JP2009222135A - Vibration removing device for reciprocating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for removing generating vibration, in a reciprocating machine driven by a single slider crank mechanism. <P>SOLUTION: This vibration removing device has a counterweight arranged on a crankshaft of the crank mechanism, a pair of primary balance shafts arranged in parallel to the crankshaft and respectively rotating in the inverse direction at the same rotating speed as a rotating speed of the crankshaft by a first rotation transmission mechanism, and a pair of secondary balance shafts held in a central part in the axial direction of the primary balance shafts and rotating in the inverse direction of the primary balance shafts at a rotating speed of two times the rotating speed of the crankshaft by a second rotation transmission mechanism. Respective gravity center positions of the primary balance shafts and the secondary balance shafts are set in a symmetrical position to the gravity center axis of a slider part of the crank mechanism, and are set on the same plane as a motion plane of a connecting rod and a crank of the crank mechanism. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration removing apparatus for a reciprocating machine driven by a slider / crank mechanism, and more particularly to a vibration removing apparatus for a reciprocating machine for preventing vibration of a single slider / crank mechanism.

  As a mechanism for converting a rotary motion into a reciprocating motion or a reciprocating motion into a rotational motion, such as an engine, a pump, and an air compressor, a slider / slank mechanism is widely used. In this mechanism, harmful vibrations and noise are generated by using the unbalanced inertial force resulting from the motions of the reciprocating motion part (slider), the crank, and the connecting rod (hereinafter referred to as connecting rod) as the excitation force. This unbalanced inertial force has a high-order component that fluctuates an even number of times per rotation of the crankshaft, in addition to the primary component synchronized with the rotation of the crankshaft of the crank.

  For example, in the case of a machine in which a plurality of slider-crank mechanisms are connected in series, such as a multi-cylinder engine for automobiles, the primary component of the unbalanced inertia force is balanced by shifting the phase of each cylinder. The vibration can be reduced.

  However, in the case of a reciprocating machine composed of only a single slider / crank mechanism such as a single cylinder engine, it is difficult to balance the first and higher order components of the unbalanced inertial force.

  Therefore, between the engine crankcase and recoil starter, a pair of weights rotating in opposite directions and symmetrically with respect to the rotation phase in conjunction with the crankshaft are rotated at the same rotational speed as the crankshaft. An engine with a balancer has been proposed in which the movement of the reciprocating portion of the engine and the movement of the weight in the reciprocating direction are provided in opposite directions (see Patent Document 1).

JP 05-149387 A

  However, the engine with a balancer has a structure that balances the primary inertial force of a single cylinder engine, and the secondary inertial force is not considered at all, and sufficient vibration removal cannot be performed.

  In view of the above problems, the present inventor, as a result of earnest research, in a reciprocating machine using a single slider / crank mechanism, the present inventors have obtained primary and secondary inertia forces by using a counterweight and two types of balance shafts. Thus, a vibration removing device for a reciprocating machine capable of removing primary and secondary vibrations by balancing the inertial forces is provided.

  For this reason, the vibration removing device for a reciprocating machine according to the present invention is provided with a counterweight provided on the crankshaft of the crank mechanism and in parallel with the crankshaft, and the number of rotations of the crankshaft by the first rotation transmission mechanism. A pair of primary balance shafts rotating in the opposite direction and in the opposite direction, and held in the central portion of the primary balance shaft in the axial direction, and twice the number of rotations of the crankshaft by the second rotation transmission mechanism A pair of secondary balance shafts that rotate in the opposite direction to the primary balance shaft at a rotational speed are provided, and the center of gravity positions of the primary balance shaft and the secondary balance shaft are symmetrical with respect to the slider portion center of gravity axis of the crank mechanism. The first feature is that the position is on the same plane as the plane of motion of the connecting rod and crank of the crank mechanism.

  The first rotation transmission mechanism includes a pair of gears provided on the crankshaft and the primary balance shaft, or a pulley and a timing belt. The pair of primary balance shafts are synchronized with the rotation of the crankshaft. A second feature is that the rotation is performed in the opposite direction and at the same rotation speed.

  The second rotation transmission mechanism includes an external gear provided at an end portion of the secondary balance shaft, and an internal gear that engages with the external gear and simultaneously inserts the primary balance shaft. This is the third feature.

  In addition, a fourth feature is that the primary balance shaft and the secondary balance shaft are formed by shifting the position of the center of gravity of the columnar member in the radial direction from the rotation axis.

  According to the vibration eliminator for a reciprocating machine according to the present invention, the counterweight provided on the crankshaft of the crank mechanism and the counterweight are arranged in parallel with the crankshaft, and are rotated in opposite directions by the first rotation transmission mechanism. A pair of primary balance shafts and the axially central portion of the primary balance shaft are held in the opposite direction to the primary balance shaft at a rotational speed twice that of the crankshaft by a second rotation transmission mechanism. Since a pair of rotating secondary balance shafts are provided, the primary and secondary unbalanced inertial force that is the vibration source of the reciprocating machine can be removed.

  The center of gravity of each of the primary balance shaft and the secondary balance shaft is symmetrical with respect to the slider portion center of gravity axis of the crank mechanism, and is on the same plane as the plane of motion of the connecting rod and crank of the crank mechanism. Therefore, there is an effect that the inertia couple around the crankshaft is not generated by installing the balance shaft.

Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view for explaining the principle of a reciprocating machine driven by a slider / crank mechanism, and FIG. 2 is an explanatory view showing the principle of a vibration removing apparatus for a reciprocating machine driven by a slider / crank mechanism of the present invention.

  FIG. 1 shows the principle of a reciprocating machine driven by a normal slider / crank mechanism. As shown in the figure, the reciprocating machine 1 includes a crank 2, a connecting rod 3, and a slider portion 4. The slider portion 4 reciprocates in the y-axis direction, the connecting rod 3 swings, and the crank 2 rotates. Along with these movements, an unbalanced inertia force shown in the following formula 1 is generated, and this inertia force generates harmful vibrations in the main body of the reciprocating machine 1 through a support portion (not shown) of the crankshaft 5.

In Equation 1, the first subscript of the unbalanced force f indicates the direction of the component force of the unbalanced inertial force, and the second subscript indicates the order of the rotational speed of the unbalanced inertial force. For example _, fx _{, 1} represents the primary component of the x-axis direction component of the unbalanced inertia force, and fy _{, 2} represents the secondary component of the y-axis direction component of the unbalanced inertia force.

  FIG. 2 is an explanatory view of the principle of the vibration removing device 20 for a reciprocating machine according to the present invention. A counterweight 6 is installed on the crankshaft 5 of the reciprocating machine 1 comprising the single slider / crank mechanism shown in FIG. A pair of primary balance shafts 7 and 7 are provided in parallel and symmetrical positions around the shaft 5, and rotate in the same direction as the rotation speed of the crankshaft 5 and in the opposite direction in synchronization with the rotation of the crank 2. Further, the primary balance shafts 7 and 7 are rotatably provided with secondary balance shafts 8 and 8, which are twice the number of rotations of the crankshaft 5 due to the engagement of the external gear 12 and the internal gear 22 described later. It rotates in the opposite direction at each rotation speed.

First, the x-direction component force fx _{, 1} of the first-order unbalanced inertia force shown in Equation 1 is canceled by the x-direction component of the centrifugal force caused by the rotation of the balance weight 6 shown in FIG. it can. Next, the x-direction components of the centrifugal force generated when the pair of primary balance shafts 7 and 7 rotate in the opposite directions at the same rotation number cancel each other and cancel each other, and the inertial force having only the y-direction component Occurs. Further, since the y-direction component of the centrifugal force due to the rotation of the counterweight 6 is added to the y-direction component force f _{y, 1} of the primary unbalanced inertial force of the equation 1, the resultant y-direction force and the above-mentioned The primary vibration is not generated by balancing the inertial force of the y-direction component of the primary balance shaft 7.

Next, as apparent from Equation 1, the secondary unbalance inertia force is only the y-direction component force f _{y, 2} , and the secondary balance shafts 8 and 8 shown in FIG. Balance is possible by rotating in the opposite direction at twice the number of rotations. That is, by rotating the secondary balance shafts 8 and 8 in opposite directions, the x-direction component of the centrifugal force of the secondary balance shafts 8 and 8 is canceled in the same manner as the primary balance shafts 7 and 7 described above, and y Only the direction component is generated. By balancing this y-direction component with the secondary component f _{y, 2} of the unbalanced inertial force of Equation 1 above, the secondary unbalanced inertial force can be balanced and the secondary vibration can be reduced.

In the slider / crank mechanism, a higher-order unbalance inertia force f _{y, n} (n = 2 (m + 1) m is a natural number) is also generated, but the above-described primary and secondary inertia forces are Since it is very small in comparison, the vibration of the reciprocating machine composed of a single slider / crank mechanism can be greatly reduced by using the above-described primary and secondary balance shafts.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. Of course, the present invention is not limited to this embodiment.

  3 to 5 show an embodiment of the vibration removing apparatus for a reciprocating machine of the present invention. FIG. 3 is a perspective view of the primary and secondary balance shafts, and FIG. 4 is a vibration removing apparatus for the reciprocating machine of the present invention. FIG. 5 is a perspective view showing the rotation transmission mechanism of the secondary balance shaft.

  As shown in FIG. 3, the primary balance shaft 7 is formed with a notch portion 9 and a bearing portion 10 in a part of a metal cylinder, and is made of a metal through the bearing portion 10 at the center in the axial direction. The secondary balance shaft 8 is rotatably held. The secondary balance shaft 8 has a notch 11 formed in the center, an external gear 12 is attached in the vicinity of the bearing 10, and meshes with an internal gear 22 described later to rotate the secondary balance shaft 8. Here, the positions of the center of gravity of the primary balance shaft 7 and the secondary balance shaft 8 are formed so as to be shifted in the radial direction from the rotary shafts 13 and 14 by the notches 9 and 11, respectively. The balance force is generated. The secondary balance shaft 8 is configured to rotate twice with respect to one rotation of the primary balance shaft 7 by meshing with the external gear 12, the internal gear 22, and the secondary component of the unbalanced inertia force described above. This creates a balancing force. The means for moving the center of gravity of the primary balance shaft 7 and the secondary balance shaft 8 in the radial direction can be not only the formation of the notches 9 and 11 but also a means for attaching a weight for correcting the center of gravity. It is. And the mass of the notch part 9 on the primary balance shaft 7, the bearing part 10, and the external gear 12 of the secondary balance shaft 8 is designed in advance in consideration of the primary unbalanced inertia force of the reciprocating machine 1 described above. .

  FIG. 4 shows a vibration removing apparatus 20 for a reciprocating machine according to the present invention. A reciprocating machine 1 placed on a gantry 15 is composed of a crank 2, a connecting rod 3, and a slider part 4. The slider 4 reciprocates in the vertical direction by the rotation of a motor (not shown) provided at the end. A pair of counterweights 6 are attached to the crankshaft 5 at symmetrical positions with respect to the crank 2, and a toothed pulley 16 and a gear pair 17 are connected to one end of the crankshaft 5. A pair of primary balance shafts 7 and 7 are rotatably held by a bearing 18 provided on the gantry 15 in parallel with the crankshaft 5, and a toothed pulley 19 is attached to the ends of the primary balance shafts 7 and 7. , 19 are mounted opposite to the toothed pulley 16, respectively. A timing belt 21 is wound around the toothed pulleys 16 and 19, and the rotation of the crankshaft 5 causes the pair of primary balance shafts 7 and 7 to rotate at the same rotational speed as the crankshaft 5 and in the opposite direction. . In addition, a secondary balance shaft 8 is provided at the center of the primary balance shaft 7 in the axial direction via a bearing portion 10, and the primary balance shaft 8 is engaged with the external gear 12 and the internal gear 22 described above. The rotation speed is twice the rotation speed of 7 and in the reverse direction. In this embodiment, the rotation transmission mechanism of the primary balance shafts 7 and 7 is configured by combining the toothed pulleys 16 and 19 and the timing belt 21, but the configuration is based on other means (for example, a combination of gears). It doesn't matter.

  FIG. 5 shows a rotation transmission mechanism of the secondary balance shaft 8. The internal gear 22 attached on the gantry 15 and the secondary balance shaft 8 attached through the opening 23 of the internal gear 22 are shown. The number of teeth of the internal gear 22 is the number of teeth that the secondary balance shaft 8 rotates at twice the number of rotations of the primary balance shaft 7 due to the meshing of the external gear 12. Yes. The center of gravity of each of the primary balance shaft 7 and the secondary balance shaft 8 is symmetrical with respect to the center of gravity axis of the slider portion 4 shown in FIG. 4 and is the same as the plane of motion of the connecting rod 3 and the crank 2. It is said to be on a plane.

  The reciprocating machine vibration removing device 20 of the present invention having the above-described configuration includes a pair of counterweights 6 provided on the crankshaft 5 and a pair of primary balance shafts 7 disposed in parallel with the crankshaft 5. The primary vibration generated during the reciprocating motion of the reciprocating machine 1 can be removed by the inertial force generated by the rotation of 7. Further, when the reciprocating machine 1 reciprocates, the inertial force generated when the secondary balance shafts 8, 8 provided on the primary balance shafts 7, 7 rotate at twice the rotational speed of the crankshaft 5. The generated secondary vibration can be removed. Moreover, even if these two types of balance shafts 7 and 8 are disposed in parallel with the reciprocating machine 1 and rotated, the center of gravity of the balance shafts 7 and 8 is symmetric with respect to the center of gravity of the slider portion 4. In addition, since the connecting rod 3 and the crank 2 are on the same plane as the motion plane, no inertia couple is generated, and no vibration is generated by the inertia couple.

  As described above, according to the vibration removing apparatus for a reciprocating machine of the present invention, in a reciprocating machine using a single slider / crank mechanism, primary and secondary inertial forces are suspended by using a counterweight and two types of balance shafts. In addition, the primary and secondary vibrations due to the balance of the inertial forces can be removed.

It is explanatory drawing which shows the principle of the reciprocating machine driven with the conventional slider crank mechanism. It is explanatory drawing which shows the principle of the vibration removal apparatus for reciprocating machines driven with the slider crank mechanism which concerns on this invention. It is a perspective explanatory view of a primary and secondary balance shaft. It is a perspective view of the vibration removal apparatus for reciprocating machines of this invention. It is a perspective view which shows the rotation transmission mechanism of a secondary balance shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reciprocating machine 2 Crank 3 Connecting rod 4 Slider part 5 Crankshaft 6 Balance weight 7 Primary balance shaft 8 Secondary balance shaft 9, 11 Notch part 10 Bearing part 12 External gear 13, 14 Rotating shaft 15 Base 16, 19 With teeth Pulley 17 Gear pair 18 Bearing 20 Reciprocating machine vibration removing device 21 Timing belt 22 Internal gear 23 Opening

Claims (4)

  In a reciprocating machine using a slider-crank mechanism, a counterweight provided on the crankshaft of the crank mechanism, and a rotation speed of the crankshaft are arranged in parallel with the crankshaft, and each of the crankshafts is rotated by a first rotation transmission mechanism. A pair of primary balance shafts rotating in the opposite direction and the same rotational speed, and held in the axial central portion of the primary balance shaft, and rotated twice the rotational speed of the crankshaft by the second rotation transmission mechanism A pair of secondary balance shafts that rotate in the opposite direction to the primary balance shaft, and the center of gravity of each of the primary balance shaft and the secondary balance shaft is symmetrical with respect to the slider center of gravity axis of the crank mechanism. And a vibration removing device for a reciprocating machine which is coplanar with a connecting plane of the crank mechanism and a movement plane of the crank.   The first rotation transmission mechanism includes a pair of gears provided on the crankshaft and the primary balance shaft, or a pulley and a timing belt, and reverses the pair of primary balance shafts in synchronization with the rotation of the crankshaft. 2. The vibration removing apparatus for a reciprocating machine according to claim 1, wherein the vibration removing apparatus rotates in the direction and at the same rotation speed.   The second rotation transmission mechanism includes an external gear provided at an end portion of the secondary balance shaft, and an internal gear that engages with the external gear and simultaneously inserts the primary balance shaft. The vibration removing apparatus for a reciprocating machine according to claim 1.   The reciprocating machine vibration removing device according to claim 1, wherein the primary balance shaft and the secondary balance shaft are formed by shifting the position of the center of gravity of the columnar member in the radial direction from the rotation axis.

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