JPH0443639Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a speedometer driven gear device that is driven by the rotation of a transmission and transmits its rotational force to a speedometer via a meter cable or the like.

[Prior Art] As shown in FIG. 5, a speedometer driven gear device includes a driven gear 100 including a gear portion 101 and a shaft portion 102, and a driven gear 10.
a sleeve 200 that rotatably supports the drive gear 100; and a seal member 300 that is held by the sleeve 200 and seals between the sleeve 200 and the driven gear 100.
It is composed of and. The driven gear 100 and the sleeve 200 are locked by a clip 500, and relative movement in the axial direction is restricted. This speedometer driven gear device is attached to a transmission 600 via an O-ring 400, as shown in FIG. The rotation of the transmission 600 is transmitted to the gear section 101, and the rotation is transmitted to the speedometer by a meter cable connected to the shaft section 102.

In a conventional speedometer driven gear device, the gear part 101 is made of resin, and the shaft part 102 is made of resin.
are generally made of metal. Shaft part 10
2. On the surface, there is a spiral groove 10 that serves as a passage for lubricating oil.
3 is formed. Further, the gear part 101 is usually formed by injection molding using the shaft 102 as an insert, but in order to further strengthen the connection between the two, the surface of the shaft 102 that comes into contact with the gear part 101 is subjected to a roulent process or the like. .

By the way, since the shaft 102 is made of metal, processing of the spiral groove 103, knurling, etc. are post-processing and require a large number of man-hours. Therefore, a speedometer driven gear device has been proposed in which the shaft portion 102 is made of resin and is integrally molded with the gear portion 101, as shown in, for example, Japanese Utility Model Application Publication No. 54-112093 shown in FIG.

However, the gear part and the shaft part usually have a hollow part. Therefore, if it is made of resin, it is difficult to obtain roundness due to distortion after molding, which is not desirable in terms of accuracy. Therefore, in Japanese Patent Application Laid-Open No. 52-104649,
A driven gear is disclosed in which a rib portion connecting the gear portion and the shaft portion is provided in a hollow portion of the gear portion, thereby improving accuracy.

[Problems to be Solved by the Invention] As described above, driven gears are increasingly being made of resin, but sleeves made of metal are still being used. The inner peripheral surface of the sleeve that makes sliding contact with the shaft portion is required to have precise roundness, and the shaft is required to extend in a perfect straight line (hereinafter referred to as axiality). If the wall thickness is increased and molded, roundness and accuracy can be satisfied, but
The overall shape is large, causing problems in terms of space for installation. Furthermore, when the molding is made thin with priority given to the arrangement space, it is difficult to achieve both roundness and axiality due to shrinkage phenomenon after molding.

Furthermore, if the sleeve is made of resin, it is necessary to deal with heat and wear during sliding, but if the sleeve is shaped like a conventional sleeve, the circulation of lubricating oil within the sleeve will not be sufficient. Ta. That is, the lubricating oil that enters the sleeve from between the sleeve and the shaft portion tends to stay inside the sleeve, so the cooling effect is insufficient and the temperature of the sliding portion increases, making it more likely to wear out.

Incidentally, Japanese Utility Model Application No. 59-23665 discloses a speedometer driven gear device in which the sleeve and the driven gear are made of resin, and at least one of them is made of oil-impregnated plastic, thereby eliminating the need for use in oil. However, even if the sleeve is made of oil-impregnated plastic, if the accuracy of the roundness and axiality is low, the temperature will rise due to wear during sliding and wear will occur easily. There is no mention of accuracy. However, since the sleeve is formed with grooves that extend in the axial direction, it is assumed that errors are absorbed by elastic deformation of the sleeve in the radial direction due to the grooves. becomes insufficient.

The present invention was developed in view of the above circumstances, and it is an object of the present invention to form the sleeve of the speedometer driven gear device entirely from resin, have sufficient strength, and satisfy roundness and axiality to prevent wear. is a technical issue.

[Means for solving the problem] The speedometer driven gear device of the present invention has the following features:
A driven gear consists of a gear part driven by the rotation of the output shaft of the transmission, a shaft part to which a cable that operates the speedometer is connected, a sleeve that rotatably supports the driven gear, and a sleeve held by the sleeve. In a speedometer driven gear device, the sleeve includes a cylindrical tube portion with which the shaft portion of the driven gear slides, and a sleeve that protrudes from the outer peripheral surface at the rear of the tube portion in the axial direction. a cylindrical shaft portion having an extending rib portion and a through hole in the wall surface that communicates the inside and the outside;
It is characterized in that it has a cylindrical seal part that holds a seal member on the inner peripheral surface behind the shaft part, and is made of synthetic resin.

The speedometer driven gear device of this invention is
It consists of a driven gear, a sleeve, and a seal member.

The driven gear is composed of a gear part and a shaft part, and the gear part rotates using the rotation of the output shaft of the transmission as a driving source. A cable for operating the speedometer is connected to the shaft section, and the cable operates the speedometer as the gear section rotates. This driven gear can be made of resin, metal, or the like as in the past.

The seal member is held on the inner circumferential surface of the sleeve to seal between the sleeve and the driven gear, and serves to prevent oil leakage. That is, the ring is usually ring-shaped and is configured to come into elastic contact with the outer circumferential surface of the driven gear. As for the material, an elastic body such as rubber or resin is used as in the past.

The feature of the present invention lies in the construction of the sleeve made of resin. That is, the sleeve consists of a cylindrical part, a shaft part, and a seal part, and its most distinctive feature is that the cylindrical part has a cylindrical shape, and the shaft part has a rib part and a through hole at the rear of the cylindrical part.

The tube portion has a cylindrical shape. Therefore, even if shrinkage occurs after molding, roundness can be ensured,
Enables uniform sliding contact with the driven gear.

Although it is difficult to ensure roundness in a shaft portion with a rib portion formed thereon, axiality can be ensured by the rib portion. This ensures that the shaft is coaxial with the axis of the sealing part, and the sealing member and the shaft part can be coaxial, increasing the sealing force. Further, by increasing the difference between the inner diameter of the shaft and the outer diameter of the shaft, contact with the shaft can be prevented even if the shaft has insufficient roundness. Note that it is desirable to provide a plurality of rib portions symmetrically with respect to the axis.

Further, the shaft portion has a through hole. Therefore, lubricating oil enters and exits from the through hole, and new lubricating oil is supplied to the sliding surfaces of the cylindrical portion and the shaft portion. This improves the circulation of lubricating oil, improves the cooling efficiency of the sliding surfaces, and allows for rapid discharge of wear particles. In addition,
The number of through holes may be one, or it is preferable to provide a plurality of through holes.

The seal part is a part that holds the seal member,
It can have the same shape as the conventional one. The sealing member is held in the conventional manner by adhesive or mechanical holding.

There are no particular restrictions on the material of the sleeve, but
Oil resistance is required, and polyamide resins, saturated polyester resins, polyphenylene sulfide and the like are preferred. Further, in order to impart strength, it is desirable to fill it with glass fiber, inorganic filler, or the like. Injection molding is a common molding method, but is not limited to this.

[Operations and effects of the invention] The speedometer driven gear device of the invention has the following features:
The sleeve is made of resin. Therefore, it is lightweight and inexpensive. Since the sleeve is formed by molding, protruding parts such as the lock plate can also be formed integrally. Additionally, clip grooves, screws, etc. can be formed simultaneously during molding, eliminating the need for post-processing such as cutting.

In the speedometer driven gear device of the present invention, the sleeve has a cylindrical portion, a shaft portion having a rib portion on its outer peripheral surface, and a seal portion. Since the cylindrical portion at the tip is cylindrical, roundness is ensured. In addition, the shaft portion maintains its axiality and strength while maintaining its light weight due to the rib portion. Therefore, the shaft portion of the driven gear is in uniform sliding contact with the cylindrical portion and rotates smoothly. Since axiality is ensured by the shaft portion, the seal member uniformly comes into elastic contact with the seal portion and is reliably sealed. In addition, the through holes improve the circulation of lubricating oil, improving the cooling efficiency of the sliding surfaces and quickly discharging wear particles. Therefore, even with a sleeve made of resin, abrasion of the sliding parts is prevented, and predetermined performance can be maintained for a long period of time.

That is, according to the speedometer driven gear device of the present invention, it is lightweight and inexpensive, and wear of the sliding surface is prevented.

[Example] Hereinafter, this will be explained in detail using examples.

FIG. 1 shows a front view of a speedometer driven gear device according to an embodiment of the present invention. This speedometer driven gear device includes a driven gear 1 whose driving source is rotation of an output shaft of a transmission, a sleeve 2 which rotatably supports the driven gear 1, and a space between the sleeve 2 and the driven gear 1 held by the sleeve 2. Seal member 3 for sealing
It is mainly composed of.

The driven gear 1 includes a gear section 10 and a shaft section 1.
1 and is mostly made of 6,6-nylon. A cylindrical sliding portion 12 is formed on a part of the surface of the shaft portion 11, and the sealing member 3
is configured to come into sliding contact with the sliding portion 12.
The material of the sliding part 12 is PPS (polyphenylene sulfide).

FIG. 2 shows a longitudinal sectional view of a portion of the shaft portion 11 having the sliding portion 12. The outer diameter of the shaft portion 11 at the portion where the sliding portion 12 is formed is approximately 1 mm smaller than the other portion, and protrusions 11a protrude in three directions. Since the protrusion 11a is embedded in the sliding part 12, the shaft part 11 and the sliding part 12
are strongly connected. Further, the outer diameter of the sliding portion 12 is made larger than the general outer diameter of the shaft portion 11, and is configured to ensure sliding contact with the seal member 3. Note that the sliding portion 12 is formed by insert injection molding using the shaft portion 11 as an insert, and the splitting surface of the mold is located at the end surface of the sliding portion 12 that protrudes from the shaft portion 11 in the radial direction. are doing. This prevents the parting line from being exposed on the sliding surface of the sliding portion 12, resulting in high sealing performance.

A tooth portion 13 that engages with a worm gear in the transmission is formed on the surface of the gear portion 10, and a locking groove 14 that engages with the clip 4 and a spiral groove 15 that serves as an oil passage are formed on the surface of the shaft portion 11. There is. The shaft portion 11 has a cylindrical shape, and a flexible meter cable connected to a speedometer is fitted into the center hole of the shaft portion 11.

The sleeve 2 is formed by injection molding from polyamide resin mixed with an inorganic filler.
This sleeve 2, as shown in FIGS. 3 and 4,
It is composed of a cylindrical tube portion 21, a cylindrical shaft portion 22 continuous to the tube portion 21, and a cylindrical seal portion 23 continuous to the shaft portion 22 from the tip. Cylinder part 21
has a perfect circular cylindrical shape with a thickness of 2.5 mm, and is in sliding contact with the shaft portion 11. The inner diameter of the shaft portion 22 is the same as that of the cylindrical portion 2.
1, and is configured so as not to come into contact with the shaft portion 11. The outer peripheral surface of this shaft portion 22 has a clip groove 20 and a clip groove 20 extending in the axial direction.
The rib portion 24 of the book is provided, and a plurality of through holes 25 are formed in the wall surface other than the position where the rib portion 24 is provided, which communicates the inside and the outside. In addition, the seal portion 23 has a ring groove 26 and a flange 27.
A male threaded portion 28 is formed, and the sealing member 3 is adhered and held on the inner peripheral surface. Flange 2
7 has a bolt hole 29 bored therein. Each component of this sleeve 2, except for the bolt hole 29, is integrally formed by injection molding.

The seal member 3 is molded from rubber, and the sleeve 2
It is fixed by adhesive to the inner peripheral surface of. Its shape is a ring, and the lip portion 30 provided on the inner peripheral surface is configured to come into elastic contact with the surface of the sliding portion 12 of the shaft portion 11 inserted into the center hole.

In the speedometer driven gear device of this embodiment, the driven gear 1 and the sleeve 2 are locked by the clip 4 with the shaft portion 11 inserted into the center hole of the sleeve 2 and the seal member 3 in elastic contact with the sliding portion 12. Ru. Although the relative movement in the axial direction between the driven gear 1 and the sleeve 2 is restricted by the clip 4, the driven gear 1 is rotatable within the sleeve 2. In this speedometer driven gear device, an O-ring 5 is attached to a sleeve 2, a gear portion 10 is placed at a predetermined position within a transmission, and is fixed by a bracket 27. When the vehicle is running, the transmission rotates from the gear section 10 to the shaft section 11.
The signal is transmitted to the flexible meter cable, etc., and the speedometer is activated. At this time, gear oil is present between the driven gear 1 and the sleeve 2, and the driven gear 1 rotates smoothly. Since the seal member 3 is in elastic contact with the sliding part 12,
Gear oil leakage is reliably prevented.

(Operations of the Embodiment) In the speedometer driven gear device of the present embodiment, the cylinder portion 21 is cylindrical and therefore has a high degree of roundness, and the shaft portion 11 uniformly slides into contact with the shaft portion 11 and rotates smoothly. Furthermore, since the rib portion 14 is formed on the shaft portion 22, high axiality and strength can be maintained. Therefore, the shaft portion 11 uniformly comes into elastic contact with the sealing member and is reliably sealed.

Furthermore, when the shaft portion 11 rotates, the spiral groove 15
As a result, gear oil flows into the sleeve 2 between the cylindrical portion 21 and the shaft 11 and from the clip groove 20, and flows out from the through hole 25 to the outside. Since the gear oil is thus easily circulated through the through hole 25, it cools the sliding surface between the cylindrical portion 21 and the shaft portion 11 and prevents wear. Further, wear particles and the like are easily discharged to the outside.

That is, according to the speedometer driven gear device of this embodiment, the shaft portion 11 rotates smoothly and wear is reliably prevented, so that a predetermined performance can be maintained for a long period of time. Furthermore, since it is made of resin, it is inexpensive and the number of parts can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of a speedometer driven gear device according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the shaft portion of FIG. 1. FIG. 3 is a sectional view of the sleeve, and FIG. 4 is a side view of the sleeve. FIGS. 5 and 6 are partially sectional front views of a conventional speedometer driven gear device;
FIG. 7 is an explanatory diagram of components when a speedometer driven gear device is installed. 1...Driven gear, 2...Sleeve, 3...
Seal member, 4... Clip, 5... O ring,
10... Gear part, 11... Shaft part, 21...
Cylinder part, 22...Shaft part, 23...Seal part, 24...
...Rib portion, 25...Through hole.

Claims (1)

[Scope of Claim for Utility Model Registration] A driven gear consisting of a gear part whose driving source is the rotation of the output shaft of a transmission and a shaft part to which a cable for operating a speedometer is connected, and a shaft part that rotatably supports the driven gear. A speedometer driven gear device comprising: a sleeve; and a sealing member held by the sleeve to seal between the sleeve and the driven gear; and a cylindrical shaft portion having, at the rear of the cylindrical portion, a rib portion protruding from the outer circumferential surface and extending in the axial direction, and a through hole communicating the inside and the outside;
A speedometer driven gear device comprising: a cylindrical seal portion that holds the seal member on an inner circumferential surface behind the shaft portion, and is made of synthetic resin.