JPH0523881Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a locking device for a worm gear that drives a meter cable of a speedometer, tachometer, or the like.

(Prior art) As a conventional technology, there is a structure shown in FIG. 3.

In Fig. 3, reference numeral 1 indicates a differential gear, and a hollow differential gear case 4 ( A pair of side gears 5 connected to the left and right axles are rotatably supported at the left and right ends of the differential gear case 4. A pair of pinion gears 6 perpendicular to the rotation axis of the moving gear case 4 are rotatably supported, and each of these pinion gears 6
are meshed with each of the side gears 5 mentioned above.

The differential gear case 4 has its left and right ends rotatably supported by bearings 8 on a casing 7 supported by the transmission case, and has a large diameter fitting shaft 4a directly to the left of the bearing 8 on the right side. The annular worm gear 10 is fitted to the shaft end of the fitting shaft 4a.

The worm gear 10 has an inner circumferential surface formed in a stepped shape with a large diameter on the left side and a small diameter on the right side, and the left part is fitted onto the outer circumference of the fitting shaft 4a, and the right inner circumferential wall 10
a to protrude in the axial direction.

Further, the fitting shaft 4a and the worm gear 10 are connected to a recess 4b formed at the right end of the fitting shaft 4a at intervals in the circumferential direction and a right inner circumferential wall 10a of the worm gear 10.
The convex portions 10b formed at intervals in the circumferential direction are engaged with each other from the axial direction, and are connected so as to be unable to rotate relative to each other.

Then, the right inner circumferential wall 10a of the worm gear 10
The left side of the inner race 8a of the bearing 8 is brought into contact with the right side of the bearing 8 to prevent the worm gear 10 from coming off the fitting shaft 4a.

Reference numeral 11 denotes a worm meshed with the worm gear 10, which is disposed perpendicular to the rotation axis of the worm gear 10 and rotatably supported by the casing 7, and a meter cable (not shown) for driving a speedometer is connected to the shaft end. ing.

As a result, when the final gear 3 is rotated by the drive gear on the transmission side, the differential gear case 4
rotates, and in conjunction with this, the left and right axles are differentially rotated via the pinion gear 6 and each side gear 5.

Furthermore, the rotation of the differential gear case 4 causes the worm gear 10 to rotate, which rotates a speedometer cable (not shown) via the worm 11.

(Problems to be Solved by the Invention) In the above-mentioned conventional device, the fitting shaft 4a of the differential gear case 4 and the worm gear 10 fitted thereto are engaged with each other by an axial recess 4b and a protrusion 10b,
Since the worm gear 10 was structured to be prevented from coming off by the inner race 8a of the bearing 8 fitted to the shaft end of the differential gear case 4, the worm gear 10
Therefore, when the worm 11 is driven, the worm gear 10 vibrates in the axial direction on the fitting shaft 4a, making the rotation of the worm 11 unstable and the meter display unstable. There was a flaw that would go away.

The present invention is an engagement of a worm gear for driving a meter cable that prevents the worm gear 10 from moving in the axial direction on the fitting shaft and allows the worm 11 that meshes with the worm gear 10 to rotate smoothly, thereby stabilizing the meter display. The purpose is to obtain a stopping device.

(Means for Solving the Problems) In order to achieve the above object, the present invention is constructed as follows.

That is, a worm gear for driving a meter cable is formed by fitting and locking an annular worm gear to the shaft end of a rotating body that is rotated by receiving torque from an output shaft, and meshing a worm connected to a meter cable with the worm gear. A fitting shaft formed in a step shape and having a large diameter is provided axially inwardly of the bearing fitting part of the rotating body, and the worm gear is locked to the end of the fitting shaft, and both are connected to each other in an axial recess. A disc spring is interposed between the worm gear and the bearing, and the outer peripheral end of the disc spring is formed into an arcuate surface and abuts against the outer surface of the worm gear. The inner peripheral end is pressed inward in the axial direction of the rotating body by the inner race of the bearing.

(Function) Since the present invention has the above configuration, the inner peripheral end of the leaf spring is pressed inward in the axial direction by the inner race and is elastically deformed, and the reaction force of this causes the worm gear to move. is pressed inward in the axial direction against the fitting shaft of the rotating body.

As a result, the fitting shaft and the worm gear are engaged with each other in a state where the concave portion and the convex portion provided between the two are always pressed against each other in the axial direction.

Further, the outer circumferential end of the disc spring smoothly contacts the outer surface of the worm gear, and when the disc spring is elastically deformed, the outer peripheral end of the disc spring smoothly slides in the radial direction along the outer surface of the worm gear.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main part thereof.

Regarding the parts with the same structure as in Fig. 3, please refer to Fig. 1.
The same reference numerals as in FIG. 3 are given to the figures and FIG. 2, and the explanation thereof will be omitted.

A stepped and large-diameter fitting shaft 14 is formed axially inward of the right bearing 8 that supports the differential gear case (rotating body) 4, and the end of this fitting shaft 14 is molded from a plastic material. Annular worm gear 1
Fit 5.

Two axially recessed recesses 14a are formed in the circumferential direction at the right end of the fitting shaft 14, and the right inner circumferential wall 15a of the worm gear 15 is made to protrude in the axial direction on the outside of the fitting shaft 14. , this right inner peripheral wall 1
A convex portion 15b is formed at the left end of 5a to fit into the concave portion 14a from the right, and the convex portion 15b is engaged with the concave portion 14a to connect the worm gear 15 to the fitting shaft 14 in a relatively non-rotatable manner.

A disc spring 16 is interposed between the right inner peripheral wall 15a and the inner race 8a of the bearing 8, and the outer peripheral end 16a of the disc spring 16 is connected to the worm gear 15.
The inner peripheral end 16b of the disc spring 16 is brought into contact with the left side surface of the inner race 8a.

The disc spring 16 is formed of a spring steel material into a conical shape whose outer peripheral part is displaced leftward with respect to the axial center, and as shown in FIG. Worm gear 15 in contact
The right side surface 15c is curved toward the left in an arc shape, and the outer peripheral end 16a has a small radius of curvature, and the right side surface 15c has a large radius of curvature.

When the inner race 8a is fitted to the right end of the differential gear case 4, the inner peripheral end 16b of the disc spring 16 is pressed leftward by its left side surface to elastically deform the disc spring 16, thereby deforming the leaf spring. The worm gear 15 is pressed leftward by the outer peripheral end 16a of the worm gear 16.
Note that the curvature of the right side surface 15c of the worm gear 15 may be omitted.

According to the above embodiment, the outer peripheral end 16a of the disc spring 16 is elastically deformed to the left in the axial direction by the inner race 8a, and the worm gear 15 is moved against the fitting shaft 14 by the reaction force of this. It will be pressed to the left in the axial direction.

Therefore, the convex portion of the worm gear 15 engages with the convex portion 15b of the worm gear 15 and the concave portion 14a of the fitting shaft 14 in a state in which they are constantly pressed in the axial direction (to the left), and the worm gear 15 does not move in the axial direction, so that the worm 11
Therefore, the meter cable can be rotated smoothly.

(Effects of the invention) As is clear from the above explanation, according to the invention, the worm gear is axially pressed by the elastic force of the disc spring to prevent movement in the axial direction, and is strongly attached to the mating shaft. It will be biased into engagement.

Therefore, the meter cable driven by the worm gear is rotated smoothly, and the meter display can be stabilized.

In addition, the outer peripheral end of the disc spring is curved into an arc shape so that it comes into contact with the outer surface of the worm gear, so even if the worm gear is made of soft material such as plastic, it will not wear out and will not wear out. Furthermore, since the disc spring is interposed between the worm gear and the inner race, the space in the axial direction does not increase.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is a sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 1... Differential device, 2... Drive gear, 3... Final gear, 4... Differential gear case, 5... Side gear, 6... Pinion gear, 7... Casing, 8... Bearing, 8a... Inner race,
11... Worm, 14... Fitting shaft, 14a...
Recessed portion, 15...Worm gear, 15a...Right inner peripheral wall, 15b...Protrusion, 15c...Right side surface, 16
...Disc spring, 16a...outer peripheral end, 16b...inner peripheral end.

Claims (1)

[Scope of utility model registration request] In a worm gear for driving a meter cable, an annular worm gear is fitted and locked to the shaft end of a rotating body that is rotated by receiving torque from an output shaft, and a worm connected to a meter cable is engaged with the worm gear, A stepped and large-diameter fitting shaft is provided axially inward of the bearing fitting portion of the rotating body, and the worm gear is locked at the end of the fitting shaft, and both are connected to the axial concave and convex portions. A disc spring is interposed between the worm gear and the bearing, the outer peripheral end of the disc spring is formed into an arcuate surface and abuts on the outer surface of the worm gear, and the inner peripheral end of the disc spring is A locking device for a worm gear for driving a meter cable, characterized in that a portion of the worm gear is pressed inward in the axial direction of a rotating body by an inner race of the bearing.