COMPACT CONTROL ARM AND SUSPENSION CYLINDER SWIVEL POINT

Abstract

work vehicle (10) comprising: a chassis (24); a drive motor (26) configured to move the chassis (24) along a ground surface; and a suspension assembly (38) coupling a wheel (20) to the chassis (24), the suspension assembly (38) comprising: a steering knuckle (54) coupled to the wheel (20), a first suspension arm (48) having a first section (70) rotatably coupled to the chassis (24) and a second section (72) extending away from the first section (70) and coupled to the steering knuckle (54), and a suspension cylinder (52) rotatably coupled to the chassis (24) and a second suspension arm (50), the first suspension arm (48) and the suspension cylinder (52) each being configured to pivot about a common pivot axis (130) relative to the chassis (24), the suspension cylinder (52) being configured to to be activated,to selectively extend and retract in length between the chassis (24) and the second suspension arm (50) in order to selectively raise and lower the height of the chassis (24) relative to the ground surface.

Description

BACKGROUND The present disclosure relates to work vehicles with an independent steering suspension, in particular to mounting configurations for suspension components. From DE 601 31 230 T2, a tractor is known which has a mechanical front-wheel drive. One wheel is bolted to the flange of the hub. The hub is supported by a steering knuckle, which in turn is supported by upper and lower steering arms of the suspension. The near ends of the upper and lower steering arms are pivotally attached to a differential housing, allowing the far ends of the steering arms to move up and down in order to raise and lower the front wheels relative to the differential housing. A hydraulic cylinder extends between the differential housing and the lower steering arm to support the load of the suspended mass. The cylinder is coupled to a gas accumulator to act like a spring.Furthermore, US Patent 4,546,997 A discloses a three-wheeled vehicle comprising a multi-tube longitudinal frame, two steerable front wheels, a single non-steerable rear wheel, and an engine. The vehicle also includes a steering and suspension assembly, which essentially comprises two support assemblies. A linkage is attached to the front end of the frame. A steering linkage is functionally connected to both support assemblies. The linkage includes a hydraulically actuated cylinder and piston assembly with a central cylinder element containing a single piston, from the opposite sides of which two piston rods extend. Each support assembly includes two A-shaped metal tube support arms. A cylindrical rod is rotatably mounted in brackets welded to the vehicle frame, such that it extends substantially horizontally along the longitudinal axis of the vehicle frame.The two support arms have cylindrical tube mounting sections that together accommodate an upright wheel support element. The cylindrical element is mounted centrally on the vehicle frame to a crossmember of the front part of the frame, so that it extends transversely between the two support assemblies. Two connecting arms are pivotally attached to the outwardly extending end of each piston rod. The connecting arms and the rear leg of the lower support arm are each attached to the cylindrical rod. Secondary connecting arms, which are essentially identical to the connecting arms, are rigidly attached to the cylindrical rod. A conventional dashpot-type shock absorber is pivotally mounted between the free ends of the secondary connecting arms about the same pivot axis as between the primary connecting arms and the associated piston rod of the cylinder and piston assembly.The shock absorber extends from there and is pivotably attached to the lower support arm. The object of the invention is to improve the adjustment of the chassis height relative to the ground surface. This is achieved by a work vehicle with the features of claim 1. SUMMARY According to the invention, a work vehicle is provided with the features of claim 1. In one embodiment, the disclosure provides a work vehicle comprising a chassis, a drive motor configured to move the chassis along a ground surface, and a suspension assembly coupling a wheel to the chassis. The chassis includes a pair of opposing flanges spaced apart along a longitudinal axis of the chassis and configured to support a pin between them. The suspension assembly includes a steering knuckle coupled to the wheel, a first suspension arm, and a suspension cylinder. The first suspension arm comprises a first section rotatably coupled to the chassis and a second section extending away from the first section and coupled to the steering knuckle.The first section comprises a first leg and a second leg spaced apart from the first leg along the longitudinal axis. The suspension cylinder is rotatably coupled to the chassis and to a second suspension arm. The second leg and the suspension cylinder are each rotatably coupled to the chassis via the pin. In a further embodiment, the disclosure provides a suspension subassembly comprising a suspension arm, a suspension cylinder, and a pin. The pin is configured to be received by each of the suspension arm and the suspension cylinder, such that during operation of the suspension assembly, the suspension arm and the suspension cylinder each rotate about a central axis of the pin. Further aspects of the revelation become apparent through consideration of the detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a work vehicle. Fig. 2 is a first perspective side view of a section of the work vehicle from Fig. 1. Fig. 3 is a front view of the section of the work vehicle shown in Fig. 2. Fig. 4 is a perspective close-up of the section of the work vehicle shown in Fig. 2. Fig. 5 is a perspective close-up from above of the section of the work vehicle shown in Fig. 2. Fig. 6 is a perspective close-up cross-sectional view of the section of the work vehicle shown in Fig. 2 along line 6-6 of Fig. 5. DETAILED DESCRIPTION Before embodiments of the disclosure are explained in detail, it should be understood that the disclosure is not limited in its application to the design details and component arrangement explained in the following description or illustrated in the following drawings. The disclosure may support other embodiments and be applied or implemented in various ways. Fig. 1 depicts a work vehicle 10 comprising a front section 12, a rear section 14, a first side section 16, a second side section 18, front wheels 20, a chassis 24, a drive motor 26, a cab 32, a control unit 34, and a user interface 36. The front wheels 20 are connected to the chassis 24 near the front section 12. While front wheels 20 are illustrated, other ground-penetrating attachments, such as crawler tracks, can be used. The drive motor 26 is coupled to the chassis 24 near the front section 12 and is configured to provide power to the front wheels 20 to move the work vehicle 10 over a ground surface. The cabin 32 is connected to the chassis 24 near the rear section 14. The control unit 34 can be positioned in or near the cabin 32 and is in electrical communication with the front wheels 20 and the drive motor 26 to send and receive signals from the front wheels 20 and the drive motor 26. The user interface 36 is located in the cabin 32, so that an operator positioned in the cabin 32 can engage the user interface 36, which is in electrical communication with the control unit 34, to send and receive signals. Referring to Figures 2 and 3, the work vehicle 10 includes a drive train 56 that transmits torque from the drive motor 26 to the front wheels 20. The drive train 56 includes a gearbox 58 coupled to the drive motor 26, an axle shaft 60 extending from the gearbox 58 along the first and second side sections 16, 18, and a wheel hub 62 coupled to each axle shaft 60. The work vehicle 10 also includes a suspension assembly 38 that connects the front wheels 20 (Fig. 1) to the chassis 24. The suspension assembly 38 allows vertical movement of the chassis 24 relative to the front wheels 20 along a vertical axis 40, which generally extends orthogonally to the ground surface (not shown). The illustrated suspension assembly 38 is an independent link suspension assembly 38, which includes a first side subassembly 42 and a second side subassembly 44. The first and second side subassemblies 42, 44 are essentially mirror images of each other about a longitudinal axis 46 of the work vehicle 10. With further reference to Fig. 2 and Fig. 3, the first and second side subassemblies 42, 44 of the suspension assembly 38 each comprise a first suspension arm or upper control arm 48, a second suspension arm or lower control arm 50, a suspension cylinder 52 (Fig. 3) and a steering knuckle 54. Each steering knuckle 54 rotatably carries a respective wheel hub 62, and each wheel hub 62 is coupled to each respective axle shaft 60 to rotate with it. Each front wheel 20 is attached to a respective wheel hub 62 at the first and second side sections 16, 18. In this way, the suspension assembly 38 is connected to each front wheel 20 via each wheel hub 62, which is carried by each respective steering knuckle 54. Referring to Fig. 4, each lower control arm 50 comprises a first section of the lower arm 64, which is coupled to the chassis 24, and a second section of the lower arm 66, which is opposite the first section of the lower arm 64 and pivotably coupled to the steering knuckle 54 (e.g., via a ball joint assembly). The first section of the lower arm 64 is rotatably coupled to the chassis 24 (e.g., via a pin connection) at a bracket of the lower arm 68, so that the second section of the lower arm 66 can pivot about the bracket of the lower arm 68 during operation of the work vehicle 10. Each suspension cylinder 52 is an elongated element extending between a first section or cylinder section 70, which is coupled to the chassis 24, and a second or rod section 72, which is coupled to the lower control arm 50. The suspension cylinder 52 is configured to extend or retract lengthwise between the cylinder section 70 and the rod section 72 (e.g., via hydraulic actuation). Referring again to Fig. 4, each upper control arm 48 similarly comprises a first section of the upper arm 74, which is coupled to the chassis 24, and a second section of the upper arm 76, which is opposite the first section 74 of the upper arm and pivotably coupled to the steering knuckle 54 (e.g., via a ball joint assembly). The first section of the upper arm 74 is also rotatably coupled to the chassis 24 (e.g., via a pin connection) at an upper arm bracket 78, so that the second section of the upper arm 76 can pivot about the upper arm bracket 78 during operation of the work vehicle 10. Referring to Figures 4 and 5, the first section of the upper arm 74 comprises a first leg 80, a second leg 82, and part of a third leg 84, which generally extends away from the first and second legs 80 and 82. The third leg 84 terminates at the second section of the upper arm 76. The first and second legs 80 and 82 are spaced apart from each other along a direction of the longitudinal axis 46 (Figure 2). The upper arm support 78 includes a front mounting structure 86 extending from the chassis 24 and a rear mounting structure 88 extending from the chassis 24 and spaced apart from the front mounting structure 86 along a direction of the longitudinal axis 46 (Fig. 2). The front mounting structure 86 couples the first leg 80 to the chassis 24, and the rear mounting structure 88 couples the second leg 82 to the chassis 24. Referring to Figures 5 and 6, the rear mounting structure 88 comprises a double clevis 90 with a first or front flange 92, a second or rear flange 94, and a third or intermediate flange 96 located between the front and rear flanges 92 and 94. The annular rear flange 94 defines a first opening 98, and the annular intermediate flange 96 defines a second opening 100. The annular front flange 92 defines a threaded bore 102 and a countersunk bore 104 adjacent to the threaded bore 102. The second leg 82 of the upper control arm 48 is accommodated in a space defined between the rear flange 94 and the intermediate flange 96. The second leg 82 defines a first bearing support 106, which accommodates a first bearing 108. In the illustrated embodiment, the first bearing 108 is configured as a pair of first bearing rings 110, which are held in the first bearing support 106 by a retaining ring 112. The second leg 82 further includes a pair of seals 114, which retain a lubricant in the first bearing support 106. In addition to coupling the second leg 82 to the chassis 24, the rear mounting structure 88 also couples the suspension cylinder 52 to the chassis 24. Specifically, the cylinder section 70 of the suspension cylinder 52 is accommodated in a space defined between the intermediate flange 96 and the front flange 92. The cylinder section 70 defines a second bearing support 116, which accommodates a second bearing 118. In the illustrated embodiment, the second bearing 118 is designed as a spherical bearing 118 comprising a pair of cup rings 120 and a cup 122 located between the cup rings 120. Referring to Fig. 6, the rear mounting structure 88 further includes a pin 124 that couples both the second leg 82 and the suspension cylinder 52 to the double clevis 90. Specifically, the pin 124 extends through the first opening 98, the first bearing 108, the second opening 100, and the second bearing 118, and further extends into the countersunk bore 104. The pin 124 includes a central bore 126, and the rear mounting structure 88 further includes a bolt 128 that extends through the central bore 126 and is screwed into the threaded bore 102 to secure the pin 124 in place. It is considered that, alternatively, in other embodiments, the bolt 128 could be screwed into a separate nut (not shown) instead of the threaded bore 102. The pin 124 defines a common pivot axis 130 around which both the upper control arm 48 and the suspension cylinder 52 rotate with respect to the chassis 24. In this respect, each of the first opening 98, the second opening 100, the threaded bore 102 and the countersunk bore 104 is centered around the common pivot axis 130. In operation, the suspension cylinder 52 exerts a force on the lower control arm 50 when the suspension cylinder 52 is actuated to extend. The exerted force causes the second section of the lower arm 66 to oscillate around the bracket of the lower arm 68, so that the chassis 24 substantially rises along the vertical axis 40 (Fig. 2) relative to the front wheels 20 and the ground surface. Similarly, when the suspension cylinder 52 is actuated to retract, the weight of the chassis 24 causes the second section of the lower arm 66 to oscillate around the bracket of the lower arm 68, so that the chassis 24 substantially lowers along the vertical axis 40 relative to the front wheels 20 and the ground surface. When the chassis 24 moves upwards or downwards relative to the front wheels 20, generally along the vertical axis 40 (Fig.2 ), both the upper control arm 48 and the suspension cylinder 52 rotate about the common pivot axis 130 relative to the chassis 24. By providing the common rear mounting structure 88 for both the second leg 82 and the suspension cylinder 52, such that the second leg 82 and the suspension cylinder 52 are supported by a common pin 124 defining a common pivot axis 130, space-saving advantages are achieved. In particular, a relatively smaller area of ​​the chassis 24 is dedicated to the common rear mounting structure 88 compared to conventional suspension assemblies with separate mounting structures for the upper control arm and the suspension cylinder. By using less space next to the chassis 24 to support the upper control arm 48 and the suspension cylinder 52, more space can subsequently be used for other purposes, e.g.to allow a larger turning radius for the wheels 20, to dimension cooling components to improve the cooling capacity of the work vehicle 10, or to add further features to the work vehicle. Additionally or alternatively, the entire vehicle body of the work vehicle 10 can be reduced as a result of the relative compactness of the common rear mounting structure 88. Another advantage of the common rear mounting structure 88 is that the first and second legs 80, 82 of the upper control arm 48 can be spaced relatively further apart compared to the arm sections of the upper control arms of conventional suspension assemblies, which use separate mounting points for the upper control arm and the suspension cylinder. By spacing the first and second legs 80, 82 relatively further apart, the weight of the chassis is distributed more efficiently, and reaction forces due to impacts of the front wheels 20 on the ground surface are better tolerated. Although the disclosure has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope of the disclosure as claimed.

Claims

work vehicle (10) comprising: a chassis (24); a drive motor (26) configured to move the chassis (24) along a ground surface; and a suspension assembly (38) coupling a wheel (20) to the chassis (24), the suspension assembly (38) comprising: a steering knuckle (54) coupled to the wheel (20), a first suspension arm (48) having a first section (70) rotatably coupled to the chassis (24) and a second section (72) extending away from the first section (70) and coupled to the steering knuckle (54), and a suspension cylinder (52) rotatably coupled to the chassis (24) and a second suspension arm (50), the first suspension arm (48) and the suspension cylinder (52) each being configured to pivot about a common pivot axis (130) relative to the chassis (24), the suspension cylinder (52) being configured to to be activated,to selectively extend and retract in length between the chassis (24) and the second suspension arm (50) in order to selectively raise and lower the height of the chassis (24) relative to the ground surface. Work vehicle according to claim 1, wherein the second suspension arm (50) is rotatably coupled to the chassis (24) and is further coupled to the axle stub (54). Working vehicle according to claim 1, wherein the suspension assembly (38) further includes a pin (124) configured to be received by each of the first suspension arm (48) and the suspension cylinder (52). Work vehicle according to one of claims 1 to 3, wherein the chassis (24) extends along a longitudinal axis (46) and wherein the first section of the first suspension arm (48) comprises a first leg (80) and a second leg (82) which is spaced apart from the first leg (80) along a direction of the longitudinal axis (46). Work vehicle according to claim 4, wherein the chassis (24) includes a first flange (92), a second flange (94) spaced apart from the first flange (92) along the direction of the longitudinal axis (46), and a third flange (96) located between the first and the second flange (92, 94), wherein the second leg (82) is received between the second flange (94) and the third flange (96), and wherein a cylinder section (70) of the suspension cylinder (52) is received between the first flange (92) and the third flange (96). Working vehicle according to claim 5, wherein a pin (124) couples the first leg (80) and the cylinder section (70) to the first, second and third flanges (92, 94, 96) respectively, and wherein the pin (124) defines the common pivot axis (130). Work vehicle according to claim 1, wherein the first section of the first suspension arm (48) comprises a first leg (80) and a second leg (82) which is spaced apart from the first leg (80) along a direction of a longitudinal axis (46) of the chassis (24), and wherein the first leg (80) and the suspension cylinder (52) are each rotatably coupled to the chassis (24) via a pin (124) which defines the common pivot axis (130). Working vehicle according to claim 7, wherein the first leg (80) defines a first bearing support (106) which accommodates a first bearing (108), and wherein the suspension cylinder (52) includes a cylinder section (70) which defines a second bearing support (116) which accommodates a second bearing (118). Working vehicle according to claim 8, wherein the first and second bearings (108, 118) each accommodate the pin (124).

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