Crankshaft vibration isolator adaptive to spring dislocation

Abstract

The crankshaft vibration isolator comprises a belt wheel, a mounting shell, a pivot, two arc-shaped springs and a driving arm, the mounting shell is arranged on the outer side of the pivot, an annular groove for mounting the arc-shaped springs is formed between the mounting shell and the pivot, the two arc-shaped springs are symmetrically arranged in the annular groove, the driving arm comprises a disc body, the disc body is fixedly connected to the end face of the belt wheel, and the disc body is fixedly connected to the end face of the belt wheel. Two arm bodies are symmetrically arranged on the outer edge of the disc body in the radial direction, the arm bodies extend into the annular groove, the two sides of each arm body are each provided with a ball joint assembly, the ends of the arc-shaped springs abut against the ball joint assemblies, and the end faces of the arc-shaped springs can be connected with the end faces of the driving arms in a self-adaptive mode through the ball joint assemblies. According to the crankshaft vibration isolator, the ball joint assembly is additionally arranged on the side face of the driving arm to adapt to the dislocation condition of the arc-shaped spring, the tail end of the arc-shaped spring is attached to the side face of the driving arm all the time under the elastic force effect of the arc-shaped spring, the requirement for the installation precision of the arc-shaped spring is lowered, the driving arm is prevented from being damaged due to stress concentration, and the service life of the crankshaft vibration isolator is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of vibration isolator, especially to a crankshaft vibration isolator suitable for spring misplacement. BACKGROUND

[0002] In the front end accessory drive system (FEADS, the abbreviation of Front End Accessory Drive System in English), the crankshaft vibration isolator is installed between the engine crankshaft and the pulley, which is used to inhibit the transmission of crankshaft torsional vibration, avoid the direct transmission of large crankshaft torsional vibration to other accessory pulleys, and affect the stability of FEADS.

[0003] The existing crankshaft vibration isolator structure is disclosed in an improved isolation device in WO2016 / 191888A1, as shown in Figure 1 Two arc springs 30a, 30b are oppositely arranged and installed between the pulley 28a and the pivot 26a, and the pivot 26a and the driving arm 26b are connected with the crankshaft. When the speed fluctuation (the main form of torsional vibration) of the engine crankshaft is transmitted to the arc springs 30a, 30b through the pivot 26a and the driving arm 26b connected therewith, the arc springs are compressed and deformed, and part of the kinetic energy of the crankshaft is converted into the elastic potential energy of the arc springs, avoiding the pulley from producing large speed fluctuation with the crankshaft (especially during the engine starting stage), and thus improving the stability of FEADS operation and the NVH performance of FEADS.

[0004] The above-mentioned crankshaft vibration isolator has the following problems:

[0005] 1. The initial installation precision of the arc spring is extremely high. The end of the arc spring is machined into a flat surface. In order to ensure that the end of the spring is in complete contact with the side surface of the driving arm, the installation angle of the spring needs to be adjusted constantly, otherwise, if the spring is not installed properly, such as the end surface of the spring is not in complete contact with the side surface of the driving arm, stress concentration will exist in the area where the side surface of the driving arm contacts with the spring. When the spring transmits a large working torque, the driving arm in this area is easy to be damaged due to excessive stress.

[0006] 2. During the transmission of torque, the arc spring is repeatedly stretched and contracted. Under long-term work, the arc spring is easy to produce permanent deformation due to fatigue, which is manifested as the section of the spring close to the end changes from the natural arc shape to a straight line. Similar to the situation of improper installation of the spring, at this time, the end of the spring cannot completely adhere to the side surface of the driving arm, and the two are changed into line contact. The driving arm is easy to be damaged due to stress concentration, which reduces the service life of the vibration isolator. CONTENT OF THE UTILITY MODEL

[0007] The utility model wants to solve the technical problem: in order to overcome the prior art's insufficient, the utility model provides a crankshaft vibration isolator adapting to spring misplacement.

[0008] The term explanation: the spring "misplacement" in the utility model refers to that the spring end face and the driving arm side face cannot completely adhere, and the driving arm and the spring are in linear contact.

[0009] The utility model adopts the technical scheme that solves its technical problem: a crankshaft vibration isolator adapting to spring misplacement, including pulley and the installation shell, pivot, arc spring and driving arm of setting in pulley, the installation shell sets up at the outside of pivot, and with the pivot between the annular groove for installing arc spring is formed, the arc spring is two, and symmetrically sets up at the both sides of pivot, and is located in the annular groove of installation shell, the driving arm includes disc body, the disc body is fixedly connected on pulley end face, and the driving arm and arc spring are located at the same side of installation shell, the outer edge of disc body is equipped with two arm bodies along the radial symmetry, the arm body is trapezoidal structure, the arm body extends to the annular groove, and one ball joint assembly is equipped on the both sides of each arm body, and the end of arc spring abuts on ball joint assembly, and can make arc spring end face self-adapting with driving arm end face joint through ball joint assembly.

[0010] Further, the ball joint assembly includes a support block and a ball head, the ball head includes an integral ball body portion and a cylindrical portion, the diameter of the ball body portion is greater than the diameter of the cylindrical portion, the side surface of the arm body is provided with a cylindrical mounting hole, the cylindrical portion is fixedly connected in the cylindrical mounting hole, the ball body portion is located outside the arm body, the end surface of the support block is provided with a spherical mounting blind hole, and the ball body portion is embedded in the spherical mounting blind hole, so that the ball body portion can freely rotate around the center of the spherical mounting blind hole, thereby forming a joint movement between the ball head and the support block.

[0011] Further, when the ball body portion freely rotates around the center of the spherical mounting blind hole, the included angle α between the ball head axis and the spherical mounting blind hole axis is maximum 15°.

[0012] Further, in order to control the rotation angle between the support block and the ball head, a first round corner is provided on the opening of the spherical mounting blind hole. By providing first round corners with different angles and widths, different maximum rotation angles can be achieved.

[0013] Further, the support block is a cuboid structure, and second round corners are provided at the corners of the periphery, so that the transition between different surfaces can be realized, thereby effectively avoiding jamming during movement.

[0014] Further, the end surface of the arc spring is a plane, and the side of the support block away from the ball head is also a plane, and the end surface of the arc spring and the end surface of the support block are adhered and abutted.

[0015] Further, at least one groove is arranged on the left and right sides of the disc body, and a center hole is arranged at the center of the disc body, so that the pivot can pass through.

[0016] Further, in order to realize the connection between the driving arm and the pivot, at least two positioning pins are arranged on the end face of the pivot, and pin holes corresponding to the positioning pins are arranged on the disc body, and when assembled, the positioning pins pass through the pin holes and the end portions are fixed on the pivot.

[0017] Further, the mounting shell is provided with a shell upper stop at the position opposite to the arm body of the driving arm.

[0018] The advantageous effect of the utility model is: the utility model provides a crankshaft vibration isolator suitable for spring misplacement, a spherical joint assembly is additionally arranged on the side surface of the driving arm to adapt to the misplacement of the arc spring, no matter how the initial installation angle of the arc spring is, and no matter whether the arc spring is permanently deformed, the end of the arc spring is always attached to the side surface of the driving arm under the action of the elastic force of the arc spring, the installation precision requirement of the arc spring is reduced, the driving arm is prevented from being damaged due to stress concentration, and the service life of the crankshaft vibration isolator is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0019] The utility model will be further described below in combination with the drawings and examples.

[0020] Figure 1 It is a structure schematic view of the prior art vibration isolation device.

[0021] Figure 2 It is a top view structure schematic view of the utility model crankshaft vibration isolator.

[0022] Figure 3 It is an explosion structure schematic view of the utility model crankshaft vibration isolator.

[0023] Figure 4 It is a side view structure schematic view of the utility model crankshaft vibration isolator.

[0024] Figure 5 It is Figure 6 The section structure schematic view of A-A in it.

[0025] Figure 6 It is Figure 6 The enlarged structure schematic view of A in it.

[0026] Figure 7 It is a hidden part component structure schematic view of the utility model crankshaft vibration isolator.

[0027] Figure 8 It is an inside part structure schematic view of the crankshaft vibration isolator.

[0028] Figure 9is the structural schematic view of the driving arm.

[0029] Figure 10 is the structural schematic view of the ball head.

[0030] Figure 11 is the structural schematic view of the ball head.

[0031] Figure 12 is the structural schematic view of the supporting block.

[0032] Figure 13 is the structural schematic view of the supporting block.

[0033] Figure 14 is the Figure 13 is the sectional structural schematic view of B-B.

[0034] Figure 15 is the structural schematic view of the arc spring.

[0035] In the figure: 1-driving arm, 11-disc body, 12-arm body, 13-cylindrical mounting hole, 14-center hole, 15-pin hole, 16-groove; 2-ball head, 21-ball body part, 22-cylinder part; 3-supporting block, 31-spherical surface mounting blind hole, 32-first round angle, 33-second round angle; 4-arc spring, 41-flat surface; 5-pivot; 6-belt wheel; 7-mounting shell, 71-shell upper stop; 8-positioning pin. DETAILED DESCRIPTION

[0036] The utility model will be further explained in detail in combination with the drawings. These drawings are all simplified schematic views, only the basic structure of the utility model is schematically shown, therefore, only the relevant constitution, direction and reference (such as up, down, left, right and the like) can be used to help the description of the features in the drawings. Therefore, the following specific embodiments are not in the restrictive sense, and the scope of the claimed subject matter is only limited by the appended claims and their equivalents.

[0037] As Figures 2-14 shown, the utility model discloses a crankshaft vibration isolator adapting to spring misplacement, including belt wheel 6 and the installation shell 7, pivot 5, arc spring 4 and driving arm 1 of setting in belt wheel 6, the connection and positional relationship of belt wheel 6 with installation shell 7, pivot 5, arc spring 4 is the structure that can realize of prior art, as Figure 1 shown, therefore, no longer detailed here. The installation shell 7 is arranged on the outside of pivot 5, and the annular groove for installing arc spring 4 is formed between the installation shell 7 and pivot 5, and the shell upper stop 71 is arranged on the position of the arm body 12 of driving arm 1. The arc spring 4 is two, and is symmetrically arranged on the two sides of pivot 5 and is arranged in the annular groove of installation shell 7, as Figure 9As shown, the driving arm 1 includes a disc body 11, which is fixed on the end face of the pulley 6, the driving arm 1 and the arc spring 4 are located on the same side of the mounting shell 7, two arm bodies 12 are symmetrically arranged on the outer edge of the disc body 11 in the radial direction, the arm body 12 is a trapezoidal structure, the arm body 12 extends into the ring groove, a ball joint assembly is arranged on each side of the arm body 12, the end of the arc spring 4 abuts on the ball joint assembly, and the arc spring 4 end face can be adaptively engaged with the driving arm 1 end face through the ball joint assembly. At least one groove 16 is arranged on the left and right side faces of the disc body 11, and a center hole 14 is arranged in the center of the disc body 11, so as to facilitate the passing of the pivot 5.

[0038] As shown in the figure, Figures 5-12 The ball joint assembly includes a support block 3 and a ball head 2, the ball head 2 includes an integral ball body part 21 and a column body part 22, the diameter of the ball body part 21 is greater than that of the column body part 22, a cylindrical mounting hole 13 is arranged on the side face of the arm body 12, the column body part 22 is fixed in the cylindrical mounting hole 13 by welding, interference fit or the like, the ball body part 21 is located on the outside of the arm body 12, the support block 3 is a cuboid structure, and can also be other shapes, and the cuboid structure is preferred in the embodiment, a spherical surface mounting blind hole 31 (i.e. a ball socket) is arranged at the center of the end face of the support block 3, the ball body part 21 is embedded in the spherical surface mounting blind hole 31 and installed in the spherical surface mounting blind hole 31 by cold shrinking or the like, the ball head 2 and the spherical surface mounting blind hole 31 are fully lubricated, so as to ensure that the ball head 2 can freely rotate around the center of the blind hole, thereby forming a joint movement between the ball head 2 and the support block 3. When the ball body part 21 freely rotates around the center of the spherical surface mounting blind hole 31, the included angle α between the axis of the ball head 2 and the axis of the spherical surface mounting blind hole 31 is at most 15°. The rotation angle of the ball head 2 is limited by the edge of the blind hole, and in this example, the rotation angle of the ball head 2 is limited to 15° by designing the size of the edge of the spherical surface mounting blind hole 31. In order to avoid stress concentration on the edge of the blind hole when the edge of the blind hole contacts the ball head 2, thereby damaging the support block 3, the edge of the opening of the spherical surface mounting blind hole 31 is chamfered, so as to form a first chamfer 32 on the edge of the opening of the spherical surface mounting blind hole 31. Different maximum rotation angles are realized by setting the first chamfer 32 with different angles and widths.

[0039] As shown in the figure, Figure 15As shown, the end face of the arc spring 4 is a plane 41, and the side of the support block 3 away from the ball head 2 is also a plane, and the end face of the arc spring 4 is attached to and abuts against the end face of the support block 3. The end face of the arc spring 4 is machined as a plane, and the arc spring 4 is always in a compressed state after installation, and under the action of the spring elastic force, the end face of the support block 3 is always abutted against the end face of the arc spring 4; in order to avoid the edge of the support block 3 from knocking against the arc spring 4, the side of the support block 3 in contact with the arc spring 4 is rounded, that is, the corners around are provided with second round corners 33, and the transition between different surfaces is realized through the second round corners 33, so that the jamming in the movement process can be effectively avoided.

[0040] As shown in the ideal embodiment of the utility model, Figure 8 In order to realize the connection between the driving arm 1 and the pivot 5, at least two positioning pins 8 are arranged on the end face of the pivot 5, and the disc body 11 is provided with pin holes 15 corresponding to the positioning pins 8 one by one, and when assembled, the positioning pins 8 pass through the pin holes 15 and the end portions are fixedly connected to the pivot 5.

[0041] Working principle:

[0042] The pivot 5 is fixedly connected with the crankshaft, the pivot 5 is also fixedly connected with the driving arm 1, and the mounting shell 7 is connected with the pulley 6. The mounting shell 7 is designed with a shell upper stop 71 structure, and the end face of the arc spring 4 also abuts against the shell upper stop 71. During the working process of the engine, the crankshaft drives the pivot 5 and the driving arm 1 to rotate, the driving arm 1 transmits the torque to the arc spring 4 through the above-mentioned ball joint assembly, the arc spring 4 is compressed, and at the same time, the torque is transmitted to the mounting shell 7 through the shell upper stop 71, and the mounting shell 7 drives the pulley 6 to rotate.

[0043] Based on the above ideal embodiment of the utility model, through the above description, relevant personnel can make various changes and modifications without deviating from the scope of the utility model. The technical scope of the utility model is not limited to the content in the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. A crankshaft vibration isolator adapted to spring misalignment, characterized in that: The device includes a pulley, a mounting housing, a pivot, an arc spring, and a drive arm disposed within the pulley. The mounting housing is located outside the pivot and forms an annular groove between it and the pivot for mounting the arc spring. There are two arc springs, symmetrically arranged on both sides of the pivot and disposed within the annular groove of the mounting housing. The drive arm includes a disc body fixed to the end face of the pulley. Two arms are symmetrically arranged radially on the outer edge of the disc body, and the arms extend into the annular groove. Each arm has a ball joint assembly on both sides. The end of the arc spring abuts against the ball joint assembly, and the end face of the arc spring can adaptively engage with the end face of the drive arm through the ball joint assembly.

2. The crankshaft vibration isolator adapting to spring misalignment as described in claim 1, characterized in that: The ball joint assembly includes a support block and a ball head. The ball head includes an integrally connected spherical part and a cylindrical part. The diameter of the spherical part is larger than the diameter of the cylindrical part. The side of the arm body is provided with a cylindrical mounting hole. The cylindrical part is fixed in the cylindrical mounting hole. The spherical part is located on the outside of the arm body. The end face of the support block is provided with a spherical mounting blind hole. The spherical part is embedded in the spherical mounting blind hole, so that the spherical part can rotate freely around the center of the spherical mounting blind hole.

3. The crankshaft vibration isolator adapting to spring misalignment as described in claim 2, characterized in that: When the spherical part rotates freely around the center of the blind hole on the spherical surface, the angle α between the axis of the spherical head and the axis of the blind hole on the spherical surface is at most 15°.

4. The crankshaft vibration isolator adapting to spring misalignment as described in claim 3, characterized in that: The opening of the spherical mounting blind hole is provided with a first rounded corner.

5. The crankshaft vibration isolator adapting to spring misalignment as described in claim 2, characterized in that: The support block has a cuboid structure with rounded corners at all four edges.

6. The crankshaft vibration isolator adapting to spring misalignment as described in claim 2, characterized in that: The end face of the arc spring is a plane, and the side of the support block facing away from the ball head is also a plane. The end face of the arc spring is in contact with and abuts against the end face of the support block.

7. The crankshaft vibration isolator adapting to spring misalignment as described in claim 1, characterized in that: At least one groove is provided on each of the left and right sides of the disc, and a central hole is provided in the center of the disc to facilitate the passage of the pivot.

8. The crankshaft vibration isolator adapting to spring misalignment as described in claim 1, characterized in that: At least two positioning pins are provided on the end face of the pivot, and the disc body is provided with pin holes corresponding to the positioning pins. During assembly, the positioning pins pass through the pin holes and their ends are fixed to the pivot.

9. The crankshaft vibration isolator adapting to spring misalignment as described in claim 1, characterized in that: The mounting housing has an upper stop at the arm body position directly opposite the drive arm.

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