JPH07332387A - Gear slip-off preventing mechanism for transmission - Google Patents

Abstract

PURPOSE:To surely prevent the slip-off of a sleeve which is easily slipped off, by forming a stage part only on the male spline of a hub at the position in one revolution direction where the sleeve of a gear slip-off preventing mechanism in a transmission is easily slipped off and by putting the rear end of the sleeve into contact with the stage part. CONSTITUTION:On a main shaft 8, a hub 5 having a male spline 5a formed on the outer periphery is fixed, and a sleeve 4 is spline-fitted in a slidable manner in the axial direction with the male spline 5. On both the sides of the hub 5, main gears 9 and 10 having each different diameter are fitted in a turnable manner with the main shaft 8, and the slip-off of the sleeve 4 is prevented by attaching the rear end of the sleeve 4 with the stage parts 5b and 5c formed on the male spline 5a of the hub 5. In this case, the stage parts 5b and 5c formed on the hub 5 are formed only at the position in one revolution direction where the slip-off of the sleeve 4 is easily caused. Accordingly, the excellent operation performance is secured, keeping the operating force of a shaft lever constant, for all the main gears 9 and 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear disengagement prevention mechanism for a transmission, and in particular, a male spline of a hub is provided with a step portion only at one rotation direction position where the sleeve is easily removed, and the rear portion of the sleeve is provided at the step portion. The dimensions of the hub and sleeve are adjusted so that the ends come into contact with each other to prevent the sleeve from coming off.
Without being affected by design specifications such as shift stroke,
The rear end of the sleeve must be securely contacted with the stepped portion of the hub to prevent the sleeve from coming off, and the specifications required for the transmission can be designed independently, greatly expanding the freedom of design. The present invention relates to a transmission gear disengagement prevention mechanism.

[0002]

2. Description of the Related Art The structure of a speed change mechanism of a constant mesh gear type transmission is such that main gears for speed change are rotatably fitted to the main shaft on both sides of a hub fixed to the main shaft, and A sleeve provided with a female spline is spline-fitted to the male spline formed on the outer periphery of the hub so as to be slidable in the axial direction.

A fork fixed to a fork rod is engaged with the sleeve, and by operating a shift lever to move the fork in the axial direction, the sleeve is slid in the axial direction to move the female of the sleeve. The spline is configured so as to be simultaneously fitted and connected to the male spline of the hub and the male spline formed on the dog of the main gear to be shifted, and the rotational force of the main gear is transmitted to the main shaft.

In the above-described transmission mechanism, the sleeve, which is spline-fitted with the dog of the main gear, sometimes comes out of the main gear, a so-called gear disengagement occurs. To prevent the gear disengagement, the conventional hub 1 is used.
5 to 7, a step portion 1b is formed on both side surfaces of the center of the male spline 1a in the width direction, and the rear end 2a of the sleeve 2 and the step portion 1b are brought into contact with each other in a meshed state of the sleeve 2. The sleeve 2 is designed to prevent the gear from slipping out of the main gear.

However, the above-mentioned gear disengagement prevention mechanism is applied to both main gears (not shown) disposed on both sides of the hub 1 and at the time of positive torque in which the sleeve 2 drives the hub 1 during vehicle acceleration (see FIG. 5) and the convex portions 1c are provided on both side surfaces of the male spline 1a so that the gear disengagement prevention mechanism operates in any state of the negative torque (FIG. 6) in which the hub 1 rotates the sleeve 2 during deceleration of the vehicle. Since the stepped portion 1b is located on the rear side with respect to the main gear, the shift stroke of the sleeve 2 is set large in order to bring the rear end 2a of the sleeve 2 into contact with the stepped portion 1b. I had to do it.

Therefore, the dimensions of the hub 1 and the sleeve 2,
Depending on how the shift stroke of the sleeve 2 is set, the sleeve 2 cannot be provided with the step portion 1b, or the step 1b is provided, which imposes great design restrictions on the dimensions of each portion and limits the degree of freedom in design. However, there is a drawback that the specifications required for the transmission cannot be designed independently.

The cause of gear disengagement is that when the power is transmitted from the main gear, which is a helical gear, to the hub 1 via the sleeve 2, the main gear is caused by the radial gap between the main gear and the main shaft depending on the rotational force transmission direction. Is slightly tilted in the direction of the hub 1, and it is considered that the force acts to rotate the sleeve 2 while returning to the hub 1 side while performing the rubbing motion.

However, the force for returning the sleeve 2 to the hub 1 side does not act on all the main gears, and does not always act in any state, and the layout and transmission of the transmission mechanism are transmitted. Torque direction (positive torque, negative torque), etc.
It has been found that at high speeds, gear loss is likely to occur when positive torque is applied.

That is, the operating force of the shift lever at the time of shifting operation varies depending on the gear to be shifted. For example, the sixth gear is heavy and the seventh gear is light, but a gear slip-off prevention mechanism is provided for all main gears. In the conventional transmission, the operating force of the shift lever at the sixth speed is not only the normal operating force but also the step portion 1b and the sleeve 2.
There is a drawback that the force for releasing the engagement with the rear end 2a is required and the force becomes heavier, resulting in poor gear shifting operability.

In order to keep the operating force of the shift levers of all the above-mentioned gears constant and to ensure good operability, the step portion 1b, which is a slight step of about 0.2 mm to 0.3 mm, is usually provided. The height has to be adjusted for each main gear for processing, which makes it extremely difficult to manufacture the hub 1 and has the drawback of high cost.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to make it easier for the sleeve to come off and to make the male hub hub at one rotational position. By forming a step only on the spline and abutting the rear end of the sleeve on the step, it is possible to reliably prevent the sleeve from coming off easily, and
The operation force of the shift lever is constant for all the main gears to ensure good operability.

Another object of the present invention is to eliminate the necessity of adjusting the height of the stepped portion provided on the sleeve for each main gear for processing by the above-mentioned construction, to improve the workability and to manufacture the sleeve inexpensively and easily. It is to be.

Still another object is to form a stepped portion on the male spline of the hub by separating the sleeve in one rotational direction position and the main gear where the sleeve is easily removed by separating the sleeve by one half or more of the width of the hub. The rear end of the sleeve is brought into contact with the step so that the rear end of the sleeve can be brought into contact with the step with a slight movement of the sleeve. Allows the step to be provided on the sleeve regardless of the size and shift stroke of the sleeve, greatly increasing the degree of freedom in design so that the specifications required for the transmission can be designed independently of the ideal specifications. It is to be.

[0014]

In summary, according to the present invention (claim 1), a hub fixed to a main shaft and having a male spline formed on the outer periphery thereof and a female spline formed on the inner periphery of the hub are a male spline of the hub. A dog that is axially slidably fitted to the spline, and a male spline that is rotatably fitted to the main shaft on both sides of the hub and that is spline-fitted to the female spline of the sleeve are attached to the dog. The main gear is provided, and the sleeve is moved in the axial direction so that the male spline of the hub and the male spline of the one dog are simultaneously spline-fitted to transmit the rotational force of the main gear to the main shaft. And the rear end of the sleeve is brought into contact with a step formed on the male spline of the hub to prevent the sleeve from coming off. In the gear disengagement prevention mechanism of the transmission, the step is formed on the male spline of the hub only at one rotational position where the sleeve is easily disengaged, and the rear end of the sleeve is brought into contact with the step. It is characterized in that it is configured to prevent the sleeve from coming off.

According to the present invention (claim 2), a hub fixed to the main shaft and having a male spline formed on the outer periphery thereof,
A female spline formed on the inner periphery of the sleeve is fitted to the male spline of the hub so as to slidably fit in the axial direction, and a sleeve is rotatably fitted to the main shaft on both sides of the hub. A female spline of the sleeve and a male gear having a male spline for spline fitting are provided on the dog, and the sleeve is moved in the axial direction to simultaneously spline the male spline of the hub and the male spline of the one dog. It is configured so that the rotational force of the main gear is transmitted to the main shaft, and the rear end of the sleeve is brought into contact with a step portion formed on the male spline of the hub to prevent the sleeve from coming off. In the gear disengagement prevention mechanism of the transmission, the sleeve is easily disengaged in one rotational position and the sleeve is easily disengaged. A step portion is formed on the male spline of the hub so as to be separated from the main gear by at least ½ of the width of the hub, and the rear end of the sleeve is brought into contact with the step portion to prevent the sleeve from coming off. It is characterized in that it is configured to.

[0016]

In the transmission gear disengagement prevention mechanism according to the present invention, the gear disengagement can be prevented by bringing the rear end of the sleeve into contact with the stepped portion formed on the hub with a slight movement amount of the sleeve. In the design of the transmission, the gear disengagement prevention mechanism can be designed with little consideration given to it, and an ideal transmission specification can be realized.

Further, since the step portion is arranged only at one rotational direction position where the sleeve is easily removed, the shift lever operating force of all the main gears can be made to have a constant magnitude, so that good operability is obtained. Thus, the step portion of the hub can be easily processed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. 1 to 4, the gear disengagement prevention mechanism 3 of the transmission according to the present invention includes a sleeve 4 and a hub 5.

In the structure of the transmission mechanism 6 of the constant mesh gear type transmission, main gears 9 and 10 for transmission are rotatably fitted to the main shaft 8 on both sides of a hub 5 fixed to the main shaft 8. A sleeve 4 provided with a female spline 4a is axially slidably spline-fitted to a male spline 5a formed on the outer periphery of the hub 5.

A fork 12 fixed to a fork rod 11 is engaged with the sleeve 4, and the sleeve 4 is moved by operating a shift lever (not shown) to move the fork 12 in the axial direction. The male spline 9b formed on the dog 9a or 10a fixed by welding or the like to the female spline 4a of the sleeve 4 and the male spline 5a of the hub 5 and the main gear 9 or 10 to be shifted is slid in the direction of arrow A or B. 10b is connected to the main shaft 8 by spline fitting at the same time, and the rotational force of the main gear 9 or 10 is transmitted to the main shaft 8.

On the male spline 5a of the hub 5, step portions 5b and 5c are formed only at the rotational position where the sleeve 4 is easily removed. To explain this more specifically, for example, 6
When the negative torque acts, the main gear for high speed 9
It is known that the gear for the high speed main gear 10 is apt to be disengaged when a positive torque is applied. Therefore, in FIG. , Also male spline 5a
A stepped portion 5c is formed on the upper surface of the and the surface opposite to the main gear 9. The steps 5b and 5c have a width of the hub 5 of 2
One-half or more of the male splines 5a are spaced apart from each other in the width direction and are formed at positions closer to the end side than the left and right centers of the male splines 5a of the hub 5, respectively.

Then, the sleeve 4 is moved in the direction of the arrow A to move the male spline 5a and the male spline 10b of the dog 10a.
When the positive torque for driving the hub 5 from the main gear 10 via the sleeve 4 is applied (FIG. 2), the right rear end 4b of the sleeve 4 contacts the step portion 5b. .

In FIG. 3, the sleeve 4 is moved in the direction of arrow B to connect the male spline 5a and the male spline 9b of the dog 9a, and drive the main gear 9 from the main shaft 8, that is, the hub 5 via the sleeve 4. The left rear end 4c of the sleeve 4 is configured to contact the step portion 5c when a negative torque is applied.

The present invention is configured as described above,
The operation will be described below. 1 and 2, in order to shift to the sixth speed, a change lever (not shown) is operated to move the fork 12 in the axial direction, and the sleeve 4 engaging with the fork 12 is moved in the direction of arrow A. To connect the male spline 5a to the male spline 10b of the dog 10a.

The rotation of the main gear 10, which is rotated by transmitting the rotational force of the engine through a counter gear (not shown), rotates the main shaft 8 through the sleeve 4 and the hub 5.
Is transmitted to the vehicle to drive the vehicle. At this time, positive torque acts, and in the sixth speed state (FIG. 2) in which the positive torque acts, normally, gear disengagement easily occurs, but the step portion 5b has a sleeve. The right rear end 4b of 4 is in contact with the sleeve 4 and the stepped portion 5b prevents the sleeve 4 from moving to the right in FIG. 2 so that gear disengagement is prevented and stable running can be ensured.

When the vehicle is decelerated during running at the sixth speed, the rotational force is transmitted from the main shaft 8 to the main gear 10 via the hub 5 and the sleeve 4. At this time, a negative torque acts. The engagement between the stepped portion 5b and the right rear end 4b of the sleeve 4 is released in the state in which is applied, but in the state in which the negative torque is applied in the sixth speed,
Since it is known that the force for separating the sleeve 4 from the dog 10a, that is, the force in the direction of pulling out the sleeve 4 does not act, the gear disengagement does not occur.

1 and 3, in order to shift to the 7th speed, a shift lever (not shown) is operated to move the fork 12 in the axial direction, and the sleeve 4 engaging with the fork 12 is moved in the direction of arrow B. Move to male spline 5a and dog 9
The male spline 9b of a is connected.

At the 7th speed, the main gear 9 is rotated by the rotational force of the engine being transmitted through the counter gear.
Is transmitted to the main shaft 8 via the sleeve 4 and the hub 5, and the positive torque for traveling the vehicle is acting, the sleeve 4 is dog-locked from the mechanism such as the layout of the hub 5 and the main gear 9. It is known that the force for separating from 9a, that is, the force in the direction of pulling out the sleeve 4 does not act, so that gear disengagement does not occur.

Further, when the seventh gear is apt to be disengaged, that is, when a negative torque is transmitted from the main shaft 8 to the main gear 9 via the hub 5 and the sleeve 4, the rotational force at the time of deceleration or the like acts on the step portion 5c. The left rear end 4c of the sleeve 4 abuts against the sleeve 4, preventing the sleeve 4 from moving to the left in FIG. 3 and preventing the gear from slipping off.

[0030]

As described above, according to the present invention, the step portion is formed only on the male spline of the hub at the one rotational direction position where the sleeve easily comes off, and the rear end of the sleeve is brought into contact with the step portion. Therefore, there is an effect that it is possible to surely prevent the sleeve, which is easy to come off, from coming off, and an effect that a good operability can be ensured by making the operation force of the shift lever constant for all the main gears.

Further, with the above construction, it is possible to eliminate the need for adjusting the height of the stepped portion provided on the sleeve for each main gear, and to improve the workability and to manufacture the sleeve inexpensively and easily. .

Further, a step portion is formed on the male spline of the hub by arranging the sleeve in one rotational direction position where the sleeve easily comes off and at least one half of the width of the hub away from the main gear where the sleeve easily comes off. Since the rear end of the sleeve is brought into contact with the rear end of the sleeve, the rear end of the sleeve can be brought into contact with the step portion by slightly moving the sleeve, and as a result, the size of the hub and the sleeve and the shift stroke of the sleeve can be adjusted. There is an effect that a step can be provided on the sleeve irrelevantly, and there is an effect that the degree of freedom in design can be greatly increased and the specifications required for the transmission can be designed independently of the ideal specifications.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of a main part of a transmission.

FIG. 2 is a plan view showing a mutual relationship between a hub, a sleeve, and a dog, in which a step portion and a right rear end of a sleeve are engaged with each other when positive torque is transmitted, and gear disengagement is prevented.

FIG. 3 is a plan view showing an interrelationship between a hub, a sleeve, and a dog in which a step portion and a left rear end of a sleeve are engaged with each other when negative torque is transmitted to prevent the gear from coming off.

FIG. 4 is a partial perspective view of a hub having a step formed on a male spline.

5 to 7 relate to a conventional example, and FIG. 5 is a plan view similar to FIG.

FIG. 6 is a plan view similar to FIG.

7 is a partial perspective view similar to FIG.

[Explanation of symbols]

 3 Gear loss prevention mechanism for transmission 4 Sleeve 4a Female spline 4b Right rear end 4c Left rear end 5 Hub 5a Male spline 5b Step 5c Step 8 Main shaft 9 Main gear 9a Dog 9b Male spline 10 Main gear 10a Dog 10b Male spline

Claims (2)

[Claims] 1. A hub fixed to a main shaft and having a male spline formed on its outer circumference, and a sleeve in which a female spline formed on the inner circumference is fitted to the male spline of the hub so as to be slidable in the axial direction. The main shaft is rotatably fitted to the main shaft on both sides of the hub, and the female spline of the sleeve and a male gear having a spline fitting male spline are provided on the dog. The male spline of the hub and the male spline of the one dog are simultaneously spline-fitted to transmit the rotational force of the main gear to the main shaft, and the male spline of the hub is formed. Gear disengagement prevention device for a transmission, in which the rear end of the sleeve is brought into contact with a step portion to prevent the sleeve from coming off In the structure, a step portion is formed on the male spline of the hub only at one rotational direction position where the sleeve easily comes off, and the rear end of the sleeve is brought into contact with the step portion to prevent the sleeve from coming off. A gear disengagement prevention mechanism of the transmission characterized by being configured. 2. A hub fixed to a main shaft and having a male spline formed on the outer circumference, and a sleeve in which a female spline formed on the inner circumference is fitted to the male spline of the hub so as to be slidable in the axial direction. The main shaft is rotatably fitted to the main shaft on both sides of the hub, and the female spline of the sleeve and a male gear having a spline fitting male spline are provided on the dog. The male spline of the hub and the male spline of the one dog are simultaneously spline-fitted to transmit the rotational force of the main gear to the main shaft, and the male spline of the hub is formed. Gear disengagement prevention device for a transmission, in which the rear end of the sleeve is brought into contact with a step portion to prevent the sleeve from coming off In the structure, a step portion is formed on the male spline of the hub at a position in one rotational direction where the sleeve is easily removed and at least ½ or more of the width of the hub with respect to the main gear where the sleeve is easily removed. A gear disengagement prevention mechanism for a transmission, characterized in that a rear end of the sleeve is brought into contact with a step portion to prevent disengagement of the sleeve.