JPS6132199Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gear slippage prevention mechanism used in a constant-mesh type transmission.

Generally, in this type of transmission, a hub is attached between a plurality of main shaft side gears that idle on the main shaft so as to be rotated integrally with the main shaft.
A sleeve that can be selectively engaged with a main shaft gear adjacent to the hub is reciprocally slidably splined to the outside of the hub, and the transmission further includes a sleeve and a main shaft gear as described above. Equipped with a mechanism to prevent gears from slipping off to ensure proper engagement.

Usually, the mechanism for preventing gear dislodgement is formed by forming the meshing portion of the sleeve and the gear spline on the main shaft side gear into a slightly tapered shape so that the sleeve and the main shaft side gear can be engaged with each other. It is constructed so that a reliable meshing state is maintained without easily coming off.

But in this way, the sleeve and
The process of slightly tapering the meshing portion of the gear spline on the main shaft gear is complicated,
In particular, when the size of the sleeve, main shaft gear, etc. is relatively small in consideration of miniaturization of the transmission, the above-mentioned machining operations become extremely complicated, and therefore special machining equipment is required for such machining, which tends to increase the production cost of the entire transmission.

The purpose of this invention was to create a constant-mesh type transmission in which the sleeve and the gear spline on the main shaft side gear do not easily come off and maintain a reliable meshing state, and which has a simple structure and low production cost. The purpose of the present invention is to provide a mechanism for preventing gear slippage.

With these issues in mind, the gear dropout prevention mechanism used in the constantly meshing transmission of this invention is installed on the main shaft between multiple main shaft side gears that idle on the main shaft, and is integrated with the main shaft. A hub that is rotated by the hub, a sleeve that is spline-coupled to the outside of the hub so that it can slide reciprocatingly and that selectively meshes with a main shaft side gear adjacent to the hub, and spline teeth formed on the hub. A sleeve stopper projecting from the surface, and a stopper step stepped on the tooth surface of the spline at both ends of the spline formed on the sleeve so as to be hookable to the sleeve stopper. It consists of

Hereinafter, preferred specific examples of the gear dropout prevention mechanism used in the constant mesh type transmission according to this invention will be described with reference to the drawings.

FIGS. 1 and 2 show a specific example 10 of a gear slippage prevention mechanism used in a constant-mesh type transmission of this invention applied to an automobile.

The gear dropout prevention mechanism 10 includes a hub 14 that is attached to the main shaft 11 and rotates integrally with the main shaft 11, and a hub 14 that is attached to the main shaft 11 and rotates integrally with the main shaft 11, between a plurality of main shaft side gears 12 and 13 that idle around the main shaft 11. a sleeve 15 that is spline-coupled to the outside of the hub 14 so as to be able to slide reciprocally and selectively mesh with the main shaft side gears 12 and 13 adjacent to the hub 14;
A sleeve stopper 17 protrudes along the tooth height direction of the hub 14 at approximately the center of the tooth surface 16 of the spline formed in the , and stopper steps 19 stepped on the tooth surfaces 18 of the spline at both ends of the spline formed on the sleeve 15.

That is, the hub 14 is connected to the main shaft 11 between one main shaft side gear 12 and the other main shaft side gear 13.
The spline tooth surface 16 of the hub 14 has a sleeve stopper 17.
are integrally formed.

The sleeve stopper 17 is connected to the hub 14.
Along the tooth height direction of the hub 14 at a substantially central position in the tooth trace direction on the tooth surface 16 of the spline,
Moreover, it is formed to have a slightly larger thickness than the tooth thickness of the hub 14.

Therefore, the sleeve stopper 17 is formed by cutting the hub 14 in a gear cutting process, leaving a small portion approximately in the center in the direction of the tooth trace.

Of course, such a gear cutting can be performed using a gear cutting machine, e.g.
The sleeve stopper 17 is easily formed by using a hobbing machine and only by a gear cutting process along the tooth trace direction.

The hub 14 configured as described above is connected to the main shaft 11.
The main shaft 11 is rotated integrally with the
On either side of the hub 14, main shaft side gears 12 and 13 are attached to the main shaft 11 via bearings 22 and 23 so as to be rotatable about the main shaft 11 (see FIG. 1).

In the main shaft side gears 12 and 13, portions adjacent to both ends of the hub 14 are formed with so-called dog clutch portions 20 and 21, respectively, into which a sleeve 15 to be described later is engaged.

Of course, the dog clutch parts 20 and 2
The inner ends of each of the sleeves 15 are tapered to facilitate engagement of the sleeve 15.

Further, the gears 12 and 13 on the main shaft side are of course meshed with a gear (not shown) on the side of the counter shaft (not shown), which is arranged substantially parallel to the main shaft 11.

Further, on the outside of the hub 14, the hub 1
4 and its main shaft side gears 12, 13, a sleeve 15 is splined.

The sleeve 15 reciprocates on the outside of the hub 14 in response to driving of a shift fork (not shown) by operating a change lever (not shown), and the spline teeth in the sleeve 15 reciprocate. At both ends of the surface 18, stopper steps 19 are formed which can be hooked onto the sleeve stopper 17 described above.

The stopper stage 19 is formed by cutting both ends of the tooth surface 18 of the spline to an appropriate length after a normal gear cutting process is performed using a gear cutting machine, for example, a hobbing machine. It is easily formed by tiering.

Of course, the tooth thickness of the sleeve 15 at the portion excluding the stopper step 19 is such that it slides back and forth between the sleeve and the stopper 17 of the hub 14. When the sleeve 15 is slid back and forth, either end of the sleeve 15 is connected to the main shaft side gear 12 described above.
or 13, so that it can be properly engaged with the dog clutch portion 20 or 21.

When the sleeve 15 is slid in this manner and, for example, one end of the sleeve 15 is engaged with the dog clutch portion 20 of one of the main shaft gears 12, the stopper stage 19 of the other end of the sleeve 15 Of course, it is hooked onto the sleeve stopper 17 on one side of the hub 14 (see FIG. 2).

Also, the stopper stage 1 in the sleeve 15
The inner end of 9 is formed into a tapered shape.

That is, when the sleeve 15 is slid to one side and one end of the sleeve 15 is engaged with the dog clutch portion 20 of the main shaft side gear 12, the stopper step 19 is moved toward the sleeve 14 of the hub 14. Although the sleeve 15 is securely hooked on the stopper 17, when a predetermined operating force is applied to the sleeve 15 to return the sleeve 15 to its original state, the stopper is The arrangement is such that the engagement between the step 19 and the sleeve stopper 17 is released, and the sleeve 15 can be easily slid back to its original state, ie, the state shown in FIG.

Next, the operation of the gear slippage prevention mechanism 10 used in the constantly meshing type transmission according to this invention will be explained.

First, when you operate the change lever (not shown) of the transmission, the shift
Sleeve 1 is driven by a fork (not shown).
5 is slid axially relative to the hub 14.

When the sleeve 15 is slid in this way,
The sleeve 15 is connected to the main shaft side gear 12 or 13.
is engaged with the dog clutch portion 20 or 21 of.

To explain such a meshing state with reference to FIG. 2, the sleeve 1 is assembled as described above.
5 is slid and one end of the sleeve 15 is properly engaged with the dog clutch portion 20 of the main shaft gear 12, the stopper stage 19 at the other end of the sleeve 15 engages the sleeve 14 of the hub 14. It is hooked on the stopper 17.

That is, since the hub 14 is rotated integrally with the main shaft 11, if the sleeve 15 is moved as described above and one end of the sleeve 15 is engaged with the dog clutch portion 20, The teeth of the sleeve 15 are the teeth of the hub 14
is biased to one side between the teeth of the stopper stage 1.
9 is hooked onto the sleeve stopper 17 of the hub 14.

Therefore, when the hub 14 and the sleeve 15 are engaged with each other, although a slight gap 24 is formed due to the sleeve 15 being biased to one side, the hub 14 is integrally connected to the main shaft 11. Since the sleeve 15 is rotated, the stopper step 19 of the sleeve 15 is securely hooked onto the sleeve stopper 17 of the hub 14, and the sleeve 15 is rotated.
Power is properly transmitted between the hub 14 and the input shaft gear 12 via the sleeve 15, and the sleeve 15 is prevented from coming off, so-called gear coming off.

Also, the change lever is operated to return the sleeve 15 to its original state, and the sleeve 1
When a predetermined operating force is applied to the sleeve stopper 5, the above-mentioned engagement between the stopper step 19 and the sleeve stopper 17 is released, and the sleeve 15 is slid back to its original state.

The other end of the sleeve 15 is connected to the main shaft side gear 13.
When engaged with the dog clutch portion 21 of the clutch, the operation is substantially the same as that described above, so a description of the operation will be omitted.

According to this invention, the sleeve stopper protrudes from the tooth surface of the spline formed on the hub, and the stopper stage protrudes from the tooth surface of the spline formed on the hub.
In order to allow the sleeve to be hooked onto a stopper, both ends of the spline formed on the sleeve have a stepped structure where the tooth surfaces of the spline are stepped, so that the sleeve is biased to one side of the hub. When the stopper stage is hooked to the sleeve stopper, the sleeve is prevented from coming off the gear spline of the main shaft side gear, and the sleeve and the gear spline are reliably maintained in a meshed state. The gears can be shifted reliably, and the structure is simple. In particular, the taper surface formed on the gear spline of the dog clutch and the tooth surface of the hub spline, which is conventionally done, can be avoided. This avoids the use of special equipment to process the tapered surface, which simplifies the processing operation and reduces production costs. This avoids increasing the size of the transmission, making it extremely useful for transmissions mounted on vehicles.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a specific example of a gear slippage prevention mechanism used in a constantly meshing type transmission according to this invention, and Fig. 2 is a schematic diagram showing a specific example of a gear slipping prevention mechanism used in a constantly meshing type transmission according to this invention. FIG. 3 is a partial cross-sectional view schematically showing a specific example of a prevention mechanism. DESCRIPTION OF SYMBOLS 10...Gear dropout prevention mechanism used in a constant mesh transmission, 11...Main shaft, 12, 13...Main shaft side gear, 14...Hub, 15...Sleeve, 1
6...Tooth surface, 17...Sleeve stopper, 18
... tooth surface, 19 ... stopper stage.

Claims (1)

[Claim for Utility Model Registration] A hub that is installed on the main shaft and rotates integrally with the main shaft between a plurality of main shaft side gears that idle on the main shaft, and a hub that can reciprocate on the outside of the hub. a sleeve spline-coupled to the hub and selectively meshed with the gear on the main shaft adjacent to the hub; a sleeve stopper protruding from the tooth surface of the spline formed on the hub; A gear slippage prevention mechanism used in a constant-mesh type transmission, comprising stopper stages stepped on tooth surfaces of the spline at both ends of a spline formed on the sleeve so that the gear can be engaged.