JPS61223368A - Vibration damping gear - Google Patents

Abstract

PURPOSE:To enable buffering of impact and damping of vibration by resiliently deforming a gear made of synthetic resin through engagement of the portion of the gear made of synthetic resin with a mating gear thereof, by a method wherein the gear made of synthetic resin is relatively rotatably disposed to the side of a gear made of a metal. CONSTITUTION:A gear 2 made of a metal is secured on a gear shaft 1 so that high torque can be transmitted. A gear 5 made of synthetic resin, e.g., nylon, polypropylene, having elasticity, is disposed to the side of the gear 2 made of a metal. The gear 5, to which the one end of a spring element 5, e.g., torsion springs, having the other end secured to the gear 2 side, is so disposed as to allow relative rotation to the gear 2 made of a metal. Further, the gear 5 is disposed in a state to be displaced in a phase so that a tooth 6 of the gear 5 is so further protruded than a tooth 3 of the gear 2 as to first gear with a mating gear thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an allocation gear having a shock absorbing function and a vibration damping function.

<Conventional technology> In a rotary power transmission system, gears used for speeding up and slowing down are generally made of metal such as steel from the viewpoint of material strength and gear life. . especially,
・For gears with large transmission torque, surface treatments such as carburizing and nitriding are applied to increase the strength of the tooth surfaces, making them extremely hard.゛On the other hand, in a power transmission system that includes gears, the meshing ratio of the gears is not an integer, and the meshing state of the gears may fluctuate due to manufacturing or assembly errors. Torque pulsations occur in various parts such as moving machines and coupling parts, and this is transmitted through the system in a form superimposed on the set torque to be transmitted6.
<Problems to be solved by the invention> Normally, screw vibration occurs within the power transmission system. Particularly during resonance or light loads, vibrations occur between gears that mesh with each other, accompanied by surface separation, which increases the impact load on the tooth surfaces and simultaneously increases the impact noise. These problems are most noticeable with metal gears that have low impact buffering and vibration damping functions.

Based on this knowledge, the present invention aims to provide a vibration damping gear for high torque transmission that has excellent shock buffering and vibration damping functions.

<Means for Solving the Problems> The allocation gear of the present invention has an annular synthetic resin gear disposed on the side of the metal gear via a spring element that effectively acts in the rotational direction of the metal gear. and a means for fixing the synthetic resin gear, which is fitted to the metal gear so as to be rotatable relative to the rotating shaft integral with the metal gear, at an arbitrary phase with respect to the metal gear. This is a characteristic feature.

<Operation> - The synthetic resin gear is rotated relative to the metal gear, and the tooth surface of the synthetic resin gear is caused to protrude in the direction of rotation by a spring element relative to the tooth surface of the metal gear, but the amount of this protrusion is is performed by the phase adjustment means. Therefore, in this gear, the synthetic resin gear portion first comes into contact with another gear that meshes with it and is elastically deformed, and then the metal gear portion comes into contact with the other gear. This elastic deformation generates a shock buffering function and a vibration damping function.

〈Example〉 First example showing the cross-sectional structure of an example of the damping gear according to the present invention
As shown in FIG. 2, which shows the right side shape of the figure, and FIG. 3, which is an enlarged view of the shape viewed from the In the embodiment, they are integrally molded, but they may be made separately and integrated using other joining methods such as keys, splines, or shrink fitting. The teeth 3 of the metal gear 2 can be applied to other types of gears, such as bevel gears and helical gears, in addition to spur gears as in this embodiment. Metal gear 20 Spring element 4 such as a screw spring that acts in the rotational direction
is connected at one end to a metal gear 2 or gear shaft 1, and at the other end to a gear 5 made of elastic synthetic resin such as nylon or polypropylene. It may be constructed of a spring, a coil spring, or a combination thereof.

Therefore, the axial thickness of the spring element 7 is not a particular problem. The annular synthetic resin gear 5 rotatably fitted to the gear shaft 1 has teeth 6 having the same conditions as the metal gear 2.
The tooth width is often about 1/3 to 1/2 that of the metal gear 2. However, the value is not particularly limited to this value, and it is also possible to add a stopper to prevent sliding in the axial direction. The teeth 6 of the synthetic resin gear 5 are attached to the metal gear 2 by the spring element 4 so that they protrude beyond the teeth 3 of the metal gear 2 in the direction of the force acting on one gear (not shown).
They are arranged slightly offset in the circumferential direction.

The amount of protrusion δ of the tooth surface of the tooth 6 of the synthetic resin gear 5 with respect to the tooth surface of the tooth 3 of the metal gear 2 is often set to several micrometers to several hundred micrometers. The tips of the teeth 6 of the gear 5 are modified to make them slightly thicker.

In addition, if this protrusion amount δ cannot be properly set via the spring element 4, the tooth thickness of the teeth 6 of the synthetic resin gear 5 should be adjusted from several micrometers to several micrometers relative to the teeth 3 of the metal gear 2. It is also possible to process it to a thickness of 10 micrometers. In short, it is not necessary that the metal gear 2 and the synthetic resin gear 8 and □ have the same tooth profile conditions, and it is necessary to adjust the protrusion amount δ and adjust the protrusion amount δ after long-term use, etc. in actual use. As shown in FIG. 4, which shows an example of an adjustment mechanism for this purpose, the suppression block 10
The side end surfaces of the resin gear 5 are integrally connected and have a slope 11 on one surface □ in the circumferential direction, and this slope 11 and a slope 13 formed on the slide block 12 are slidably in contact with each other. are doing. The slide block 12 is movable in the axial direction by a telescoping arm 14 whose one end is supported by the gear shaft 1. Therefore, by moving the slide block 12 a desired amount to the left in FIG. 4, the synthetic resin gear can be moved. 5 is made of metal and rotates relative to the gear 2 at a desired angle in the direction opposite to the direction of the force acting on the mating gear 1, and the amount of protrusion of the tooth surface of the polymer gear 5 relative to the tooth surface of the metal gear 2 δ can be set to an appropriate value. In addition, in order not to reduce the effect of the spring element 4, it is also possible to interpose a spring element that is elastically deformed in the rotational direction at the joint between the synthetic resin gear 5 and the suppression block 10.

The vibration damping gear of this embodiment is applied to at least one of the gears that mesh with each other. For example, various torque pulsations that occur in the drive system cause screw vibration or screw bending vibration in the gear system, but since the synthetic resin gear 5 always hits first during steady meshing, the meshing impact is alleviated and the torque is increased. The pulsation itself becomes smaller. Also, during the material damping of the synthetic resin gear 5, vibration energy is absorbed by the material and structural damping effect of the spring element 4 itself, making it possible to reduce the vibration level, which is particularly effective during resonance.

Furthermore, during tooth surface separation vibration, the synthetic resin gear 5 collides first, which creates a buffering effect and weakens the impact on the metal gear 2, which is advantageous in terms of stress and reduces knocking noise. Ru. In addition, when the load is light, it is also possible to drive only the 5 parts of the synthetic resin gear, which can reduce vibration and reduce noise.

<Effects of the Invention> According to the present invention, since the synthetic resin gear can be rotated relative to the metal gear and fixed at a desired position, the protrusion of the tooth surface of the synthetic resin gear from the tooth surface of the metal gear can be avoided. The amount can be adjusted to an appropriate value. During steady meshing, the meshing impact is alleviated by the elastic deformation of the synthetic resin gears, and the torque pulsation itself can be reduced.

Also, vibration energy is absorbed by the synthetic resin gears and spring elements, reducing the vibration level.

This phenomenon is particularly effective during resonance. In addition, during tooth surface separation vibration, the synthetic resin gear produces a buffering effect, weakening the impact on the metal gear, which is advantageous in terms of stress, and the knocking noise is also alleviated.

Also, when the load is light, it is possible to drive only the synthetic resin gear part, which is effective in allocating vibration and reducing noise.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of one embodiment of the present invention, Fig. 2 is a right side view thereof, Fig. 3 is an enlarged view of the same in the direction of the ■ arrow, and Fig. 4 is a conceptual diagram showing an example of a mechanism for adjusting the protrusion amount δ. It is. Also, in the figures, 1 is a gear shaft, 2 is a metal gear, 3, 6
is a tooth, 4 is a spring element, 5 is a synthetic resin gear, 10 is a suppression block, 12 is a slide block, 11.13 is a slope, 14 is a telescopic arm, δ is the synthetic resin gear relative to the tooth surface of the metal gear This is the amount of tooth surface protrusion. Patent Applicant: Mitsubishi Heavy Industries, Ltd. Patent Attorney, Patent Attorney, Motogata (and 1 other person) Figure 1 Figure 2 Figure 2, m (○. Figure 3

Claims (1)

[Claims] An annular synthetic resin gear is disposed on the side of the metal gear via a spring element that effectively acts in the direction of rotation of the metal gear, and is rotatable relative to the rotating shaft integrated with the metal gear. A vibration damping gear, characterized in that means is provided for fixing the synthetic resin gear fitted to the metal gear in an arbitrary phase with respect to the metal gear.