CN110905938A - Decoupling type one-way belt pulley - Google Patents

Abstract

The invention discloses a decoupling type one-way belt pulley, which comprises a mandrel and a belt pulley shell, wherein an upper bearing, a lower bearing and an isolator are arranged between the mandrel and the belt pulley shell, the isolator comprises a radial limiting shaft sleeve, an axial limiting bearing shaft sleeve and a coupling spring, the radial limiting shaft sleeve is in interference fit with the belt pulley shell, the axial limiting shaft sleeve is in interference fit with the mandrel, and the bottom of the radial limiting shaft sleeve is in sliding fit with the top of the axial limiting bearing shaft sleeve; the tail end of the coupling spring is inwards wound to form an inner spring, the inner spring is abutted against an axial limiting surface of an axial bearing limiting shaft sleeve, the inner wall of an outer spring of the coupling spring is in interference fit with the radial limiting shaft sleeve and the axial limiting bearing shaft sleeve, and the top end of the coupling spring is connected with the radial limiting shaft sleeve. The invention adopts the coupling spring with a double-layer structure, has stronger anti-torsion characteristic and can form a movable locking block.

Description

Decoupling type one-way belt pulley

Technical Field

The invention relates to the field of automobile engines, in particular to the field of unidirectional belt pulleys of automobile generators, and specifically relates to a decoupling type unidirectional belt pulley.

Background

The belt pulley of the one-way clutch of the automobile generator can avoid reverse current generated in the reverse rotation process so as to prevent electronic devices in an automobile from being damaged, prolong the service life of a generator system and reduce carbon monoxide emission. An existing one-way clutch for a generator of an automobile is disclosed in Chinese patent CN 104074951B. The structure of the clutch is shown in figure 1, and the clutch comprises a mandrel 1 ' and a belt pulley shell 9 ', wherein a top bearing 2 ', a one-way clutch, a clamp spring 7 ' and a bottom bearing 8 are sequentially arranged between the mandrel 1 ' and the belt pulley shell 9 ', and the one-way clutch comprises a bearing outer ring 4 ', a one-way spring 5 ' and a one-way thrust ring 6 '; the bearing outer ring 4 'is fixedly connected with the belt pulley shell 9' in an interference fit manner; the one-way spring 5 is arranged in the bearing outer ring 4 ', the bottom end of the one-way spring is suspended, and the top end of the one-way spring is fixed on the one-way thrust ring 6'; the one-way thrust collar 6 'is fixedly connected with the mandrel 1' and is axially positioned through the clamp spring 7.

When the rotating speed of the belt pulley shell 9 'exceeds the rotating speed of the mandrel 1', the bearing outer ring 4 'pushes the suspension end of the one-way spring 5' in the rotating process and expands the one-way spring, and the mandrel 1 'and the belt pulley shell 9' realize the same-direction movement. When the rotating speed of the belt pulley shell 9 'is lower than that of the mandrel 1', the bearing outer ring 4 'generates pulling force on the suspension end of the one-way spring 5' to enable the one-way spring 5 'to contract and deform and unlock with the bearing outer ring 4', and the mandrel 1 'is separated from the belt pulley shell 9'.

According to the technical scheme, the deformable characteristic of the one-way spring is utilized, the one-way spring is driven to be in a contraction or expansion state through the different relative movement directions of the bearing outer ring to the one-way spring, so that the bearing outer ring and the one-way spring are unlocked or locked, and the clutch of the mandrel and the belt pulley shell is realized. Because the relative motion of the bearing outer ring to the one-way spring forms flexible friction instead of hard friction of the traditional structure, the noise is low, and the service life of the clutch is prolonged.

However, the above solution is in an expanded state during clutch engagement. Because the engaged state is the normal state of the clutch, the one-way spring is easy to generate permanent deformation and damage after being in the expanded state for a long time. Meanwhile, in the process of clutch separation, the whole one-way spring and the bearing outer ring form friction, and the service life of the one-way spring can be also reduced.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art and provides a decoupling type one-way belt pulley.

In order to solve the problems, the invention adopts the following technical scheme: a decoupling type one-way belt pulley comprises a mandrel and a belt pulley shell, wherein an upper bearing, a lower bearing and an isolator are arranged between the mandrel and the belt pulley shell, and the decoupling type one-way belt pulley is characterized in that the isolator comprises a radial limiting shaft sleeve, an axial limiting bearing shaft sleeve and a coupling spring, the radial limiting shaft sleeve is in interference fit with the belt pulley shell, the axial limiting bearing shaft sleeve is in interference fit with the mandrel, and the bottom of the radial limiting shaft sleeve is in sliding fit with the top of the axial limiting bearing shaft sleeve; the tail end of the coupling spring is inwards wound to form an inner spring, the inner spring is abutted against an axial limiting surface of an axial bearing limiting shaft sleeve, the inner wall of an outer spring of the coupling spring is in interference fit with the radial limiting shaft sleeve and the axial limiting bearing shaft sleeve, and the top end of the coupling spring is connected with the radial limiting shaft sleeve.

When the automobile generator belt pulley is started and runs clockwise, the radial limiting shaft sleeve in an interference state with the shell of the unidirectional belt pulley pulls the coupling spring to rotate. Because of interference between the coupling spring and the axial limiting bearing shaft sleeve, the axial limiting bearing shaft sleeve drives the mandrel to generate synchronous motion, and the clutch is jointed.

When the rotating speed of the belt pulley shell is lower than that of the mandrel, the radial limiting shaft sleeve in an interference state with the belt pulley shell applies a reverse thrust to the coupling spring to expand the coupling spring, and the inner diameter of the coupling spring is larger than the outer diameter of the axial limiting bearing shaft sleeve fixed on the mandrel, so that the mandrel and the belt pulley shell are separated, and the clutch is separated.

The coupling spring is always in a contraction state and does not deform in the process of clutch engagement. Because the engaging state is the normal state of the clutch, the coupling spring keeps tightened in most of time in the using process of the clutch, the coupling spring is effectively protected, and the service life of the coupling spring is greatly prolonged.

Since the coupling spring is relatively stationary during the engagement of the clutch, no friction is generated with the axial limit bearing bushing, and therefore little noise is generated during the driving of the vehicle. Meanwhile, in the process of clutch separation, the coupling spring only generates flexible friction between the tail end and the axial limiting bearing shaft sleeve, so that the friction area is greatly reduced, and the service life of the one-way spring is further prolonged.

The invention has simple structure and less parts, can reduce the assembly difficulty and the manufacturing cost, and simultaneously improves the running stability and the performance reliability of the product.

More importantly, the coupling spring adopts a double-layer structure, has stronger anti-torsion deformation characteristic and can form a movable locking block. The conventional single layer spring reaches an upper limit in terms of rotational friction when the torque is greater than 80Nm, while the double layer spring of the present invention can still work normally when the torque reaches 150 Nm.

As an improvement of the invention, the number of turns of the inner layer spring is 1-3. Preferably, the number of turns of the inner layer spring is 1.5-2.5 turns. More preferably, the number of turns of the outer spring is 8.

As a further improvement of the invention, the cross section of the coupling spring is rectangular. The rectangular section spring and the preferred alloy material have great bearing capacity and long service life.

As a further improvement of the invention, the top end face of the axial limiting bearing shaft sleeve is provided with a positioning convex ring, and the bottom of the radial limiting shaft sleeve is provided with a positioning counter bore matched with the positioning convex ring.

As a still further improvement of the invention, the section of the positioning convex ring is conical, and the positioning counter bore is provided with a corresponding conical surface.

As a further improvement of the present invention, the axial limiting bearing sleeve has a T-shaped cross section, and has an upper large-diameter section, a lower small-diameter section and a central through hole, the outer circumferential wall of the large-diameter section is in interference fit with the inner wall of the outer spring of the coupling spring, the outer circumferential wall of the small-diameter section is in interference fit with the inner wall of the inner spring of the coupling spring, and the inner wall of the central through hole is in interference fit with the mandrel.

As a further improvement of the coupling spring, the cross section of the radial limiting shaft sleeve is in a T shape and is provided with an upper large-diameter section, a lower small-diameter section and a central through hole, the outer circumferential wall of the large-diameter section is in interference fit with the belt pulley shell, and the outer circumferential wall of the small-diameter section is in interference fit with the inner wall of the outer-layer spring of the coupling spring.

As a further improvement of the invention, the large-diameter section of the radial limiting shaft sleeve is also provided with a mounting hole matched with the top end of the coupling spring. One end of the coupling spring is inserted into the mounting hole, so that the coupling spring is convenient to assemble and disassemble.

As a further improvement of the invention, a lower bearing limiting groove is also arranged in the belt pulley shell.

As a further improvement of the invention, the mandrel adopts a hollow steel pipe, and the steel pipe is extruded and formed in a center positioning mode. The traditional mandrel processing mode is mostly one-time extrusion forming of a solid iron block or spinning forming of a thin steel plate. However, the problem that the extruded part is not coaxial and the ovality is increased due to the fact that a mold of a product formed in one step belongs to a factor of artificial assembly is caused, so that when a unidirectional bearing set is impacted by strong force, a roller pin retainer is deformed and broken due to different displacements of the unidirectional roller pins, the unidirectional roller pins are not positioned, and the unidirectional belt pulley of the automobile generator fails. The invention adopts the extrusion molding of the hollow steel pipe, and can ensure the coaxiality and the ellipse controllability of the unidirectional tooth part and each part. The specific mode is as follows: (1) annealing the steel pipe to soften the material; (2) extruding and forming the softened steel pipe; (3) the formed steel pipe was carburized to make the hardness 60 degrees.

Drawings

The invention is further illustrated by the following figures and examples.

Fig. 1 is a schematic view of a conventional one-way clutch pulley.

Fig. 2 is a schematic structural diagram of the decoupling type one-way belt pulley of the invention.

Fig. 3 is an isometric view of the decoupled one-way pulley of the present invention.

Fig. 4 is a schematic structural view of the mandrel of the present invention.

Figure 5 is an isometric view of a mandrel of the present invention.

Fig. 6 is a schematic structural view of the coupling spring of the present invention.

Fig. 7 is an isometric view of a coupling spring of the present invention.

Fig. 8 is a schematic structural view of the axial restraining bearing sleeve of the present invention.

Fig. 9 is an isometric view of an axial restraining load bearing sleeve of the present invention.

Fig. 10 is a schematic structural view of the radial limit shaft sleeve of the invention.

Fig. 11 is an isometric view of the radial stop bushing of the present invention.

Fig. 12 is a schematic view of the structure of the lower bearing of the present invention.

Fig. 13 is a longitudinal sectional view of the lower bearing.

Fig. 14 is an isometric view of the lower bearing.

Fig. 15 is a schematic structural view of the upper bearing.

Fig. 16 is an isometric view of the upper bearing.

FIG. 17 is a schematic view of the construction of the pulley housing of the present invention.

Fig. 18 is a schematic structural view of the coupled isolator of the present invention.

Fig. 19 is an external view of the coupled isolator of the present invention.

Fig. 20 is a schematic view showing a coupling state of the coupled isolator according to the present invention.

Fig. 21 is a schematic view of the decoupled state of the coupled isolator of the present invention.

In the figure, 1-a mandrel, 2-a lower bearing, 3-a coupling spring, 4-an axial limiting bearing shaft sleeve, 5-a radial limiting shaft sleeve, 6-an upper bearing and 7-a belt pulley shell;

101-a first section of the mandrel, 102-a second section of the mandrel, 103-a third section of the mandrel;

301-inner spring, 302-outer spring, 303-coupling spring top;

401-outer circumferential wall of small diameter section, 402-axial limiting surface, 403-positioning convex ring, 404-central through hole, 405-large diameter section, 406-small diameter section, 407-outer circumferential wall of large diameter section, 408-conical surface and 409-inner wall;

501-small diameter section, 502-large diameter section, 503-mounting hole, 504-central through hole, 505-limiting surface, 506-conical surface, 507-positioning counter bore, 508-small diameter section outer circumferential wall and 509-large diameter section outer circumferential wall;

701-lower bearing limit groove, 702-dust cap limit groove.

Detailed Description

Referring to fig. 1, the drawbacks of the conventional one-way clutch pulley have been described above and will not be described again.

Referring to fig. 2 and 3, the decoupling type one-way belt pulley of the invention comprises a mandrel 1, a lower bearing 2, a one-way device, an upper bearing 6 and a belt pulley shell 7. The upper bearing 6, the isolator and the lower bearing 2 are arranged between the mandrel 1 and the belt pulley shell 7 and are sequentially arranged from top to bottom.

The isolator include radial spacing axle sleeve 5, the spacing axle sleeve 4 and coupling spring 3 of bearing of axial, radial spacing axle sleeve 5 with belt pulley shell 7 interference fit, the axial bear spacing axle sleeve 4 with 1 interference fit of dabber, the top sliding fit of the spacing axle sleeve 4 of bottom and the axial of radial spacing axle sleeve 5.

Referring to fig. 4 and 5, the mandrel 1 has a first section 101 cooperating with the lower bearing, a second section 102 cooperating with the isolator and a third section 103 cooperating with the upper bearing. The three sections are arranged in a ladder shape, and the diameters are reduced in sequence. The transition surface between two adjacent sections forms a limiting step.

The mandrel adopts a hollow steel pipe, and the steel pipe is extruded and formed in a center positioning mode. The specific mode is as follows: (1) carrying out complete annealing treatment on the steel pipe, wherein the heating temperature is about 900 ℃, and cooling at normal temperature to soften the material; (2) extruding and forming the softened steel pipe; (3) the formed steel pipe was carburized to make the hardness 60 degrees. The invention adopts the extrusion molding of the hollow steel pipe, and can ensure the coaxiality and the ellipse controllability of the unidirectional tooth part and each part.

Referring to fig. 6 and 7, the end of the coupling spring 3 is wound inwards to form an inner layer spring 301, the inner layer spring 301 abuts against an axial limiting surface 402 of an axial bearing limiting shaft sleeve 4, the inner wall of an outer layer spring 302 of the coupling spring is in interference fit with the radial limiting shaft sleeve 5 and the axial limiting bearing shaft sleeve 4, and the top end 303 of the coupling spring is connected with the radial limiting shaft sleeve 5.

The number of turns of the inner layer spring 301 is 1-3. Preferably, the number of turns of the inner layer spring is 1.5-2.5 turns. In this embodiment, the number of turns of the inner spring is 1.5, and the number of turns of the outer spring 302 is 8.

The section of the coupling spring 3 is rectangular and is made of alloy materials. The spring with the rectangular section is made of alloy materials, so that the bearing capacity is high and the service life is long.

Referring to fig. 8 and 9, the cross-section of the axial limiting bearing sleeve 4 is T-shaped, and has an upper large-diameter section 405, a lower small-diameter section 405 and a central through hole 404, the outer circumferential wall 407 of the large-diameter section is in interference fit with the inner wall of the outer spring of the coupling spring 3, the outer circumferential wall 401 of the small-diameter section is in interference fit with the inner wall of the inner spring of the coupling spring 3, and the inner wall 409 of the central through hole 404 is in interference fit with the mandrel 1.

An axial stop surface 402 is formed at the transition between the upper large diameter portion 405 and the lower small diameter portion 405. The axial limiting surface 402 abuts against the top of the inner spring 301 to axially limit the coupling spring 3.

The top end face of the axial limiting bearing shaft sleeve 4 is provided with a positioning convex ring 403 which is matched with the radial limiting shaft sleeve 5 in a sliding mode, and the section of the positioning convex ring 403 is conical, so that the positioning convex ring 403 can bear the radial limiting shaft sleeve 5 and reduce sliding friction.

Referring to fig. 10 and 11, the radial restriction sleeve 5 has a T-shaped cross-section, and has an upper large diameter section 502, a lower small diameter section 501 and a central through hole 504, wherein the outer circumferential wall 509 of the large diameter section is in interference fit with the pulley housing 7, and the outer circumferential wall 508 of the small diameter section is in interference fit with the inner wall of the outer spring of the coupling spring.

The bottom of the radial limiting shaft sleeve 5 is provided with a positioning counter bore 507 matched with the positioning convex ring 403 of the axial limiting bearing shaft sleeve 4. The positioning counter bore 507 is provided with a conical surface 506 matched with the positioning convex ring 403.

The large-diameter section 502 of the radial limiting shaft sleeve is also provided with a mounting hole 503 matched with the top end 303 of the coupling spring. The top end 303 of the coupling spring is inserted into the mounting hole 503, so that the assembly and disassembly are convenient.

Referring to fig. 12, 13 and 14, the lower bearing 2 of the present invention employs a slide bearing.

Referring to fig. 15 and 16, the upper bearing 6 of the present invention employs a ball bearing.

Referring to fig. 17, a lower bearing limiting groove 701 and a dust cap limiting groove 702 are further disposed in the pulley housing 7.

Referring to fig. 18 and 19, the clutch of the pulley housing 7 and the mandrel 1 is realized by decoupling and coupling between the coupling spring 3 and the mandrel 1 through a one-way clutch composed of the radial limit shaft sleeve 5, the axial limit bearing shaft sleeve 4 and the coupling spring 3.

The invention discloses a decoupling type one-way belt pulley, which has the following working principle:

referring to fig. 20, when the automobile generator pulley is started and runs clockwise as shown by an arrow 8, the radial restriction bush 5 in an interference state with the one-way pulley housing 7 pulls the coupling spring 3 to rotate. Because of interference state between the coupling spring 3 and the axial limiting bearing shaft sleeve 4, the axial limiting bearing shaft sleeve 4 drives the mandrel 1 to generate synchronous motion, and the clutch is jointed. At the moment, the coupling spring 3 contracts inwards in the directions of arrows 9, 10 and 11 to form extrusion force to interfere with the limiting bearing shaft sleeve 4, so that the aim of increasing the anti-torsion moment is fulfilled.

Referring to fig. 21, when the rotation speed of the pulley housing 7 is lower than that of the mandrel 1, the pulley housing 7 rotates counterclockwise relative to the mandrel 1, the radial limit bushing 5 in interference with the pulley housing 7 applies a reverse thrust to the coupling spring 3 to expand the coupling spring 3, and the inner diameter of the coupling spring is larger than the outer diameter of the axial limit bearing bushing 4 fixed on the mandrel 1, so that the mandrel 1 and the pulley housing 7 are in a separated state, and the clutch is separated. At this time, the coupling spring 3 is under the action of counterclockwise tension, and expands in the directions of arrows 13, 14 and 15, so that the external dimension is enlarged, and a decoupling state is formed to enable the mandrel to freely move in an inertia mode.

The invention has the following beneficial effects:

1. the coupling spring is always in a contraction state and does not deform in the process of clutch engagement. Because the engaging state is the normal state of the clutch, the coupling spring keeps tightened in most of time in the using process of the clutch, the coupling spring is effectively protected, and the service life of the coupling spring is greatly prolonged.

2. Since the coupling spring is relatively stationary during the engagement of the clutch, no friction is generated with the axial limit bearing bushing, and therefore little noise is generated during the driving of the vehicle. Meanwhile, in the process of clutch separation, the coupling spring only generates flexible friction between the tail end and the axial limiting bearing shaft sleeve, so that the friction area is greatly reduced, and the service life of the one-way spring is further prolonged.

3. The invention has simple structure and less parts, can reduce the assembly difficulty and the manufacturing cost, and simultaneously improves the running stability and the performance reliability of the product.

4. The coupling spring of the invention adopts a double-layer structure, has stronger anti-torsion characteristic and can form a movable locking block. The conventional single layer spring reaches an upper limit in terms of rotational friction when the torque is greater than 80Nm, while the double layer spring of the present invention can still work normally when the torque reaches 150 Nm.

It should be understood that: the above-mentioned embodiments are merely illustrative of the present invention, not restrictive, and any invention which does not depart from the spirit and scope of the present invention will fall within the protection scope of the present invention.

Claims (10)

1. A decoupling type one-way belt pulley comprises a mandrel and a belt pulley shell, wherein an upper bearing, a lower bearing and an isolator are arranged between the mandrel and the belt pulley shell, and the decoupling type one-way belt pulley is characterized in that the isolator comprises a radial limiting shaft sleeve, an axial limiting bearing shaft sleeve and a coupling spring, the radial limiting shaft sleeve is in interference fit with the belt pulley shell, the axial limiting bearing shaft sleeve is in interference fit with the mandrel, and the bottom of the radial limiting shaft sleeve is in sliding fit with the top of the axial limiting bearing shaft sleeve; the tail end of the coupling spring is inwards wound to form an inner spring, the inner spring is abutted against an axial limiting surface of an axial bearing limiting shaft sleeve, the inner wall of an outer spring of the coupling spring is in interference fit with the radial limiting shaft sleeve and the axial limiting bearing shaft sleeve, and the top end of the coupling spring is connected with the radial limiting shaft sleeve.

2. A decoupled unidirectional pulley as claimed in claim 1 wherein the inner spring has between 1 and 3 coils.

3. A decoupled unidirectional pulley as claimed in claim 2 wherein the coupling spring is rectangular in cross-section.

4. A decoupling type one-way pulley as claimed in claim 1, wherein the top end face of the axial limiting bearing sleeve is provided with a positioning convex ring, and the bottom of the radial limiting bearing sleeve is provided with a positioning counter bore matched with the positioning convex ring.

5. A decoupled unidirectional pulley as claimed in claim 4, wherein the locating bead is tapered in cross-section and the locating counterbore has a corresponding conical surface.

6. A decoupled one-way pulley according to claim 1, wherein the axial limiting bearing sleeve has a T-shaped cross-section, and has an upper large diameter section, a lower small diameter section, and a central through hole, wherein the outer circumferential wall of the large diameter section is in interference fit with the inner wall of the outer spring of the coupling spring, the outer circumferential wall of the small diameter section is in interference fit with the inner wall of the inner spring of the coupling spring, and the inner wall of the central through hole is in interference fit with the mandrel.

7. A decoupled one-way pulley according to claim 1, wherein the radial limiting boss has a T-shaped cross-section with an upper large diameter section, a lower small diameter section and a central through hole, the outer circumferential wall of the large diameter section is in interference fit with the pulley housing, and the outer circumferential wall of the small diameter section is in interference fit with the inner wall of the outer spring of the coupling spring.

8. A decoupling type one-way pulley according to claim 7, wherein the large diameter section of the radial limiting shaft sleeve is further provided with a mounting hole matched with the top end of the coupling spring.

9. A decoupled unidirectional pulley as claimed in claim 1 wherein a lower bearing retaining groove is provided in the pulley housing.

10. A de-coupled unidirectional pulley according to any one of claims 1 to 9, wherein the core shaft is a hollow steel tube which is extruded in a centrally located manner.

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