JPS6123695Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an overrunning clutch device.

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In the figure, reference numeral 1 denotes a cylindrical drive body connected to an armature shaft of a starting motor (not shown), and tapered cam surfaces 1a are formed at equal intervals on the circumference of the inner periphery of the drive body.
The intrusion angle of the roller, which will be described later, is approximately 5 degrees and is configured in one step. Reference numeral 2 denotes a rotating shaft, which is a driven body, which forms a wedge-shaped space between it and the inner circumference of the driving body, and has a pinion 3 at its other end that meshes with a ring gear of an engine (not shown). 4 is a cylindrical roller movably mounted within the wedge-shaped space, and 5 is a spring that presses this roller in the narrowing direction of the wedge-shaped space. 6 is a half washer, 7 is a packing, and 8 is a cover to which each of the above members is engaged and assembled as shown, and is fixed to the drive body 1 by caulking. Reference numeral 9 denotes a sleeve bearing fitted to the inner peripheral portion of the rotating shaft 2, and is slidably fitted to the armature shaft. 10 is the driving body 1
This is a washer that is loosely fitted into a concave groove on the rear end of the outer periphery, and constitutes an engaging part of a shift lever (not shown).

Next, the operation will be explained with reference to FIG. 3. When the starting motor is now driven and the driver 1 rotates in the direction of arrow A in FIG. 2, the roller 4 rotates and bites into the narrowing direction of the wedge-shaped space. acts as a wedge to fix the driving body 1 and rotating shaft 2 by frictional force, and these driving body 1, roller 4, and rotating shaft 2 rotate together. Therefore, the pinion 3 provided at the other end of the rotating shaft 2 drives the ring gear of the engine to start the engine. At this time, when abnormally high torque is generated, such as when the engine locks, the amount of biting of the roller 4 becomes large, and the third
As shown in the figure, a transmission torque is generated according to the relative rotation angle (the rotation angle between the driving body 1 and the rotating shaft 2), and when the relative rotation angle reaches θ in the figure, the drive system reaches point B in the figure. destroys.

Since the conventional overrunning clutch is constructed as described above, it has had drawbacks such as the drive system being destroyed at point B in FIG. 3 when impact torque is generated.

This idea was made in order to eliminate the drawbacks of the conventional ones as mentioned above.The angle of the wedge-shaped space of the overrunning clutch is configured in two stages, and the transmission torque is applied to the rollers so as not to cause damage to the drive system. An object of the present invention is to provide an overrunning clutch device having a protection mechanism that absorbs abnormal impact torque generated in an overrunning clutch by suppressing jamming.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 4, 11 is a driving body, and a first cam surface 11d and a second cam surface 11e are connected to the rotating shaft 2.
A wedge-shaped space is formed by the rollers 4, and a one-way transmission function is obtained by engagement of the rollers 4. Here, in the cam surface 11d portion (range D in the figure), a wedge-shaped space is formed where the bite angle of the roller 4 is equal to or less than the friction angle. In this specification, the biting angle is an inclination angle formed by the outer circumferential surface of the rotating shaft 2 and the cam surfaces 11d and 11e of the driving body 11 that form a wedge-shaped space, and the roller 4 biting in, and is also referred to as an operating angle. Furthermore, the friction angle is defined as the state in which the roller 4 acts as a wedge and fixes the driving body 11 and the rotating shaft 2 by frictional force and there is no slippage, and the state in which the roller 4 leaves the fixed state and starts to slide. Refers to the angle of inclination. This invented device has a biting angle of about 5 degrees. In addition, the cam surface 11e (range E in the figure) is configured with a biting angle that is larger than the friction angle (usually an angle of about 15° is adopted).
In this range, the amount of biting of the roller 4 can be suppressed. The operation of the devised device with the above configuration is explained in the fifth section.
To explain with reference to the drawings, when the drive body 11 rotates in the direction of arrow F shown in FIG. 4, the roller 4 bites into the wedge-shaped space and the transmitted torque increases to point G in the range of the cam surface 11d. The roller 4 has a cam surface 11e
When the roller 4 bites in, that is, when the relative rotation angle between the driving body 11 and the rotating shaft 2 exceeds R, the roller 4 slips, the transmitted torque is suppressed, and the torque increases gradually. Therefore, when a high-intensity impact torque occurs, the roller 4 reaches the cam surface 11e and slides, and the impact torque is absorbed. In the above description, the drive body 11 is provided with cam surfaces 11d and 11e, but a similar cam surface may be formed on the rotating shaft 2 side.

Further, in the above embodiment, an overrunning clutch device used in a starter motor has been described, but the same effect can be obtained when applied to an overrunning clutch device used in general equipment.

As described above, according to this invention, the bite angle of the wedge-shaped space into which the roller bites is configured in two stages,
When the relative rotation angle between the driving body and the driven body exceeds a certain value, the mutual transmission torque is suppressed, so the overrunning clutch protection device can be made at low cost and highly reliable. effective.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional device, and Figure 2 is a cross-sectional view of a conventional device.
3 is a diagram illustrating the operating characteristics of a conventional overrunning clutch, FIG. 4 is an enlarged sectional view showing an embodiment of this invention, and FIG. 5 is a cross-sectional view of the overrunning clutch shown in FIG. 4. FIG. 4 is an explanatory diagram of operating characteristics for explaining the operation. In the figure, 1 and 11 are driving bodies, 1a, 11d, and 11e are cam surfaces, 2 is a rotating shaft, 3 is a pinion, and 4
is a roller. In addition, in the figure, the same reference numerals are the same,
or a corresponding portion.

Claims (1)

[Scope of utility model registration request] It consists of a cylindrical driving body, a driven body forming a wedge-shaped space between the inner periphery of the driving body, and a roller movably mounted in the wedge-shaped space. In a device that transmits power from the driving body to the driven body only in the rotational direction, a cam surface into which the roller bites in the wedge-shaped space,
The first one in which the biting angle of the roller is less than or equal to the friction angle.
An overrunning clutch device comprising: a cam surface and a second cam surface where the bite angle of the roller exceeds the friction angle.