CN115388146A

CN115388146A - Decoupling belt pulley with overload protection

Info

Publication number: CN115388146A
Application number: CN202110555949.8A
Authority: CN
Inventors: 刘增岗
Original assignee: Weifang Pilot Transmission Technology Co ltd
Current assignee: Weifang Pilot Transmission Technology Co ltd
Priority date: 2021-05-22
Filing date: 2021-05-22
Publication date: 2022-11-25

Abstract

The invention discloses a crankshaft decoupling belt pulley with an overload protection function, which is used for transmitting torque between a belt pulley and a transmission shaft and comprises: the left end of the mandrel is provided with a boss and a groove which are radially outward; the left end of the belt wheel is provided with a groove and a boss which are radially inward, and a rotating space with a certain angle is formed by corresponding the boss of the mandrel and the groove of the belt wheel; two ball bearings, the bearing supports the mandrel and the belt wheel left and right; the first scroll spring is positioned in the accommodating space formed by the mandrel and the belt wheel, the first end of the first scroll spring is combined with the mandrel, and the second end of the first scroll spring is combined with the belt wheel; the inner boss of the inner side pad is combined with the groove of the mandrel; the outer lug boss of the outer pad is combined with the groove of the belt wheel; an elastic pad located between the spiral springs; a retainer ring between the right bearing and the end cap; and the end cover is combined with the right bearing and the inner wall of the belt wheel.

Description

Decoupling belt pulley with overload protection

Technical Field

The invention relates to a part of a vehicle, in particular to a crankshaft decoupling belt pulley and an assembly of a front-end gear train of an internal combustion engine.

Background

In the process of operation of the engine crankshaft, due to the specific working condition that the cylinders work alternately at certain intervals, the phenomenon of torque and rotating speed fluctuation exists during the operation of the engine crankshaft, which can cause the phenomenon of unstable rotating speed with a front end wheel system of the engine, so that the phenomena of belt slipping, belt shaking, overlarge oscillation amplitude of a tensioner and unstable rotating speed of a belt driving accessory are caused, and the phenomena of NVH (vibration, noise and instability) and early failure of various parts of a wheel train and the like are caused.

A crankshaft decoupling pulley used in the prior art is shown in fig. 1, and mainly includes a mandrel 1, a pulley 2, a rubber ring 3, and a signal panel 4. During the rotation of the crankshaft, the rubber ring transmits torque to the belt pulley and absorbs part of the energy of the rotation speed fluctuation. However, rubber itself is unstable and is susceptible to aging at different temperatures and excitation frequencies, thereby reducing the life of the crank pulley. The rubber belt pulley can slip when overloaded, and the rubber belt pulley fails in long-term use.

In 201911358550.X, the volute spiral spring type crankshaft decoupling belt pulley can achieve the effects of buffering vibration isolation and decoupling damping, the NVH of a front-end gear train is reduced, and the problem of reliability of all parts of the front-end gear train is solved. However, in the event of extreme overload, the crankshaft decoupling pulley will fail in the event of a failure of the wrap spring.

In view of the above, there is a need in the art for a new crankshaft decoupling pulley with overload protection that overcomes one or more of the shortcomings in the prior art. Even under the condition that the spiral spring fails, the crankshaft pulley can still transmit torque, and the front-end wheel system of the engine can work.

Disclosure of Invention

The invention aims to provide a crankshaft decoupling belt pulley with an overload protection function, which overcomes the defects of the existing crankshaft decoupling belt pulley and can ensure the reliability of a front-end wheel train under any condition. In order to achieve the above object, the present invention discloses a crankshaft decoupling pulley with an overload protection function for transmitting torque between a pulley and a transmission shaft, comprising: the left end of the mandrel is provided with a boss and a groove which are radially outward; the left end of the belt wheel is provided with a groove and a boss which are radially inward, and a rotating space with a certain angle is formed by corresponding the boss of the mandrel and the groove of the belt wheel; two ball bearings, the bearing supports the spindle and the belt pulley left and right; the first scroll spring is positioned in the accommodating space formed by the mandrel and the belt wheel, the first end of the first scroll spring is combined with the mandrel, and the second end of the first scroll spring is combined with the belt wheel; the inner boss of the inner side pad is combined with the groove of the mandrel; the outer boss of the outer gasket is combined with the groove of the belt wheel; an elastic pad located between the spiral springs; a retainer ring between the right bearing and the end cap; and the end cover is combined with the right bearing and the inner wall of the belt wheel.

Still further, the left end of the mandrel is provided with at least one boss and a groove which are radially outward.

Still further, the left end of the belt wheel is provided with at least one groove and a boss which are radially inward. The groove of the belt wheel and the boss of the mandrel are correspondingly combined together to form a rotating space with a certain angle.

Still further, a first bearing is included that is coupled between the spindle and the pulley, and a second bearing is coupled between the spindle and the end cap.

Still further, still include first cushion, first cushion is located between the spring coil of first spiral spring, and/or is located between first spiral spring and the band pulley, and/or is located between first spiral spring and the dabber.

Still further, still include second spiral spring, second spiral spring is located the accommodation space that dabber and band pulley formed, the first end of second spiral spring with the dabber combines together, the second end of second spiral spring is located the outside of first end and combines together with the band pulley, first spiral spring is the same with second spiral spring's coiling direction or opposite, first spiral spring and second spiral spring's both sides and centre all have the gasket.

Furthermore, the grooves of the inner hitching leg mandrels of the first and second scroll springs are connected, and the grooves of the outer hitching leg pulleys of the first and second scroll springs are connected. And the inner side pad and the outer side pad realize radial limit to the volute spiral spring.

Further, at least one section of the resilient pad is disposed between the coils of the first and second scroll springs and extends inwardly toward the outer surface of the spindle and outwardly toward the inner surface of the pulley.

Still further, still include the packing ring, the packing ring is located between right bearing and the end cover for protect bearing seal circle.

Furthermore, the end cover is further included, the inner wall of the end cover is combined with the outer wall of the right bearing and is positioned between the mandrel and the belt wheel, and a relatively closed accommodating space is formed by the end cover, the mandrel and the belt wheel.

Compared with the prior art, the crankshaft decoupling belt pulley with the overload protection function can avoid overlarge swing of a vehicle during starting and stopping, avoid increasing NVH (noise, vibration and harshness), and enable the front-end wheel train to normally transmit torque even under the condition that a volute spiral spring fails under an overload working state, so that the reliability of the front-end wheel train and an engine is ensured.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a schematic diagram of a prior art construction of one of the crank pulleys;

FIG. 2 is a cross-sectional view of a pulley for a crankshaft in a preferred embodiment of the present invention;

FIG. 3 is an exploded view of a crankshaft pulley in accordance with a preferred embodiment of the present invention

FIG. 4 is a cross-sectional view of a pulley provided by the present invention;

FIG. 5 is a cross-sectional view of a mandrel provided by the present invention;

FIG. 6 is a diagram of the overload protection provided by the present invention;

FIG. 7 is a schematic diagram of the stiffness curve and overload protection of a crankshaft pulley provided in the present invention.

In the figure:

1-belt wheel; 2-mandrel; 3-end cover; 4-right bearing; 5-a gasket;

6-elastic cushion; 7-intermediate pad; 8-inside pad; 9-outer pad;

10-left bearing; 11-a retainer ring; 12-a volute spiral spring;

101-pulley protection boss; 102-pulley protection groove;

201-mandrel protection boss; 202-mandrel protection groove.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms than those specifically described herein, and it will be apparent to those skilled in the art that many more modifications are possible without departing from the spirit and scope of the invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "left," "right," "up," "down," and the like are for purposes of illustration only and do not denote a single embodiment. The terms "outer" and "outboard" as used herein generally refer to a location away from the axis of the propeller shaft, and "inner" and "inboard" generally refer to a location closer to the axis of the propeller shaft.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terms "first" and "second" used herein do not denote any particular order or quantity, but rather are used to distinguish one element from another.

The invention aims to provide a crankshaft decoupling belt pulley with an overload protection function, and solves the problems that the existing crankshaft decoupling belt pulley is low in reliability and/or fails under extreme load.

Fig. 2 is a sectional view of a crankshaft decoupling pulley according to a first preferred embodiment of the invention. As shown in fig. 2, the crankshaft decouples the pulley, for transmitting torque between the pulley 1 and the spindle 2, comprising: a mandrel 2, the mandrel 2 being rigidly fixed to the crankshaft; a pulley 1, the pulley 1 driving accessories (generator, compressor, water pump, fan, etc.) of the front end gear train of the engine; first and second scroll springs 12, the first and second scroll springs 12 being located in a receiving space formed by the spindle 2 and the pulley 1, first ends of the first and second scroll springs 12 being combined with the spindle 2, and second ends of the first and second scroll springs 12 being located outside the first ends and combined with the pulley 1; an inner pad 8, wherein the inner boss of the inner pad 8 is combined with the groove of the mandrel; the outer side pad 9, the outer boss of the outer side pad 9 combines with the groove of the belt wheel, the inner side pad 8 and the outer side pad 9 realize the radial limit to the volute spiral spring 12; an elastic pad 6, the elastic pad 6 is positioned between the scroll springs 12, and absorbs the deformation energy of the transmission torque fluctuation; a retainer ring 11, the retainer ring 11 is arranged between the right bearing and the end cover; and the end cover 3 is combined with the right bearing 4 and the inner wall of the belt wheel 1. The spiral spring, commonly called spring, is made of steel strip and is fixed at one end and the material is elastically deformed by bending and extruding the elastic cushion after the other end acts on torque. When the force disappears, the elastic potential energy accumulated by the spring and the deformation energy of the elastic cushion are released to return to the original state. During this compression and release, the pads 5 and the intermediate pads 7 rub against the elastic pads 6, creating damping. When the mandrel 2 fluctuates along with the rotation of the crankshaft, the volute spiral spring 12 and the elastic pad 6 store energy through deformation, and then release and transmit the absorbed energy to the belt wheel 1, so that the aim of vibration reduction is achieved. The torque transmission path is shown in fig. 3.

As shown in fig. 4, at least one boss 101 and a groove 102 are circumferentially arranged on the left-side inner wall of the pulley 1.

As shown in fig. 5, at least one boss 201 and groove 202 are circumferentially arranged on the outer wall of the left side of the mandrel 2.

As shown in fig. 6, the lands 101 of the pulley 1 and the lands of the spindle 2 are circumferentially staggered to form an overload protection angle.

In one embodiment, as shown in FIG. 7, the crankshaft decouples the pulley's torque-angle curve, and the overload protection torque and overload protection angle are at the location of the torque-angle curve.

The magnitude of the overload protection torque depends on the magnitude of the maximum load torque of the front-end train accessories, and generally speaking, the overload protection torque is slightly larger than the maximum load torque of the front-end train accessories. Once the overload protection torque is determined, the overload protection angle can be determined on the torque-angle curve of the crankshaft decoupling pulley.

Compared with the prior art, the crankshaft decoupling belt pulley provided by the invention can avoid overlarge swing when a vehicle starts or stops or impacts, reduce NVH (noise vibration harshness), and can transmit torque even when a vortex spring fails in an overload working state, thereby ensuring the reliability of a front-end gear train of an engine. Meanwhile, the technical scheme is simple in process, the belt tension can be reduced when the belt is used for a front-end wheel train of a vehicle, the friction power consumption of the belt is reduced, the fluctuation range of the rotating speed of each part of the front-section wheel train is reduced, the damage of the rotational kinetic energy is reduced, and the oil can be saved. The vibration damper provided by the invention can reduce the vibration frequency and amplitude of a crankshaft/transmission shaft. Meanwhile, the crankshaft decoupling belt pulley and the belt pulley assembly of the shock absorber are applied, so that the sum amplitude from a crankshaft/a transmission shaft can be reduced, the influence on a front-section wheel train can be reduced, and the NVH is reduced to the maximum extent. The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.

Claims

1. A crankshaft decoupling pulley with overload protection, comprising: the left end of the mandrel is provided with a boss and a groove which are radially outward; the left end of the belt wheel is provided with a groove and a boss which are radially inward, and the boss of the mandrel and the groove of the belt wheel are correspondingly arranged together to form a rotating space with a certain angle; two ball bearings, the bearing supports the spindle and the belt pulley left and right; the first scroll spring is positioned in the accommodating space formed by the mandrel and the belt wheel, the first end of the first scroll spring is combined with the mandrel, and the second end of the first scroll spring is combined with the belt wheel; the inner boss of the inner side pad is combined with the groove of the mandrel; the outer boss of the outer gasket is combined with the groove of the belt wheel; an elastic pad located between the spiral springs; a retainer ring between the right bearing and the end cap; and the end cover is combined with the right bearing and the inner wall of the belt wheel.

2. The crankshaft decoupling pulley of claim 1 further comprising at least one radially outward projection and recess on the left end of the spindle.

3. A crankshaft decoupling pulley as claimed in claim 1 further comprising a pulley left end having at least one radially inward groove and land. The groove and the groove of the belt wheel are correspondingly connected with the boss of the mandrel to form a rotating space with a certain angle.

4. A crankshaft decoupling pulley as claimed in claim 1 further comprising a first bearing coupled between said arbor and said pulley and a second bearing coupled between said arbor and said end cap.

5. The crankshaft decoupling pulley of claim 5 further comprising a first elastomeric pad between coils of said first scroll spring and/or between said first scroll spring and said pulley and/or between said first scroll spring and said spindle.

6. The crankshaft decoupling pulley of claim 1 further comprising a second spiral spring disposed within said receiving space defined by said spindle and said pulley, said second spiral spring having a first end coupled to said spindle and a second end disposed outside said first end and coupled to said pulley, said first and second spiral springs being wound in the same or opposite directions, said first and second spiral springs having spacers disposed on opposite sides and between said first and second spiral springs.

7. The crankshaft decoupling pulley of claim 1 wherein said recesses of said inner hanger spools of said first and second scroll springs are connected and said recesses of said outer hanger pulleys of said first and second scroll springs are connected. And the inner pad and the outer pad realize radial limit to the volute spiral spring.

8. The crankshaft decoupling pulley of claim 1 wherein at least one section of elastomeric pad is disposed between the coils of said first and second spiral springs, said elastomeric pad extending inwardly to the outer surface of said spindle and outwardly to the inner surface of said pulley.

9. The crankshaft decoupling pulley of claim 1 further comprising a washer positioned between the right bearing and the end cap for protecting the bearing seal.

10. The crankshaft decoupling pulley of claim 1 further comprising an end cap, said end cap inner wall bonded to said right bearing outer wall and located between said spindle and said pulley and forming a relatively enclosed receiving space with said spindle and pulley.