JPH058367Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention consists of a driving gear attached to the crankshaft of an engine, and a driven gear attached to the main shaft and meshing with the driving gear. A gear device rotatably connected to the main shaft via a clutch provided on one side, and integrally provided with an output rotating member on the other side of the driven gear for directly extracting power from the driven gear. Regarding. Such gear devices are widely used, for example, as primary reduction gears for motorcycles.

BACKGROUND OF THE INVENTION Generally, in a gear transmission, a back gap is provided between tooth surfaces in consideration of manufacturing errors in gears and manufacturing errors in the distance between the axes of gears. However, gear devices tend to generate noise during operation due to this bumping, for example, when the rotation speed of the gear on the drive side fluctuates or the direction of rotation changes, the gear device generates a banging sound.

For this reason, by fitting an elastic body or a friction body such as rubber or a spring between the teeth of one of the engaged gears and the shaft, the teeth can move a certain amount in the radial direction with respect to the shaft. For example, a gear device that eliminates backlash by installing these two gears with a distance between their axes that is slightly smaller than the normal installation distance is known as Utility Model Publication No. 48-44543.
It is proposed by the publication No.

Problems to be Solved by the Invention However, in the gear device in which the bucklash removal means is provided as described above, torque is transmitted from the shaft portion to the tooth portion or from the tooth portion to the shaft portion via an elastic body. Therefore, the transmission torque can only be used within a relatively small range, and since the shaft part and the tooth part try to slide against each other in the circumferential direction via the elastic body, the elastic body tends to wear out easily and the durability decreases. It wasn't good. In particular, when applied to the primary deceleration part of a motorcycle, etc., it is most susceptible to engine torque fluctuations, and the elastic body for noise suppression is likely to wear out.

To solve this problem, a stopper device can be provided between the tooth portion and the shaft portion to restrict the relative rotation between the two. Since the clutch is located on the side of the clutch, sufficient space cannot be secured for the above-mentioned stopper device.

Therefore, the present invention provides such a gear device with the above-described backlash removal means, and also aims to prevent wear of the elastic body and improve durability.

Means and Effects for Solving the Problems Therefore, in the present invention, the output of a gear, sprocket, etc. is attached to the side of a gear coaxially and integrally with the gear, and transmits the torque of this gear to another. A rotating member is utilized to prevent sliding between the shaft portion and the tooth portion.

That is, the gear device of the present invention consists of a driving gear mounted on the crankshaft of an engine, and a driven gear mounted on the main shaft and meshing with the driving gear, and the driven gear is connected to a clutch provided on one side thereof. In the gear mounting, the driven gear is rotatably connected to the main shaft via a gear and is integrally provided with an output rotating member on the other side of the driven gear for directly extracting power from the driven gear. divided into an outer circumferential portion having teeth and an inner circumferential portion loosely fitting into the main shaft,
An O-ring made of an elastic body is inserted between the inner circumferential surface of the outer circumferential portion and the outer circumferential surface of the inner circumferential portion, and an O-ring made of an elastic body is inserted on the boundary line between the outer circumferential portion and the inner circumferential portion. The invention is characterized in that a recess or a projection is provided, and the output rotation member is provided with a projection or a recess that engages with the recess or projection.

According to the present invention, the elastic body can be space-efficiently placed in the area where noise reduction is most desired, and the output rotating member originally attached to the gear can be used without adding any extra parts. With simple processing, it is possible to suppress the sliding between the shaft portion and the tooth portion and prevent wear of the elastic body.
Furthermore, by utilizing the space-saving nature of the elastic body, a space-saving structure can be adopted to suppress sliding.

Embodiments Hereinafter, the present invention will be explained with reference to illustrated embodiments.
This embodiment is a gear device installed between a crankshaft and a main shaft of an engine of a motorcycle. In FIG. 1, 1 is a crankshaft, 2 is a main shaft, and 3 is a gear device. Reference numeral 4 denotes a drive gear, which is attached to the crankshaft 1 and rotates integrally with the crankshaft 1. 5 is a driven gear that meshes with the drive gear 4 and is driven by the drive gear 4. The driven gear 5 is rotatably supported relative to the main shaft 2 and is connected to the main shaft 2 via a clutch. That is, as shown in FIG. 2, a drum-shaped clutch outer 6 is connected to one side of the driven gear 5 so as to rotate integrally with the driven gear 5. However, a damper spring 17 in the circumferential direction is interposed between the clutch outer 6 and the driven gear 5 to absorb vibrations caused by engine rotational fluctuations and the like. The clutch outer 6 is also fixed to the presser foot 19 on the opposite side through a large diameter hole 18 provided in the driven gear 5. A clutch inner 20 that engages with the clutch outer 6 is connected to the main shaft 2. Therefore, when the clutch outer 6 and the clutch inner 20 are engaged, the torque of the crankshaft 1 is transmitted to the main shaft 2 via the driving gear 4 and the driven gear 5, and the main shaft 2 rotates.

The driven gear 5 is rotatably mounted on a bush 7 fitted to the main shaft 2 via a needle bearing 8. This driven gear 5 consists of an outer peripheral portion 10 having teeth 9 on its outer periphery, and a collar or inner peripheral portion 11 rotatably supported relative to the main shaft 2 via the needle bearing 8 as described above. There is. There is a gap between the inner circumferential surface of the outer circumferential portion 10 and the outer circumferential surface of the inner circumferential portion 11, and within this gap, as shown in FIG.
is compressed and fitted between the outer peripheral portion 10 and the inner peripheral portion 11. Therefore, the outer circumferential portion 10 becomes the inner circumferential portion 11 due to the elastic deformation of the O-ring 12.
can move to some extent in the radial direction. In this embodiment, as shown in FIG. 3, the tooth thickness a of the teeth 9 of the driven gear 5 is
It is thicker than the tooth thickness b. The chain line 9a shows the tooth profile of a regular gear that meshes with the teeth 13 of the drive gear 4, and the tooth thickness of the tooth 9a is naturally equal to the tooth thickness b of the tooth 13. Therefore, the tooth 9 has a tooth thickness a larger than b.
When the tooth 6a enters between the teeth 13 and 13 at a shallower depth than the tooth 6a, both surfaces thereof come into contact with the tooth surfaces of the teeth 13 and 13 on both sides, resulting in a state where there is no backlash. At this time, the distance between the axes of the driving gear 4 and the driven gear 5 becomes longer by l than when the gears are in mesh with each other. However, the distance L between the crankshaft 1 and the main shaft 2
(FIG. 1) is maintained at the regular distance between the axes, so as shown in FIG. The distance increment l is absorbed. Then, the O-ring 12 is elastically deformed as shown in the figure, and the driven gear 5 is pressed against the driving gear 4 by the reaction force thereof, so that the meshing state of the teeth 9 and the teeth 13 without backlash is maintained.

By the way, in the driven gear 5, the torque transmitted from the driving gear 4 to the driven gear 5 due to the meshing between the teeth 9 and the teeth 13 is transmitted from the outer peripheral portion 10 to the outer peripheral portion 10.
Since it is transmitted to the inner peripheral part 11 via the ring 12, a circumferential frictional force acts on the contact surfaces of the O-ring 12 with the outer peripheral part 10 and the inner peripheral part 11, and as a result, the O-ring 12 is worn out and the gear is damaged. For this reason, in this embodiment, the relative relationship between the outer circumferential portion 10 and the inner circumferential portion 11 is determined using the sprocket 14 attached to the driven gear 5 to drive the oil pump. This is to prevent sliding in the circumferential direction. Sprocket 1
4 is fixed to the outer circumferential portion 10 of the driven gear 5 on the side opposite to the clutch outer 6, rotates together with the driven gear 5 around the same axis, and rotates through a chain meshed with the driven gear 5. to drive the oil pump. As mentioned above, since the driven gear 5 is rotatably supported relative to the main shaft 2, it goes without saying that the sprocket 14, which rotates integrally therewith, is also rotatable relative to the main shaft 2. stomach.

The outer peripheral portion 10 of the driven gear 5 is provided on the end face of the sprocket 14 facing the driven gear 5.
One or more engaging protrusions 15 are provided to protrude along a circumferential line corresponding to the gap between the inner circumferential portion 11 and the inner circumferential portion 11 . An engagement recess 16 is formed on the driven gear 5 side in correspondence with the engagement protrusion 15 . are provided in the radial direction. The engagement protrusion 15 and the engagement recess 16 are
Although there is a gap in the radial direction that is sufficient to allow movement of the outer circumferential portion 10 with respect to the inner circumferential portion 11, there is also a slight gap C in the circumferential direction as shown in FIG. . However, since the outer circumferential portion 10 and the inner circumferential portion 11 are connected to each other by the engaging protrusion 15 and rotate as a unit, there is almost no circumferential sliding between them, and the O-ring 12 is caused by friction. It will not be worn out by Providing engaging convex portions that align with each other on the outer circumferential portion 10 and the inner circumferential portion 11,
Engagement recesses that fit into these engagement protrusions may be provided on the sprocket 14 side.

Effects of the Invention As described above, the present invention consists of a driving gear mounted on the crankshaft of the engine, and a driven gear mounted on the main shaft and meshing with the driving gear, and the driven gear is provided on one side of the driving gear. In the gear device, the gear device is rotatably connected to the main shaft via a clutch, and is integrally provided with an output rotating member on the other side of the driven gear for directly extracting power from the driven gear. The driving gear is divided into an outer circumferential portion having teeth and an inner circumferential portion loosely fitting into the main shaft,
An O-ring made of an elastic body is inserted between the inner circumferential surface of the outer circumferential portion and the outer circumferential surface of the inner circumferential portion, and an O-ring made of an elastic body is inserted on the boundary line between the outer circumferential portion and the inner circumferential portion. Since the output rotating member is provided with a concave portion or a convex portion and a convex portion or a concave portion that engages with the concave portion or convex portion, it is possible to eliminate backlash and prevent noise generation by elastic deformation of the O-ring. At the same time, it is possible to save space by using O-rings, and in addition, without adding any extra parts, you can use the parts originally attached to the gear and simply process it to remove the inner periphery. It is possible to prevent the O-ring from wearing out by suppressing sliding between the outer circumferential portion and the outer circumferential portion. Furthermore, because of its compact structure that prevents sliding on the boundary line between the outer circumferential portion and the inner circumferential portion, it can be effectively applied to locations where there is insufficient space around the clutch.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of the gear device according to the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a partially enlarged view of Fig. 1, and Fig. 4. FIG. 2 is a circumferential cross-sectional view of the concavo-convex engaging portion. 1... Crankshaft, 2... Main shaft, 3... Gear device, 4... Driving gear, 5... Driven gear, 6...
Clutch outer, 7... Bush, 8... Needle bearing, 9... Teeth, 10... Outer circumference part, 11... Inner circumference part, 12... O-ring, 13... Teeth, 14...
...Sprocket, 15...Engagement protrusion, 16...Engagement recess, 17...Damper spring, 18...
Hole, 19...presser foot, 20...clutch inner.

Claims (1)

[Scope of utility model registration request] It consists of a driving gear attached to the crankshaft of the engine, and a driven gear attached to the main shaft and meshing with the driving gear, and the driven gear is rotatably connected to the main shaft via a clutch provided on one side of the driven gear. In the gear device, the driven gear is connected to an outer peripheral portion having teeth and the main shaft, and an output rotating member for directly extracting power from the driven gear is integrally provided on the other side of the driven gear. an inner circumferential portion that fits loosely into the driven gear; an O-ring made of an elastic body is inserted between the inner circumferential surface of the outer circumferential portion and the outer circumferential surface of the inner circumferential portion; and the other side surface of the driven gear. A gear device characterized in that a concave portion or a convex portion is provided on a boundary line between the outer circumferential portion and the inner circumferential portion, and a convex portion or a concave portion that engages with the concave portion or the convex portion is provided on the output rotation member.