JPS623563Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a gear device for transmitting the rotation of an output shaft to a governor device with a very small load in, for example, an automatic transmission for a vehicle, and particularly relates to a gear device having a shock-resistant synthetic resin gear.

[Conventional technology]

In this type of transmission system from the output shaft to the governor device via the gear device, the drive gear on the governor device side meshes with the drive gear on the output shaft side of the gear device, and the driven gear on the governor device side is in mesh with the drive gear on the output shaft side of the gear device. It is influenced by various things. In particular, during sudden acceleration or deceleration, torque fluctuations in the drive gear cause bending force to act on the cantilevered shaft of the driven gear that meshes with the drive gear. When both the drive and the driven gear are made of metal with high rigidity, the bending force is directly applied to the tooth surfaces of the gears, resulting in large wear. As a countermeasure against this problem, a buffer means is interposed between the drive gear or the driven gear and the rotation transmission shaft of these gears, as disclosed in, for example, Japanese Utility Model Application Publications No. 16984/1984 and No. 1783/1983. It has been proposed. In addition, as a countermeasure to the above, it is possible to make the drive gear or driven gear made of elastic synthetic resin, based on the description in Japanese Utility Model Publication No. 44-30561. In this case, the impact caused by bending during sudden acceleration and deceleration can be effectively Although it is absorbed by the metal and does not suffer from abrasion, etc., it may break due to large deformation due to bending.

[Problem that the invention attempts to solve]

An object of the present invention is to provide an improved gear device that can prevent breakage due to bending when the drive gear or driven gear is made of synthetic resin.

[Means to solve the problem]

In order to achieve this object, the present invention molds at least the teeth of one of the gears of a pair of mutually meshing gears having shaft portions with a synthetic resin, and at least the teeth of the gears molded with the synthetic resin. A metal core is integrally molded, and the metal core is configured to have flexibility at least at the boundary between the tooth portion and the shaft portion, and the tooth portion made of synthetic resin absorbs bending impact, and the metal core is made of reinforcing metal. It is characterized in that the core prevents breakage, and its relatively low rigidity prevents increased wear on the tooth surface.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. Fig. 1 shows an embodiment in which the present invention is applied to a gear device provided between the output shaft of an automatic transmission and a governor device. A driven gear 3 meshes orthogonally with the driven gear 2 to transmit the rotation of the output shaft 1. In the driven gear 3, one end of a rod-shaped highly rigid metal core 3b is integrally molded inside an elastic toothed portion 3a made of synthetic resin for reinforcement. A small diameter portion 4 is formed by constricting the portion near the portion, and is configured to have flexibility in this portion. Then, such a metal core 3b is inserted into one end of the shaft 6 of the governor device 5, and is secured by a fixing pin 7, and the shaft 6 is rotated toward the transmission case 9 by a bearing 8. A governor valve 11 is freely supported and fitted into the sleeve 10 so as to be movable in the radial direction of the shaft 6 on the side opposite to the driven gear 3. A small weight 12 is integrally provided at one end of the governor valve 11, and a large weight 13 is provided to move by a predetermined stroke via a governor spring 18. Line pressure is led through a passage 15, and governor pressure generated at the other port 16 is led out through an oil passage 17. Since the gear device according to the present invention is configured as described above, the rotation of the output shaft 1 is taken out by the drive gear 2 when the vehicle is running, and the teeth 3a of the driven gear 3 mesh with the drive gear 2; Shaft 6 of governor device 5 via metal core 3b and fixing pin 7
transmitted to. At this time, when a bending force is applied to the cantilever-supported driven gear 3 due to torque fluctuations during sudden acceleration or deceleration, the metal core 3b
The bending impact is absorbed by the synthetic resin teeth 3a. Further, the metal core 3b is appropriately bent by the bending force due to the formation of the small diameter portion 4, thereby reducing the force acting on the tooth surfaces of the drive and driven gears 2 and 3, increasing wear and damage to the teeth. It has the flexibility to avoid this. On the other hand, in the governor device 5, as the governor valve 11 rotates together with the shaft 6, in the first stage before a predetermined rotation speed, the centrifugal force of the large weight 13 is also transmitted to the governor valve 11 via the governor spring 13; The hydraulic pressure acting on the area difference between the ports 14 and 16 of the governor valve 11 is regulated so as to counteract the resultant force of the centrifugal force acting on the weight 12 and the governor valve 11 itself. Next, in the second stage where the rotational speed increases, the large weight 13 is stopped by a stopper or the like, and its centrifugal force no longer works, and the spring force of the governor spring 18 and the small weight 1
The pressure is regulated so as to oppose the resultant force of the centrifugal forces of the governor valve 2 and the governor valve 11 itself, and thus the governor pressure is obtained in accordance with the output shaft rotation speed, that is, the vehicle speed. Note that the present invention is not limited to the above-mentioned embodiment, and as shown in FIG. It is constructed by integrally molding a short metal core 3b' recessed with a small diameter part 4 inside the holder, or as shown in FIG. It may be configured by integrally molding the metal core 3b''.Conversely, this method may be applied to the drive gear, and the driven gear may be made of metal.

[Effect of the idea]

As described above, according to the present invention, shocks such as bending are absorbed by the synthetic resin teeth 3a of one of the pair of mutually meshing gears, for example, the driven gear 3, and the flexible metal core 3b etc. Breakage due to bending force is prevented, and increase in wear on the tooth surfaces is prevented, making it possible to smoothly transmit rotation and increasing durability. Further, by using the synthetic resin tooth portion 3a or the tooth portion 3a and the shaft portion 3c, effects such as weight reduction, noise reduction, and cost reduction can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the gear device of the present invention, and FIGS. 2 and 3 are sectional views of essential parts of the second and third embodiments. 2... Drive gear, 3... Driven gear, 3
a...Tooth portion, 3b, 3b', 3b''...Metal core, 4...
...Small diameter section.

Claims (1)

[Scope of utility model registration request] At least the teeth of one of the gears of a pair of mutually meshing gears having shaft portions are molded of synthetic resin, and a metal core is integrally molded on at least the teeth of the gear molded of the synthetic resin, and the metal core is A gear device characterized in that it is configured to have flexibility at least at a boundary between a tooth portion and a shaft portion.