US20160251999A1

US20160251999A1 - Fan drive assembly

Info

Publication number: US20160251999A1
Application number: US15/149,509
Authority: US
Inventors: Jason D. Pape; Craig P. HITTLE
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2016-05-09
Filing date: 2016-05-09
Publication date: 2016-09-01

Abstract

A fan drive assembly for a cooling system of an engine is provided. The engine includes an engine housing and a crankshaft. The fan drive assembly includes a fan pulley, a drive pulley, and a connection assembly. The fan pulley rotates a fan unit. The drive pulley defines a central cavity and rotates the fan pulley about a first axis. The connection assembly is provided in association with the engine and the drive pulley. The connection assembly includes a coupling member and a support bracket. The coupling member couples the crankshaft to the drive pulley. The support bracket is attached to the engine housing and is extended along a second axis. The second axis is perpendicular to the first axis. The support bracket further includes at least two attachment members and a hollow projecting portion. The hollow projecting portion axially extends through the central cavity of the drive pulley.

Description

TECHNICAL FIELD

The present disclosure relates generally to a fan drive assembly for a cooling system of an engine. More specifically, the present disclosure relates to a connection assembly for the fan drive assembly.

BACKGROUND

Engines, such as internal combustion engines, generally employ a cooling system to cool various mechanical components of the engine. The cooling system of the engine typically includes a radiator and a fan unit installed on a frontal end of the engine. The fan unit is utilized to encourage airflow towards the radiator in order to disperse heart from inflowing engine coolant to the surrounding air. Further, a fan drive assembly may rotate and power the fan unit of the cooling system. The fan drive assembly transfers rotational torque from a crankshaft of the engine to the fan unit to power and drive the fan unit.
The fan drive assembly includes a fan pulley, a drive pulley, and a belt arrangement. The drive pulley engages with the fan pulley via the belt arrangement. The fan pulley rotates the fan unit. The drive pulley is fixedly attached to and driven by the crankshaft of the engine. In general, the drive pulley receives rotational torque from the crankshaft and rotates the fan pulley. The fan pulley then transfers the rotational torque to the fan unit in order to drive the fan unit.
In conventional fan drive assemblies, the drive pulley is connected to and supported by the crankshaft, which is rotatably supported on an engine housing. Therefore, a vertical fan drive load exerted on the drive pulley of the fan drive assembly may be transferred to the crankshaft of the engine. In certain situations, such as heavy loaded conditions of the fan unit, an increased vertical fan belt load may be observed on the drive pulley. As the drive unit is attached to and supported by the crankshaft, the increased vertical fan belt load may further be transferred and imparted to the crankshaft of the engine. This may induce stresses in the crankshaft and may lead to failure of the crankshaft.
U.S. Pat. No. 8,833,337 describes a front drive power take-off system, to drive an auxiliary unit (for example the fan unit) mounted on the engine. A pulley and belt drive assembly includes a drive sprocket mounted on a crankshaft, a toothed belt interconnecting the drive sprocket, and a pulley mounted on a drive shaft of the auxiliary unit (for example the fan unit), to transmit power from the crankshaft to the auxiliary unit (for example the fan unit). A vertical fan drive load is still imparted on the crankshaft, while driving the auxiliary unit (for example the fan unit), sometimes leading to failure of the crankshaft.
In known systems, component failure of the crankshaft may in turn lead to an increase in operating cost, resulting in high system downtime and affecting an overall productivity of the system. Hence, there is a need for an improved fan drive assembly design.

SUMMARY OF THE INVENTION

Various aspects of the present disclosure describe a fan drive assembly for a cooling system of an engine. The engine includes a crankshaft and an engine housing. The fan drive assembly includes a fan pulley, a drive pulley, and a connection assembly. The fan pulley is adapted to rotate a fan unit. The drive pulley is adapted to rotate the fan pulley about a first axis. The drive pulley is adapted to rotate the fan pulley about a first axis. The drive pulley defines a central cavity therewithin. The connection assembly is provided in association with the engine and the drive pulley. The connection assembly includes a coupling member and a support bracket. The coupling member is adapted to couple the crankshaft to the drive pulley. The support bracket is fixedly attached to the engine housing. The support bracket extends along a second axis. The second axis is perpendicular to the first axis. The support bracket includes at least two attachment members spaced apart from each other. Further, the support bracket includes a hollow projecting portion that extends axially through the central cavity of the drive pulley. The connection assembly at least partially decouples a fan belt load from the crankshaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a front portion of an engine, illustrating a cooling system having a radiator, a fan unit, and a fan drive assembly, in accordance with the concepts of the present disclosure;

FIG. 2 is a sectional side view a section of the front portion of the engine of FIG. 1, illustrating various components of the fan drive assembly of the cooling system, in accordance with the concepts of the present disclosure; and

FIG. 3 is a perspective view of a support bracket member of a connection assembly of the fan drive assembly of FIG. 2, in accordance with the concepts of the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, a front portion of an exemplary engine 10 is illustrated. The engine 10 is a petrol engine that includes an engine housing 1 crankshaft 14 (see FIG. 2), and a cooling system 16. Although, the engine 10 is described as a petrol fuel engine in the present disclosure, various other types of the engine 10 may also be contemplated. Examples of the engine 10 may include, but is not limited to, a diesel fuel engine, a gaseous fuel engine, and a dual fuel engine.
The engine housing 12 encloses various mechanical components (not shown) of the engine 10, which facilitate the engine 10 to produce mechanical power. Mechanical components (not shown) of the engine 10 may include, but not limited to, pistons, combustion cylinders, valves, and gear arrangements. The crankshaft 14 (see FIG. 2) rotates within the engine housing 12. Additionally, the crankshaft 14 (see FIG. 2) extends beyond the engine housing 12, to drive a number of outboard mechanical ancillaries of the engine 10.
The cooling system 16 may cool the mechanical components (not shown) of the engine 10 enclosed by the engine housing 12. The cooling system 16 includes a radiator 18 and a fan unit 20 installed on a frontal end 24 of the engine housing 12. In addition, the cooling system 16 employs a fan drive assembly 22 to power and drive the fan unit 20 of the cooling system 16.
The radiator 18 is positioned proximate to the frontal end 24 of the engine housing 12. The radiator 18 is in fluid communication with the engine housing 12. An engine coolant may circulate between the engine housing 12 and the radiator 18. The engine coolant may extract heat from the mechanical components (not shown) and disperse this heat to external environment. More specifically, the engine coolant extracts heat from the mechanical components (not shown) while flowing through the engine housing 12. Upon exiting the engine housing 12, the engine coolant passes through the radiator 18 for cooling and recirculation to the engine housing 12.
The fan unit 20 is positioned between the engine housing 12 and the radiator 18. The fan unit 20 is adapted to cool the engine coolant flowing through the radiator 18. More specifically, upon rotation, the fan unit 20 encourages airflow towards the radiator 18 in order to disperse heat from inflowing engine coolant to the surrounding air. The fan unit 20 is supported and driven by the fan drive assembly 22.
Referring to FIG. 2, a sectional view of a portion of the engine 10 including the fan drive assembly 22 that drives the fan unit 20 is illustrated. The fan drive assembly 22 is positioned between the engine housing 12 and the fan unit 20. The fan drive assembly 22 transfers rotational torque from the crankshaft 14 to the fan unit 20 in order to drive the fan unit 20. The fan drive assembly 22 includes a fan pulley 26, a drive pulley 28, a belt arrangement 30, a fan pulley support assembly 32, and a connection assembly 34.
The fan pulley 26 is a hollow cylindrical structure that defines a central hollow section 38 and a first axis X-X′. Further, the fan pulley 26 is attached to the fan unit 20. In general, a shaft 36 of the fan unit 20 is fixedly attached to the fan pulley 26, facilitating an attachment between the fan unit 20 and the fan pulley 26. Therefore, a rotational motion of the fan pulley 26 corresponds to rotation of the fan unit 20. An attachment means between the shaft 36 of the fan unit 20 and the fan pulley 26 may include, but not limited to, a bolt attachment, a weld attachment, and a rivet attachment.
The drive pulley 28 is a hollow cylindrical structure that defines a central cavity 40 and a drive axis A-A′. The drive pulley 28 is engaged with the fan pulley 26 via the belt arrangement 30. In general, a number of belts 31 of the belt arrangement 30 pass over each of the fan pulley 26 and the drive pulley 28 to facilitate the driving engagement between the drive pulley 28 and the fan pulley 26. Therefore, a rotational motion of the drive pulley 28 corresponds to rotation of the fan pulley 26 about the first axis X-X′. The first axis X-X is parallel to the drive axis A-A′. Although, the present disclosure contemplates usage of V-belts as the belts 31 of the belt arrangement 30, various other types of the belts 31 may also be utilized without any limitation. Examples of the belts 31 may include, but not limited to, flat belts, round belts, and multi-groove belts.
The fan pulley support assembly 32 is provided in association with the engine 10 and the fan pulley 26 to rotatably support the fan pulley 26 on the engine housing 12. The fan pulley support assembly 32 includes a spacer member 42 and a support member 44. One end of the spacer member 42 is fixedly attached to the engine housing 12 and another end of the spacer member 42 is fixedly attached to the support member 44. The support member 44 includes a cylindrical portion 46 that extends through the central hollow section 38 of the fan pulley 26 to rotatably support the fan pulley 26. More specifically, the cylindrical portion 46 of the support member 44 rotatably supports the fan pulley 26 via a first bearing arrangement 48. Such arrangement of the spacer member 42 and the support member 44 facilitates the fan pulley 26 to be rotatably supported on the engine housing 12.
The connection assembly 34 is provided in association with the engine 10 and the drive pulley 28 to connect the drive pulley 28 to the crankshaft 14 of the engine 10. Additionally, the connection assembly 34 supports the drive pulley 28 on the engine housing 12. The connection assembly 34 includes a coupling member 50 and a support bracket 52.
The coupling member 50 of the connection assembly 34 attaches the drive pulley 28 to the crankshaft 14. The coupling member 50 may he any conventional flange coupling that includes a first member 54 and a second member 56. The first member 54 is attached to the crankshaft 14. In an embodiment, the first member 54 of the coupling member 50 is attached to the crankshaft 14 via a crankshaft adapter 58. The second member 56 of the coupling member 50 is attached to the drive pulley 28. In an embodiment, the second member 56 of the coupling member 50 is attached to the drive pulley 28 via a drive arrangement 60. The drive arrangement 60 includes a cylindrical portion 62 and an end plate portion 64. The cylindrical portion 62 is attached to the second member 56 and extends through the central cavity 40 of the drive pulley 28. The end plate portion 64 further attaches to the drive pulley 28 to facilitate the attachment between the second member 56 of the coupling member 50 and the drive pulley 28. Although a flange coupling is described as the coupling member 50 in the present disclosure, alternatively, various other types of the coupling member 50 may also be contemplated. Examples of the coupling member 50 may include, but not limited to, fluid coupling, Oldham coupling, rag joint coupling, and universal joint coupling.
Referring to FIG. 3, the support bracket 52 that supports the drive pulley 28 on the engine housing 12 is illustrated. The support bracket 52 may be made of casted steel material. The support bracket 52 includes a first end portion 66, a second end portion 68 opposite to the first end portion 66, and a hollow projecting portion 70. Further, an elongate aperture 80 is defined on the support bracket 52.
The first end portion 66 is attached to the support member 44 of the fan pulley support assembly 32, which in turn is attached to the engine housing 12. Attachment between the first end portion 66 and the support member 44 (see FIG. 2) mounts and supports the support bracket 52 on the engine housing 12. The first end portion 66 includes first through holes 72 to receive an attachment means (not shown) that attaches the first end portion 66 to the support member 44 (see FIG. 2). The attachment means (not shown) between the support member 44 and the first end portion 66 may include, but not limited to, a bolt attachment, a weld attachment, and a rivet attachment.
When installed, the support bracket 52 extends from the first end portion 66 to the second end portion 68 along a second axis Y-Y′ (see FIG. 2). The second axis Y-Y′ is perpendicular to the first axis X-X′. The second end portion 68 is attached to the engine housing 12 to mount and support the support bracket 52 on the engine housing 12. The second end portion 68 includes two attachment members 74, 76 spaced apart from each other, namely a first attachment member 74 and a second attachment member 76. Each of the first attachment member 74 and the second attachment member 76 includes second through holes 78 to receive an attachment means (not shown) that attaches the second end portion 68 to the engine housing 12. The attachment means (not shown) between the engine housing 12 and the second end portion 68 may include, but not limited to, a bolt attachment, a weld attachment, and a rivet attachment. Although, the present disclosure describes two attachment members 74, 76, a number of the attachment members 74, 76 may also be contemplated. The number of the attachment members 74, 76 used may vary based on the application and do not limit the scope of the disclosure.
The hollow projecting portion 70 is positioned between the first end portion 66 and the second end portion 68. The hollow projecting portion 70 passes through the central cavity 40 of the drive pulley 28 and rotatably supports the drive pulley 28 on the engine housing 12. More specifically, the hollow projecting portion 70 defines an outer peripheral portion 82 and an inner peripheral portion 84. The drive pulley 28 is supported on the outer peripheral portion 82 of the hollow projecting portion 70 via a second bearing arrangement 86. While the drive pulley 28 is supported on the outer peripheral portion 82, the cylindrical portion 62 of the drive arrangement 60 passes through the inner peripheral portion 84 to allow a connection between the coupling member 50 and the drive pulley 28. The shape, size, and dimensions of the support bracket 52 illustrated in the accompanying figures are exemplary and do not limit the scope of the present disclosure. Although, the support bracket 52 is described to be made of casted steel material, various other materials of the support bracket 52 may also be contemplated. Examples of the materials may include, but not limited to, casted aluminum, cast iron, and various alloys of iron.

INDUSTRIAL APPLICABILITY

In operation, the fan unit 20 may rotate to generate airflow towards the radiator 18 and disperse heat from the inflowing engine coolant to external environment. To facilitate rotation of the fan unit 20, the fan drive assembly 22 may transmit rotational torque from the crankshaft 14 to the fan unit 20. More specifically, the drive pulley 28 of the fan drive assembly 22 may receive rotational torque from the crankshaft 14 and transmit the torque to the fan pulley 26. The belt arrangement 30 may transmit the rotational torque from the drive pulley 28 to the fan pulley 26. The fan pulley 26 may then transmit the rotational torque to the fan unit 20 in order to rotate the fan unit 20.
Moreover, torque transmission between the crankshaft 14 and the drive pulley 28 is facilitated, via the connection assembly 34. The connection assembly 34 facilitates connection between the crankshaft 14 and the drive pulley 28. Additionally, the connection assembly 34 supports the drive pulley 28 on the engine housing 12. In an embodiment, the coupling member 50 of the connection assembly 34 connects the crankshaft 14 to the drive pulley 28. The support bracket 52 of the connection assembly 34 supports the drive pulley 28 on the engine housing 12.
During normal operation of torque transmission by the fan drive assembly 22, the belt arrangement 30 may exert a fan belt load on the drive pulley 28 in a vertical direction B (see FIG. 2). As the drive pulley 28 is supported on the support bracket 52, the fan belt load may be transmitted to the support bracket 52. Further, as the support bracket 52 is supported on the engine housing 12, the fan belt load may be transmitted to and supported by the engine housing 12. Therefore, the crankshaft 14 is decoupled from the fan belt load of the fan drive assembly 22.
More specifically, such structure and arrangement of the support bracket 52 facilitates decoupling of the crankshaft 14 from the fan belt load and may reduce or prevent unwanted stresses in the crankshaft 14. This in turn may reduce chances of crankshaft failure, resulting in improved life of the crankshaft 14. Therefore, such arrangement may reduce frequent service and repair events of the engine 10, resulting in a reduction in service and repair cost of the engine 10. Additionally, the structure and arrangement of the connection assembly 34 is such that the connection assembly 34 provides a compact coupling of the associated components so that the fan drive assembly 22 may be brought closer to the engine housing 12.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claim(s) and any equivalents thereof.

Claims

What is claimed is:

1. A fan drive assembly for a cooling system of an engine, the engine including a crankshaft and an engine housing, the fan drive assembly comprising:

a fan pulley adapted to rotate a fan unit;

a drive pulley adapted to rotate the fan pulley about a first axis, the drive pulley defining a central cavity therewithin; and

a connection assembly provided in association with the engine and the drive pulley, the connection assembly including:

a coupling member adapted to couple the crankshaft to the drive pulley; and

a support bracket fixedly attached to the engine housing and extending along a second axis, wherein the second axis is perpendicular to the first axis, the support bracket including at least two attachment members provided spaced apart from each other, the support bracket further including a hollow projecting portion axially extending through the central cavity of the drive pulley,

wherein the connection assembly is adapted to at least partially decouple a fan belt load from the crankshaft.