DESC:TECHNICAL FIELD
[0001] The present subject matter relates generally to a two-wheeled vehicle. More particularly but not exclusively, the present invention relates to a steering system for the two-wheeled vehicle.
BACKGROUND
[0002] Generally, in a two-wheeled vehicle, a steering assembly is provided to control the movement of the vehicle while travelling on the road. The steering assembly facilitates smooth rotation of the front wheel corresponding to the input given by the rider through the handle bar and to sustain the load transfer from the front wheel to the vehicle frame assembly. Generally, the steering assembly is integrated to the vehicle frame assembly through a lock nut. One or more steering races and balls are used in the steering assembly to sustain the load and to provide the smooth rotation of the steering assembly. One or more dust seals are used in the steering assembly to prevent the dust entry, water entry, foreign particles entry, etc. inside the steering assembly, which are detrimental to the durability and to the smooth rotation of the steering shaft. Further, in a two-wheeled vehicle, an upper bracket is provided to connect a front suspension and the handle bar assembly to the vehicle frame assembly. The upper bracket is capable of withstanding shock, impact, torsion, and clamping loads. Furthermore, a lower bracket is used to connect the front suspension to a main frame of the vehicle frame assembly. The lower bracket acts as a structural member to enable support for a steering bearing. The load is transferred from the front wheel to the vehicle frame assembly and the handlebar assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0004] Fig. 1 shows a side view of a two-wheeled motorcycle in accordance with an embodiment.
[0005] Fig. 2 illustrates a right side view of the steering assembly.
[0006] Fig. 3 depicts a cross sectional view of a portion of the steering assembly taken along the longitudinal direction of the vehicle.
[0007] Fig. 4 illustrates a detailed view of a top portion of the cross-sectional view of the steering assembly as shown in Fig. 3.
[0008] Fig. 5a illustrates an integrated steering arrestor and a tool placed on top of the integrated steering arrestor.
[0009] Fig. 5(b) illustrates the tool engaged with the integrated steering arrestor.
[00010] Fig. 6 illustrates an integrated steering arrestor according to an embodiment.
[00011] Fig. 7 illustrates a portion of an integrated steering arrestor.
[00012] Fig. 8 illustrates a sectional view of the integrated steering arrestor, section taken along xy plane as illustrated in Fig.6
DETAILED DESCRIPTION
[00013] Typically, the steering assembly for the two-wheeled vehicle comprises mainly of a lower bracket, a steering shaft, steering races top and bottom, ball bearings, steering arrestor, an upper bracket and a lock nut. The lower bracket enables the mounting of a pair of front forks through it. The front wheel is assembled to one end of the pair of front forks and an upper bracket is mounted at the other end. The lower bracket provides provision for the mounting of the steering shaft. The steering shaft is threaded at one end to enable mounting of the steering arrestor and the lock nut. A bottom cone is press fitted on to the steering shaft at a lower bracket end. The steering balls are later assembled onto the bottom cone.
[00014] The conventional steering assembly comprises of a teeth arrangement on the outer diameter of the steering arrestor to enable torqueing of the steering arrestor while assembling onto the steering shaft. Few steering systems comprises of knurling pattern or hexagonal pattern on the outer diameter of the steering arrestor. Both teeth arrangement and the knurling pattern are found on the outer diameter of the steering arrestor. All the designs including the teeth arrangement, the knurling pattern, and the hexagonal pattern are used to provide required torque to the steering arrestor while assembling, through several tools. However, not all of the above-mentioned patterns on the outer diameter provide required grip while assembling to provide required torque. Further, the engaging of the special tools on the outer diameter of the steering arrestor requires an additional space to accommodate the special tool in the vehicle layout. Thus, the vehicle cannot be maintained compact resulting in increased manufacturing cost.
[00015] Furthermore, the teeth arrangement on the steering arrestor cannot be provided on neither the outer diameter nor the inner diameter, since, the steering arrestor has to accommodate ball races. It is desirable that the outer diameter of the steering arrestor and the outer diameter of the special tools is the same. Further, during periodic servicing and maintenance, the steering arrestor has to be accessed by dismantling the entire steering assembly typically for hexagonal pattern and knurled pattern, which is undesirable. Further, due to the problem of not being able to reduce the vehicle layout space in order to accommodate the tools, the size of the steering arrestor integrated with the lock nut cannot be reduced further. Hence, the vehicle is not maintained compact.
[00016] Hence, according to an embodiment of the present invention, the problem involved in maintaining an additional space in the vehicle layout is overcome. An additional space need not be provided in the vehicle layout to accommodate the special tools.
[00017] According to the present invention, the torqueing of the steering arrestor can be done by utilizing the tools that do not demand for additional space in the vehicle layout design. In the present embodiment, the teeth feature is provided on a top surface of the steering arrestor instead of the outer diameter of the steering arrestor. Hence, the outer diameter of the special tool lies within the outer diameter of the steering arrestor and no additional space is required in the vehicle to accommodate the tools. Therefore, the vehicle layout space is saved and the vehicle becomes compact.
[00018] Further, manufacturing cost is reduced due to non-requirement of the additional space to accommodate the tools while assembling the steering arrestor. Further, the servicing of the steering arrestor is also easy and does not require dismantling of the entire steering assembly of the two-wheeled vehicle.
[00019] Further, during servicing of the steering arrestor, involving tightening or loosening of the steering arrestor can be done without dismantling the entire steering assembly.
[00020] Furthermore, the additional space saved in the vehicle layout design enables to accommodate other vehicular parts including lockset and the like parts and provides more freedom to design vehicles with more compact packaging.
[0001] The previously mentioned and other advantages of the present subject matter would be described in detail in conjunction with the figures in the following description.
[00021] Fig. 1 illustrates a side view of a two-wheeled vehicle, for example, a motorcycle 1 according to an embodiment. The motorcycle 1 according to an embodiment includes a front wheel 101 steered by a handlebar 102 and a rear wheel 103 supported by a swing arm 104. A steering assembly 200 parts including the handlebar 102 and the front wheel 101 and front suspension are supported for pivotal steering operation on a head pipe 105 at the front end of the vehicle body frame 106. A seat 110 for a driver and a pillion is placed rearward to a fuel tank 114. An engine assembly 113 is disposed below the fuel tank 114. A front fender 111 is provided above the front wheel 101 to avoid the said vehicle and its occupants from being splashed with mud. Likewise, a rear fender 112 is placed above the rear wheel 103, and to the outer side in the radial direction of rear wheel 103. Rear fender 112 inhibits rainwater or other foreign particles from being thrown up by rear wheel 103.
[00022] The swing arm 104 along with a shock absorber 109 is supported at a front portion thereof for pivotal motion and upward and downward rocking motion on the rear side of a lower portion of the vehicle body frame 106. A suspension assembly including a pair of front forks 108 and the shock absorber 109 is provided in the two-wheeled vehicle 1 for providing better ride comfort to the rider. In general terms, the shock absorbers help cushion vehicles on uneven roads. In the two-wheeled vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved ride quality and vehicle handling.
[00023] The vehicle body frame 106 includes the head pipe 105, a pair of left and right main frames 107. The head tube 105 is positioned at a front-end portion of the vehicle body frame 106. The main frames 107 extend in a leftwardly and rightwardly branching state obliquely downwardly rearwardly from a lower portion of the head tube 105.
[00024] Fig. 2 illustrates a right side view of the steering assembly 200. The steering assembly 200 comprises a steering shaft 220 that is rotatably connected to the head tube 105 of the vehicle body frame 106. An upper bracket 210 is mounted with a handle bar assembly 102 to a top portion. A lower bracket 215 is affixed to a bottom portion of the steering shaft 220. A first front fork and a second front fork are connected to the lower bracket 215 and the upper bracket 210. The front wheel 101 is rotatably connected to the first fork and the second fork therebetween. A steering shaft 220 rotates within an angle with respect to an axis of the steering shaft 220.
[00025] Fig. 3 depicts a cross sectional view of a portion of the steering assembly taken along the longitudinal direction of the vehicle. A steering shaft 220 is rotatably mounted through the head tube 105. A lower bearing assembly 235A is positioned at a lower end of the head tube 105. The lower bearing assembly 235A comprises a lower ball(s) and a lower race(s). The lower bracket 215 is positioned below the lower bearing assembly 235A. The lower bracket 215 is affixed to the steering shaft 220.An upper bearing assembly 235B is positioned at a top end of the head tube 105. The upper bearing assembly 235B comprises an upper ball(s) and an upper race(s). An upper end of the steering shaft 220 is provided with threads. An integrated steering arrestor 230 is positioned above the upper bearing assembly 235B member and the integrated steering arrestor 230 is fastened to the steering shaft 220 through the threads. In the present embodiment, a single integrated steering arrestor 230 is used. The upper bracket 210 is positioned above the steering arrestor 230. An inner diameter of the upper bracket 210 is greater than that the outer diameter of the steering shaft 220 enabling easy assembly of the upper bracket 210. A locking member is positioned above the upper bracket 210 and is fastened to the steering shaft 220 through the threads. In an embodiment, a seal may be provided above the upper bearing assembly 235B assembly to avoid entry of dust and water.
[00026] Fig. 4 illustrates a detailed view of a top portion of the cross-sectional view of the steering assembly as shown in Fig. 3. The integrated steering arrestor 230 is fastened above the upper bearing assembly 235B. According to an embodiment of the present invention, a top cone portion 230a, and a dust seal 230b are integrated with the steering arrestor portion 230c to form an integrated steering arrestor 230. During assembly of the integrated steering arrestor 230 onto the top portion Tp of the steering shaft 220, an additional space to accommodate the tools is not required. The necessary torqueing of the integrated steering arrestor 230 can be achieved by engaging the tools on the top surface of the steering arrestor 230. According to an embodiment of the present invention, the outer diameter of the tools remains same as that of the outer diameter of the integrated steering arrestor 230. Hence, the assembly of the integrated steering assembly 230 is made easy. Likewise, during servicing of the vehicle, loosening, or tightening of the integrated steering arrestor 230 can be achieved without dismantling the entire steering assembly.
[00027] Fig. 5a illustrates an integrated steering arrestor and a tool placed on top of the integrated steering arrestor. In the Fig 5a, the tool 300 is not yet engaged with the integrated steering arrestor 230. The outer diameter A of the tool 300 and the outer diameter B of the integrated steering arrestor 230 are almost same. Hence, assembly of the integrated steering arrestor 230 on top of the steering shaft 220 using the tool 300 is simpler as compared to the conventional methods. The tool 300 according to the present invention does not require any additional space in the vehicle layout design while engaged with the integrated steering arrestor 230. Teeth like arrangement are provided on the top surface of the integrated steering arrestor 230 to receive the tool 300 during assembly onto the steering shaft 220.
[00028] Fig. 5(b) illustrates the tool engaged with the integrated steering arrestor. During assembly of the integrated steering arrestor 230 onto the steering shaft 220, the tool 300 is engaged with the top surface of the integrated steering arrestor 230. It can be observed from the figure that the tool 300 is easily accommodated above the integrated steering arrestor 230 without any additional space in the vehicle layout. The outer diameter A of the tool 300 matches with that of the integrated steering arrestor 230. Hence, the additional space saved makes the vehicle compact. Further, the integrated steering arrestor 230 reduces the number of parts used in the steering assembly as compared to that of the conventional steering assembly. The top cone portion 230a and the dust seal 230b are integrated with the steering arrestor portion 230c to form a single piece integrated steering arrestor 230. Hence, manufacturing cost is reduced.
[00029] Fig. 6 illustrates an integrated steering arrestor according to an embodiment. The integrated steering assembly comprises of the top cone portion 230a integrated with the steering arrestor portion 230c to form an integrated steering arrestor 230. It can be observed from the figure that the steering arrestor portion 230c lies on the top surface of the top cone portion 230a. The top most surface of the steering arrestor portion 230c comprises of one or more teeth 401a, 401b, 401c (not shown) to receive the tools used to provide required torqueing during assembly process. The threading for the purpose of fastening the integrated steering arrestor 230 is provided on an inner surface 402.
[00030] According to an embodiment of the present invention, the steering arrestor portion 230c includes an outer circumferential surface 405 comprising one or more teeth 401a, 401b, 401c projecting radially outwardly from the outer circumferential surface 405. The one or more teeth 401a, 401b, 401c includes at least a pair of teeth 401a, 401b that are adjacently disposed to each other. These adjacently disposed pair of teeth 401a, 401b is capable of receiving at least a portion of the tool 300 therebetween.
[00031] Further, according to an embodiment of the present invention, area 403 illustrates material removed adequately to minimize the weight and cost of the integrated steering arrestor 230. Furthermore, according to an embodiment of the present invention, to improve easy of manufacturing, to improve productivity and to reduce cost, one or more rounded edges 404 are provided as shown in the figure. The rounded edges 404 have a radius approximately in the range of 1-3mm.
[00032] Fig. 7 illustrates a portion of an integrated steering arrestor. According to another embodiment of the present invention, the two adjacent teeth 401a, 401c are placed at a different distance D1 and D2 from each tooth 401b. According to an embodiment of the present invention, the distance D1 is smaller than the distance D2. According to an embodiment of the present invention, at least one first edge 404a of the one or more teeth 401a, 401b, 401c is rounded and least one joining portion (404b) of the one or more teeth (401a, 401b, 401c) with at least a portion of the top cone portion (230a) is rounded. The at least one joining portion (404b) and the at least one first edge (404a) are configured with a radius of approximately 1-3mm.
[00033] Fig. 8 illustrates a sectional view of the integrated steering arrestor, section taken along xy plane as illustrated in Fig.6. From the figure, it can be observed that the integrated steering arrestor is a single piece. The steering arrestor portion 230c forms an integrated part of the top cone portion 230a. However, the steering arrestor portion 230c is present on top of the top cone portion 230a. The one or more provisions 401 are provided on the top surface of the integrated steering arrestor 230. The one or more provisions 401 are capable of receiving the tool 300 during assembly process. The threading for the purpose of fastening the integrated steering arrestor 230 is provided on the inner surface 402.
[00034] According to another embodiment of the present invention, the top cone portion 230a and the steering arrestor portion 230c are integrally made to form an integrated steering arrestor 230.
[00035] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein.
,CLAIMS:I/We claim:
1. A steering assembly (200) for a two-wheeled vehicle (100), said steering assembly (200) comprising:
a steering shaft (220) rotatably disposed within and co-axial to a head tube (105); and
an upper bearing assembly (235B) covering at least a top portion (Tp) of the steering shaft (220),
wherein, an integrated steering arrestor (230) is fastened to said top portion (Tp) of the steering shaft (220) and is disposed above said upper bearing assembly (235B) along a shaft axis (PQ), said integrated steering arrestor (230) comprises a top cone portion (230a) disposed abuttingly to at least an upper surface (230aa) of the upper bearing assembly (235B), and a steering arrestor portion (230c) disposed away from said upper bearing assembly (235B) along said shaft axis (PQ), wherein said steering arrestor portion (230c) includes an outer circumferential surface (405) comprising one or more teeth (401a, 401b, 401c) projecting radially outwardly from said outer circumferential surface (405) and wherein, at least a pair of teeth (401a, 401b) of said one or more teeth (401a, 401b, 401c) are adjacently placed to each other.
2. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said one or more teeth (401a, 401b, 401c) includes two adjacent teeth (401a, 401c) disposed at a distance (D1) and (D2) respectively from each teeth (401b), said distance (D1) is not equal to said distance (D2).
3. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said steering arrestor portion (230c) has a smaller diameter than said top cone portion (230a).
4. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein at least one first edge (404a) of the one or more teeth (401a, 401b, 401c) is rounded and at least one joining portion (404b) of the one or more teeth (401a, 401b, 401c) with at least a portion of the top cone portion (230a) is rounded.
5. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 4, wherein said at least one joining portion (404b) and at least one first edge (404a) are configured with a radius of approximately 1-3mm.
6. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said at least a pair of teeth (401a, 401b) are capable of receiving at least a portion of the tool (300) therebetween.
7. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said integrated steering arrestor (230) includes a threaded inner surface (402) capable of enabling fastening of said integrated steering arrestor (230) to said top portion (Tp) of said steering shaft (220).
8. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1 and claim 6, wherein said tool includes an outer diameter (A) equal to an outer diameter (B) of said integrated steering arrestor (230).
9. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said top cone portion (230a) is integrated with said steering arrestor member (230c).
10. The steering assembly (200) for a two-wheeled vehicle (100) as claimed in claim 1, wherein said integrated steering arrestor (230) is made of a group of metals including cast iron, steel, and aluminum.