JP2023042079A - Auxiliary machine belt, pulley and power transmission device - Google Patents

Abstract

To provide an auxiliary machine belt capable of improving transmission efficiency without increasing a thickness of a belt (body part).SOLUTION: An auxiliary machine belt 1 comprises: a body part 1a that has elasticity, and is formed so as to be curved inward in an arc shape and warped in a cross section along a width direction when not in contact with a pulley 2; and a pair of outside ribs 1b that is formed so as to extend in a length direction at both ends of the body part 1a, and when not in contact with the pulley 2, formed so that a distance between the ribs widens from a base end part to a tip part in the cross section along the width direction. When in contact with the outer peripheral surface of the pulley 2, the body part 1a elastically deforms and becomes substantially straight in the cross section along the width direction, and the pair of outside ribs 1b is in contact with the side surface of the pulley 2 with the distance between the ribs narrowing from the base end part to the tip part in the cross section along the width direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to an accessory belt, a pulley around which the accessory belt is wound, and a power transmission device including the accessory belt and the pulley.

Conventionally, for example, it is wound around a drive pulley attached to the crankshaft of an engine and an accessory pulley (driven pulley) attached to an accessory such as a water pump arranged around the engine, and the engine is driven. Accessory belts are widely used to transmit power to accessory pulleys to drive accessories such as water pumps. In addition to the water pump described above, the auxiliary equipment includes, for example, an alternator, an air compressor, a power steering pump, and the like.

As such an accessory belt, for example, in Patent Document 1, a plurality of V-shaped ribs (V ribs) each formed so as to extend in the belt length direction are arranged inside the belt so as to be aligned in the belt width direction. A V-ribbed belt is disclosed that is disposed and wrapped around pulleys so that the plurality of V-ribs thereof contact to transmit power. A V-ribbed belt has V-ribs formed in the length direction for the purpose of increasing the coefficient of friction with a pulley. Since the V-ribbed belt can be made thin, it has excellent resistance to bending fatigue, and is less likely to cause peeling between the cord (core material) and the rubber or cracks in the rubber.

JP 2006-144988 A

However, for example, if the thickness of the accessory belt is reduced, the height of the V-ribs is lowered, and the contact area between the V-ribs and the pulleys is reduced, which may deteriorate the transmission efficiency. On the other hand, if it is attempted to further increase the transmission efficiency, the height of the V-rib increases, and there is a risk that the accessory belt will increase (thicken).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. To provide a pulley around which a belt is wound, and a power transmission device including the accessory belt and the pulley.

An accessory belt according to one aspect of the present invention is an endless accessory belt that is wound around pulleys to transmit power, and has elasticity. In cross-section, the main body portion is formed so as to be curved and warped inward, and the main body portion is formed so as to extend in the length direction at both ends of the main body portion, and in the state in which it is not in contact with the pulley, in the width direction. and a pair of outer ribs formed so that the distance between them widens from the proximal end to the distal end in a cross section along the .

According to the present invention, it is possible to further improve the transmission efficiency without increasing the thickness of the belt (main body).

It is a figure showing the whole power transmission device composition concerning an embodiment. 3 is a schematic cross-sectional view along the width direction of the accessory belt according to the embodiment; FIG. FIG. 4 is a schematic cross-sectional view showing an engagement state between an accessory belt and a pulley according to the embodiment; 1 is a schematic cross-sectional view of a pulley according to an embodiment; FIG.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

First, referring to FIGS. 1 to 4 together, the accessory belt 1 according to the embodiment, the crank pulley 2A around which the accessory belt 1 is wound, the accessory pulleys 2B to 2E, and the accessory belt 1 A configuration of the power transmission device 3 including the crank pulley 2A and the accessory pulleys 2B to 2E will be described. FIG. 1 is a diagram showing the overall configuration of the power transmission device 3. As shown in FIG. FIG. 2 is a schematic cross-sectional view along the width direction of the accessory belt 1. As shown in FIG. FIG. 3 is a schematic sectional view showing the state of engagement between the accessory belt 1, the crank pulley 2A, and the accessory pulleys 2B to 2E. FIG. 4 is a schematic cross-sectional view of the crank pulley 2A and auxiliary pulleys 2B to 2E.

As shown in FIG. 1, the power transmission device 3 mainly includes a crank pulley (driving pulley) 2A attached to the crankshaft of the engine, an auxiliary machine mounted to the rotary shaft of the auxiliary machine arranged around the engine. Pulleys (driven pulleys) 2B to 2E, tensioner pulley 2F attached to the auto tensioner, idler pulley 2G, crank pulley 2A, accessory pulleys 2B to 2E, tensioner pulley 2F, and idler pulley 2G. It is equipped with an accessory belt 1 that is attached.

More specifically, the accessories include, for example, a water pump, an alternator, an air compressor, and a power steering pump. Further, the accessory pulleys 2B to 2E include a water pump pulley 2B, an alternator pulley 2C, an air compressor pulley 2D, and a power steering pump pulley 2E. That is, the power transmission device 3 is a serpentine power transmission device that drives accessories such as a water pump, an alternator, an air conditioner compressor, and a power steering pump with a single accessory belt 1 (serpentine belt). Hereinafter, the crank pulley 2A and the accessory pulleys 2B to 2E may be collectively referred to as a pulley 2 (corresponding to the pulley described in the claims).

When the engine is started and the crankshaft is rotated, the driving force is transmitted to the accessory belt 1 through the crank pulley 2A, and the accessory belt 1 is driven in the direction of the arrow in FIG. The accessory belt 1 transmits the driving force of the crank pulley 2A to the water pump pulley 2B, the alternator pulley 2C, the air compressor pulley 2D, and the power steering pump pulley 2E. By rotating the water pump pulley 2B, alternator pulley 2C, air compressor pulley 2D, and power steering pump pulley 2E, the water pump, alternator, air compressor, and power steering pump are driven.

Incidentally, the tensioner pulley 2F of the auto-tensioner is displaced by spring force or the like according to the slackness of the accessory belt 1 in order to keep the belt tension constant in order to secure the frictional force. More specifically, the tensioner pulley 2F is a flat pulley that contacts the back surface of the accessory belt 1 and presses the accessory belt 1 from the back side to apply tension to the accessory belt 1 .

The accessory belt 1 is wound around a crank pulley 2A, accessory pulleys 2B to 2E (a water pump pulley 2B, an alternator pulley 2C, an air compressor pulley 2D, and a power steering pump pulley 2E), a tensioner pulley 2F, and an idler pulley 2G. It is an endless belt that transmits power through That is, the accessory belt 1 is a serpentine belt that simultaneously drives a plurality of accessories (water pump, alternator, air compressor, power steering pump, etc.).

The accessory belt 1 mainly includes a main body portion 1a formed with a plurality of inner ribs 1c and a pair of outer ribs 1b formed on both ends (both side surfaces) of the main body portion 1a. The body portion 1a has elasticity, and as shown in FIG. 2, in a state in which it is not in contact with the pulley 2 (a steady state in which no force is applied from the outside), in a cross section along the width direction, the body portion 1a is arcuate inward. It is formed so as to curve and warp.

The degree of warping of the main body portion 1a can be arbitrarily set in consideration of the balance with the tension of the accessory belt 1, for example. Further, the thickness and elasticity (flexibility) of the accessory belt 1 can be arbitrarily set so that it can bend appropriately within the range of use such as tension and rotation speed.

A pair of outer ribs 1b are formed on both ends (both side surfaces) of the body portion 1a so as to extend in the longitudinal direction. In a state in which the pair of outer ribs 1b are not in contact with the pulley 2 (a steady state in which no force is applied from the outside), the distance between the pair of outer ribs 1b increases from the proximal end to the distal end in a cross section along the width direction. It is formed in such a way (for example, that it spreads out in an inverted V shape).

When the accessory belt 1 contacts the outer peripheral surface of the pulley 2 (when a radially outward force is applied from the contact surface with the pulley 2), as shown in FIG. As a result, the cross section along the width direction has a substantially linear shape. Along with the deformation of the main body portion 1a, the pair of outer ribs 1b contact the side surface of the pulley 2, with the distance between the pair of outer ribs 1b narrowing from the base end to the tip in the cross section along the width direction. That is, the main body portion 1a and the outer ribs 1b form an acute angle (<90°), and the pair of outer ribs 1b are deformed so as to sandwich (hold) the pulley 2 from both sides.

The height (length) of the outer rib 1b, the angle formed with the body portion 1a, and the like are arbitrarily set within a range in which the accessory belt 1 can hold the pulley 2 when it comes into contact with the outer peripheral surface of the pulley 2. be able to.

The inner rib (V-rib) 1c is formed inside the accessory belt 1 (body portion 1a) so as to extend in the longitudinal direction. In addition, the inner rib 1c is formed in a substantially V-shaped or substantially trapezoidal shape in a cross section along the width direction. A plurality of (four in the example of FIGS. 2 and 3) inner ribs 1c are provided side by side in the width direction.

Here, the accessory belt 1 (body portion 1a) mainly includes a plurality of core wires 1d that generate tension and a rubber material such as EPDM (ethylene propylene diene rubber) that covers the core wires 1d. It is As the core wire 1d, for example, an organic material such as high-tension Tetron, a piano wire, or the like is used.

Here, when molding the rubber material, the main body portion 1a may be formed so as to warp, or the main body portion 1a may be warped depending on the shape and arrangement of the core wire 1d. Further, for example, by making the diameter of the core wire 1d thinner toward the ends, the outer ribs 1b can move more easily.

The pulley 2 is formed in a substantially cylindrical shape, and the accessory belt 1 is wound around the pulley 2 . As shown in FIG. 4, the pulley 2 is held (covered) by the pair of outer ribs 1b when it comes into contact with the accessory belt 1 in a cross section along the axial direction, and the pair of outer ribs 1b A protruding portion 2a protruding axially outward (outside) is provided so as to come into surface contact with. The projecting portion 2a is formed to have a wedge-shaped (triangular) or semicircular cross-section, for example. Note that FIG. 4 shows a wedge-shaped (triangular) example. In this case, it is preferable to form the projecting portion 2a so as to fit the angle (shape) formed by the main body portion 1a and the outer rib 1b of the accessory belt 1. As shown in FIG.

Further, as shown in FIGS. 3 and 4, the outer peripheral surface of the pulley 2 is formed with grooves (mountains and valleys) corresponding to (engaging with) the shape of the inner rib 1c of the accessory belt 1. As shown in FIGS. The axial shape of the outer surface of the pulley 2 (virtual line connecting peaks or troughs) may be flat (this embodiment) or curved slightly radially outward in an arc shape. good too.

With the configuration as described above, when not in contact with the pulley 2, the main body portion 1a of the accessory belt 1 is curved inward in an arc shape, and the pair of outer ribs 1b are at the proximal ends. The distance between them increases, for example, in a V-shape as it goes from the tip to the tip (see FIG. 2).

When the accessory belt 1 comes into contact with the outer peripheral surface of the pulley 2, the main body portion 1a is pushed by the outer peripheral surface of the pulley 2, elastically deformed, and becomes substantially linear in cross section along the width direction. . Along with this, the pair of outer ribs 1b move to close, that is, move so that the distance between them narrows from the proximal end to the distal end, and abut against the side surface of the pulley 2. As shown in FIG. As a result, the pulley 2 is sandwiched (embraced) from both sides by the outer ribs 1b (see FIG. 3).

As described in detail above, according to the present embodiment, when not in contact with the pulley 2, the main body portion 1a of the accessory belt 1 is curved inwardly in an arc shape to form a pair of outer sides. The distance between the ribs 1b increases, for example, in a V-shape from the proximal end to the distal end. When the accessory belt 1 comes into contact with the outer peripheral surface of the pulley 2, the main body portion 1a is pushed by the outer peripheral surface of the pulley 2 and elastically deforms into a substantially straight shape. , move so as to close, that is, move so that the distance between them narrows from the proximal end to the distal end, and abut against the side surface of the pulley 2 . Therefore, the pulley 2 is sandwiched (embraced) from both sides by the outer ribs 1b, so that the contact area between the accessory belt 1 and the pulley 2 is enlarged, the frictional force is increased, and the transmission efficiency can be further improved. . As a result, the transmission efficiency can be further improved without increasing the thickness of the accessory belt 1 (main body portion 1a).

Further, according to the present embodiment, it is possible to suppress deflection of the accessory belt 1 during rotational driving by increasing rigidity due to warping of the main body portion 1a. Furthermore, according to the present embodiment, holding the pulley 2 can improve the resistance to detachment of the accessory belt 1 .

According to the present embodiment, the plurality of inner ribs 1c extending in the length direction and having a substantially V-shaped or substantially trapezoidal shape in cross section along the width direction are provided on the main body portion 1a of the accessory belt 1. They are arranged side by side in the width direction. Therefore, the contact area (frictional force) between the accessory belt 1 and the pulley 2 can be increased.

According to this embodiment, when the accessory belt 1 is contacted, the protruding portions 2a are held by the pair of outer ribs 1b and are in surface contact with the pair of outer ribs 1b, respectively. protruded. Therefore, the contact area (frictional force) when the pulley 2 is held by the outer ribs 1b of the accessory belt 1 can be further increased.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible. For example, the shapes, dimensions, materials (raw materials), and other specific numerical values of the accessory belt 1 and the pulleys 2 shown in the above embodiment are examples for facilitating the understanding of the present invention, and when specifically refused. The invention is not limited except for

In addition, the types, numbers, arrangements, etc. of the auxiliary machines and the auxiliary machine pulleys 2B to 2E described above are examples, and the types, numbers, arrangements, etc. of the auxiliary machines and the auxiliary machine pulleys 2B to 2E are not limited to those of the above embodiment. . Further, the pulley 2 may be configured without the projecting portion 2a.

1 accessory belt 1a main body 1b outer rib 1c inner rib (V-rib)
1d core wire 2A crank pulley (drive pulley)
2B-2E Auxiliary pulley (driven pulley)
2B water pump pulley 2C alternator pulley 2D air compressor pulley 2E power steering pump pulley 2F tensioner pulley 2G idler pulley 2a projection 3 power transmission device

Claims (5)

An endless accessory belt that is wound around a pulley to transmit power,
a main body portion that has elasticity and is curved inwardly in an arcuate shape and warped in a cross section along the width direction when not in contact with the pulley;
When the main body is formed to extend in the length direction and is not in contact with the pulley, in a cross section along the width direction, the distance between them increases from the base end to the tip end. and a pair of flared outer ribs. When contacting the outer peripheral surface of the pulley,
the main body part is elastically deformed and becomes substantially straight in a cross section along the width direction;
2. The supplement according to claim 1, wherein the pair of outer ribs contact the side surface of the pulley, with the distance between the pair of outer ribs narrowing from the base end to the tip in a cross section along the width direction. machine belt. A plurality of inner ribs extending in the length direction and having a substantially V-shaped or substantially trapezoidal shape in a cross section along the width direction are provided side by side in the width direction inside the main body. 3. The accessory belt according to claim 1 or 2. A pulley that is formed in a substantially cylindrical shape and around which the accessory belt according to any one of claims 1 to 3 is wound,
In a cross-section along the axial direction, when it comes into contact with the accessory belt, it is held by the pair of outer ribs and protrudes axially outward so as to come into surface contact with each of the pair of outer ribs. A pulley characterized by comprising a section. an accessory belt according to any one of claims 1 to 3;
A power transmission device comprising: the pulley according to claim 4 .

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