axis (A) as the reciprocating unit (2).

2. 2. The shake-off device (1) according to claim 1, characterized in that the reference pitch diameter of the reversing gear (42) is set to half the reference pitch diameter of the internal gear (49).

3. The shake-off device (1) according to claim 1 or 2, characterized in that the center of gravity of the reversing part (52) including the counterweight (44) and the reversing gear (42) is located on a reference pitch circle of the reversing gear (42).

4. The shake-off device (1) according to claim 1 or 2, characterized in that the connecting axis between the forward rotating member (22) and the connecting rod (10) and the second rotation axis (E) are provided on opposite sides of the first rotation axis (C).

5. The shake-off device (1) according to claim 1 or 2, characterized in that the counterweight (44) is arranged closer to the reciprocating axis (A) than the reversing gear (42).

6. The shake-off device (1) according to claim 1 or 2, characterized in that the center of gravity of the reversing part (52) including the counterweight (44) and the reversing gear (42) is positioned at the retracted position when the reciprocating part (2) is in the advanced position, and is positioned at the advanced position when the reciprocating part (2) is in the retracted position.

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