Claims:1. An arrangement for mounting a load cell adjacent to an operative end of a crankshaft of a vehicle, said arrangement comprising:
a shaft extension rotatably coupled with said crankshaft at said operative end thereof such that said shaft extension extends beyond the surface of a crankcase that houses said crankshaft;
a bearing cup disposed over said shaft extension at a free end thereof such that said bearing cup partially houses said shaft extension, said bearing cup being stationary with respect to the rotary motion of said shaft extension; and
a fixture mounted on said crankcase such that said fixture facilitates holding of a load cell operatively between said bearing cup and said fixture, wherein in an operative configuration, said load cell includes a pre-loading nut assembled thereon, which is configured to apply a pre-load on said crankshaft, subsequent to which said load cell is configured to sense axial load exerted on said crankshaft by a clutch assembly of said vehicle.
2. The arrangement as claimed in claim 2, wherein the pre-load applied on said crankshaft ranges from 5%-10% of the load exerted by said clutch assembly onto said crankshaft.
3. The arrangement as claimed in claim 1, which includes a bearing disposed operatively between said shaft extension and said bearing cup to prevent the rotary motion of said shaft extension from being transmitted to said bearing cup.
4. The arrangement as claimed in claim 1, wherein said shaft extension is rotatably coupled with said crankshaft via fasteners.
5. The arrangement as claimed in claim 1, which includes an oil seal disposed operatively between said crankcase and said shaft extension to prevent leakage of oil from said crankcase.
6. The arrangement as claimed in claim 1, wherein said bearing cup is securely coupled with said fixture. , Description:FIELD
The present disclosure relates to the field of mechanical engineering. In particular, the present disclosure relates to the field vehicles.
DEFINITIONS
Crankshaft: A rotating member of an engine that is able to perform a conversion between reciprocating motion and rotational motion. An axial load from a flywheel is transmitted to the crankshaft.
Flywheel: A heavy disk or wheel rotating on a shaft so that its momentum gives almost uniform rotational speed to the shaft and to all connected machinery.
Crankgear: A rotating member assembled with the crankshaft which transmits power to another gear train in connection.
Crankshaft end float: The space, allowing the crankshaft to move from end to end in its bore.
Crankcase: A case or covering enclosing a crankshaft.
Load cell: A transducer used to create an electrical signal whose magnitude is directly proportional to the force or load being measured. The various types of load cells include hydraulic load cells, pneumatic load cells and strain gauge load cells.
BACKGROUND
A clutch is a mechanical device that facilitates an engagement and disengagement between two drives for enabling power transmission between the two drives. Conventionally, the clutch exerts an axial load or a thrust load on one of the drives to facilitate the engagement with another drive. It is desired that the working parameters of the clutch are such that it provides necessary clutching between the two drives without any slippage therebetween. Thrust load measurement facilitates the monitoring of the clutch operation and can be used to optimize the clutch for a better performance.
A conventional arrangement 100 for thrust load measurement in a vehicle, has been illustrated in Fig. 1. The arrangement 100 comprises a flywheel 105 that is coupled with a crankshaft 110. The crankshaft 110 has crankshaft collars 115 configured thereon. The arrangement 100 further includes a bearing 120 that is disposed operatively between the two crankshaft collars 115. In order to sense the thrust load or axial load exerted by a clutch assembly (not shown in Fig. 1) onto the crankshaft 110, a strain gauge load cell 130 is mounted operatively between thrust washers 125 and the bearing 120.
The conventional arrangement 100 used to measure the thrust load has certain disadvantages. Firstly, the positioning of the strain gauge load cell 130 hampers easy access during maintenance as a human operator needs to disassemble the entire engine just to gain access to the strain gauge load cell 130. Also, the strain gauge load cell is subjected to high temperature oil inside the engine cover, due to which dynamic load measurement is not feasible during dynamic testing. Moreover, the conventional arrangement 100 for axial load measurement is complicated, and requires 4-5 days for assembling.
Therefore, there is a need for an arrangement for mounting a load cell that overcomes the above mentioned drawbacks of the conventional arrangements for thrust load measurement.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide an arrangement for mounting a load cell that facilitates the measurement of axial load exerted on the crankshaft by a clutch assembly during static and dynamic operation thereof.
Another object of the present disclosure is to provide an arrangement for mounting a load cell that prevents load transfer to a thrust washer mounted on the crankshaft.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages an arrangement for mounting a load cell adjacent to an operative end of a crankshaft of a vehicle. The arrangement comprises a shaft extension that is rotatably coupled with the crankshaft at the operative end thereof such that the shaft extension extends beyond the surface of a crankcase that houses the crankshaft. A bearing cup is disposed over the shaft extension at a free end thereof such that the bearing cup partially houses the shaft extension. The bearing cup is stationary with respect to the rotary motion of the shaft extension. A fixture is mounted on the crankcase such that the fixture facilitates the holding of a load cell operatively between the bearing cup and the fixture, wherein in an operative configuration load cell includes a pre-loading nut assembled thereon, which is configured to apply a pre-load on the crankshaft, subsequent to which the load cell is configured to sense axial load exerted on the crankshaft by a clutch assembly of the vehicle.
Preferably, the pre-load applied on the crankshaft ranges from 5%-10% of the load exerted by the clutch assembly onto the crankshaft.
In an embodiment, the arrangement includes a bearing disposed operatively between the shaft extension and the bearing cup to prevent the rotary motion of the shaft extension from being transmitted to the bearing cup.
Typically, the shaft extension is rotatably coupled with the crankshaft via fasteners.
In an embodiment, the arrangement includes an oil seal disposed operatively between the crankcase and the shaft extension to prevent leakage of oil from the crankcase.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
An arrangement for mounting a load cell of the present disclosure, will now be described with the help of the non-limiting accompanying drawing, in which:
Figure 1 illustrates a schematic representation of a conventional arrangement for measuring axial load exerted on a crankshaft;
Figure 2A illustrates a sectional view of an arrangement for mounting a load cell, in accordance with an embodiment of the present disclosure;
Figure 2B illustrates an enlarged sectional view of the an arrangement of Figure 2A; and
Figures 3A and 3B illustrate schematic representation of an arrangement for mounting a load cell depicting the pre-loading and load measurement.
DETAILED DESCRIPTION
The conventional arrangement 100 for measuring the axial load exerted by the clutch assembly on the crankshaft 110 has already been described in the previous sections of the present disclosure. The conventional arrangement 100 used to measure the thrust load has certain disadvantages. Firstly, the configuration of the strain gauge load cell 130 on the crankshaft 110 is such that it hampers easy access during maintenance as a human operator needs to disassemble the entire engine just to gain access to the strain gauge load cell 130. Also, the strain gauge load cell is subjected to high temperature oil inside the engine cover, due to which dynamic load measurement is not feasible during dynamic testing. Moreover, the conventional arrangement 100 for axial load measurement is complicated, and requires 4-5 days for assembling.
The present disclosure envisages an arrangement for mounting a load cell that overcomes the aforementioned drawbacks associated with the conventional arrangement 100.
The arrangement for mounting a load cell 200 (hereinafter referred to as arrangement 200) is now described with reference to Fig. 2A and Fig. 2B. The arrangement 200 facilitates the mounting of a load cell 202 adjacent to an operative end of a crankshaft 204 of a vehicle. The arrangement 200 comprises a shaft extension 206 rotatably coupled with the crankshaft 204 at the operative end thereof such that the shaft extension 206 extends beyond the surface of a crankcase 208 that houses the crankshaft 204. In an embodiment, the rotatable coupling between the crankshaft 204 and the shaft extension 206 is facilitated via fasteners. A bearing cup 210 is disposed over the shaft extension 206 at a free end thereof such that the bearing cup 210 partially houses the shaft extension 206. The bearing cup 210 is stationary with respect to the rotary motion of the shaft extension 206. In an embodiment, a bearing 211 is disposed operatively between the shaft extension 206 and the bearing cup 210 to prevent the rotary motion of the shaft extension 206 from being transmitted to the bearing cup 210. The arrangement 200 further includes a fixture 212 mounted on the crankcase 208 such that the fixture 212 facilitates holding of a load cell 202 operatively between the bearing cup 210 and the fixture 212. In an operative configuration, the load cell 202 is configured to sense the axial load exerted on the crankshaft 204 by a clutch assembly 214 of the vehicle.
The load cell 202 also includes a pre-loading nut 216 assembled thereon and is configured to apply a pre-load on the crankshaft 204, subsequent to which the load cell 202 senses the axial load exerted on the crankshaft 204 by the clutch assembly 214. In an embodiment, the pre-load applied on the crankshaft ranges from 5%-10% of the load exerted by the clutch assembly 214 onto the crankshaft 204. In an embodiment, the arrangement 200 also includes an oil seal 218 disposed operatively between the crankcase 208 and the shaft extension 206 to prevent leakage of oil from the crankcase 208.
The operative configuration of the arrangement 200 is now explained with reference to Fig. 2A through Fig. 3B. In an embodiment, the arrangement 200 is configured at an operative end of the crankshaft 204. A crankgear 220 is assembled on the operative end of the crankshaft 204. The crankshaft 204 receives axial loads transmitted from the clutch assembly 214 to a flywheel 222. Further, the shaft extension 206, which is a rotating member, is assembled on a face of the crankgear 220, bolted to the crankshaft 204 via fasteners. The bearing 211, which is a partially rotating member, is assembled such that the inner surface of the bearing 211 abuts the shaft extension 206, while the outer surface of the bearing 211 abuts the bearing cup 210. The bearing cup 210 is a fixed and stationary member that transmits the axial load between the bearing 211 and the load cell 202. The bearing 211 prevents the rotary motion of the shaft extension 206 from being transmitted to the bearing cup 210 and transmits only the axial component of force to the bearing cup 210. The axial load exerted on the crankshaft 204 by the clutch assembly 214 is transmitted to the load cell 202 via the shaft extension 206. The load cell 202 is coupled with a data logger and is configured to sense the axial load exerted on the crankshaft 204 and feed the same to the data logger by transmitting signals to a data logger (not shown).
Further, the pre-loading nut 216 is assembled on the load cell 202. The pre-loading nut 216 is in threaded connection with the load cell 202 and is configured to move along the load cell 202, thereby applying an axial pre-load on the crankshaft 204 which acts against the axial load exerted by the clutch assembly 214 onto the crankshaft 204. The pre-loading nut 216, upon rotation, applies the pre-load on the crankshaft 204 along the direction of the arrow shown in Fig. 3A and releases the load acting upon a rear thrust washer 310 disposed operatively between a main bearing cap 308 and an adjoining crankshaft collar 312, thus preventing the load transfer to the thrust washer 310, so that the entire axial load exerted by the clutch assembly gets applied onto the load cell 202.
In the operational configuration, the load cell 202 is fitted along with the bearing 211 and the oil seal 218 on the crankcase 208, thereby connecting with the crankshaft 204. A pre-load is applied, by tightening the pre-loading nut 216 (shown by a curved arrow, Figure 3A), through the load cell 202, to avoid load transfer to the thrust washer 310 disposed between the crankshaft collars 312. In accordance with one embodiment, 5-10% of the axial load exerted by the clutch assembly 214 is applied as preload, depending on the type vehicle. Subsequently, the clutch assembly 214 is operated using force measurement. The axial load is transferred through the flywheel 222 and the crankshaft 204 to the load cell 202. The axial load exerted by the clutch assembly 214 can be measured and viewed directly on a computer 315 connected to the load cell 202 via a DAQ (data acquisition) device 320. In static condition, the crankshaft is not rotating and the axial load exerted by the clutch assembly 214 is directly transferred to the load cell 202. In dynamic condition, when the crankshaft is rotating, the bearing 211 prevents the rotary motion of the crankshaft 204 and the shaft extension 206 from being transmitted to the bearing cup 210 and the load cell 202 and only axial load is sensed by the load cell 202.
The arrangement 200 of the present disclosure has a simple configuration which facilitates the maintenance of the load cell without having to undock/disassemble the entire engine of the vehicle. The arrangement 200 can be accessed easily without having to undock/disassemble the entire engine of the vehicle because of the positioning the arrangement 200 adjacent to the crankcase 208.
Although the system and method of the present invention is described with reference to the aforementioned embodiments, other configurations of the system are included in the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an arrangement for mounting a load cell that:
• facilitates the measurement of axial load exerted on the crankshaft by a clutch assembly during static and dynamic operation thereof;
• prevents load transfer to a thrust washer mounted on the crankshaft; and
• avoids the need to undock the entire engine for the measurement of axial load.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.