Cone clutch for vehicle

A cone clutch apparatus for the vehicle according to an exemplary embodiment of the present invention includes a hub, a sleeve, a clutch ring including a clutch cone, a first friction ring, an internal middle cone, a second friction ring, an external middle cone, and a third friction ring, wherein clutch ring passages allowing oil to be supplied are formed in the clutch cone, and inclined surfaces for increasing areas with which the oil passing through the clutch ring passages are in contact while moving are formed on the internal middle cone, the second friction ring, and the external middle cone.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2019-0113282, filed Sep. 16, 2019, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a clutch for a vehicle, and more particularly, to a lubricating structure of a clutch which may be used in a transmission.

Description of Related Art

A plurality of clutches are used in a transmission or the like of a vehicle to intermit power transfer between rotating bodies rotating relative to each other

The clutch as described above has a large torque transfer capacity while occupying as small a volume as possible, but generally, to secure a large torque transfer capacity, a volume of the clutch tends to be increased.

Meanwhile, to increase a torque transfer capacity of the clutch, a friction area that generates a frictional force needs to be increased, and in a structure of increasing the friction area by use of a plurality of components in a relatively narrow space, heat capacities of the components themselves are small and it is not easy to secure a space necessary for lubrication and cooling, such that it is difficult to secure durability of the components.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a cone clutch for a vehicle which is configured for implementing a relatively large torque transfer capacity while having a simple and compact configuration and occupying a relatively small volume and is configured for securing sufficient durability by allowing lubrication and cooling of used components to be smoothly performed.

According to an exemplary embodiment of the present invention, a cone clutch for a vehicle, includes: a hub mounted so that movement thereof in an axial direction and rotation thereof are restricted to a shaft; a sleeve mounted so that a rotation of the sleeve is restricted to an external side of the hub and a movement of the sleeve in the axial direction is allowed; a clutch ring mounted so that a movement of the clutch ring in the axial direction is restricted and a rotation of the clutch ring is allowed with respect to the shaft and integrally including a clutch cone protruding toward the hub and having a gradually reduced external diameter, a first friction ring provided between the clutch ring and the hub, mounted so that rotation thereof is restricted with respect to the hub, and pressed toward the clutch ring along the axial direction thereof to allow a frictional force to be formed between the first friction ring and the clutch cone; an internal middle cone mounted so that a rotation of the internal middle cone is restricted with respect to the clutch ring and having an internal side surface in contact with an external side surface of the first friction ring; a second friction ring mounted so that a rotation of the second friction ring is restricted with respect to the hub and having an internal side surface in contact with an external side surface of the internal middle cone; an external middle cone mounted so that a rotation of the external middle cone is restricted with respect to the clutch ring and having an internal side surface in contact with an external side surface of the second friction ring; and a third friction ring mounted so that a rotation of the third friction ring is restricted with respect to the hub and having an internal side surface in contact with an external side surface of the external middle cone when the third friction ring is pressed by the sleeve, wherein clutch ring passages through which oil supplied through an internal portion of the shaft and discharged in a radial direction passes and is supplied to a space positioned between the first friction ring and the clutch ring are formed in the clutch cone, and inclined surfaces for increasing areas with which the oil passing through the clutch ring passages are in contact while moving are formed on the internal middle cone, the second friction ring, and the external middle cone.

The shaft may be provided with shaft holes for supplying the oil to the clutch ring passages, and when a portion of the hub is positioned between the shaft holes and the clutch ring passages, the hub may be provided with hub passages through which the oil passing through the shaft holes linearly moves to the clutch ring passages.

The hub passage may be formed of an oil groove, and the clutch ring passage may be formed of an oil hole.

A plurality of oil grooves may be formed in the internal middle cone so that phases thereof along a circumferential direction coincide with those of the clutch ring passages, and some of the oil grooves may form a first inclined surface which is one of the inclined surfaces.

The first inclined surface may be formed by a trajectory along which a straight line inclined toward the clutch ring toward an external diameter direction in a cross section of the internal middle cone along the axial direction rotates along the circumferential direction thereof.

An end portion of the second friction ring close to the clutch ring may form a second inclined surface which is one of the inclined surfaces.

The second inclined surface may be formed by a trajectory along which a straight line starting from a position at which an internal side in the radial direction is further biased toward the clutching ring as compared with the first inclined surface and inclined toward the clutch ring toward the external diameter direction in a cross section of the second friction ring along the axial direction rotates along the circumferential direction thereof.

The second inclined surface may form an angle smaller than an angle formed by the first inclined surface with respect to the shaft.

A plurality of oil grooves may be formed in the external middle cone so that phases thereof along the circumferential direction coincide with those of the oil grooves of the internal middle cone, and some of the oil grooves may form a third inclined surface which is one of the inclined surfaces.

The oil grooves of the external middle cone may be formed to have a width greater, in the circumferential direction, than that of the oil grooves of the internal middle cone.

The third inclined surface may be formed by a trajectory along which a straight line starting from a position at which an internal side in the radial direction is further biased toward the clutching ring as compared with the second inclined surface and inclined toward the clutch ring toward the external diameter direction in a cross section of the external middle cone along the axial direction rotates along the circumferential direction thereof.

The third inclined surface may form an angle smaller than an angle formed by the second inclined surface with respect to the shaft.

DETAILED DESCRIPTION

Referring toFIG. 1,FIG. 2,FIG. 3,FIG. 4, andFIG. 5, a cone clutch for a vehicle according to an exemplary embodiment of the present invention is configured to include a hub3mounted so that movement thereof in an axial direction and rotation thereof are restricted to a shaft1; a sleeve5mounted so that rotation thereof is restricted to an external side of the hub3and a movement thereof in the axial direction is possible; a clutch ring9mounted so that movement thereof in the axial direction is restricted and rotation thereof is possible with respect to the shaft1and integrally including a clutch cone7protruding toward the hub3and having a gradually reduced external diameter; a first friction ring11provided between the clutch ring9and the hub3, mounted so that rotation thereof is restricted with respect to the hub3, and pressed toward the clutch ring9along the axial direction thereof to allow a frictional force to be formed between the first friction ring11and the clutch cone7; an internal middle cone13mounted so that rotation thereof is restricted with respect to the clutch ring9and having an internal side surface in contact with an external side surface of the first friction ring11; a second friction ring15mounted so that rotation thereof is restricted with respect to the hub3and having an internal side surface in contact with an external side surface of the internal middle cone13; an external middle cone17mounted so that rotation thereof is restricted with respect to the clutch ring9and having an internal side surface in contact with an external side surface of the second friction ring15; and a third friction ring19mounted so that rotation thereof is restricted with respect to the hub3and having an internal side surface in contact with an external side surface of the external middle cone17when the third friction ring is pressed by the sleeve5.

That is, in a state in which the hub3is mounted so that both of the movement thereof in the axial direction thereof and the rotation thereof are restricted onto the shaft1and the clutch ring9is mounted so that the movement thereof in the axial direction is restricted and the rotation thereof is possible, the cone clutch according to an exemplary embodiment of the present invention is configured to switch between a state in which a torque is transferred between the hub3and the clutch ring9and a release state in which the torque is not transferred between the hub3and the clutch ring9, and a gear or the like is connected integrally with the clutch ring9, such that the cone clutch according to an exemplary embodiment of the present invention is ultimately configured to intermit power between the shaft1and the gear.

For reference, a gear21is coupled integrally with the clutch ring9.

Here, the cone clutch according to an exemplary embodiment of the present invention may continuously change the transferred torque by continuously varying a frictional force between the hub3and the clutch ring9, and does not transfer a torque by gears by engaged with each other as in a synchromesh device according to the related art.

For reference, the axial direction refers to a longitudinal direction of the shaft1, and a radial direction refers to a radial direction of the shaft1. In an operation state as illustrated inFIG. 4, the first friction ring11, the second friction ring15, and the third friction ring19rotating together with the hub3forms a frictional force while being in close contact with the internal middle cone13and the external middle cone17rotating together with the clutch ring9to allow power to be transferred between the hub3and the clutch ring9. In a release state as illustrated inFIG. 5, the first friction ring11, the second friction ring15, and the third friction ring19rotate together with the hub3, and the internal middle cone13and the external middle cone17may have a speed different from that of the hub3, together with the clutch ring9.

Here, as illustrated inFIG. 4, in a state in which the third friction ring19is pressed by the sleeve5, such that all of the third friction ring19, the external middle cone17, the second friction ring15, the internal middle cone13, the first friction ring11, and the clutch cone7are in close contact with each other, distances by which these components are spaced from the hub3in the axial direction are configured to be gradually increased in a sequence of the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19, as illustrated inFIG. 1.

For reference,FIG. 4illustrates an operation state in which the sleeve5actually presses the third friction ring19to allow the torque to be transferred between the hub3and the clutch ring9, andFIG. 1illustrates a state in which only the sleeve5retreats to a neutral state from the state as illustrated inFIG. 4, to compare a distance by which the third friction ring19is spaced from the hub3in the axial direction with distances by which the other components are spaced from the hub3.

That is, in the state in which the third friction ring19is pressed by the sleeve5, such that all of the third friction ring19, the external middle cone17, the second friction ring15, the internal middle cone13, the first friction ring11, and the clutch cone7are maximally moved toward the clutch ring9to be sequentially in close contact with each other, distances by which the components described above are spaced from the hub3are configured to be gradually increased in a sequence of the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19.

As described above, when the distances by which the components described above are spaced from the hub3are configured to be increased toward the radial direction on the basis of the shaft1in the state in which all of the components described above (the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19) are in close contact with each other toward the clutch ring9, as illustrated inFIG. 5, in the state in which all of the components described above are in close contact with each other toward the hub3, gaps G are naturally formed between the respective components due to a structural feature.

When the gaps G are formed between the components as described above, frictional forces are hardly generated between the respective components, such that drags may be significantly reduced.

The state as illustrated inFIG. 5is the release state in which the cone clutch according to an exemplary embodiment of the present invention does not transfer the power, and a state in which the drags are hardly generated between the respective components is formed to minimize unnecessary power consumption at the time of driving the vehicle, such that fuel efficiency of the vehicle may be ultimately improved.

In an exemplary embodiment of the present invention, the distances by which the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19are spaced from the hub3in the axial direction are configured to be sequentially increased as multiples of a distance D by which the first friction ring11is spaced from the hub3.

Therefore, when all of the components described above are in close contact with each other toward the hub3, as illustrated inFIG. 5, all constant intervals are formed between the components, which prevents a gap G formed between any specific components from being relatively small or relatively large to prevent occurrence of an increase phenomenon or the like of a local drag.

Meanwhile, in an exemplary embodiment of the present invention, a surface of the hub3facing the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19forms a plane perpendicular to the shaft1.

Furthermore, clutch ring passages25through which oil supplied through an internal portion of the shaft1and discharged in the radial direction passes and is supplied to a space positioned between the first friction ring11and the clutch ring9are formed in the clutch cone7, and inclined surfaces for increasing areas with which the oil passing through the clutch ring passages25are in contact while moving to increase a cooling effect and pressing the components toward the hub3by a pressure applied by the oil while the oil moves to form the state as illustrated inFIG. 5and thus generate an effect to reduce the drags are formed on the internal middle cone13, the second friction ring15, and the external middle cone17.

A flow of the oil discharged from the shaft1in the radial direction and the inclined surfaces will be described.

The shaft1is provided with shaft holes22for supplying the oil to the clutch ring passages25, and when a portion of the hub3is positioned between the shaft holes22and the clutch ring passages25, the hub3is provided with hub passages23through which the oil passing through the shaft holes22may linearly move to the clutch ring passages25.

That is, in a case in which the hub3is mounted in a state in which it does not block the shaft holes22, the hub passages23as described above are not separately required, but in a case of the exemplary embodiment illustrated inFIG. 1, the hub3is mounted in a state in which it blocks portions of the shaft holes22, and the hub passages23that are in communication with the shaft holes22are provided so that the oil passing through the shaft holes22may be smoothly discharged in the radial direction thereof.

In an exemplary embodiment of the present invention, the hub passage23is formed of an oil groove, and the clutch ring passage25is formed of an oil hole.

In a case in which the hub3is mounted in a state in which it completely blocks the shaft holes22, the hub passages23need to be processed in a form of an oil hole.

Since the rotation of the hub3and the movement of the hub3in the axial direction are restricted to the shaft, a plurality of hub passages23are formed in the same phases as those of the shaft holes22along a rotation direction thereof.

A plurality of oil grooves26is formed in the internal middle cone13so that phases thereof along a circumferential direction coincide with those of the clutch ring passages25, and some of the oil grooves form a first inclined surface27, which is one of the inclined surfaces.

That is, since the internal middle cone13is mounted in a state in which the rotation thereof is restricted to the clutch ring9, when the oil grooves of the internal middle cone13are formed so that the phases thereof along the circumferential direction coincide with those of the clutch ring passages25, the oil grooves of the internal middle cone13are always maintained in a state in which they are aligned with the clutch ring passages25, such that a smooth flow of the oil may be secured.

The first inclined surface27is formed by a trajectory along which a straight line inclined toward the clutch ring9toward an external diameter direction in a cross section of the internal middle cone13along the axial direction rotates along the circumferential direction thereof, as illustrated inFIG. 9.

Therefore, a contact area and time between the internal middle cone13and the oil are relatively increased as compared with a case in which a surface perpendicular to the shaft1is formed instead of the first inclined surface1while the oil discharged in the radial direction through the clutch ring passages25forms a flow as illustrated by an arrow along the first inclined surface27, such that cool performance of the internal middle oil13by the oil is improved, and a force for pressing the internal middle cone13toward the hub3is generated.

The second friction ring15is a component whose end portion itself close to the clutch ring9forms a second inclined surface29, which is one of the inclined surfaces, as illustrated inFIG. 10.

The second inclined surface29is formed by a trajectory along which a straight line starting from a position at which an internal side in the radial direction is further biased toward the clutching ring9as compared with the first inclined surface27and inclined toward the clutch ring9toward the external diameter direction in a cross section of the second friction ring15along the axial direction rotates along the circumferential direction thereof, and the second inclined surface29forms an angle smaller than an angle formed by the first inclined surface27with respect to the shaft1.

Therefore, due to a contact between the oil passing through the first inclined surface27and the entirety of the second inclined surface29when the oil moves from an internal side of the second inclined surface29to an external side of the second inclined surface29while being in contact with the second inclined surface29, cooling performance of the second friction ring15may be effectively secured and the second friction ring15may be effectively pressed toward the hub3.

A plurality of oil grooves30is formed in the external middle cone17so that phases thereof along the circumferential direction coincide with those of the oil grooves of the internal middle cone13, as illustrated inFIG. 11andFIG. 12, and some of the oil grooves form a third inclined surface31, which is one of the inclined surfaces.

The oil grooves of the external middle cone17are formed to have a width greater, in the circumferential direction, than that of the oil grooves of the internal middle cone13, such that the oil passing through the internal middle cone13and the second friction ring15may be smoothly moved in the external diameter direction thereof.

The third inclined surface31is formed by a trajectory along which a straight line starting from a position at which an internal side in the radial direction is further biased toward the clutching ring9as compared with the second inclined surface29and inclined toward the clutch ring9toward the external diameter direction in a cross section of the external middle cone17along the axial direction rotates along the circumferential direction thereof, and the third inclined surface31forms an angle smaller than an angle formed by the second inclined surface29with respect to the shaft1.

Therefore, due to a contact between the oil passing through the second inclined surface29and the entirety of the third inclined surface31when the oil moves from an internal side of the third inclined surface31to an external side of the third inclined surface31while being in contact with the third inclined surface31, cooling performance of the external middle cone17may be effectively secured and the external middle cone17may be effectively pressed toward the hub3.

For reference, the third friction ring19is cooled and lubricated by oil along a wall surface of a case of a transmission.

As described above, excellent cooling performance of the components described above is secured due to increases in a relative contact area and time between the components and the oil by the inclined surfaces, such that durability of the respective components may be improved, and a force for moving the components toward the hub3is applied to the components by a flow of the oil advancing in the radial direction of the shaft1through the hub passages23and the clutch ring passages25, such that the state as illustrated inFIG. 5is naturally formed to enable a significant reduction of the drag in the release state.

That is, in a state in which the third friction ring19is not pressed toward the clutch ring9by the sleeve5, a state in which the components are basically pressed toward the hub3by the flow of the oil is formed.

Therefore, when the sleeve5is in the neutral state as illustrated inFIG. 1, the components are naturally pressed toward the hub3by the flow of the oil to form the release state as illustrated inFIG. 5, such that a state in which the drags are minimized is formed.

One side portion of the first friction ring11is positioned adjacent to the hub3on the basis of the center portion of the clutch ring passages25, and the first friction ring11is thus pressed by the oil passing through the hub passages23and the clutch ring passages25and then discharged in the radial direction thereof. Therefore, the first friction ring11is pressed toward the hub3.

Meanwhile, the second inclined surface29of the second friction ring15is formed so that the angle formed by the second inclined surface29with respect to the shaft1is smaller than the angle formed by the first inclined surface27of the internal middle cone13with respect to the shaft1, and the third inclined surface31of the external middle cone17is formed so that the angle formed by the third inclined surface31with respect to the shaft1is smaller than the angle formed by the second inclined surface29of the second friction ring15with respect to the shaft1, such that the oil discharged through the hub passages23and the clutch ring passages25sequentially applies a pressure to the first inclined surface27, the second inclined surface29, and the third inclined surface31while advancing in the radial direction thereof, generating a force for moving the components toward the hub3.

That is, in an exemplary embodiment of the present invention, due to a structural feature that the first friction ring11, the internal middle cone13, the second friction ring15, the external middle cone17, and the third friction ring19form together with the hub3and the clutch ring9, in the operation state in which the power is transferred between the hub3and the clutch ring9, relatively wide friction surfaces are formed within a relatively small volume to provide a larger torque transfer capacity, and in the release state in which the power is not transferred, the gaps G between the respective components used to form the friction surfaces may be naturally secured to minimize the drags, which may contribute to improvement of fuel efficiency of the vehicle, and the contact area and time between the oil and the respective components may be increased to improve cooling and lubrication performance, improving durability.

The cone clutch for a vehicle according to an exemplary embodiment of the present invention may implement a relatively large torque transfer capacity while having a simple and compact configuration and occupying a relatively small volume and may secure sufficient durability by allowing lubrication and cooling of used components to be smoothly performed.