JPH0533813Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is attached to the rotating shaft of an alternator, air conditioner, etc., and transmits torque from the engine crankshaft to the rotating shaft, and also transmits the torque from the engine crankshaft to the rotating shaft. This invention relates to a pulley coupling that absorbs torsional vibrations.

[Conventional technology]

Conventionally, as shown in FIG. 7, the above-mentioned pulley coupling spring has a hub 101 fixed to the rotating shaft of an automobile alternator or air conditioner, and a pulley member 104 located on the outer circumferential side of the hub 101.
They are fitted so that they can be relatively displaced in the circumferential direction through a sliding bearing 102 near one end in the axial direction between the mutually opposing circumferential surfaces, and are elastically connected through a rubber bush 103 near the other end. By winding an endless belt between a pulley attached to the end of the crankshaft of the engine and the pulley coupling, output torque from the engine is transmitted to the rotating shaft of the alternator, etc., and The vibration in the torsional direction transmitted to the pulley member 104 along with the torque is absorbed by elastic deformation of the rubber bush 103 so that the vibration is not transmitted to the rotating shaft.

[Problem that the invention attempts to solve]

By the way, in order to exhibit sufficient vibration absorption properties in such a vibration absorption structure that utilizes the elastic deformation of a rubber material, it is necessary to make the torsional spring constant of the rubber bush 103 as low as possible. When large-amplitude torsional vibration is input from the crankshaft at low rotation speeds,
There is a risk that the amount of strain on the rubber bushing 103 will become excessive and it may be damaged. Therefore, rubber bushing 1
It was not possible to set the spring constant of 03 so low, and it was not possible to obtain sufficient vibration absorption performance.

In view of these problems, the present invention was developed with the aim of improving the durability and vibration absorbing properties of a pulley coupling.

[Means for solving problems]

The pulley cut spring of the present invention includes a hub fixed to a rotating shaft, and a part of the pulley member disposed concentrically on the outer circumference of the hub, which is fitted into the hub through a sliding bearing so as to be relatively displaceable in the circumferential direction. At the same time, the other part in the axial direction is elastically connected via a rubber bushing,
Stoppers are provided on the outer circumferential surface of the hub and on the inner circumferential surface of the pulley member, respectively, and are opposed to each other at appropriate intervals in the circumferential direction. A lubricant is sealed and a rubber block is loosely inserted between a stopper on the hub side and a stopper on the pulley member side.

[Effect]

During large amplitude input, when the circumferential relative displacement between the pulley member and the hub reaches a certain level, both stoppers come into contact with the rubber mass from both sides in the circumferential direction, compressing it. The relative displacement is suppressed by the increase in the repulsive force. The maximum allowable displacement amount at this time is set within a range that does not cause excessive strain on the rubber bushing, depending on the distance between the opposing stoppers, the size, shape, material, etc. of the rubber lump.

In addition, the lubricant not only lubricates between the rubber mass and other parts around it, but also flows within the annular space with the relative displacement of the opposing stoppers, creating flow resistance, so it is difficult to resist input vibration. Demonstrates damping force.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the figure, 1 is a hub, and 4 is a pulley member that exists concentrically on the outer circumferential side of the hub 1. Both 1 and 4 are fitted in a part of the axial direction via a sliding bearing 2 so that they can be relatively displaced in the circumferential direction. An annular rubber bushing 3 is press-fitted between opposed circumferential surfaces 1a and 4a that are spaced apart from each other in the other axial direction. Stoppers 6 are provided at three equally spaced positions on the inner peripheral surface 4a of the pulley member 4.
Further, each stopper 6 is provided on the outer circumferential surface 1a of the hub 1.
Stoppers 5 are provided to protrude from both sides in the circumferential direction so as to sandwich them at an appropriate distance.
These stoppers 5 and 6 include a hub 1, a sliding bearing 2,
The annular space surrounded by the rubber bush 3 and the pulley member 4 is roughly partitioned in the circumferential direction, that is, through the gap 9 between the stopper 5 and the pulley member 4 and the gap 10 between the stopper 6 and the hub 1. It forms chambers 7 and 8 that communicate with each other. Among these, spherical rubber masses 11 are loosely inserted into the chambers 7 between the stopper 6 and the stoppers 5 on both sides in the circumferential direction. Further, the outer surface of the rubber bush 3 is flat, but the inner surface has an undulating shape in the axial direction, that is, thick parts 3a having a large axial dimension and thin parts 3b having a small axial dimension alternate. The thick portions 3a are formed so as to be arranged at three equal intervals in the circumferential direction, and are located so as to protrude into the chamber 8 between the stoppers 5, 5. Furthermore, grease 13 as a lubricant is sealed in the annular space including the chambers 7 and 8.

In the above configuration, the rotational force accompanied by torsional vibration is transmitted from the pulley (torsional damper) attached to the engine crankshaft to the endless belt 12.
When the input vibration is transmitted through the rubber bush 3, the pulley member 4 on the outer periphery rotates while vibrating in the torsional direction (circumferential direction), but this input vibration is absorbed by the elastic deformation of the rubber bush 3 in the torsional direction. The hub 1 and the rotating shaft fixed to its inner periphery rotate smoothly.
In other words, the pulley member 4, which twists due to input vibration from the endless belt 12, and the hub 1, which attempts to rotate at a constant speed due to inertia, are repeatedly displaced relative to each other in the circumferential direction. The distance between them changes repeatedly. When the torsional vibration of the pulley member 4 reaches a certain amplitude, the stoppers 5 and 6 close the chamber 7.
The rubber bush 3 comes into contact with the rubber bush 3 from both sides in the circumferential direction, that is, the rubber bush 11 suppresses the relative displacement within a certain range.
This prevents damage due to excessive deformation. Therefore, by setting the spring constant of the rubber bush 3 low (in this embodiment, the spring constant is sufficiently low due to the formation of the thin portion 3b), the vibration absorbing property can be improved. Furthermore, due to the repeated change in the distance between the stoppers 5 and 6 due to the relative displacement,
The volumes of the chambers 7, 7 on both sides of the stopper 6 expand and contract alternately, and along with this, chambers 7, 7 are enclosed in order to lubricate between the rubber mass 11 and other members and prevent wear of the rubber mass 11. The grease 13 actively fills the spaces between the chambers 7, 8, 7, 7, the gap around the rubber lump 11, the gap between the thick part 3a of the rubber bush 3 and the pulley member 4, etc. through the gaps 9, 10. It flows, and the flow resistance at this time exerts a vibration damping effect.

In this embodiment, the rubber mass 11 is spherical, but as shown in Nos. 6A and 6B, it may be cylindrical or other shapes, and the number and shape of the stoppers 5, 6 are also arbitrary. In addition, the rubber button 3 is
A thin wall portion that seals the grease 13 and a thick wall portion 3a
The part corresponding to may be made separate.

[Effect of idea]

As explained above, in the pulley coupling according to the present invention, the amount of relative displacement between the hub and the pulley member is determined by the contact between the stopper on the hub side, the stopper on the pulley member side, and the rubber mass inserted loosely between the two stoppers. In order to prevent damage due to excessive deformation of the rubber bushing, the spring constant of the rubber bushing is sufficiently low to enhance the torsional vibration absorption effect, and there is no impact noise between the stoppers. When the lubricant sealed for lubricating the lump flows through the stopper and the gap around the rubber lump, it exhibits a vibration damping effect due to the flow resistance, and its practical effect is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing an embodiment of the present invention, Fig. 2 is a half-cut side sectional view taken along line O-A in Fig. 1, and Fig. 3 is a side sectional view taken along line O-B in Fig. 1. The half-cut side sectional view, Figure 4, is also O-C.
The half-cut side sectional view cut along the line, Figure 5, is also O-
6A and 6B are perspective views showing examples of the shape of the rubber mass, and FIG. 7 is a side sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 1...Hub, 1a...Outer peripheral surface, 2...Sliding bearing, 3...Rubber butt, 3a...Thick wall part, 3b
... Thin wall part, 4 ... Pulley member, 4a ... Inner peripheral surface, 5, 6 ... Stopper, 7, 8 ... Chamber, 9, 1
0...Gap, 11...Rubber lump, 12...Endless belt, 13...Grease as a lubricant.

Claims (1)

[Scope of utility model registration request] A hub 1 fixed to a rotating shaft and a part of a pulley member 4 disposed concentrically on the outer circumferential side of the hub 1 in the axial direction are fitted via a sliding bearing 2 so as to be relatively displaceable in the circumferential direction, The other portion in the axial direction is elastically connected via a rubber bush 3, and stoppers 5, 6 are provided on the outer peripheral surface 1a of the hub 1 and the inner peripheral surface 4a of the pulley member 4.
are respectively protruded and opposed to each other at appropriate intervals in the circumferential direction, and a lubricant 13 such as oil or fat is sealed in an annular space surrounded by the hub 1, sliding bearing 2, rubber bush 3, and pulley member 4, and the hub A pulley coupling characterized in that a rubber mass 11 is loosely inserted between a stopper 5 on the first side and a stopper 6 on the pulley member 4 side.