JPH0579543A - Gear mechanism for preventing excessive torque transmission - Google Patents

Abstract

PURPOSE:To provide a gear mechanism for preventing excessive torque transmission between a driving shaft and a following shaft. CONSTITUTION:Rotational force of a driving shaft 6 of a motor 4 is transmitted from a first gear 8 to a second gear 26. The second gear 26 is pressed to a frictional plate 28 by a belleville spring 30, and the rotational force is transmitted to the frictional plate 28 by the frictional force. Slipping occurs between the gear 26 and the frictional plate 28 when excessive torque exceeding a fixed level is generated, and transmission of the excessive torque is inhibited thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear mechanism for preventing excessive torque transmission that prevents excessive torque from being transmitted between a drive shaft and a driven shaft.

[0002]

2. Description of the Related Art Conventionally, for example, in a piston crank device 2 shown in FIG. 3, a first gear 8 provided on a drive shaft 6 of a motor 4 is provided on a rotary shaft 11 having an eccentric shaft 10. Piston 1 that meshes with the gear 12 of No. 2 and makes the rotational force of the motor 4 contact the ring body 14 of the eccentric shaft 10.
It is transmitted to 6. In this case, a stopper 18 is provided in order to regulate the rotation range of the second gear 12.

[0003]

In the piston crank device 2 thus constructed, as shown in FIG.
When excessive torque acts from the motor 4 or the piston 16, the second gear 12 collides with the stopper 18,
Alternatively, the first and second gears 8 and 12 may be damaged. Therefore, for example, a method of installing a damper such as rubber or a spring between the stopper 18 and the second gear 12 can be considered as a countermeasure, but this requires a space and has been a problem from the viewpoint of downsizing.

The present invention has been made in order to solve this kind of problem, and is a small and simple excessive torque which can prevent the excessive torque from being transmitted between the drive shaft and the driven shaft. An object is to provide a transmission preventing gear mechanism.

[0005]

In order to achieve the above object, the present invention provides a first gear engaged with a drive shaft, a second gear engaged with the first gear, and a driven gear. Engage the shaft,
It is characterized in that it is provided with a sliding contact member which is in sliding contact with the second gear, and a pressing means which presses the second gear against the sliding contact member.

[0006]

The rotating force of the drive shaft is transmitted to the second gear via the first gear, and then to the driven shaft via the sliding contact member against which the second gear is pressed by the pressing means. It At this time, when excessive torque is generated in the drive shaft or the driven shaft, slippage occurs between the sliding contact member and the second gear, and the excessive torque is absorbed thereby.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gear mechanism for preventing excessive torque transmission according to the present invention will be described in detail below with reference to the accompanying drawings with reference to preferred embodiments.

An antilock brake modulator 20 using a gear mechanism for preventing excessive torque transmission will be described with reference to FIGS. 1 and 2. It should be noted that the same components as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

The modulator 20 basically comprises a motor 4, an excessive torque transmission preventing gear mechanism 22, an eccentric shaft 10,
It is composed of a piston 24.

As shown in FIG. 2, the excessive torque transmission preventing gear mechanism 22 includes a second gear 26 meshing with the first gear 8 of the drive shaft 6 and a friction plate spline-fitted to the rotary shaft 11. 28, a disc spring 30 for pressing the side surface of the second gear 26 against the side surface of the friction plate 28. Friction plate 28
A ring-shaped contact portion 32 that generates a predetermined frictional force is provided on the side surface portion that is in sliding contact with the second gear 26. Further, a locking member 33 for preventing the disc spring 30 from coming off is attached to the groove 34 of the friction plate 28, and a spacer 35 is provided for adjusting the pressing force of the disc spring 30.
And the disc spring 30.

On the other hand, the modulator 20 is provided, for example, in a brake oil path between a master cylinder driven by a brake lever operation of a motorcycle and a caliper cylinder mounted on a disc brake of the wheel, and the brake oil is provided. Hydraulic control.

An eccentric shaft 10 is mounted on the rotary shaft 11. The ring body 14 mounted on the eccentric shaft 10 is in contact with the piston 24. The piston 24 opens and closes the valve 36, connects and disconnects the brake hydraulic pressure, and controls the hydraulic pressure.

As shown in FIG. 2, the rotation range of the eccentric shaft 10 is restricted by the stoppers 38 and 40. Further, the coil spring 42 urges the ring body 14 of the eccentric shaft 10 so that the valve 36 is normally opened.

The antilock brake modulator 20 thus constructed operates as follows.

When the open valve 36 is closed,
First, the motor 4 is driven. The rotational force of the drive shaft 6 is the first
It is transmitted from the gear 8 to the second gear 26. Since the side surface portion of the second gear 26 is pressed against the contact portion 32 of the friction plate 28 by the disc spring 30, the rotational force of the second gear 26 is reduced by the friction plate 2.
It is transmitted via 8 to the rotary shaft 11 that is spline-fitted. The rotation of the rotary shaft 11 is performed by the eccentric shaft 10 and the ring body 14.
And the piston 24 is displaced accordingly to close the valve 36.

The antilock brake modulator 20 operates as described above. Here, when the excessive torque of the motor 4 biases the drive shaft 6 for some reason, the second gear 26 rotates in accordance with the excessive torque. However, since the second gear 26 and the friction plate 28 are in slidable contact with each other via the contact portion 32, when a torque equal to or greater than the friction force due to the pressing force of the disc spring 30 is applied,
Slip occurs between the second gear 26 and the friction plate 28, and transmission of excessive torque is blocked. Therefore, the gears 8, 2
6. It is possible to prevent the friction plate 28 from being damaged or the ring body 14 from colliding with the stoppers 38 and 40. On the contrary, excessive torque due to brake hydraulic pressure etc.
Even if it acts on the rotary shaft 11 from No. 4, the excessive torque is not transmitted because slippage similarly occurs between the second gear 26 and the friction plate 28.

Further, in this embodiment, the transmission of the excessive torque is blocked by the friction plate 28 which is spline-fitted to the rotary shaft 11 and is in sliding contact with the second gear 26. Therefore, the excessive torque transmission preventing gear mechanism is prevented. 22 can be stored compactly and space can be saved.

This excessive torque transmission preventing gear mechanism 22
Is not limited to this embodiment, and can be used for other devices.

[0019]

According to the gear mechanism for preventing excessive torque transmission according to the present invention, the following effects can be obtained.

That is, since the first gear and the second gear are connected via the sliding contact member pressed by the pressing means, the excessive torque generated on the drive shaft or the driven shaft is transmitted from one to the other. It can be prevented that the gears and the like are prevented from being damaged. Moreover, it is easy to configure the sliding contact member coaxially with the second gear, and it is possible to achieve miniaturization.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an antilock brake modulator using an excessive torque transmission preventing gear mechanism according to the present invention.

FIG. 2 is a perspective view of a main part of an antilock brake modulator using the excessive torque transmission preventing gear mechanism according to the present invention.

FIG. 3 is a perspective view of a main part of a piston crank device according to a conventional example.

[Explanation of symbols]

 4 ... Motor 6 ... Drive shaft 8, 12, 26 ... Gear 10 ... Eccentric shaft 11 ... Rotation shaft 24 ... Piston 28 ... Friction plate 30 ... Disc spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuro Ota 1-4-1 Chuo, Wako City, Saitama Prefecture Honda R & D Co., Ltd.

Claims (1)

[Claims] 1. A first gear engaged with a drive shaft, a second gear engaged with the first gear, and a sliding contact member engaged with a driven shaft and slidably contacting the second gear. And a pressing unit that presses the second gear against the sliding contact member, and a gear mechanism for preventing excessive torque transmission.