JPH0687036U - Anti-vibration structure of power train - Google Patents

Abstract

(57) [Summary] [Purpose] The resonance point in the vibration transmission system of the power train is shifted to the low frequency range to prevent the occurrence of abnormal vibration and noise by avoiding overlapping with other resonance systems. A propeller shaft 11 is connected to one of a pair of companion flanges 13 facing each other via a cross shaft 14, and a drive shaft 12a of a final reduction gear 12 has a through hole 15a provided in the other companion flange 15. The nut 16 is screwed and fixed to a male screw portion formed at the tip of the nut 16 inserted into the. The pair of companion flanges 13 and 14 facing each other are coupled by bolts 18 and nuts 19 with a flywheel 17 as a vibration damping means sandwiched therebetween, and the power of the engine is terminated via the propeller shaft 11. It is adapted to be transmitted to the speed reducer 12. The flywheel 17 is formed in a disk shape and has a thick portion 17a on the outer peripheral portion thereof to secure a sufficient inertial weight to obtain a vibration damping effect.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vibration isolation structure for a power train, and more particularly to a technique for preventing abnormal vibration in a power train by providing vibration damping means at a connecting portion between a propeller shaft and a final reduction gear.

[0002]

[Prior art]

 Conventionally, there is a structure of a power train as shown in FIG. That is, in this figure, the power of the engine 2 provided on the front side of the vehicle 1 is transmitted from the propeller shaft 4 via the transmission 3 to the drive wheels 6 via the final reduction gear 5 in the figure. is there. That is, the input torque that has been changed in speed by the transmission 3 and has passed through the propeller shaft 4 is decelerated by the final reduction gear 5, and the rotational speed and rotational direction are converted and transmitted to the drive shaft.

The connecting portion between the propeller shaft 4 and the final reduction gear 5 in the power transmission system of the power train is connected by bolts 8a and nuts 8b via companion flanges 7a and 7b, as shown in FIG. ing. In the vehicle 1 in which the transmission distance between the transmission 3 and the final reduction gear 5 is long, the middle portion of the propeller shaft 4 is attached to the vehicle body frame 1a by the support device 9 in order to suppress the vibration of the propeller shaft 4 during traveling. It is supported.

[0004]

[Problems to be solved by the device]

 By the way, in the power transmission system of such a power train, the transmission 3 is elastically supported together with the engine 2 with respect to the vehicle body frame 1a, and the final deceleration device 5 is suspended on the vehicle body frame 1a via the spring of the suspension. Since the vehicle is in a state, when the resonance occurs in the power train, the vibration is transmitted to the entire vehicle through the body frame 1a, so that the resonance point of the vibration transmission system of the power train is generated in a certain vehicle speed range while the vehicle is running. There was a problem that abnormal vibration occurred and noise was generated based on it, overlapping with other resonance systems.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and the resonance point in the vibration transmission system of the power train is shifted to a low frequency range to avoid overlapping with other resonance systems. It is an object of the present invention to provide an anti-vibration structure for a power train that prevents the occurrence of abnormal vibration and noise.

[0006]

[Means for Solving the Problems]

 Therefore, in the power train configured to transmit the power of the engine from the propeller shaft to the drive wheels through the final reduction gear, the present invention provides a vibration damping at the connection portion between the propeller shaft and the final reduction gear. Means are provided.

[0007]

[Action]

 According to such a configuration, in the vibration transmission system of the power train configured to transmit the power of the engine from the propeller shaft to the drive wheels via the final reduction gear, at the connection portion between the propeller shaft and the final reduction gear, For example, by providing vibration damping means such as a flywheel or a dynamic damper, the resonance point in the vibration transmission system of the power train shifts to a lower frequency range than before, and it is possible to avoid overlapping with other resonance systems. As a result, abnormal vibration is reduced compared to the conventional one, and noise can be prevented from being generated based on the abnormal vibration.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The overall structure of the power train in which the power of the engine is transmitted from the propeller shaft to the drive wheels via the final reduction gear is the same as that of the conventional example shown in FIG. 5, and therefore its explanation is omitted here. Then, only the connection between the propeller shaft and the final reduction gear, which is the main part of the present invention, will be described.

In FIG. 1 showing an embodiment of the present invention, a propeller shaft 11 is connected to one of a pair of companion flanges 13 facing each other via a cross shaft 14, and a drive shaft 12 a of a final reduction gear unit 12 is A nut 16 is screwed and fixed to a male screw portion formed at the tip of the through hole 15a provided in the other companion flange 15.

The pair of companion flanges 13 and 15 facing each other are coupled by bolts 18 and nuts 19 with a flywheel 17 serving as a vibration damping means sandwiched therebetween so that the power of the engine can be transmitted to the propeller shaft 11. It is adapted to be transmitted to the final reduction gear transmission 12 via the. The flywheel 17 is formed in a disc shape, and has a thick portion 17a on the outer peripheral portion thereof to secure a sufficient inertial weight for obtaining a vibration damping effect.

The flywheel 17 can be integrally formed with any one of the companion flanges 13 and 15, and the product cost can be reduced by reducing the number of parts. Fig. 2 shows the vibration damping effect of the flywheel 17. Compared to the case without the flywheel 17 shown by the solid line, the case with the flywheel 17 installed is shown by the dotted line in a certain vehicle speed range. The vibration damping effect can be obtained.

Next, a connecting portion between the propeller shaft and the final reduction gear unit according to another embodiment will be described with reference to FIGS. 3 and 4. This is a modification of the embodiment shown in FIG. 1 in which the flywheel 17 is replaced with a dynamic damper 20. Since the other construction is the same as that of the above-mentioned embodiment, the same reference numerals are used for the description. Omit it. That is, the companion flanges 13 and 15 are connected by the bolt 18 and the nut 19 with the dynamic damper 20 as a vibration damping means being sandwiched therebetween.

In the dynamic damper 20, an elastic body 22 such as rubber is fixed to an outer peripheral portion of a support plate 21, and an inertial mass 23 is fixed to the elastic body 22. FIG. 4 shows the vibration damping effect of this dynamic damper 20. Compared to the case without the dynamic damper 20 shown by the solid line, the one with the dynamic damper 20 is shown by the dotted line in a certain vehicle speed range. Thus, the vibration damping effect can be obtained. This is because the vibration energy generated at the connection portion between the propeller shaft and the final reduction gear is absorbed by the elastic body 22, and at this time, this vibration energy is replaced with heat energy, and the vibration generated at the connection portion. Is absorbed. Then, the elastic body 22 emits heat, and this heat is radiated through the inertial mass 23.

As described above, according to the vibration isolation structure of the power train having the configuration shown in the embodiment, the resonance point in the vibration transmission system of the power train is shifted to a lower frequency range than the conventional one, and the resonance point is different from that of other resonance systems. Since it is possible to avoid the duplication, it is possible to reduce the vibration and prevent the generation of noise as compared with a conventional flywheel, a dynamic damper or the like which does not have a vibration damping means.

[0015]

[Effect of device]

 As described above, according to the present invention, in the vibration transmission system of the power train, by providing a vibration damping means such as a flywheel or a dynamic damper at the connecting portion between the propeller shaft and the final reduction gear, The resonance point in the vibration transmission system of the power train shifts to a lower frequency range than in the past, and it is possible to avoid overlapping with other resonance systems.Therefore, abnormal vibration is reduced and noise is prevented compared to the past. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a vibration isolation structure of a connecting portion between a propeller shaft and a final reduction gear according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between vehicle speed and sound pressure level for explaining a vibration damping effect by a flywheel.

FIG. 3 is a cross-sectional view showing a vibration isolation structure of a connecting portion between a propeller shaft and a final reduction gear device according to another embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between vehicle speed and sound pressure level for explaining the vibration damping effect of the dynamic damper.

FIG. 5 is a sectional view showing the structure of a conventional power train.

FIG. 6 is a cross-sectional view showing a vibration isolating structure at a connection portion between a conventional propeller shaft and a final reduction gear transmission.

[Explanation of symbols]

 11 Propeller shaft 12 Final reduction gear 12a Drive shaft 13,15 Companion flange 17 Flywheel 17a Thick part 18 Bolt 19 Nut 20 Dynamic damper 21 Support plate 22 Elastic body 23 Inertia mass

Claims (1)

[Scope of utility model registration request] 1. A power train configured to transmit engine power from a propeller shaft to a drive wheel side via a final reduction gear, wherein a vibration damping means is provided at a connection portion between the propeller shaft and the final reduction gear. Anti-vibration structure of the power train characterized by