DESC:FIELD
The present invention relates to mass balancer units of vehicles.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Balancing shafts, configured with eccentric weights, are used in internal combustion engines to reduce the free mass forces of an engine to reduce the operating noise and vibrations of the engine.
Conventional mass balancers are located in the engine such that they are partially immersed in an oil sump containing lubricating oil to facilitate lubrication of bearings of the shafts. However, due to the very partial immersion of the shafts, the bearings undergo the phenomenon of churning during which a high friction torque is generated. This high friction torque not only leads to drag losses and resultant high temperature, but also into a higher level of noise and vibrations. The counter methods known till date, include surface transformation methods such as smoothening the surfaces by applying coats. However, regular wear and tear of the components would result in deterioration of the coatings. Also it has been observed, that such surface transforming operations are not effective in reducing the noise and vibrations caused due to churning losses.
Therefore, there is felt a need for a mass balancer unit that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a mass balancer unit for an engine.
Another object of the present disclosure is to provide a mass balancer unit which by virtue of its configuration achieves reduction in churning losses and thereby, friction power losses thereof.
Yet another object of the present disclosure is to provide a mass balancer unit which reduces vibrations of the engine.
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 a mass balancer unit for an engine having a crankcase provided with a plurality of crankshafts and an oil sump containing lubricating oil. The mass balancer unit comprises a housing unit configured to be sealably immersed in the oil sump. The housing unit is defined by a lower casing and an upper casing connected to the lower casing. The lower casing and the upper casing have a pair of grooves configured on operatively opposite edges. At least one supporting bearing is configured to be mounted on each groove. A tube is configured to facilitate fluid communication of pressurized oil from the crankcase to the bearings to facilitate lubrication of the bearings.
The mass balancer unit further comprises a pair of mass balancer shafts. The mass balancer shafts are configured to be rotated in opposite directions, in an operative configuration thereof, to counter-balance the weight of the crankcase. Each mass balancer shaft is defined by a counter-weight having a truncated cylindrical configuration. Each shaft includes a pair of arms configured to extend from the counter-weight along an operative longitudinal axis thereof. The arms are configured to be received in the bearings. The truncated cylindrical configuration is defined as semi-cylindrical having its flat surface configured to taper downwards from an operative central longitudinal axis towards the operative side walls of the counter-weight at a predetermined draft angle. A plurality of openings is configured on the upper casing. Oil seeped inside the housing during lubrication of the bearings, is hurled away through the openings in the operative configuration of the mass balancer shafts.
In an embodiment, the predetermined draft angle ranges between 1° to 2°.
In another embodiment, the mass balancer shafts are provided in the housing such that a clearance 3mm to 6mm is defined between mass balancer shafts and the inner surface of the lower casing.
In an embodiment, a first mass balancer shaft of the pair of mass balancer shafts includes an appendage extending from an arm thereof.
In another embodiment, the mass balancer unit includes at least one oil pump integrated to an operative first side of the housing. The oil pump is configured to pump oil from the oil sump and further configured to deliver oil to the engine. The oil pump has an aperture configured thereon for coaxially nesting the appendage therein.
In an embodiment, the mass balancer unit includes at least one driven member mounted on the arms of the mass balancer shafts. The driven member is configured to be connected to crankshaft. The driven member is configured to be driven to the crankshaft for rotating the mass balancer shafts with respect to the crankshaft speed.
In yet another embodiment, the housing includes an auxiliary casing provided at an operative second side of the housing. The auxiliary casing is configured to house the driven member therein.
In an embodiment, the driven member is a spur gear.
In another embodiment, the housing includes a passage configured in the housing to guide the tube.
In an embodiment, each of the openings have different configurations.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A mass balancer unit, of the present disclosure, for an enginefor will now be described with the help of the accompanying drawing, in which:
Figures 1A & 1B illustrate different views of the mass balancer unit of the present disclosure;
Figure 2 illustrates an exploded view of the mass balancer unit of Figure 1;
Figure 3 illustrates an exploded view of mass balancer shafts and a pump of the mass balancer unit of Figure 1;
Figure 4A illustrates cross sectional views of the mass balancer unit, of Figure 1, depicting the housing and oil throw passages of the mass balancer unit;
Figure 4B illustrates a cross sectional view of the mass balancer shaft, of Figure 1;
Figure 4C illustrates a cross sectional view of a crankcase containing the mass balancer shaft, of Figure 1, and depicting an oil path in the housing;
Figure 4D illustrates a cross sectional view of a crankcase containing the mass balancer shaft, of Figure 1, and depicting an oil path in the housing;
Figure 5 illustrates different views of a bearing of a mass balance shaft of the mass balancer unit of Figure 1;
Figure 6 illustrates different views of a gear cover containing the gears of the mass balancer unit of Figure 1;
Figure 7a illustrate different views of an integrated oil pump of the mass balancer unit of Figure 1;
Figure 7b illustrates a bottom view of a lower casing of the mass balancer unit of figure 1;
Figure 7c illustrates a cross-sectional view of Figure 7B showing a dowel pin interface configured between the lower casing and the upper casing of the mass balancer unit of Figure 1;
Figure 8A illustrates a graph showing the measurement values for the frictional horsepower achieved by an engine with and without the mass balancer unit of the present disclosure;
Figure 8B illustrates a graph showing the measurement values for the torque achieved by an engine with and without the mass balancer unit of the present disclosure;
Figure 9 illustrates a graph showing the vibration test results with and without using the mass balancer unit (MBU-P2 – phase 1 of trial, and MBU-P2 – phase 2 of trial) of the present disclosure for lateral order firing and vertical order firing; and
Figure 10 illustrates a graph showing the noise test results with and without using the mass balancer unit of the present disclosure.
LIST OF REFERENCE NUMERALS
10 – Crankcase
100 – Mass balancer unit
101 – Mass Balancer Unit (MBU) housing
102 – Upper casing
104 – Lower casing
105, 106 – Balancer Shafts
109 – Counterweight
111 – flat surface of the counter-weight
112 – arm
113 – groove
115 – Bearing
117, 118 – Openings
119 – auxiliary casing
119A – driven member
125 – Oil Pump
130 – Dowel pins
132 – Tube
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including”, “includes” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A mass balancer unit (100), of the present disclosure, for an engine will now be described in detail with reference to Figure 1 through Figure 10.
The engine has a crankcase (10) provided with a plurality of crankshafts and an oil sump containing lubricating oil therein.
The mass balancer unit (100) comprises a housing (101) configured to be sealably immersed in the oil pump (125). The housing (101) is defined by a lower casing (104) and an upper casing (102) connected to the lower casing (104). The lower casing (104) and the upper casing (102) has a pair of grooves (not specifically shown in Figures) configured on operatively opposite edges. The grooves define slots (not specifically shown in Figures) when the lower casing (104) and the upper casing (102) are conjoined with each other to form the housing (101) with the help of dowel pins (130). The mass balancer unit (100) includes at least one supporting bearing (115) mounted on each groove, more specifically in the slots, and a tube (132) configured to facilitate fluid communication of pressurized oil from the crankcase (10) to the bearings (115) to facilitate lubrication of the bearings (115) to ensure proper working of the bearings (115).
The mass balancer unit (100) further comprises a pair of mass balancer shafts (105, 106). The mass balancer shafts (105, 106) are configured to be rotated in opposite directions to each other, in an operative configuration thereof, to counter-balance the weight of the crankcase (10). Each mass balancer shaft (105, 106) is defined by a counter-weight (109) having a truncated cylindrical configuration. Each mass balancer shaft (105, 106) includes a pair of arms (112) extending from the counter-weight (109) along an operative longitudinal axis thereof. The arms (112) are configured to be received in the bearings (115).
The truncated cylindrical configuration of the counter-weight (109) is defined as semi-cylindrical having its flat surface (111) configured to taper downwards from an operative central longitudinal axis towards the operative side walls of the counter-weight (109) at a predetermined draft angle. Such downward inclined configuration of the truncated semi-cylindrical counter-weight (109) prevents formation of oil pockets on the flat surface (111) of counter-weight, thereby preventing oil accumulation thereon.
The mass balancer unit (100) also comprises a plurality of openings (117, 118) configured on the upper casing (102), more specifically above the location of the mass balancer shafts (105, 106). Oil that tends to seep inside the housing (101) during lubrication of the bearings (115), is hurled away through the openings in the operative configuration of the mass balancer shafts (105, 106).
In an embodiment, each of the openings have different configurations to help achieve the dispersal of oil therethrough.
In an embodiment, the predetermined draft angle ranges between 1° to 2°.
In another embodiment, the mass balancer shafts (105, 106) are provided in the housing (101) such that a clearance 3mm to 6mm is defined between mass balancer shafts (105, 106) and the inner surface of the lower casing (104).
Exposure of the mass balancer shafts (105, 106) to pressurized oil film formed in the housing (101) due to oil seepage can increase the vibrations of the crankshafts beyond their natural period of vibrations and result in crankshaft breakage. The envisaged mass balancer unit (100) helps in preventing formation of oil film and thereby preventing excessive vibrations of the crankshaft by the following provisions:
a) The lower casing (104) and the upper casing (102) of the housing (101) protects the mass balancer unit (100) from oil splashes or contact with oil contained in the oil sump or contact with pressurized oil trickling from the crankcase (10);
b) The downward inclined configuration of the truncated semi-cylindrical counter-weight (109) prevents formation of oil pockets on the flat surface (111) of counter-weight, thereby preventing oil accumulation thereon if oil seeps from the bearing (115) or from the tube;
c) The relatively lesser clearance defined between the mass balancer shafts (105, 106) and the inner surface of the lower casing (104);
d) The rotation of the mass balancer shafts (105, 106) is used to drag away oil collected in the housing (101) there along in the direction of rotation of the mass balancer shafts (105, 106); and
e) The provision of the openings allow the oil to be thrown out of the housing (101) into the oil sump.
In an embodiment, a first mass balancer shaft of the pair of mass balancer shafts (105, 106) includes an appendage extending from an arm thereof.
In another embodiment, the mass balancer unit (100) includes at least one oil pump (125) integrated to an operative first side of the housing (101). The oil pump (125) is configured to pump (125) oil from the oil sump and is further configured to deliver oil to the engine. The oil pump (125) has an aperture configured thereon for coaxially nesting the appendage therein.
In an embodiment, the mass balancer unit (100) includes at least one driven member (119A) mounted on the arms (112) of the mass balancer shafts (105, 106). The driven member (119A) is configured to be connected to crankshaft. The driven member (119A) is configured to be driven to the crankshaft for rotating the mass balancer shafts (105, 106) with respect to the crankshaft speed.
In another embodiment, the housing (101) includes an auxiliary casing (119) provided at an operative second side of the housing (101). The auxiliary casing (119) is configured to house the driven member (119A) therein.
In yet another embodiment, the driven member (119A) is a spur gear of relatively higher addendum. In still another embodiment, the spur gear is of DIN9/7 quality.
In an embodiment, the housing (101) includes a passage configured in the housing (101) to guide the tube (132). In another embodiment, the tube (132) is welded to the housing (101).
Figure 8 illustrates a graph showing the measurement values for optimum design of journal diameter and width for the drive connection between the balance shaft and the crankshaft. By using the proposed mass balancer unit (100), the measurement values for optimum design of journal diameter and width for the drive connection between the balance shaft and the crankshaft helps to reduce the frictional horsepower and the torque required.
Figure 9 illustrates a graph showing the vibration test results with or without using the mass balancer unit (100). By using the mass balancer unit (100) (both in phase 1 and phase 2 trials), it was observed that more that 80% of vibration reduction is achieved in engines instead of no mass balancer units.
Figure 10 illustrates a graph showing the noise test results with or without using the mass balancer unit (100), in accordance with an embodiment of the present disclosure. As can be seen from the graph, a noise reduction from 91.8 dB (A) to 90.6 dB (A) is achieved in engines using the proposed mass balancer unit (100).
In an embodiment, the mass balancer unit (100) can be used in vehicles such as tractors.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a mass balancer unit for an engine which:
• achieves reduction in churning losses and thereby, friction power losses thereof; and
• reduces vibrations of the engine by at least 80%.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
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 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.
Any discussion of 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. ,CLAIMS:WE CLAIM:
1. A mass balancer unit (100) for an engine having a crankcase (10) provided with a plurality of crankshafts and an oil sump containing lubricating oil, said mass balancer unit (100) comprising:
• a housing (101) configured to be sealably immersed in the oil pump (125), said housing (101) defined by a lower casing (104) and an upper casing (102) connected to said lower casing (104), said lower casing (104) and said upper casing (102) having a pair of grooves configured on operatively opposite edges;
• at least one supporting bearing (115) mounted on each groove;
• a tube configured to facilitate fluid communication of pressurized oil from the crankcase (10) to said bearings (115) to facilitate lubrication of said bearings (115);
• a pair of mass balancer shafts (105, 106), said mass balancer shafts (105, 106) configured to be rotated in opposite directions, in an operative configuration thereof, to counter-balance the weight of the crankcase (10), each mass balancer shaft being defined by a counter-weight (109) having a truncated cylindrical configuration, and including a pair of arms (112) extending from said counter-weight (109) along an operative longitudinal axis thereof, said arms (112) configured to be received in said bearings (115),
wherein said truncated cylindrical configuration is defined as semi-cylindrical having its flat surface (111) configured to taper downwards from an operative central longitudinal axis towards the operative side walls of said counter-weight (109) at a predetermined draft angle; and
• a plurality of openings configured on said upper casing (102);
wherein oil seeped inside said housing (101) during lubrication of said bearings (115), is hurled away through said openings in said operative configuration of said mass balancer shafts (105, 106).
2. The mass balancer unit (100) as claimed in claim 1, wherein said predetermined draft angle ranges between 1° to 2°.
3. The mass balancer unit (100) as claimed in claim 1, wherein said mass balancer shafts (105, 106) are provided in said housing (101) such that a clearance 3mm to 6mm is defined between mass balancer shafts (105, 106) and the inner surface of said lower casing (104).
4. The mass balancer unit (100) as claimed in claim 1, wherein a first mass balancer shaft of said pair of mass balancer shafts (105, 106) includes an appendage extending from an arm thereof.
5. The mass balancer unit (100) as claimed in claim 4, which includes at least one oil pump (125) integrated to an operative first side of said housing (101), said oil pump (125) configured to pump (125) oil from the oil sump and further configured to deliver oil to the engine, said oil pump (125) having an aperture configured thereon for coaxially nesting said appendage therein.
6. The mass balancer unit (100) as claimed in claim 1, which includes at least one driven member (119A) mounted on said arms (112) of said mass balancer shafts (105, 106), said driven member (119A) configured to be connected to crankshaft, said driven member (119A) configured to be driven to said crankshaft for rotating said mass balancer shafts (105, 106) with respect to the crankshaft speed.
7. The mass balancer unit (100) as claimed in claim 6, wherein said housing (101) includes an auxiliary casing provided at an operative second side of said housing (101), said auxiliary casing configured to house said driven member (119A) therein.
8. The mass balancer unit (100) as claimed in claim 6, wherein said driven member (119A) is a spur gear.
9. The mass balancer unit (100) as claimed in claim 1, wherein said housing (101) includes a passage configured in said housing (101) to guide the tube.
10. The mass balancer unit (100) as claimed in claim 1, wherein each of said openings have different configurations.
Dated this 19th day of January, 2024

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI