JPH09203454A - Noise reducing device in helical gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the thickness of an auxiliary gear in a minimum gear width by arranging a stopper plate for preventing the outer peripheral part of the auxiliary gear from being deformed so as to warp while being brought slidably into contact with the outer peripheral part of the outer side surface of the auxiliary gear. SOLUTION: A stopper plate 6 for preventing the outer peripheral part of the auxiliary gear 2 from being deformed so as to warp in a direction of a shape shown by two point chain line while being brought slidably into contact with the outer peripheral part of the outer side surface of the auxiliary gear 2 while thinning the gear width S of the auxiliary gear 2 till the thickness to the extent to resist a torque, is arranged on a counterpart gear 20 side by a adhesive working method which thickness of press-in and point welding is not increased. The stopper plate 6 is formed on the back surface of a thin ring shaped metal plate by projecting a ring shaped holding part 6A, and it is pressed in an annular groove part 20c arranged on the counterpart gear 20 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device for a helical gear used in a place where torque fluctuation is large, such as an engine of an automobile or an air compressor.

[0002]

2. Description of the Related Art A helical gear has the great advantages that transmission is extremely smooth, vibration noise is small, and a large force can be transmitted because meshing is continuously performed. As with gears of other tooth profiles, it is necessary to provide a backlash so as to prevent excessive meshing in consideration of machining errors such as tooth profile error, pitch error, and eccentricity.

If this backlash is used in a place where torque fluctuation is large and torque in the direction opposite to the transmission torque is generated, the tooth surface to be contacted is changed according to the change in the direction of the torque acting on the meshing portion. When the teeth are separated and contacted repeatedly, tooth flapping occurs, which causes noise. In the prior art, as a noise reduction device for a helical gear, as shown in FIGS. 4 and 5, one of the gear trains is connected to the main gear 1 and the sub gear, as in the case of a gear (spur gear). A scissors gear 10 is used which is formed of two gears composed of two pieces, and both of these gears are biased by a spring 3 so as to be displaced in the circumferential direction. The spring 3 has one end fixed to the main gear 1 with a pin 9A and the other end with a pin 9B.
It is fixed to the sub gear 2.

In the scissors gear 10, the teeth of the main gear 1 and the teeth of the sub gear 2 are separated by the force of the spring 3 against torque fluctuations that try to open a gap between the teeth of the main gear 1 and the teeth of the mating gear 20. By sandwiching the teeth of the mating gear 20 at the meshing portions, the contact between the three teeth of the main gear 1, the sub gear 2, and the mating gear 20 is maintained, thereby reducing the rattling noise.

However, unlike the case of the gear (spur gear),
In the scissors gear 10 having the helical tooth surface 5, since the teeth are twisted with respect to the axial direction, a thrust force which is an axial acting force is generated in addition to the rotational torque. This thrust force also acts on the sub gear 2 and changes the direction according to the change in the direction of the fluctuating torque. When the thrust force acting on the sub gear 2 acts in the direction of the main gear 1, the adjacent main gear 1 prevents elastic deformation of the sub gear 2, but when acting in the opposite direction, the rigidity of the sub gear 2 itself is sufficient. It will support.

This thrust force acts on the sub gear 2 at the meshing portion of the teeth so as to deform the sub gear 2 into a dish shape. Therefore, the thrust force is multiplied by the lever from the supporting portion of the sub gear 2 to the meshing portion of the teeth. In addition, the tooth width S of the sub gear 2 is about 30 to 50% of the tooth width T of the main gear 1, which is a thick factor.

[0007]

As described above, in the case of the prior art, the tooth width S of the sub gear is the tooth width T of the main gear.
Since the thickness is about 30 to 50%, the sub gear needs to be subjected to gear cutting with a hob or a rack tool like the main gear, which causes a high cost. Further, when the helical gear that is generating noise is replaced with a scissors gear for noise reduction, it is necessary to increase the tooth width V of the mating mating gear in accordance with the tooth width S of the sub gear to be added. The space used in both the side and mating gears increases in the axial direction, so significant design changes are necessary, or if there is a constraint in the axial space for either or both, then abandon the adoption. The problem arises. An object of the present invention is to obtain a noise reduction device for a compact helical gear which has a sub gear having a small tooth width and has a small increase in space in the axial direction.

[0008]

According to the present invention, a main gear having a helical tooth surface, a sub gear coaxially laminated on one side surface of the main gear, and the main gear and the sub gear are displaced from each other in the circumferential direction. It consists of a scissors gear with a spring that urges it in this way, and a mating gear that meshes with this scissors gear, and prevents the outer periphery of this subgear from warping and deforming by sliding contact with the outer periphery of the outer surface of the subgear. There is provided a noise reduction device characterized in that a stopper plate is provided on the mating gear side.

Further, a main gear having a helical tooth surface, a sub gear coaxially stacked on one side surface of the main gear, and a spring for urging the main gear and the sub gear so as to shift from each other in the circumferential direction are provided. Scissors gear, a mating gear that meshes with this scissor gear, and a mating gear adjacent to the sub gear side coaxially with the mating gear side and having a larger diameter than the mating gear. Provided is a noise reduction device, which supports a side surface portion and prevents the outer peripheral portion of the sub gear from being deformed so as to warp. With such a device, it is possible to obtain a compact noise reduction device for a helical gear train having a sub gear having a small tooth width and having a small increase in the tooth width of a scissors gear.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 1, the present invention, like the prior art shown in FIGS. 4 and 5, has a main gear 1 having a helical tooth surface 5 fixed on a shaft 4 (driving shaft), and a main gear 1 of the main gear 1. A sub gear 2 coaxially laminated on one side, a scissor gear 10 including a spring 3 stretched between the gears 1 and 2, and a shaft 24 (driven shaft) so as to mesh with the scissor gear 10. It is composed of a mating gear 20 provided above.

However, unlike the prior art, in the present invention,
The tooth width S of the sub gear 2 is reduced to a thickness that can withstand the torque, and the sub gear 2 is slidably contacted with the outer peripheral surface of the outer surface of the sub gear 2. A stopper plate 6 for preventing the warp from being deformed so as to warp is provided on the mating gear 20 side by a bonding method such as press-fitting or spot welding that does not increase the thickness.

With respect to which surface of the main gear 1 the sub gear 2 is arranged, the magnitude and direction of the thrust force are determined by the relationship between the magnitude and direction of the fluctuating torque and the direction of the torsion angle of the tooth. It is preferable to estimate the thrust force generated from the above and to provide it on the side where the magnitude of the thrust force is small. However, since there is a relationship with the available space, it will be decided taking both into consideration.

The stopper plate 6 is formed by projecting a ring-shaped retaining portion 6A on the back surface of a thin ring-shaped metal plate, and press-fitting this into an annular groove portion 20C provided on the side of the mating gear 20. To do. In this case, when the fixing strength is insufficient, spot welding is further performed, or the retaining portion 6A and the groove portion 20 are
Thread C and C to make the bond strength sufficient. Further, since the support portion 6B of the stopper plate 6 is in sliding contact with the sub gear 2 while receiving the thrust force acting on the sub gear 2,
Lubrication is carried out by using a bearing material with good slippage or by flowing the lubricating oil used for the meshing portion of the teeth also to this contact portion.

2 (A) to 2 (E) show examples of various shapes of the support portion 6B of the stopper plate 6 and the support portion 2B of the sub gear 2. As shown in FIG. As shown in FIG.
When B is smoothed, the shape of the sub gear 2 side is (B)
As shown in FIG. 4C, a support portion 2B that is convex outward from the tooth 2E is provided, or by removing the meat on one surface of the tooth 2E of the sub gear 2 as shown in (C), the tooth 2E of the sub gear 2 and the stopper plate. A slight gap 8 is provided between 6 to prevent the side surface of the tooth 2E of the sub gear 2 from directly contacting the supporting portion 6B of the stopper plate 6 and promoting wear. Further, as shown in (D), a shallow groove portion 6C is provided on the stopper plate 6 side so as to avoid the teeth 2E of the sub gear 2, or as shown in (E), the support portion 6B is made of a ceramic or a bearing material that is resistant to abrasion. The support member 6D made of may be fitted and provided.

The stopper plate 6 may be any one as long as it can prevent the deformation of the sub gear 2, and it is preferable to make it as thin as possible so as to occupy a small space and to reduce the weight. Further, even if the gear train can move a little in the axial direction, when the stopper plate 6 needs to support the sub gear 2, the thrust force is the direction that pushes the sub gear 2 toward the stopper plate 6, so the sub gear 2
The supporting portion 2B of the above contacts the supporting portion 6B of the stopper plate 6 and can be reliably supported.

Next, a second embodiment will be described. As shown in FIG. 3, the gear train is a scissors gear 10.
And the mating gear 20 meshing with the mating gear 20 and the mating gear 20 coaxially adjacent to the mating gear 20 and adjacent to the sub gear 2 side.
It is formed of an adjacent gear 21 having a diameter larger than zero. In this gear train, the support portions 21B on the side surfaces near the roots of the adjacent gears 21 are in sliding contact with the support portions 2B near the outer peripheral portion of the sub gear 2 to prevent the sub gear 2 from warping and deforming.

The support portion 21B of the adjacent gear 21 and the support portion 2B of the sub gear 2 also adopt the shape described in FIGS. 2A to 2E so that the teeth 2E of the sub gear 2 do not come into direct contact with each other. Can be Therefore, in the second embodiment, since the adjacent gear 21 plays the role of the stopper plate 6, it can be made extremely compact.

When there is a margin in the thickness direction of the gear train, the ring-shaped stopper plate 6 is used as the mating gear 20.
It may be provided by a method of being sandwiched between and the adjacent gear 21 on the opposite side. Since the scissors gear 10 is used with the above configuration, the main gear 1, the sub gear 2, and the mating gear 2 are used.
The contact of the three teeth with 0 is maintained by the force of the spring 3,
The rattling noise can be reduced, and the stopper plate 6 or the adjacent gear 21 can prevent the outer peripheral portion of the sub gear 2 from being deformed so as to warp, so that the tooth width S of the sub gear 2 can endure the acting force in the rotation direction. It is possible to provide a noise reduction device that can be thinned to a minimum tooth width and that has a small increase in tooth width U of the scissors gear.

Therefore, in the scissors gear 10 having a helical tooth surface, if the torque to be transmitted is the same, the tooth width U of the scissors gear 10 can be reduced, and conversely, the tooth width U of the scissors gear 10 is the same as in the prior art. Then, the tooth width T of the main gear 1 can be made larger than that of the scissors gear of the prior art, so that a larger torque can be transmitted.

When the helical gear train used in the air compressor of an automobile diesel engine is used in the noise reduction device of the present invention, the stopper plate 6 is used.
The thickness W can be made approximately equal to the tooth width S of the sub gear 2, and can be made as thin as approximately 1 mm, which is approximately 10% of the tooth width T of the main gear 1.

[0021]

According to the first aspect of the present invention, the tooth width of the sub gear is set to a minimum tooth width that can withstand the acting force in the rotational direction, the tooth width of the scissor gear is not increased so much, and the noise is compact as a whole. The device is obtained. Further, according to the invention of claim 2, it is possible to obtain a more compact noise reduction device in which the tooth width of the sub gear is set to the minimum tooth width that can withstand the acting force in the rotational direction.

As described above, since the tooth width of the sub gear can be made thin, the sub gear can be manufactured by press working, and the cost can be reduced. Further, when changing the helical gear that is generating noise with large torque fluctuation to the scissors gear, by using the scissors gear of the present invention, it is possible to provide a noise reduction device with little increase in tooth width, so a significant design change can be made. No longer needed,
Changes can be made even if there is axial space constraint for either or both gear trains.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment.

FIG. 2 is a perspective view showing an embodiment of a stopper plate and a supporting portion of a sub gear.

FIG. 3 is a side sectional view showing a second embodiment.

FIG. 4 is a front view showing an embodiment of a conventional technique.

FIG. 5 is a cross-sectional view taken along the line AA showing the embodiment of the prior art.

[Explanation of symbols]

1 Main Gear 2 Sub Gear 2B Support Part 2E Tooth 3 Spring (Elastic Body) 4 Shaft 5 Helical Tooth Surface 6 Stopper Plate 6A Holding Part 6B Support Part 6C Groove 6D Support Member 8 Gap 9A, 9B Pin 10 Scissors Gear 20 Opposite Gear 21 Adjacent Gear 21B Support 24 Shaft

Claims (2)

[Claims] 1. A main gear having a helical tooth surface,
The main gear includes a sub gear that is coaxially stacked on one side surface, a scissor gear provided with a spring that biases the main gear and the sub gear so as to shift in the circumferential direction, and a mating gear that meshes with the scissor gear. A noise reduction device characterized in that a stopper plate, which is in sliding contact with the outer peripheral portion of the outer side surface of the sub gear and prevents the outer peripheral portion of the sub gear from being warped and deformed, is provided on the mating gear side. 2. A main gear having a helical tooth surface,
A sub gear that is coaxially stacked on one side of the main gear, a scissors gear that is provided with a spring that biases the main gear and the sub gear so as to shift in the circumferential direction, and a mating gear that meshes with the scissors gear. Adjacent to the sub gear side coaxially with the mating gear side, it consists of a mating side adjacent gear having a larger diameter than the mating gear, and the mating side adjacent gear supports the side surface part of the sub gear so that the outer peripheral part of the sub gear warps. A noise reduction device characterized in that it is prevented from being deformed.