JP2014095419A - Pulley with damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulley with a damper including a dust seal capable of closing a clearance gap in which a journal bearing is disposed, over the whole periphery from the outside with no gap, without being affected by tensile force of an endless belt hung on the pulley.SOLUTION: A pulley with a damper includes a dust seal 30 composed of a rubber elastic body for closing a gap G formed along the circumferential direction between a damper unit 2 and a pulley unit 4 axially assembled, from the outside over the whole periphery, the dust seal 30 is mounted on the damper unit, and the dust seal 30 is disposed in a state that its lip portion 30b is constantly kept into contact with the whole periphery of a side face 4s of the pulley unit 4 in a state that the damper unit 2 and the pulley unit 4 are axially assembled.

Description

  The present invention relates to a pulley with a damper that is attached to a rotary shaft such as a crankshaft of an engine, for example, and transmits torque of the rotary shaft to various auxiliary machines via an endless belt.

  Conventionally, various pulleys with dampers are attached to a rotating shaft (crankshaft) in order to transmit the driving force of a rotating shaft such as an engine crankshaft to an auxiliary machine such as a generator or a compressor via an endless belt. Yes. As an example, a pulley with a damper disclosed in Patent Document 1 includes a damper unit that is attached to a crankshaft and a pulley unit that extends in an annular shape so as to face the outer periphery of the damper and over which an endless belt is stretched. It is assembled and assembled.

  In such a pulley with a damper, a gap provided with a journal bearing is formed between the damper unit and the pulley unit in the circumferential direction, and the journal is caused by dust (for example, dust) entering from the outside into the gap. In order to prevent the bearing from being worn out at an early stage, a dust seal (described as the first dust lip in FIG. 2 of Patent Document 1) is provided to prevent dust from entering. In this case, the dust seal is continuous in the circumferential direction along the gap so as to block the gap between the damper unit and the pulley unit from the outside, and the inertia mass body in which the base end portion on the inner diameter side of the dust seal constitutes the damper The outer peripheral surface is vulcanized and bonded, and the outer diameter end portion is in contact with the inner peripheral surface of the pulley.

JP 2004-278726 A (FIG. 2)

  By the way, in the pulley with a damper disclosed in Patent Document 1, a dust seal is provided in a gap between the outer peripheral surface of the inertia mass body that constitutes the damper unit and the inner peripheral surface of the pulley portion that constitutes the pulley unit. When the pulley portion is displaced in the radial direction by the tension of the passed endless belt, the tip of the dust seal is partially separated from the inner peripheral surface of the pulley portion depending on the degree of the displacement (in other words, the pulley portion In some cases, a partial gap is generated between the inner peripheral surface and the tip of the dust seal. In such a case, there is a possibility that the journal bearing may be worn early due to dust entering from a partial gap between the inner peripheral surface of the pulley portion and the tip of the dust seal.

  The present invention has been made in order to solve such a problem, and the object thereof is not to be affected by the tension of the endless belt stretched around the pulley, and the clearance provided with the journal bearing is disposed around the entire circumference thereof. An object of the present invention is to provide a pulley with a damper that can be closed without any gap from the outside.

In order to achieve such an object, the present invention provides a damper unit attached to a rotating shaft, a pulley unit disposed on the outer peripheral side of the damper unit, and the damper unit and the pulley unit in the axial direction. A journal bearing provided between the pulley unit and the damper unit or a member that rotates integrally with the damper unit in the assembled state, and a rubber-like elastic material that covers the gap provided with the journal bearing from the outside over the entire circumference. A dust seal composed of a body,
The dust seal is attached to the damper unit or a member that rotates integrally with the damper unit, and in a state where the damper unit and the pulley unit are assembled in the axial direction, the dust seal has a lip portion of the dust seal. Always in contact with the side of the pulley unit.

In the present invention, the damper unit or the member that rotates integrally with the damper unit is provided with a seal mounting portion that extends continuously or intermittently in the circumferential direction, and the dust seal is the seal mounting You may comprise so that it may be attached to a part.
Further, in the present invention, the dust seal has a base end portion attached to the damper unit or a member that rotates integrally with the damper unit, and the lip portion has a radial direction from the base end portion and the pulley. You may comprise so that it may extend in the direction approaching a unit and may contact the side surface of the said pulley unit with the elastic force of the said lip | rip part.
Moreover, in this invention, you may comprise the said lip | rip part so that it may contact the side surface of the said pulley unit within the range of the axial direction width | variety of the said base end part.
Further, in the present invention, the dust seal may be configured such that the entire shape is annular and is detachably attached to the seal attachment portion by its elastic force.
Furthermore, in the present invention, at least a lip portion of the dust seal may be configured to contain a friction reducing material.

According to the present invention, since the lip portion of the dust seal is configured to contact the side surface of the pulley unit, the lip portion of the dust seal can be used even if the pulley portion is displaced in the radial direction due to the tension of the endless belt stretched over the pulley portion. The part can maintain a contact state with the side surface of the pulley unit.
Therefore, without being affected by the tension of the endless belt stretched around the pulley, the gap provided with the journal bearing can be closed without any gap from the outside over the entire circumference, preventing the intrusion of dust and the journal bearing. Can prevent early wear.

(a) is sectional drawing which expands partially and shows the structure of the pulley with a damper which concerns on one Embodiment of this invention, (b) is a cross section which expands partially the example of the method of attaching a dust seal to a pulley with a damper Figure. Sectional drawing which expands and partially shows the structure of the pulley with a damper which concerns on other embodiment of this invention.

Hereinafter, a pulley with a damper according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1A, the damper-equipped pulley of the present embodiment includes a damper unit 2 configured to be attachable to a rotating shaft (not shown) (for example, an engine crankshaft) and an endless belt (not shown). And the pulley unit 4 over which is stretched are assembled in the axial direction. The axial direction refers to a direction parallel to the rotation center Ax of the rotation axis.

  The damper unit 2 includes an annular hub 2a that is attached to a rotating shaft and rotates integrally with the rotating shaft, and a damper portion 2b that reduces torsional vibration of the rotating shaft. The damper portion 2b includes: In addition, it is configured continuously in the circumferential direction along the outer peripheral side of the hub 2a. During the rotation of the rotating shaft, the damper unit 2 rotates concentrically around the central axis Ax.

  Here, the hub 2a includes an annular boss portion 6 having an attachment hole 6h for attachment to the rotating shaft, a disc portion 8 extending radially from the boss portion 6, and a central axis Ax from the outer peripheral side of the disc portion 8. An outer cylindrical portion 10 that extends concentrically along the circumferential direction, and an inner cylindrical portion that extends in parallel with the outer cylindrical portion 10 from a portion near the boss portion 6 of the disk portion 8 and continues in the circumferential direction. Part 12. In the damper portion 2 b, the inertia mass body 16 is attached to the outer peripheral side of the outer cylindrical portion 10 via the annular elastic body 14. Note that the mounting hole 6h provided in the hub 2a is not necessarily a through hole, and a configuration in which the mounting hole 6h is simply provided without providing the boss portion 6 may be employed.

  The annular elastic body 14 is formed of an elastic material such as rubber, for example, and is press-fitted between the outer cylindrical portion 10 of the hub 2 a and the inertia mass body 16. The inertia mass body 16 is formed of a metal material such as cast iron or cast steel.

  On the other hand, the pulley unit 4 is concentrically opposed and provided with a predetermined gap along the outer peripheral side of the damper portion 2b in a state where the pulley unit 4 and the damper unit 2 are assembled in the axial direction. A pulley having a cylindrical shape, and a disc-shaped cover portion 4b which is continuous from the pulley portion 4a radially inward and is arranged so as to cover one side of the damper portion 2b. The part 4a is formed with a plurality of pulley grooves 4g around which an endless belt (not shown) is stretched. A journal bearing 18 that allows relative displacement (relative rotation) between the damper unit 2 and the pulley unit 4 is interposed in the gap between the damper portion 2b and the pulley portion 4a.

  Further, the pulley unit 4 includes a disc-shaped isolation ring 20 that is opposed to the inner side surface Sin of the cover portion 4b in the axial direction and is opposed to the disc portion 8 of the hub 2a, and the cover portion 4b. And an annular elastic body 22 vulcanized and bonded to each other. The isolation ring 20 includes an inner cylindrical portion of the damper unit 2 (hub 2a). The cylindrical fitting part 20a arrange | positioned concentrically facing the outer peripheral side of 12 is formed.

Further, the pulley with damper is provided with a pressure ring 24 in order to apply axial preliminary compression to the annular elastic body 22 vulcanized and bonded to the cover portion 4 b and the isolation ring 20.
The pressure ring 24 includes a cylindrical fitting portion 24a that can be fitted to the outer circumference of the inner cylindrical portion 12 of the damper unit 2 (hub 2a) and the inner circumference of the fitting portion 20a of the isolation ring 20, and a fitting portion. A disc-shaped pressing portion 24b that extends in a radial direction from one end side (the left end portion in FIG. 1A) of 24a and is disposed to face the circumferential direction along the outer side surface Sout of the cover portion 4b. And.

  Here, after the thrust bearing 28 that allows relative displacement (relative rotation) between the damper unit 2 and the pulley unit 4 is positioned on the outer side surface Sout of the cover portion 4b, the fitting portion 24a of the pressure ring 24 is isolated. By engaging with the outer periphery of the fitting portion 20a of the ring 20, the pulley unit 4 is constructed in which the thrust bearing 28 is sandwiched between the pressing portion 24b of the pressure ring 24 and the outer side surface Sout of the cover portion 4b. . Next, in a state where the journal unit 18 is interposed in the gap between the damper portion 2b and the pulley portion 4a and the pulley unit 4 and the damper unit 2 are assembled to each other, the fitting portion 24a of the pressure ring 24 is connected to the damper unit 2 ( The hub 2a) is fitted to the outer periphery of the inner cylindrical portion 12.

  At this time, by adjusting the fitting amount of the fitting portion 24a of the pressure ring 24 with respect to the outer periphery of the inner cylindrical portion 12 of the damper unit 2 (hub 2a), that is, the pushing amount of the pressure ring 24, the cover portion 4b is isolated. Preliminary compression in the axial direction is applied to the annular elastic body 22 vulcanized and bonded to the oscillation ring 20.

  Here, when the above-described pulley with a damper is attached to an engine rotation shaft (for example, a crankshaft), when the engine rotates (when the damper-equipped pulley rotates with the rotation of the rotation shaft), the rotation shaft ( When torsional vibration is generated in the crankshaft, the damper portion 2b of the damper unit 2 has a function of reducing torsional vibration of the rotating shaft (crankshaft) (torsional vibration reducing function).

  When the engine torque fluctuates during engine rotation (mainly at low engine speed in the idling state), the annular elastic body 22 interposed between the damper unit 2 and the pulley unit 4 A function (speed fluctuation) that suppresses (for example, cuts or reduces) the speed fluctuation of the rotating shaft (crankshaft) generated by the torque fluctuation of the engine by being elastically deformed in the shear direction. Transmission suppression function).

  The pulley with a damper according to the present embodiment has a gap G formed between the damper unit 2 and the pulley unit 4 in the circumferential direction in a state where the damper unit 2 and the pulley unit 4 are assembled in the axial direction. A dust seal 30 made of a rubber-like elastic body that is closed from the outside is provided.

  Here, the gap G will be described. The pulley unit 4 has a pulley portion 4a extending opposite to the outer peripheral side of the damper unit 2 in a state where the damper unit 2 and the pulley unit 4 are assembled in the axial direction. Therefore, the gap G is annularly formed in the circumferential direction between the pulley portion 4a and the damper unit 2 (specifically, the inertia mass body 16).

  The dust seal 30 is formed in an annular shape continuously in the circumferential direction so that the gap G described above can be closed from the outside, and a base end portion 30 a on the inner diameter side is attached to the damper unit 2. The dust seal 30 is configured such that a predetermined amount of a low-friction material such as fluororesin or molybdenum disulfide is blended and kneaded into a base rubber material, and the friction coefficient of the lip portion 30b is reduced. Yes.

  The damper unit 2 is formed with a seal attachment portion 2p extending in the circumferential direction, and the base end portion 30a of the dust seal 30 is fixed to the seal attachment portion 2p by vulcanization adhesion. As an example in FIG. 1, the seal attachment portion 2 p is formed in a convex shape that is continuous in the circumferential direction with a part of the configuration of the damper unit 2 (for example, a part of the inertia mass body 16).

  The shape and size (width, height, etc.) of the seal mounting portion 2p are preferably set so that the base end portion 30a of the dust seal 30 is not displaced or dropped off. In FIG. 1, as an example, the seal mounting portion 2p has a rectangular cross section, and is set to a size that can be stably fixed in a state where the base end portion 30a of the dust seal 30 is straddled.

  Although the example in which the base end portion 30a of the dust seal 30 is directly vulcanized and bonded to the seal mounting portion 2p is illustrated, as another mounting mode, for example, a separate metal mounting member (such as a metal ring) A configuration is adopted in which the dust seal 30 is formed by vulcanizing and bonding unvulcanized rubber, and the separate metal mounting member is press-fitted into the seal mounting portion 2p to attach the dust seal 30 to the damper unit 2. May be.

  In addition, for example, an annular dust seal 30 having a smaller diameter than the outer diameter of the seal attachment portion 2p is formed, and the dust seal 30 is detachably attached to the seal attachment portion 2p by its own elastic force while expanding the diameter. May be.

  Here, in a state where the base end portion 30a is attached to the seal attachment portion 2p, the dust seal 30 is configured so that the lip portion 30b on the outer diameter side is inclined in a direction approaching the pulley unit 4, Due to the elastic force of the dust seal 30 (lip portion 30b), the lip portion 30b extends over the entire circumference of the side surface 4s of the pulley unit 4 (specifically, the pulley portion 4a), and the width W of the base end portion 30a in the central axis Ax direction. Within the range of, it is comprised so that it may contact.

  According to such a configuration, in the state where the dust seal 30 is attached to the damper unit 2 (specifically, the seal attaching portion 2p) and the damper unit 2 and the pulley unit 4 are assembled in the axial direction, the dust seal 30 The entire circumference of the lip portion 30b comes into contact with the side surface 4s of the pulley unit 4 (specifically, the pulley portion 4a).

When the damper unit 2 is not rotating and while the damper unit 2 is rotating together with the rotating shaft (crankshaft), the dust seal 30 always has the lip portion 30b of the pulley unit 4 (specifically, the pulley unit 4). The portion 4a) is maintained in contact with the side surface 4s, and the lip portion 30b is not separated from the side surface 4s of the pulley portion 4a by the centrifugal force during rotation.
Further, the lip portion 30b is configured to contact the side surface 4s of the pulley unit 4 (specifically, the pulley portion 4a) within the range of the width W of the base end portion 30a in the central axis Ax direction. Therefore, the large deformation due to the warp of the lip portion 30b does not occur, and the early breakage of the dust seal 30 can be prevented.

  As described above, according to this embodiment, the gap G formed between the damper unit 2 and the pulley unit 4 (pulley part 4a) in the circumferential direction can be closed without any gap from the outside over the entire circumference by the dust seal 30. it can. For this reason, it is possible to prevent intrusion of dust (for example, dust) from the outside, and as a result, early wear of the journal bearing 18 provided in the gap G can be prevented.

  Even when the pulley unit 4 is displaced in the radial direction due to the tension of the endless belt stretched over the pulley portion 4a, the lip portion 30b of the dust seal 30 is separated from the side surface 4s of the pulley unit 4 (pulley portion 4a). Without being affected by the radial displacement of the pulley unit 4, and the gap G described above can be completely removed from the gap G since the contact state with the side surface 4 s of the pulley unit 4 (pulley unit 4 a) can be maintained. It can be closed without a gap from the outside over the circumference.

  Further, a seal attachment portion 2p is formed in a part of the configuration of the damper unit 2 (for example, a part of the inertia mass body 16), and this seal attachment portion 2p defines the vulcanization adhesion position of the dust seal 30. Since it becomes a positioning part, the vulcanization adhesion of the dust seal | sticker 30 becomes easy, and the precision of an attachment position can be improved.

  Further, as described above, an annular dust seal 30 having a smaller diameter than the outer diameter of the seal attachment portion 2p is formed, and the dust seal 30 is detachably attached to the seal attachment portion 2p by its own elastic force while expanding the diameter. In this case, the dust seal 30 can be easily replaced simply by replacing the dust seal 30 with the seal mounting portion 2p.

In the present embodiment, an example in which a convex seal mounting portion 2p continuous in the circumferential direction is provided in a part of the configuration of the damper unit 2 (for example, a part of the inertia mass body 16) is shown. Instead of this, although not particularly illustrated, a part of the configuration of the damper unit 2 (for example, a part of the inertial mass body 16) may be provided with a seal mounting portion formed in a concave shape continuous in the circumferential direction. In this case, the dust seal 30 is attached to the damper unit 2 by fitting a part thereof into the concave seal attachment portion.
Further, the convex or concave (not shown) seal attaching portion 2p does not need to be continuously formed in the circumferential direction, and may be intermittently formed in the circumferential direction.

  Furthermore, in the present embodiment, as the seal attachment portion 2p, an example in which a part of the inertial mass body 16 is continuously formed in a convex shape in the circumferential direction is illustrated, but instead, for example, as shown in FIG. A support ring 100 that rotates integrally with the damper unit 2 and supports the journal bearing 18 is interposed between the damper unit 2 and the pulley unit 4, and a part of the support ring 100 is continuous in the circumferential direction. Alternatively, the circumferential seal mounting portion 2p may be formed by forming a convex shape. In place of this, although not particularly shown, a circumferential seal mounting portion in which a part of the support ring 100 is continuously depressed in the circumferential direction may be formed. In addition, in the pulley with a damper shown in FIG. 2, the description of the same configuration as that of the above-described embodiment (FIG. 1) is omitted by adding the reference numerals attached to the configuration in FIG. 2. To do.

2 Damper unit 4 Pulley unit 4s Side surface of pulley unit 18 Journal bearing 30 Dust seal G Gap

Claims (6)

A damper unit attached to the rotary shaft;
A pulley unit disposed on the outer peripheral side of the damper unit;
A journal bearing provided between the pulley unit and the damper unit or a member that rotates integrally with the damper unit in a state where the damper unit and the pulley unit are assembled in the axial direction;
A dust seal made of a rubber-like elastic body that closes the gap provided with the journal bearing from the outside over the entire circumference,
The dust seal is attached to the damper unit or a member that rotates integrally with the damper unit,
In the state where the damper unit and the pulley unit are assembled to each other in the axial direction, the dust seal has a lip portion that is always in contact with a side surface of the pulley unit.   The damper unit or a member that rotates integrally with the damper unit is provided with a seal attachment portion that extends continuously or intermittently in the circumferential direction, and the dust seal is attached to the seal attachment portion. The pulley with a damper according to claim 1.   The dust seal has a base end portion attached to the damper unit or a member that rotates integrally with the damper unit, and the lip portion is in a radial direction from the base end portion and in a direction approaching the pulley unit. The pulley with a damper according to claim 1 or 2, wherein the pulley is extended and is in contact with a side surface of the pulley unit by an elastic force of the lip portion.   The pulley with a damper according to claim 3, wherein the lip portion is in contact with a side surface of the pulley unit within a range of an axial width of the base end portion.   The pulley with a damper according to any one of claims 2 to 4, wherein the dust seal has an annular shape as a whole and is detachably attached to the seal attachment portion by its elastic force.   The pulley with a damper according to any one of claims 1 to 5, wherein a friction reducing material is contained in at least a lip portion of the dust seal.

Images