JPH034768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to a shock absorbing device for a power transmission mechanism of an engine, and particularly to a device improved to absorb backlash generated in a cam damper.

(Prior Art) The present applicant has developed a shock absorber for a power transmission mechanism as shown in Fig. 4 and has already filed an application (Japanese Patent Application No. 14121/1982, filed on January 27, 1982). ).

In this prior art, a rotary drive shaft 11 and a rotary driven shaft (not shown) are interlocked and connected by a gear type power transmission mechanism 13, and a cam damper 14 and a friction damper are provided on the side of the rotary drive shaft 11 than the gear type power transmission mechanism 13. 12
are spline-fitted to the spline teeth 29 of the drive shaft 11, and the cam damper 14 and the friction damper 1
2 absorbs torque fluctuations and shocks and transmits power to the driving gear 18 and driven gear 21 of the gear type power transmission mechanism 13.

However, in such prior art, when the spline teeth 29 wear out due to long-term use, play occurs between the rotary drive shaft 11, the cam damper 14, and the friction damper 12, and the absorption of torque fluctuations and shocks of the rotary drive shaft 11 becomes difficult. There is an inconvenience that this becomes insufficient and noise is generated due to rattling.

(Objective of the Invention) The present invention provides a shock absorber for a power transmission mechanism that can effectively absorb torque fluctuations and shocks of a drive shaft even if it wears out due to long-term use, and can transmit power quietly over a long period of time. is intended to provide.

(Structure of the Invention) The present invention rotatably supports a cylindrical body 24 having an inner circumferential surface with a larger diameter than the rotary drive shaft 11, and connects the cylindrical body 24 and the rotary driven shaft 20 with a gear type or cable. It is interlocked and connected by a strip-wrap type power transmission mechanism 13, and is fitted into the cam face 27 on the inner end surface of the cylinder body 24 and the spline teeth 29 on the rotary drive shaft 11 inside the cylinder body 24, and is connected to the cam face 27. The cam damper 14 is provided with a support ring 28 having an opposing follower 26 and a compression coil spring 30 that biases the support ring 28 toward the cam face 27.
A fixing ring 31 has a tapered surface 34 that is fixed on the rotary drive shaft 11 inside and has a tapered surface 34 whose diameter decreases toward the cam damper 14 side, and a tapered surface 44 that is in contact with the tapered surface 34, and is divided into a plurality of parts on the circumference. A shoe 32 made of friction material and a fixing ring 31
A friction damper 15 consisting of a shoe 32 supported slidably only in the axial direction, an outer circumferential surface of which is in contact with an inner circumferential surface of the cylindrical body 24, and which is biased toward the fixed ring 31 by the compression coil spring 30. This is a shock absorber for the power transmission mechanism.

(Example) In FIG. 1 showing a two-cylinder, two-crankshaft engine to which the present invention is applied, each cylinder 16 is provided with a rotary drive shaft 11 (crankshaft), and both drive shafts 11
are arranged parallel to each other. Both drive shafts 11 are each equipped with a drive gear 18 (crank gear), and both drive gears 18 are connected to the driven gear 21 of the driven shaft 20.
(clutch gear). The driven gear 21 is connected to the driven shaft 20 via a clutch,
The drive gear 18 is connected to the rotary drive shaft 11 via a shock absorber according to the present invention.

In FIG. 2, which is an enlarged cross-sectional view of FIG. ing. The drive gear 18 is connected to the cam damper 14 which is spline-fitted to the spline teeth 29.
The rotary drive shaft 11 is interlocked with the rotary drive shaft 11 via a friction damper 15 fixed to the rotary drive shaft 11 .

The cam damper 14 is composed of a follower 26 (cam) and a cam face 27, and the semicircular follower 26 (a member on the rotational drive shaft side) is integrally formed with the support ring 28 and is attached to the outer peripheral spline of the rotational drive shaft 11. It is spline fitted to the tooth 29 so as to be slidable in the axial direction. The cam face 27 is formed in the cylindrical body 24 in a concave shape. The follower 26 is brought into contact with the cam face 27 by the elastic force of the compression coil spring 30.

The friction damper 15 includes a fixed ring 31 and a shoe 3.
The rotary drive shaft 11 is fixed to the tip of the rotary drive shaft 11 adjacent to the cam damper 14 . The fixing ring 31 (member on the rotary drive shaft 11 side) is formed into an annular shape, the outer circumferential surface of which is in close contact with the inner circumferential surface of the cylindrical body 24, and the diameter of the right side in the figure widening toward the tip of the rotary drive shaft 11. It has a rough tapered surface 34 (see FIG. 3). A half-moon key 36 is fitted between the fixed ring 31 and the rotary drive shaft 11, and is tightened with a nut 40 on the left side surface of the fixed ring 31 via a washer 38. 42 is a C-shaped retaining ring.

A shoe 32 made of a friction material such as asbestos is arranged opposite to the tapered surface 34 . The shoe 32 is formed into an annular shape divided into three parts spaced apart by, for example, 120 degrees in the circumferential direction. A tapered surface 44 along the tapered surface 34 is formed on the left side surface of the shoe 32 in the figure, the outer circumferential surface of the shoe 32 is in close contact with the inner circumferential surface of the cylinder body 24, and the right end surface of the shoe 32 is provided with a washer. 46 is interposed, and the compression coil spring 30 is in pressure contact with the spring 30. One end of a pin 48 protrudes from the tapered surface 34, and the shoe 32 is slidably fitted onto the pin 48 as shown in FIG. Note that 50 is an oil passage.

Next, the effect will be explained. The rotation of the rotary drive shaft 11 is transmitted to the cylindrical body 24 via the cam damper 14 and the friction damper 15, and from the drive gear 18 via the driven gear 21 to the driven shaft 20 (FIG. 1).

Torque fluctuations and impacts of the rotary drive shaft 11 are
This is absorbed by the cam damper action in which the follower 26 slides against the cam face 27 against the elastic force of the compression coil spring 30.

The shoe 32 of the friction damper 15 is pressed to the left in the figure by the elastic force of the compression coil spring 30, and the tapered surface 44 slides along the tapered surface 34, and the outer circumferential surface of the shoe 32 touches the cylindrical body 24. Pressed against the inner peripheral surface.

In the unlikely event that the spline teeth 29 are worn out due to long-term use and play occurs between the follower 26 and the rotary drive shaft 11, part of the rotational force of the rotary drive shaft 11 will be absorbed by the fixing ring 31. Since the play is transmitted to the cylindrical body 24 via the friction damper 15 fixed to the cylindrical body 24, the play is absorbed by the sliding friction force between the shoe 32 of the friction damper 15 and the cylindrical body 24. Drive shaft 20 (first
Figure) is connected without girders, and the rotation drive shaft 1
Rotating drive shaft 11 quietly even if torque fluctuation occurs in 1
Power is transmitted from the drive shaft 20 to the driven shaft 20 (FIG. 1).

(Effects of the Invention) As explained above, in the present invention, the cylindrical body 2
4 is rotatably supported on the rotary drive shaft 11, but the shoe 32 made of friction material is rotated by the elasticity of the compression coil spring 30 against the fixed ring 31 fixed on the shaft 11 in the cylinder body 24. Since the shoe 32 is constantly pressed to the left in Figure 2 and is divided into multiple pieces on the circumference, the shoe 32 slides on the tapered surface 44 of the fixing ring 31 and moves to the left in the figure. At the same time as the shoe 32 moves, the outer peripheral surface of the shoe 32 comes into pressure contact with the inner peripheral surface of the cylindrical body 24, thereby permanently integrating the cylindrical body 24 with the rotary drive shaft 11 via the shoe 32 and the fixing ring 31. On the other hand, since the support ring 28 of the cam damper 14 is normally in pressure contact with the cam face 27 on the inner end surface of the cylinder body 24 at the follower 26 portion due to the elasticity of the compression coil spring 30, the support ring 28 itself is also normally (at a predetermined torque). (until the rotational drive shaft 11 is reached). Therefore, when large torque fluctuations are transmitted even though the transmitted torque is low, such as when the engine is idling, the outer spline teeth 29 may wear out due to long-term use, causing damage to the rotary drive shaft 11 and the cam damper. Even if there is play between the outer spline teeth 29 and 14,
There is no rattling noise due to relative rotation in the parts.
That is, since a part of the rotational force of the rotary drive shaft 11 is transmitted to the cylinder body 24 through the friction damper 15 attached to the rotary drive shaft 11, the force between the shoe 32 and the cylinder body 24 is
The above-mentioned backlash can be absorbed by the sliding friction force between the spline teeth 29 and
This has the advantage that it is possible to prevent the hammering sound of the tooth surface, prevent an increase in rattling in that part, and quietly transmit the power of the rotary drive shaft 11 to the driven shaft 20 over a long period of time. Further, in the present invention, since the friction damper 15 has a structure in which the shoe 32 is joined to the fixed ring 31 at the tapered surfaces 34, 44 and expands,
This has the advantage of being able to shorten the axial dimension and also reduces the number of parts. Further, the cylindrical body 24 of the present invention is connected to the rotational drive shaft 1.
1, the cam damper 14 and the friction damper 15 can be assembled as a unit within the cylinder 24, which has the advantage of facilitating handling, especially assembly.

(Another embodiment) (1) The present invention is not limited to the gear type transmission mechanism as described above, but also applies to a cable-wrapping type power transmission mechanism composed of a chain, a sprocket, a belt, a pulley, etc. can be applied.

(2) The present invention is also suitable as a shock absorber between a rear wheel (driven shaft) and a drive shaft (drive shaft) of an automobile.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical cross-sectional view of a two-cylinder, two-crankshaft engine to which the present invention is applied, and Fig. 2 is a -
FIG. 3 is an enlarged cross-sectional view, FIG. 3 is a view taken in the direction of the arrow in FIG. 2, and FIG. 4 is an enlarged vertical cross-sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 11... Rotation drive shaft, 13... Gear type power transmission mechanism, 14... Cam damper, 15... Friction damper, 20... Driven shaft, 26... Follower, 27... Cam face, 2
9...Spline teeth, 31...Fixing ring, 32...Show, 34, 44...Tapered surface, 36...Half-moon key.

Claims (1)

[Claims] 1 A cylindrical body 24 having an inner circumferential surface with a larger diameter than that of the rotary drive shaft 11 is rotatably supported, and power transmission is performed between the cylindrical body 24 and the rotary driven shaft 20 using a gear type or a cable wrapping type. The mechanism 13 interlocks and connects the cylindrical body 2.
4, a support ring 28 having a follower 26 that fits into the spline teeth 29 on the rotary drive shaft 11 in the cylinder body 24 and opposes the cam face 27; A cam damper 14 consisting of a compression coil spring 30 that urges the cam damper 14 is fixed on the rotary drive shaft 11 in the cylindrical body 24 adjacent to the cam damper 14, and a taper whose diameter decreases toward the cam damper 14. A fixing ring 31 having a surface 34, and a shoe 32 made of a friction material having a tapered surface 44 in contact with the tapered surface 34 and divided into a plurality of parts on the circumference, and sliding only in the axial direction with respect to the fixing ring 31. It is freely supported, and the outer peripheral surface is a cylinder 24.
A shock absorber for a power transmission mechanism, comprising a friction damper 15 consisting of a shoe 32 that is in contact with the inner peripheral surface of the shoe 32 and is urged toward a fixing ring 31 by the compression coil spring 30.