Belt pulley capable of eliminating squeal of tooth-shaped V belt

Abstract

The utility model relates to the field of automobile parts, in particular to a belt pulley capable of eliminating squeal of a tooth-shaped V belt. The wedge angle at the bottom of the wheel groove is reduced from 36 degrees to 18 degrees, so that the belt teeth are suspended after being embedded and are prevented from being squeezed and rolled with the groove wall, and specific-order howling is eliminated. The scheme is easy and convenient to machine, low in cost, compatible with existing gear train layout and suitable for tooth-shaped V-belt transmission systems such as light diesel engines and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of automobile parts, and particularly relates to a belt pulley for eliminating howling of toothed V-belt. BACKGROUND

[0002] V-belt drive is a widely used mechanical transmission mode, which transmits power by friction generated by the compression of the two side surfaces of the V-belt and the side surfaces of the belt pulley groove. Common V-belts mainly include ordinary V-belt, toothed V-belt, and group V-belt (multi-wedge belt), the cross-sectional shape and groove entry state of which are shown in Figure 1 The toothed V-belt and the group V-belt are widely used in the driving of the front end wheel train accessories (generator, air conditioner compressor, steering pump, water pump, etc.) of the vehicle engine. The inner circumference of the toothed V-belt is toothed, and the added teeth are used to improve the longitudinal flexibility of the belt and prevent stress concentration, so that the belt can work on a smaller belt pulley without reducing the lateral stiffness of the belt. The toothed V-belt is the best V-belt in terms of flexibility, and has the advantages of fast heat dissipation, stable operation, and reliable durability, and is widely used on diesel commercial vehicles. The tooth height of the toothed V-belt is about one-third of the total height of the belt, and the shape of the tooth is not yet standardized. However, since the belt is made of rubber, its machining precision is far inferior to that of the belt pulley made of metal, and the new belt basically has a certain burr. Since the ordinary V-belt and the group V-belt do not have teeth, the contact between the belt and the belt pulley groove during transmission does not produce periodic extrusion, so there is no problem of generating order howling, while the toothed V-belt is prone to generate howling.

[0003] Although the system driven by the toothed V-belt can improve the howling by increasing the alignment of the belt pulley and the precision of the belt surface, the precision of the belt as a rubber part is difficult to guarantee, and the belt also shakes during driving, so it is still difficult to guarantee that the belt teeth do not extrude the belt pulley groove to produce howling. UTILITY MODEL CONTENTS

[0004] The utility model solves the above-mentioned problems from the source, provides a belt pulley with variable wedge angle, appropriately reduces the wedge angle of the belt pulley groove at the tooth contact part of the toothed V-belt, so that the belt tooth does not contact the belt pulley groove during transmission, thereby avoiding the possibility of generating howling.

[0005] A belt pulley for eliminating howling of toothed V-belt, the groove of the belt pulley is designed with segmented wedge angle, the upper wedge angle is 36°, the bottom wedge angle is 18°, and the toothed V-belt does not contact the bottom of the groove after being embedded.

[0006] Further, the groove depth is matched with the total thickness of the belt to ensure that the non-tooth part completely fits the groove wall.

[0007] Further, the ratio of the tooth height of the toothed V-belt to the total height of the belt is not more than 25%.

[0008] The utility model only makes fine adjustment to the wedge angle of the pulley groove bottom, can eliminate the common fault of toothed V belt howling from the root; the wedge angle of the pulley groove bottom is trimmed, and the difficulty of machining is not big, and there is no obvious cost increase; only the wedge angle of the pulley groove bottom is trimmed, and the original wheel system arrangement design is not changed, and no additional development expenditure is generated. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 Different V belt slotting schematic diagram in prior art;

[0010] Figure 2 Comparison diagram of howling order spectrum of toothed and non-toothed contact state;

[0011] Figure 3 Pulley bottom wedge angle reduction design drawing;

[0012] Figure 4 Pulley groove after the belt is embedded state diagram. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model. EMBODIMENT

[0014] Taking the front end wheel howling of a light diesel engine driven by toothed V belt as an example, the air conditioner compressor level belt exists 72 order howling, and the order theory calculation is as follows: the crankshaft pulley diameter is 145mm, the belt tooth spacing is 6.32mm, and the meshing order = crankshaft pulley circumference / tooth spacing = Pi*145 / 6.32 approximately equal to 72; and the belt tensioning wheel support has monitored the corresponding order vibration, and the theory confirms that the howling is caused by the extrusion of the tooth and the pulley groove.

[0015] The tooth part of the toothed V belt is cut off (approximate to ordinary V belt), and the belt meshing frequency corresponding to the howling order feature almost disappears, further confirming that the howling is caused by the extrusion of the tooth and the pulley groove contact. The comparison diagram of howling order spectrum of toothed and non-toothed contact state is as shown in Figure 2 .

[0016] As shown in Figure 3 and Figure 4The conventional design size of the belt wheel groove is taken as an example, the belt wedge angle is 36°, the upper part of the wheel groove is deepened according to the thickness of the belt, so that the non-tooth part on both sides of the toothed V-belt can fully adhere to the groove wall and participate in friction, and the wedge angle is reduced to 18° at the bottom of the wheel groove, so that after the V-belt is installed into the groove, the tooth part does not contact the groove wall, thereby avoiding howling. Generally, the tooth height accounts for one-third of the thickness of the belt, in order to make up for the reduced friction of the tooth side, the tooth height ratio can be appropriately reduced to not higher than 25%, so that the noise is optimized on the basis of retaining the flexibility of the toothed V-belt. Through real vehicle verification, the howling order characteristic disappears, and the transmission efficiency and reliability remain unchanged.

[0017] The above describes the preferred embodiments of the patent in detail, but the patent is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the patent.

Claims

1. A pulley for eliminating squeal of toothed V-belt, characterized by: The wheel groove of the belt pulley adopts a segmented wedge angle design, the upper wedge angle is 36°, the bottom wedge angle is 18°, and the toothed V-belt is embedded in the rear tooth part without contacting the bottom of the wheel groove.

2. A pulley for eliminating the squeal of toothed V-belts according to claim 1, characterized in that: The wheel groove depth is matched with the total thickness of the belt, so as to ensure that the non-tooth part completely adheres to the groove wall.

3. A pulley for eliminating the squeal of toothed V-belts according to claim 1, characterized in that: The tooth height of the toothed V-belt accounts for not more than 25% of the total height of the belt.

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