JPH0747629Y2 - Worm gear locking device for driving the meter cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a locking device for a worm gear that drives a meter cable such as a speedometer or a tachometer.

(Conventional Technology) As a conventional technology, there is a structure shown in FIG.

In FIG. 7, reference numeral 1 is a differential gear, which is a final gear (ring gear) 3 meshing with a drive gear 2 mounted on the output shaft side of an automatic transmission (transmission).
A hollow differential gear case 4 (rotating body) is integrally connected to the above, and 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 orthogonal to the rotation axis of the differential gear case 4 are rotatably supported at the center of the dynamic gear case 4, and the pinion gears 6 are meshed with the side gears 5.

The differential gear case 4 has bearings 8 at its left and right ends.
A casing 7 supported by a case of the transmission by 9 is rotatably supported, and a large-diameter step portion 4a is formed on the left side of the bearing 8 on the right side, and an annular portion is formed at the shaft end portion of the step portion 4a. Fit the worm gear 10.

The worm gear 10 has an inner peripheral surface formed in a step shape in which the left part has a large diameter and the right part has a small diameter, and is fitted to the step part 4a,
The right inner peripheral wall 10a is projected in the axial direction.

Further, the step portion 4a and the worm gear 10 are provided with a concave portion 4b formed at the right end of the step portion 4a at a circumferential interval and a convex portion 10b formed at a circumferential interval on the right inner peripheral wall 10a of the worm gear 10.
And are engaged with each other in the axial direction so that they cannot rotate relative to each other.

Then, the left side surface of the inner race 8a of the bearing 8 is brought into contact with the right side surface of the right portion inner peripheral wall 10a of the worm gear 10 to prevent the worm gear 10 from coming off from the stepped portion 4a.

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

Accordingly, when the final gear 3 is rotated by the drive gear on the transmission side, the differential gear case 4 is rotated, and accordingly, the left and right axles are differentially rotated via the pinion gear 6 and each side gear 5. It

Further, the worm gear 10 is rotated by the rotation of the differential gear case 4, and the speedometer is rotated via the worm 11.

(Problems to be Solved by the Invention) In the above-mentioned conventional one, the step portion 4a of the differential gear case 4 and the worm gear 10 fitted to the step portion 4a are provided with a recess 4b and a protrusion 10 in the axial direction.
The inner race 8a of the bearing 8 in which the worm gear 10 is fitted and fixed to the shaft end of the differential gear case 4 by engaging with the b.
The worm gear 10
It is not possible to eliminate the axial play of the worm 11, which causes the worm gear 10 to vibrate axially on the stepped portion 4a when the worm 11 is driven, and the rotation of the worm 11 becomes unstable and the meter display becomes unstable. There was a flaw.

Further, when the axial distance between the step portion 4a formed in the differential gear case 4 and the bearing 8 fitted to the shaft end of the differential gear case 4 changes depending on the model, a worm gear having a width corresponding to this is required, Alternatively, a collar for adjusting the gap is required, and in addition to the above-mentioned drawback, there is a drawback that the number of parts increases.

An object of the present invention is to obtain a novel locking device for a worm gear for driving a meter cable, which solves the above drawbacks.

(Means for Solving the Problem) A stepped portion having a small diameter on the outer side in the axial direction is formed on a rotating body, and an annular engagement cylinder protruding axially outward on a ring-shaped worm gear fitted to the stepped portion. And an outer peripheral locking portion and an inner peripheral locking portion are provided in a part of the outer peripheral portion and the inner peripheral portion of the engagement cylinder, and a washer-shaped leaf spring that abuts the outer surface of the engagement cylinder is provided. An outer circumference and an inner circumference of the leaf spring that are bent in mutually opposite axial directions and that can be engaged with one of the outer circumference locking portion and the inner circumference locking portion by reversing the leaf spring. An inner race of a bearing in which a projection and an inner projection are provided, and an abutting piece protruding in the axial direction is provided at a tip end portion of the inner projection, and an axial center end of the abutting piece is fitted to a shaft end portion of the rotating body. It is configured to be pressed inward in the axial direction by.

(Operation) Since the present invention is configured as described above, the leaf spring has its end on the axial center side pressed axially inward by the inner race to be elastically deformed, and the reaction force of the leaf spring causes the worm gear to rotate. It will be elastically pressed inward in the axial direction with respect to the stepped portion.

When the leaf spring that contacts the outer surface of the engagement cylinder is inverted and brought into contact, one of the outer protrusion and the inner protrusion alternates with one of the outer peripheral engaging portion and the inner peripheral engaging portion of the worm gear. , The relative rotation of the two is blocked, and the contact piece is axially displaced with respect to the outer surface of the engagement cylinder.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

First, in the drawings, FIGS. 1 to 6 show an embodiment of the present invention, FIG. 1 is a sectional view of an essential part showing the first embodiment, and FIG. 2 is a sectional view of an essential part showing the second embodiment. FIG. 3 is a front view of the worm gear, FIG. 4 is a IV-IV sectional view thereof, FIG. 5 is a front view of a leaf spring, and FIG. 6 is a VI-VI sectional view thereof.

Incidentally, in FIGS. 1 and 2, parts having the same structure as FIG. 7 are denoted by the same reference numerals as those in FIG. 7 in FIGS. 1 and 2 and their explanations are omitted.

In FIG. 1, reference numeral 15 is a ring-shaped worm gear fitted to the step portion 4a of the differential gear case (rotating body) 4.

The worm gear 15 has a stepped large diameter on the left side of its inner peripheral surface, and is fitted into the stepped portion 4a from the right side, and the axial contact between the two is the same as in FIG. The concave portion and the convex portion are engaged with each other so that they cannot rotate relative to each other.

As shown in FIG. 3 and FIG. 4, the worm gear 15 has an annular engagement cylinder 16 protruding rightward on its right side surface, and an outer peripheral surface 16a of the engagement cylinder 16 has a radial outer surface. A small width outer peripheral locking portion 17 protruding inward is formed, and a wide inner peripheral locking portion 18 recessed outward in the radial direction is formed on the inner peripheral surface 16b of the engagement cylinder 16 at two circumferential positions at equal pitches. I will do it.

A washer-shaped leaf spring 19 is interposed between the worm gear 15 and the bearing 8 fitted to the left end of the differential gear case 4.

As shown in FIGS. 5 and 6, the leaf spring 19 is made of a spring steel material, and has an outer protrusion 20 that bends rightward and an outer protrusion 20 that bends rightward on the outer peripheral portion and the inner peripheral portion of the main body 19a. Inner protrusions 21 that project are formed at two locations in the circumferential direction at equal pitches,
The inner protrusion 21 is integrally provided with an abutment piece 22 extending in the axial direction from its tip (left end).

Each of the outer projections 20 is located on a diameter circle corresponding to the outer peripheral surface 16a of the engagement cylinder 16, and each of the inner projections 21 is located on a diameter circle corresponding to the inner circumference locking portion 18, and its circumferential direction. The width of is to be engageable with the inner peripheral locking portion 18. In addition, the contact piece
22 has its axial end 22a curved in a tubular shape, and this axial end 22a faces the left side surface of the inner race 8a of the bearing 8.

Next, the manner of use of the above embodiment will be described.

First, as shown in FIG. 1, in the case of a model in which the worm gear 15 and the bearing 8 are close to each other, the leaf spring 19 is arranged so that the inner projection 21 thereof faces leftward, and the inner projection 21 is arranged in the worm gear 15 The inner peripheral locking portion 18 of the main body 19a
To the right side of the worm gear 15.

Then, the axial end 22a of the contact piece 22 is pressed to the left by the inner race 8a of the bearing 8 fitted into the operating gear case 4.

Then, the worm gear 15 is elastically pressed to the left in the axial direction via the main body 19a by the reaction force of the contact piece 22, engages with the step portion 4a, and the worm gear 15 does not move in the axial direction. 11 Therefore, the meter cable will rotate smoothly.

Further, the inner protrusion 21 of the leaf spring 19 engages with the inner peripheral locking portion 18 of the worm gear 15, and the relative rotation between the two is blocked.

Further, as shown in FIG. 2, in the case of a model in which the worm gear 15 and the bearing 8 are largely separated from each other in the axial direction, the leaf spring 19 is reversed so that the outer protrusion 20 thereof faces leftward, and the outer protrusion 20 Is fitted to the outer peripheral surface 16a of the worm gear 15, and the main body 19a is brought into contact with the right surface of the worm gear 15.

Then, the axial end 22a of the contact piece 22 is pressed to the left by the inner race 8a of the bearing 8 fitted into the operating gear case 4.

Then, the worm gear 15 is elastically pressed leftward in the axial direction via the main body 19a by the reaction force of the contact piece 22, engages with the step portion 4a, and the worm gear 15 does not move in the axial direction.

In addition, the outer protrusion 20 of the leaf spring 19 engages with the outer peripheral engagement portion 17 of the worm gear 15 in the circumferential direction, and the relative rotation between the two is blocked.

(Effect of the Invention) As is apparent from the above description, according to the present invention, the elastic force of the leaf spring causes the worm gear to be elastically pressed in the axial direction to prevent the worm gear from moving in the axial direction. The rotation of is stable and the display of the meter can be stabilized.

Further, by reversing the leaf spring, the leaf spring can be shared by the models having different axial gaps between the engagement cylinder and the bearing, and the type of the leaf spring can be reduced.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention, and FIG.
FIG. 2 is a sectional view of an essential part showing an embodiment, FIG. 2 is a sectional view of an essential part showing a second embodiment, FIG. 3 is a front view of a worm gear, FIG. 4 is its IV-IV sectional view, and FIG. Is a front view, FIG. 6 is a sectional view taken along line VI-VI, and FIG. 7 is a sectional view showing a conventional example. 1: Differential device, 2: Drive gear, 3: Final gear, 4: Differential gear case (rotating body), 4a: Step, 5: Side gear, 6: Pinion gear, 7: Casing, 8: Bearing, 8a: Inner Race, 11: Worm, 15: Worm gear, 16: Engagement tube, 16
a: outer peripheral surface, 16b: inner peripheral surface, 17: outer peripheral locking portion, 18: inner peripheral locking portion, 19: leaf spring, 19a: main body, 20: outer protrusion, 21: inner protrusion, 22:
Abutting piece, 22a: shaft end,

Claims (1)

[Scope of utility model registration request] 1. A rotary body (4) is formed with a step portion (4a) having a small diameter outward in the axial direction, and a ring-shaped worm gear (15) fitted to the step portion (4a) is axially outward. A ring-shaped engaging cylinder (16) is formed so as to protrude to the outer periphery of the engaging cylinder (16) and a part of the outer peripheral portion and the inner peripheral portion of the outer peripheral engaging portion (17) and the inner peripheral engaging portion (18). And a washer-shaped leaf spring (19) that comes into contact with the outer surface of the engagement cylinder (16). The outer and inner peripheral portions of the leaf spring (19) are bent in mutually opposite axial directions. By reversing the leaf spring (19), the outer peripheral locking part (17) and the inner peripheral locking part (1
8) An outer protrusion (20) and an inner protrusion (21) that can be engaged with either one of them are provided, and a contact piece (22) protruding in the axial direction is provided at the tip of the inner protrusion (21). The axial center of the contact piece (22) is axially inwardly pressed by the inner race (8a) of the bearing (8) fitted to the axial end of the rotating body (4). Worm gear locking device for driving the meter cable.