JPH09217816A - Gear damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce idle noise by providing a driven gear and a driven plate which is installed coaxially at a position adjacent to the driven gear, fixing one end of a pin to one of the gears, drilling a close-fit hole in the other gear corresponding to the pin, and supporting the outer peripheral end of a coiled spring in the close-fit hole. SOLUTION: In an engine, a fan gear 1a for driving a fan located on the driven gear side is fixed at the end part of a fan center shaft 12, and the power of a crank gear is transmitted to the gear 1a through three stages of idle gears 3a. An idle gear 13 among the three stages of idle gears 3a which is supported on a stepped shaft 25 supports the idle gear 4a on the large diameter part 25a of the stepped shaft 25 through a bearing cylinder 26. Then pins 15 and 15a are pressed into those holes providing in the idle gears 13 and 4a, coiled springs 17 and 17a are fitted closely into those close-fit holes 16 and 16a formed in the idle gears 4a and 13 at those positions corresponding to the pins 15 and 15a, and the center ends of the springs 17 and 17a are fixed to the pins 15 and 15a, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear damper capable of reducing idle noise in an idle gear portion provided when transmitting power from a driving gear side of an engine to a driven gear side.

[0002]

2. Description of the Related Art In a conventional engine, for example, FIG.
In the second gear train, the fan gear 1 for driving the fan, which is the driven gear side, and the crank gear 2 provided at the end of the crankshaft, which is the driving gear side for transmitting power to the fan gear 1, are directly connected. Instead, a plurality of gears, for example, three-stage gears are coaxially arranged, and the three-stage idle gear 3 shown in FIG. 13 is provided to collect the gear train in a limited space in the engine. Idle gear 4 of 3-stage idle gear 3 that drives fan gear 1
Is fixed to an idle gear 6 that transmits drive to a gear 5 for driving the injection pump.

In FIG. 12, the cam gear 7 transmits power to the three-stage idle gear 3 via idle gears 8 and 9, and the water pump gear 10 and the power steering gear are also transmitted via these gear trains. 11
Power is transmitted to. On the other hand, a gear striking sound generated due to torsional vibration generated in the crankshaft 2 due to combustion of each cylinder of the engine, and a blade caused by vibrating the fan blade from the crank gear 2 via the fan gear 1 And the fan gear 1 vibrates in the thrust direction due to the fact that the gear portion of the fan gear 1 is a helical gear, idle noise due to the knocking sound of the gear hitting the gear case, etc. is generated in the engine. It is the main cause of the deterioration of front sound.

Further, as described above, in order to absorb the torsional vibration generated at the time of torque transmission, there is provided a plurality of bushes around which elastic members made of a rubber material are attached, and a flange is formed on the outer periphery of the hub. , A plurality of accommodation windows are formed in either one of the flange and the gear ring arranged in the axial direction, and bushes are fitted into the accommodation windows, respectively, and the other end thereof is engaged with the tip end portion of the pin, and further, with the hub. A gear damper with a spigot set on the gear ring is actually opened 63-110.
759.

However, inside the engine,
Because it is in a high temperature environment where it is constantly exposed to lubricating oil,
In the case of an elastic member made of a rubber material, the rubber characteristics are deteriorated with time, and as a result, the damping characteristics are gradually deteriorated. In the worst case, the rubber may be damaged and the engine life may not be completed. Further, when the driven gear receives power from the drive gear between the driven gear and the driven plate provided adjacent to the driven gear, vibration is generated on the driven plate side due to the meshing state of both gears. It may be transmitted and smooth power transmission may not be performed.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a gear capable of reducing the front sound, particularly at the time of idling, such as the vibration of the fan blade and the fan gear due to the torsional vibration of the crankshaft and the rattling sound of the gear. The first problem to be solved is to provide a damper. A second problem to be solved is to provide a device for smoothly transmitting power between a driven gear that meshes with a drive gear and a driven plate provided adjacent to the driven gear.

[0007]

A gear damper according to the present invention comprises a driven gear, a driven plate coaxially provided adjacent to the driven gear, and one end of a pin on one of the driven gear or the driven plate. It is fixed, and a fitting hole corresponding to the pin is opened on the other side, the outer peripheral end of the winding spring is supported in the fitting hole, and the center end of the winding spring is fixed to the other end of the pin. Has been done.

Further, one end of a pin is fixed to one gear of an idle gear in which a plurality of gears are coaxially arranged in order to transmit the power of the driving gear side to the driven gear side, and the other gear is fixed to the other gear. A fitting hole is provided at a position corresponding to the pin, an outer peripheral end of the winding spring is supported in the fitting hole, and a damper part that fixes the center end of the winding spring to the other end of the pin, At least one or more are arranged. Further, a stopper for restricting the movement amount of the pin in the fitting hole is provided in the fitting hole to which the outer peripheral end of the winding spring is fixed, concentrically with the pin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A gear damper according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of an idle gear, and FIG. 2 is a front view taken along line DD in FIG. Although each of the cross-sectional views is shown, as in the conventional example described with reference to FIG. 12, a plurality of coaxial units are provided to transmit the power of the drive gear, that is, the crank gear 2 to the fan gear 1 that is the driven gear side. 3 is a cross-sectional view corresponding to a three-stage idle gear 3 portion in which the gear of FIG.

The fan gear 1a in FIG. 1 is fixed to the end of the fan center shaft 12, and the power of the crank gear 2 in FIG. 12 is set by the idle gear 4a constituting the three-stage idle gear 3a. Is transmitted.
Next, the stepped shaft 25 is supported in a hole at the center of the idle gear 13 that constitutes the three-stage idle gear 3a of FIG. 1, and the idle gear 4a is supported by the large diameter portion 25a of the stepped shaft 25. The idle gear 13 is supported via the cylinder 26, and further supported by the small diameter portion 25b.

Then, the pin 15 is press-fitted into the hole provided in the idle gear 13, and the pin 15a is press-fitted into the hole provided in the facing idle gear 4a. The pin 1
5, 15a are alternately provided on the idle gears 13 and 4a with a predetermined interval, and these pins 15,
A fitting hole 16 is provided on the idle gear 4a side at a position corresponding to 15a.
And the fitting holes 16a are formed on the idle gear 13 side. Then, the winding springs 17 and 17a are inserted into the fitting holes 16 and 16a, respectively, and the outer peripheral ends thereof are fitted into the fitting holes 1 and
It is supported on the wall surfaces of 6, 16a. On the other hand, the winding spring 1
The central ends of 7, 17a are fixed to the pins 15, 15a, respectively, to form a damper portion.

That is, the winding springs 17 are respectively inserted and fixed in the plurality of fitting holes 16 provided around the idle gear 4a side, and the winding springs are wound in the plurality of fitting holes 16a provided around the facing idle gear 13 side. Pins 1 to which 17a are fitted respectively and which are fixed to the central portions of these winding springs 17 and 17a
5 and 15a are provided respectively, and the winding springs 17 and 17a are dispersedly arranged in the idle gears 4a and 13. The idle gear 13a is integrally formed on the side of the idle gear 13 to form a three-stage idle gear 3a.

The torque in the damper portion having the above structure, that is, the transmission of power from the crankshaft 2 side shown in FIG. 12, is transmitted from the pins 15 and 15a to the winding springs 17 and 1.
7a through the route of the idle gear 4a,
The damper portion of each of the winding springs 17 and 17a can absorb the torsional vibration. FIG. 3 shows a gear damper according to another embodiment, in which all the pins 15 are connected to the idle gear 1
Fix it to the 3 side and set all the winding springs 17 to the idle gear 4a.
Inserted into the fitting hole 16 provided on the side and supported,
It has essentially the same function as the gear damper described in the above embodiment.

Next, the principle of the damper portion composed of the winding spring 17 and the pin 15 will be described. In FIG. 4, the pin 1 placed at the center of the winding spring 17 in accordance with the torque fluctuation.
When 5 is moved in an arbitrary X direction, a reaction force is obtained in the winding spring 17 in a state where the semi-circular springs are combined so as to be continuous, and the reaction force is used to make the crankshaft. The torsional vibration transmitted from No. 2 is damped by the portion of the winding spring 17.

However, for example, at the maximum displacement between the idle gear 4a and the idle gear 13 as shown in FIG. 4, the stress due to the deformation of the winding spring 17 becomes excessive and the target life may not be satisfied. I have something to do. As a countermeasure against this, in the present invention, in order to achieve the target life while satisfying the damping function of the damper portion, as shown in FIG. 5, FIG. 6 and FIG. A stopper 20 is provided in the dowel hole 16 concentrically with the pin 15 and limits the movement amount of the pin 15 in the fitting hole 16.

That is, FIGS. 5 and 6 show the stopper 2
It shows the neutral state when 0 does not work. When the transmission torque exceeds the elastic force of the coil spring 17, the elastic support of the coil spring 17 is damped as shown in FIG.
By providing the mechanism in contact with the inner wall surface of 6, it is possible to achieve the target life while satisfying the damping function.

Incidentally, in FIG. 1, the stopper 2
Pin 1 with 0 planted in both idle gears 4a and 13
Although it is formed on each of No. 5 and 15a, the stop effect can be sufficiently exhibited only by providing on either one. Next, referring to FIG. 9, in the engine having the gear damper according to the embodiment of the present invention and the conventional engine not having the gear damper as described above, the rotation fluctuations of the respective fan idle gears at the time of the engine ring Each measured value is shown in the diagram. A case according to the present invention is shown in a diagram A, and a conventional case against the case is shown in a diagram B. It is shown in these diagrams that as the measured value approaches 0, smooth rotation with less rotation fluctuation can be obtained. I mean.

That is, in the conventional diagram B, as shown in FIG. 13, the idle gear 4 has a larger diameter.
Since it is fixed to 3, the rotation fluctuation on the crank gear 2 side is directly transmitted and has a large fluctuation waveform. On the other hand, in the diagram A according to the present invention, as shown in FIGS. 1 to 3, between the idle gears 13 and 4a, the coil spring 1
It has been confirmed that since the damper part composed of 7 (17a) and the pin 15 (15a) is provided, the rotational fluctuation due to the torsional vibration is attenuated and the device smoothly rotates as compared with the conventional device shown in the diagram B. .

Next, FIG. 10 is a diagram showing the effect of the gear damper when the engine is idling, and the forward sound is shown in dB. A diagram according to the invention
In the case of the conventional engine, the measured values are shown in the diagram B, and the portion indicated by the arrow E surrounded by the diagrams A and B indicates the noise of the forward sound by adopting the present invention. It is a reduction effect.

Further, FIG. 11 is a diagram showing the relationship between the forward sound (noise) dB and the engine speed of an engine having a gear damper according to an embodiment of the present invention and an engine having no conventional gear damper. An engine in an embodiment of the invention is shown in diagram A, and a conventional engine is shown in diagram B. The hatched portion between the two diagrams A and B indicates the range in which the forward sound of the engine having the gear damper according to the embodiment of the present invention is lower than that of the conventional engine.

In the present invention, not only the effect of reducing the front sound but also the effect of reducing the left sound and the sound in the other direction are recognized. FIG. 8 shows another embodiment of the present invention, in which the drive shaft 30 and the driven shaft 31 are connected by the drive gear 32 and the driven gear 33, and the driven plate 33 is fixed to the driven plate 34. , The driven plate 34 and the driven gear 3
A gear damper mechanism 35 is provided between the gear damper 3 and the gear 3.

According to the drive mechanism constructed as described above, fluctuations in power transmitted from the drive shaft 30 to the driven gear 33 are absorbed and relaxed between the driven gear 33 and the driven plate 34, and the fluctuation is transmitted to the driven shaft 31. Smooth power is transmitted, and as a result, the fan 36 can be driven smoothly. It should be noted that this embodiment can be effectively applied not only to the power transmission system including the fan shaft, but also to other power transmission systems.

[0023]

According to the above-described gear damper of the present invention, the damping function absorbs and alleviates the rotation fluctuation of the gear in the drive system in which the drive shaft and the driven shaft are connected by the gear, and thus the vibration and noise are reduced. The power can be smoothly transmitted from the drive shaft to the driven shaft without being generated.

Further, the damping function of the damper portion reduces the resonance noise of the fan blade in the fan driving portion caused by the torsional vibration of the crankshaft of the engine and the noise in the other direction due to the hammering sound of the fan gear. You can Further, while satisfying the above-mentioned damping function, the stopper mechanism of the present invention can fulfill the target life of the engine and can prolong the life.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of an idle gear of the present invention.

FIG. 2 is a front sectional view of a main part in a DD direction of FIG.

FIG. 3 is a side sectional view showing a modified example of the idle gear of FIG.

FIG. 4 is a front view showing a working state of a damper portion having no stopper.

FIG. 5 is a front view of a damper portion having a stopper.

FIG. 6 is a side sectional view of the damper portion of FIG.

FIG. 7 is a front view showing a state in which the stopper of the damper part in FIG. 5 is functioning.

FIG. 8 is an explanatory view showing a cross section of a main part of an apparatus to which the present invention is applied between a screw shaft and a drive shaft.

FIG. 9 is a diagram of respective measured values of rotation fluctuations of a fan idle gear in an engine having a gear damper according to an embodiment of the present invention and a conventional engine.

10 is a diagram showing an engine front sound in the engine of the present invention and the conventional engine similar to FIG. 9. FIG.

FIG. 11 is a relationship diagram of forward sound and rotation speed of an engine having a gear damper according to an embodiment of the present invention and a conventional engine having no gear damper.

FIG. 12 is a layout view of a gear train of a conventional engine.

13 is an enlarged side sectional view of the three-stage idle gear shown in FIG.

[Explanation of symbols]

 3 Idle gear 15 Pin 16 Fitting hole 17 Winding spring 20 Stopper

Claims (3)

[Claims] 1. A driven gear, a driven plate coaxially provided adjacent to the driven gear, one end of a pin fixed to one of the driven gear or the driven plate, and a fitting corresponding to the pin to the other. A gear damper in which a hole is opened, the outer peripheral end of the winding spring is supported in the fitting hole, and the center end of the winding spring is fixed to the other end of the pin. 2. One end of a pin is fixed to one gear of an idle gear in which a plurality of gears are coaxially arranged for transmitting power on the drive gear side to the driven gear side, and one pin is fixed to the other gear. A fitting hole is provided at a position corresponding to the pin, an outer peripheral end of the winding spring is supported in the fitting hole, and a damper part that fixes the center end of the winding spring to the other end of the pin, At least one gear damper. 3. A fitting hole for fixing an outer peripheral end of a spiral spring,
The gear damper according to claim 1 or 2, wherein a stopper that limits the amount of movement of the pin within the fitting hole is provided concentrically with the pin.