CA2253047A1 - Balancing apparatus for a vehicle engine - Google Patents
Balancing apparatus for a vehicle engine Download PDFInfo
- Publication number
- CA2253047A1 CA2253047A1 CA 2253047 CA2253047A CA2253047A1 CA 2253047 A1 CA2253047 A1 CA 2253047A1 CA 2253047 CA2253047 CA 2253047 CA 2253047 A CA2253047 A CA 2253047A CA 2253047 A1 CA2253047 A1 CA 2253047A1
- Authority
- CA
- Canada
- Prior art keywords
- gear
- balancing apparatus
- rotation
- hollow shaft
- balance weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Gear Transmission (AREA)
Abstract
A balancing apparatus for a vehicle engine has a housing assembly constructed and arranged to be mounted to the vehicle engine. The housing has spaced apart endwalls and two parallel extending support shafts connected to the endwalls. A first hollow shaft is rotatably mounted concentrically about a first of the support shafts. A first gear is mounted for rotation with the first hollow shaft. A first balance weight is mounted for rotation with the first hollow shaft and spaced from the first gear. A second hollow shaft is rotatably mounted concentrically about a second of the support shafts. A second gear is mounted for rotation with the second hollow shaft. The second gear is in driven engagement with the first gear for counter rotation therewith. The first of the support shafts is positioned relative to the engine crankshaft for drivingly engaging the first gear with the crankshaft. A second balance weight is mounted for rotation with the second hollow shaft and spaced from the second gear for rotation in a plane common with the first balance weight. The second balance weight is positioned diametrically opposite to the first balance weight for counter rotation therewith.
Description
CA 022~3047 1998-11-0~
BALANCING APPARATUS FOR A VEHICLE ENGINE
Field of the Invention This invention relates to balancing apparatus for a vehicle engine and more particularly 5 to a twin counter-rotating balance shaft assembly for a four cylinder in-line internal combustion engine, which reduces engine vibration.
Background of the Invention Internal combustion engines of the reciprocating type have movable portions which 10 become off-balance during operation of the engine, causing vibration. The vibrations generate noise and degrade or damage engine parts, such as individual bearings. In order to compensate for these vibrations, balancing devices have been developed to cancel the inertia force or the inertial couple of the piston, connecting rod and the like to reduce the vibration of the engine.
A conventional b~l~ncing device of this type typically includes a pair of cast or forged 15 steel balance shafts which incorporate un-machined, as-cast eccentric weights as well as machined journal bearing surfaces or roller bearing surface seats. The bearings are held in split housings, line-bored after pre-assembly. Since the balance shafts turn at over 12,000 rpm (twice the engine speed), tolerances of the machined surfaces must be closely held. Thus, these devices require costly m~çhining steps to achieve accuracy. Further, during operation of the 20 engine, the eccentric weights cause shaft deflection resulting in mi~lip;nment between the shafts and bearing housings. This mi~lignment is greatest when the engine speed and bearing loads are highest, which has necessitated the use of costly, extra-precision bearings or pressure-fed lubrication of journals with engine oil.
Conventional balance shaft pairs typically incorporate sprockets and chains or steel 25 gears to drive one of the balance shafts via an engine crank shaft drive gear. The first balance shaft drives the second balance shaft by the steel gears to produce counter-rotating motion.
During operation, gear noise and rattles occur which are caused by gear meshing and torsional crank shaft vibrations. Counter-measures to avoid these problems have been proposed including the use of anti-backlash gears and powder metal steel gears (with improved internal 30 damping), but have been only partially successful. Non-metallic gears have also been tried unsuccessfully, due to high cyclic stresses caused by the torsional vibration of the crank shaft, CA 022~3047 1998-11-0~
transmitted through the gears, resisted by the high inertia of the rotating balance shaft components. Accordingly, a need exists to provide an improved balancing apparatus for an internal combustion engine which overcomes the deficiencies of the conventional devices.
5 Summary of the Invention The disadvantages of the prior art may be overcome by providing a b~l~ncing apparatus for suppressing vibrations in an engine.
It is desirable to provide a balancing apparatus which reduces the size and mass of rotating components, thereby reducing mi~lignment of shafts and bearings at high engine 10 speeds and reducing gear noise and to increase reliability.
It is desirable to provide a balancing apparatus which is simple in construction, effective in operation and economical to m~mlf~cture and m~int~in According to one aspect of the invention there is provided a balancing apparatus having a housing assembly constructed and arranged to be mounted to the engine. First and second 15 support shafts are fixed in spaced relation within the housing assembly. First and second rotatable shafts are associated with said first and second support shafts, respectively. Bearing structure is disposed between each rotatable shaft and its associated support shaft such that each rotatable shaft may rotate about its associated support shaft. A hydrodynamically designed balance weight is coupled to each of the first and second rotatable shafts, 20 respectively, so as to rotate therewith. A pair of driven gears are provided, with a driven gear of the pair of driven gears being coupled to each of the first and second rotatable shafts, respectively. One of the driven gears is constructed and arranged to be driven by the drive gear. The driven gears are in meshing relation such that rotation thereof causes rotation of the balance weights.
According to another aspect of the invention, there is provided a b~l~ncin,~ apparatus for a vehicle engine which has a housing assembly constructed and arranged to be mounted to the vehicle engine. The housing has spaced apart endwalls and two parallel extending support shafts connected to the endwalls. A first hollow shaft is rotatably mounted concentrically about a first of the support shafts. A first gear is mounted for rotation with the first hollow 30 shaft. A first balance weight is mounted for rotation with the first hollow shaft and spaced from the first gear. A second hollow shaft is rotatably mounted concentrically about a second CA 022~3047 1998-11-0~
of the support shafts. A second gear is mounted for rotation with the second hollow shaft.
The second gear is in driven engagement with the first gear for counter rotation therewith. The first of the support shafts is positioned relative to the engine cr~nk.qh~ PL for drivingly eng~ging the first gear with the crankshaft. A second balance weight is mounted for rotation with the 5 second hollow shaft and spaced from the second gear for rotation in a plane common with the first balance weight. The second balance weight is positioned diametrically opposite to the first balance weight for counter rotation therewith.
Description of the Drawings The invention may best be understood with reference to the accompanying drawingswherein an illustrative embodiment is shown.
Figure 1 is a perspective view of a balancing apparatus provided in accordance with the principles of the present invention;
Figure 2 is an elevational view, partially in section, of a balancing apparatus of Figure 1;
Figure 3 is a plan view, in section, of the apparatus of Figure 1, taken through the center of the support shafts;
Figure 4 is an exploded perspective view of the rotating shafts of the apparatus of Figure 1.
Description of the Invention Referring now more particularly to the drawings, there is shown therein a balancing apparatus, generally indicated at 10, which embodies the principles of the present invention.
The balancing apparatus 10 is constructed and arranged to suppress second order vibrations in 25 a conventional four cylinder in-line internal combustion engine, as disclosed, for example, in U.S. Patent No. 5,305,656, the disclosure of which is hereby incorporated into the present specification by this reference. The conventional engine includes a rotatable crank shaft and a plurality of piston and cylinders for causing rotation of the crank shaft. As is typical, the crank shaft includes a helical drive gear mounted for rotation therewith, of the type disclosed in U. S .
30 Patent No. 5,305,656.
CA 022=,3047 1998-11-0=, As shown in Figure 1, the apparatus 10 incllldes a housing assembly, generally indicated at 12, preferably of alllminllm or other light-weight material. The housing assembly 12 includes pairs of opposing sidewalls 13 and 14, respectively, connected together by support shafts 20 and 22. The housing assembly 12 includes mounting bosses, 18, for mounting the 5 housing assembly 12 to the engine cylinder block 19 by bolts (not shown). Thus, the apparatus 10 is constructed and arranged to be mounted to the engine block 19 under the crankshaft and within the oil pan.
First and second solid, hardened and ground support shafts, 20 and 22, respectively, are spaced in generally parallel relation and are fixed within the housing assembly 12 against 10 rotation and axial displacement. Both ends 21 and 25 of each shaft 20 and 22 are fitted in bores 23 in the walls 14 of the housing assembly 12. They are coupled to the housing assembly via associated cross-pins 24.
First and second cylindrical, hollow rotatable shafts 26 and 28, respectively, are mounted for rotation about the first and second support shafts 20 and 22, respectively, by 15 means of bearing structure, including pairs of associated needle rolling bearings 30.
Cast or powder metal balance weights 32 and 34 are fixed to one end of each of the rotatable shafts 26 and 28, respectively. As shown in Figures 1 and 2, the balance weights 32 and 34 are hydrodynamically shaped having mass distribution designed in such manner that it gives required eccentricity inertia in respect to the axes of rotation of each shaft 20 and 22 20 respectively. Balance weights 32 and 34 space envelope conforms to the maximum radius B
and minimllm radius C. Balance weights generally have a semi-circular, semi-spherical or semi-toroidal shaped portion with leading and trailing edges smoothly contoured or tapered to the minimllm radius C opposite the shaped portion.
In the illustrated embodiment, a driven helical gear is coupled to an end of each hollow, 25 rotatable shaft 26 and 28 opposite a respective balance weight. Thus, each driven gear is disposed in spaced relation with respect to a balance weight on an associated rotatable shaft.
Driven gear 36 is coupled to a periphery ofthe rotatable shaft 26. Gear 36 is preferably phenolic or non-ferrous material or ferrous material with high damping quality or powder metal and is constructed and arranged to be driven by the crank shaft drive gear (not shown), in the 30 known manner, as disclosed, for example, on U.S. Patent No. 5,305,656.
CA 022~3047 1998-ll-0~
Gear 38 iS coupled to the periphery of the rotatably shaft 28 and is preferably of phenolic or non-ferrous material or ferrous material with high damping quality or powder metal selected to match gear 36 in such manner to obtain the best noise and wear characteristics. The two gears 36 and 38 are in meshing relation with each other at teeth 37 and 39, respectively.
Shaft 22 iS radially offset relative to shaft 20. The offset spaces gear 38 to engage the crank shaft gear without eng~ging gear 36 The needle rolling bearings 30 are disposed in pairs about each support shaft, between an outer peripheral surface of support shaft and an inner peripheral surface of a rotatable shaft.
In the illustrated embodiment, one needle bearing 30 iS located generally under a balance 10 weight and one needle bearing 30 iS located under a driven gear 36,38. Thus, one needle bearing is disposed on a common axis D with a driven gear and another needle bearing is disposed on a common axis E with a balance weight.
Pairs of thrust washers 40 are disposed about each of the support shafts 20 and 22 with one thrust washer being disposed between an inner surface 43 of side wall 14 and each end 15 surface 45 of an associated rotatable shaft 26,28. The thrust washers 40 are constructed and arranged to absorb axial loads caused by the helical gear forces.
Each of the support shafts 20 and 22 includes lubrication or oil passage structure therein. In the illustrated embodiment, the oil passage structure includes an axial passage 42 and a cross passage 44 in communication therewith for directing a lubricant or oil in the 20 direction of arrows A, so as to lubricate the moving parts of the apparatus 10 such as the bearings 30. Lubrication is assisted by the pumping action of the needle rolling bearings 30.
The widths and masses of the balance weights 32 and 34 are minimi7ed by ma~imi7.ing their large radii B and minimi7.in3~ their small radii C. Further, the rotatable shafts 26 and 28 are made as light as possible, while the driven gears 36 and 38 are weight reduced by material 25 selection or provision of hydrodynamically shaped webs and holes, as is well know in the art.
These features greatly reduce the length, weight, and complexity of the apparatus 10.
The balancing apparatus 10 operates as follows. The app~s 10 is mounted to an engine within the oil pan such that the crank shaft helical gear is in meshing relation with teeth 39 of the driven gear 38. Rotation ofthe crank shaft gear is transmitted to the driven gear 38 30 to rotate the first balance weight 34 via shaft 28. Since gears 36 and 38 are in meshing relation, rotation ofthe second gear 38 iS transmitted to the first gear 36 to rotate the second CA 022~3047 1998-11-0~
balance weight 32 via shaft 26. Rotation of the balance weights 32 and 34 generates a load which cancels the inertial forces caused by the pistons and connecting rods of the engine, which in turn reduces vibration of the crank shaft.
Applicant has found that the mass moment of inertia of the rotating components of the 5 balancing apparatus 10 of the invention is the same as conventional designs, but utilizing only half of the mass. This permits the potential use of a phenolic gear or a non-ferrous gear for one of the driven gears, so as to reduce noise of the driven gears. It also allows for use of a high damping ferrous material or powder metal provided that it reduces the noise of the driven gears as opposed to steel gears. In the illustrated embodiment, the phenolic gear is preferably 10 driven gear 38 which is driven by the crank shaft gear. Other plastic or non-ferrous materials or high damping ferrous materials or powder metal may be used instead of the phenolic material, as long as noise and reliability criteria are met. The crank shaft gear can be of any material mentioned above provided that noise and reliability criteria are met.
It can be appreciated that the length of the support shafts 20 and 22, the rotating shafts 15 26 and 28 the housing assembly 12 can be changed to accommodate any designed spacing from the crank shaft gear to the center of gravity of the engine.
The housing assembly 12 can be made of ~ mimlm or other lightweight material having sufficient strength. Since the thermal coefficient of expansion of phenolic lies between that of steel and alllminllm, with the structure of the invention, gear tooth clearances have been found 20 to be acceptable in an operating range of-40~C to 150~C.
The installation of the needle bearings 30 in the appal~ s 10 is similar to the proven design of the planetary gears in automotive tr~n.cmi~ions. The needle bearings 30 may be cage-guided shell bearings, press-fitted into the rotating shaft 26 or 28, or unit cages with hardened or ground raceways in the rotating shafts 26 and 28, or unit cages with hardened or 25 ground raceways in the rotating shafts 26 and 28. The low deflection of the fixed support shafts 20 and 22 under the bearings 30 assures minim~l shaft and bearing mi~lignment and maximizes bearing life.
It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing plerelled embodiment of the 30 present invention has been shown and described for the purposes of illustrating the structural and functional principles of the present invention and is subject to change without departure from such principles.
BALANCING APPARATUS FOR A VEHICLE ENGINE
Field of the Invention This invention relates to balancing apparatus for a vehicle engine and more particularly 5 to a twin counter-rotating balance shaft assembly for a four cylinder in-line internal combustion engine, which reduces engine vibration.
Background of the Invention Internal combustion engines of the reciprocating type have movable portions which 10 become off-balance during operation of the engine, causing vibration. The vibrations generate noise and degrade or damage engine parts, such as individual bearings. In order to compensate for these vibrations, balancing devices have been developed to cancel the inertia force or the inertial couple of the piston, connecting rod and the like to reduce the vibration of the engine.
A conventional b~l~ncing device of this type typically includes a pair of cast or forged 15 steel balance shafts which incorporate un-machined, as-cast eccentric weights as well as machined journal bearing surfaces or roller bearing surface seats. The bearings are held in split housings, line-bored after pre-assembly. Since the balance shafts turn at over 12,000 rpm (twice the engine speed), tolerances of the machined surfaces must be closely held. Thus, these devices require costly m~çhining steps to achieve accuracy. Further, during operation of the 20 engine, the eccentric weights cause shaft deflection resulting in mi~lip;nment between the shafts and bearing housings. This mi~lignment is greatest when the engine speed and bearing loads are highest, which has necessitated the use of costly, extra-precision bearings or pressure-fed lubrication of journals with engine oil.
Conventional balance shaft pairs typically incorporate sprockets and chains or steel 25 gears to drive one of the balance shafts via an engine crank shaft drive gear. The first balance shaft drives the second balance shaft by the steel gears to produce counter-rotating motion.
During operation, gear noise and rattles occur which are caused by gear meshing and torsional crank shaft vibrations. Counter-measures to avoid these problems have been proposed including the use of anti-backlash gears and powder metal steel gears (with improved internal 30 damping), but have been only partially successful. Non-metallic gears have also been tried unsuccessfully, due to high cyclic stresses caused by the torsional vibration of the crank shaft, CA 022~3047 1998-11-0~
transmitted through the gears, resisted by the high inertia of the rotating balance shaft components. Accordingly, a need exists to provide an improved balancing apparatus for an internal combustion engine which overcomes the deficiencies of the conventional devices.
5 Summary of the Invention The disadvantages of the prior art may be overcome by providing a b~l~ncing apparatus for suppressing vibrations in an engine.
It is desirable to provide a balancing apparatus which reduces the size and mass of rotating components, thereby reducing mi~lignment of shafts and bearings at high engine 10 speeds and reducing gear noise and to increase reliability.
It is desirable to provide a balancing apparatus which is simple in construction, effective in operation and economical to m~mlf~cture and m~int~in According to one aspect of the invention there is provided a balancing apparatus having a housing assembly constructed and arranged to be mounted to the engine. First and second 15 support shafts are fixed in spaced relation within the housing assembly. First and second rotatable shafts are associated with said first and second support shafts, respectively. Bearing structure is disposed between each rotatable shaft and its associated support shaft such that each rotatable shaft may rotate about its associated support shaft. A hydrodynamically designed balance weight is coupled to each of the first and second rotatable shafts, 20 respectively, so as to rotate therewith. A pair of driven gears are provided, with a driven gear of the pair of driven gears being coupled to each of the first and second rotatable shafts, respectively. One of the driven gears is constructed and arranged to be driven by the drive gear. The driven gears are in meshing relation such that rotation thereof causes rotation of the balance weights.
According to another aspect of the invention, there is provided a b~l~ncin,~ apparatus for a vehicle engine which has a housing assembly constructed and arranged to be mounted to the vehicle engine. The housing has spaced apart endwalls and two parallel extending support shafts connected to the endwalls. A first hollow shaft is rotatably mounted concentrically about a first of the support shafts. A first gear is mounted for rotation with the first hollow 30 shaft. A first balance weight is mounted for rotation with the first hollow shaft and spaced from the first gear. A second hollow shaft is rotatably mounted concentrically about a second CA 022~3047 1998-11-0~
of the support shafts. A second gear is mounted for rotation with the second hollow shaft.
The second gear is in driven engagement with the first gear for counter rotation therewith. The first of the support shafts is positioned relative to the engine cr~nk.qh~ PL for drivingly eng~ging the first gear with the crankshaft. A second balance weight is mounted for rotation with the 5 second hollow shaft and spaced from the second gear for rotation in a plane common with the first balance weight. The second balance weight is positioned diametrically opposite to the first balance weight for counter rotation therewith.
Description of the Drawings The invention may best be understood with reference to the accompanying drawingswherein an illustrative embodiment is shown.
Figure 1 is a perspective view of a balancing apparatus provided in accordance with the principles of the present invention;
Figure 2 is an elevational view, partially in section, of a balancing apparatus of Figure 1;
Figure 3 is a plan view, in section, of the apparatus of Figure 1, taken through the center of the support shafts;
Figure 4 is an exploded perspective view of the rotating shafts of the apparatus of Figure 1.
Description of the Invention Referring now more particularly to the drawings, there is shown therein a balancing apparatus, generally indicated at 10, which embodies the principles of the present invention.
The balancing apparatus 10 is constructed and arranged to suppress second order vibrations in 25 a conventional four cylinder in-line internal combustion engine, as disclosed, for example, in U.S. Patent No. 5,305,656, the disclosure of which is hereby incorporated into the present specification by this reference. The conventional engine includes a rotatable crank shaft and a plurality of piston and cylinders for causing rotation of the crank shaft. As is typical, the crank shaft includes a helical drive gear mounted for rotation therewith, of the type disclosed in U. S .
30 Patent No. 5,305,656.
CA 022=,3047 1998-11-0=, As shown in Figure 1, the apparatus 10 incllldes a housing assembly, generally indicated at 12, preferably of alllminllm or other light-weight material. The housing assembly 12 includes pairs of opposing sidewalls 13 and 14, respectively, connected together by support shafts 20 and 22. The housing assembly 12 includes mounting bosses, 18, for mounting the 5 housing assembly 12 to the engine cylinder block 19 by bolts (not shown). Thus, the apparatus 10 is constructed and arranged to be mounted to the engine block 19 under the crankshaft and within the oil pan.
First and second solid, hardened and ground support shafts, 20 and 22, respectively, are spaced in generally parallel relation and are fixed within the housing assembly 12 against 10 rotation and axial displacement. Both ends 21 and 25 of each shaft 20 and 22 are fitted in bores 23 in the walls 14 of the housing assembly 12. They are coupled to the housing assembly via associated cross-pins 24.
First and second cylindrical, hollow rotatable shafts 26 and 28, respectively, are mounted for rotation about the first and second support shafts 20 and 22, respectively, by 15 means of bearing structure, including pairs of associated needle rolling bearings 30.
Cast or powder metal balance weights 32 and 34 are fixed to one end of each of the rotatable shafts 26 and 28, respectively. As shown in Figures 1 and 2, the balance weights 32 and 34 are hydrodynamically shaped having mass distribution designed in such manner that it gives required eccentricity inertia in respect to the axes of rotation of each shaft 20 and 22 20 respectively. Balance weights 32 and 34 space envelope conforms to the maximum radius B
and minimllm radius C. Balance weights generally have a semi-circular, semi-spherical or semi-toroidal shaped portion with leading and trailing edges smoothly contoured or tapered to the minimllm radius C opposite the shaped portion.
In the illustrated embodiment, a driven helical gear is coupled to an end of each hollow, 25 rotatable shaft 26 and 28 opposite a respective balance weight. Thus, each driven gear is disposed in spaced relation with respect to a balance weight on an associated rotatable shaft.
Driven gear 36 is coupled to a periphery ofthe rotatable shaft 26. Gear 36 is preferably phenolic or non-ferrous material or ferrous material with high damping quality or powder metal and is constructed and arranged to be driven by the crank shaft drive gear (not shown), in the 30 known manner, as disclosed, for example, on U.S. Patent No. 5,305,656.
CA 022~3047 1998-ll-0~
Gear 38 iS coupled to the periphery of the rotatably shaft 28 and is preferably of phenolic or non-ferrous material or ferrous material with high damping quality or powder metal selected to match gear 36 in such manner to obtain the best noise and wear characteristics. The two gears 36 and 38 are in meshing relation with each other at teeth 37 and 39, respectively.
Shaft 22 iS radially offset relative to shaft 20. The offset spaces gear 38 to engage the crank shaft gear without eng~ging gear 36 The needle rolling bearings 30 are disposed in pairs about each support shaft, between an outer peripheral surface of support shaft and an inner peripheral surface of a rotatable shaft.
In the illustrated embodiment, one needle bearing 30 iS located generally under a balance 10 weight and one needle bearing 30 iS located under a driven gear 36,38. Thus, one needle bearing is disposed on a common axis D with a driven gear and another needle bearing is disposed on a common axis E with a balance weight.
Pairs of thrust washers 40 are disposed about each of the support shafts 20 and 22 with one thrust washer being disposed between an inner surface 43 of side wall 14 and each end 15 surface 45 of an associated rotatable shaft 26,28. The thrust washers 40 are constructed and arranged to absorb axial loads caused by the helical gear forces.
Each of the support shafts 20 and 22 includes lubrication or oil passage structure therein. In the illustrated embodiment, the oil passage structure includes an axial passage 42 and a cross passage 44 in communication therewith for directing a lubricant or oil in the 20 direction of arrows A, so as to lubricate the moving parts of the apparatus 10 such as the bearings 30. Lubrication is assisted by the pumping action of the needle rolling bearings 30.
The widths and masses of the balance weights 32 and 34 are minimi7ed by ma~imi7.ing their large radii B and minimi7.in3~ their small radii C. Further, the rotatable shafts 26 and 28 are made as light as possible, while the driven gears 36 and 38 are weight reduced by material 25 selection or provision of hydrodynamically shaped webs and holes, as is well know in the art.
These features greatly reduce the length, weight, and complexity of the apparatus 10.
The balancing apparatus 10 operates as follows. The app~s 10 is mounted to an engine within the oil pan such that the crank shaft helical gear is in meshing relation with teeth 39 of the driven gear 38. Rotation ofthe crank shaft gear is transmitted to the driven gear 38 30 to rotate the first balance weight 34 via shaft 28. Since gears 36 and 38 are in meshing relation, rotation ofthe second gear 38 iS transmitted to the first gear 36 to rotate the second CA 022~3047 1998-11-0~
balance weight 32 via shaft 26. Rotation of the balance weights 32 and 34 generates a load which cancels the inertial forces caused by the pistons and connecting rods of the engine, which in turn reduces vibration of the crank shaft.
Applicant has found that the mass moment of inertia of the rotating components of the 5 balancing apparatus 10 of the invention is the same as conventional designs, but utilizing only half of the mass. This permits the potential use of a phenolic gear or a non-ferrous gear for one of the driven gears, so as to reduce noise of the driven gears. It also allows for use of a high damping ferrous material or powder metal provided that it reduces the noise of the driven gears as opposed to steel gears. In the illustrated embodiment, the phenolic gear is preferably 10 driven gear 38 which is driven by the crank shaft gear. Other plastic or non-ferrous materials or high damping ferrous materials or powder metal may be used instead of the phenolic material, as long as noise and reliability criteria are met. The crank shaft gear can be of any material mentioned above provided that noise and reliability criteria are met.
It can be appreciated that the length of the support shafts 20 and 22, the rotating shafts 15 26 and 28 the housing assembly 12 can be changed to accommodate any designed spacing from the crank shaft gear to the center of gravity of the engine.
The housing assembly 12 can be made of ~ mimlm or other lightweight material having sufficient strength. Since the thermal coefficient of expansion of phenolic lies between that of steel and alllminllm, with the structure of the invention, gear tooth clearances have been found 20 to be acceptable in an operating range of-40~C to 150~C.
The installation of the needle bearings 30 in the appal~ s 10 is similar to the proven design of the planetary gears in automotive tr~n.cmi~ions. The needle bearings 30 may be cage-guided shell bearings, press-fitted into the rotating shaft 26 or 28, or unit cages with hardened or ground raceways in the rotating shafts 26 and 28, or unit cages with hardened or 25 ground raceways in the rotating shafts 26 and 28. The low deflection of the fixed support shafts 20 and 22 under the bearings 30 assures minim~l shaft and bearing mi~lignment and maximizes bearing life.
It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing plerelled embodiment of the 30 present invention has been shown and described for the purposes of illustrating the structural and functional principles of the present invention and is subject to change without departure from such principles.
Claims (10)
1. A balancing apparatus for a vehicle engine having a driving crankshaft, comprising:
a housing assembly constructed and arranged to be mounted to said vehicle engine and comprising spaced apart endwalls and two parallel extending support shafts connected to said endwalls, a first hollow shaft rotatably mounted concentrically about a first of said support shafts, a first gear mounted for rotation with the first hollow shaft, a first balance weight mounted for rotation with the first hollow shaft and spaced from said first gear, a second hollow shaft rotatably mounted concentrically about a second of said support shafts, a second gear mounted for rotation with the second hollow shaft, said second gear in driven engagement with the first gear for counter rotation therewith, said first of said support shafts positioned relative to said crankshaft for drivingly engaging the first gear with the crankshaft, a second balance weight mounted for rotation with the second hollow shaft and spaced from said second gear for rotation in a plane common with said first balance weight, said second balance weight positioned diametrically opposite to said first balance weight for counter rotation therewith.
a housing assembly constructed and arranged to be mounted to said vehicle engine and comprising spaced apart endwalls and two parallel extending support shafts connected to said endwalls, a first hollow shaft rotatably mounted concentrically about a first of said support shafts, a first gear mounted for rotation with the first hollow shaft, a first balance weight mounted for rotation with the first hollow shaft and spaced from said first gear, a second hollow shaft rotatably mounted concentrically about a second of said support shafts, a second gear mounted for rotation with the second hollow shaft, said second gear in driven engagement with the first gear for counter rotation therewith, said first of said support shafts positioned relative to said crankshaft for drivingly engaging the first gear with the crankshaft, a second balance weight mounted for rotation with the second hollow shaft and spaced from said second gear for rotation in a plane common with said first balance weight, said second balance weight positioned diametrically opposite to said first balance weight for counter rotation therewith.
2. A balancing apparatus as claimed in claim 1 wherein said each of said first and second balance weights is hydrodynamically shaped.
3. A balancing apparatus as claimed in claim 2 wherein said hydrodynamically shape comprises a shaped portion with smoothly contoured leading and trailing edges.
4. A balancing apparatus as claimed in claim 3 wherein said shaped portion is selected from a group comprising semi-circular, semi-spherical and semi-toroidal.
5 . A balancing apparatus as claimed in claim 2 wherein a set of needle bearings rotatably supports each of said hollow shafts in regions of each of said balance weights and each of said gears.
6. A balancing apparatus as claimed in claim 5 wherein each of said support shafts has an oil passage structure communicating between an end of said support shaft to an opening between said balance weights and said gears.
7. A balancing apparatus as claimed in claim 6 wherein each of said hollow shafts are mounted between thrust washers which frictionally engage said endwalls.
8. A balancing apparatus as claimed in claim 2 wherein at least one of said first and second gears has a gear engaging surface material selected from a group comprising high damping ferrous material, powder metal, plastic and non-ferrous material.
9. A balancing apparatus as claimed in claim 2 wherein at least one of said first and second gears has a phenolic gear engaging surface.
10. A balancing apparatus as claimed in claim 2 wherein said first and second gears each has a phenolic gear engaging surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US6438497P | 1997-11-06 | 1997-11-06 | |
| US60/064,384 | 1997-11-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2253047A1 true CA2253047A1 (en) | 1999-05-06 |
Family
ID=29547853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2253047 Abandoned CA2253047A1 (en) | 1997-11-06 | 1998-11-05 | Balancing apparatus for a vehicle engine |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2253047A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103438146A (en) * | 2013-08-09 | 2013-12-11 | 常州亚美柯机械设备有限公司 | Balance mechanism of single cylinder diesel |
-
1998
- 1998-11-05 CA CA 2253047 patent/CA2253047A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103438146A (en) * | 2013-08-09 | 2013-12-11 | 常州亚美柯机械设备有限公司 | Balance mechanism of single cylinder diesel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5535643A (en) | Anti-rattle engine balancer which drives associated oil pump | |
| US20130042990A1 (en) | Shaft with roller bearing | |
| US20100224164A1 (en) | Crankshaft for a variable compression ratio engine | |
| EP0851148A2 (en) | Balancer apparatus for an engine | |
| WO2009018863A1 (en) | A reciprocating piston mechanism | |
| US6286474B1 (en) | Engine balancer | |
| US4489683A (en) | Engine with crank mounted balancer for secondary shaking forces | |
| EP1370755A1 (en) | Balance shaft assembly | |
| US6659060B2 (en) | Crankshaft drive for an internal-combustion engine | |
| WO2000006870A9 (en) | Engine balance apparatus and accessory drive device | |
| CN109340306A (en) | A kind of uniaxiality balance axle system of variable compression ratio engine | |
| CA2253047A1 (en) | Balancing apparatus for a vehicle engine | |
| US5778835A (en) | Internal combustion engine | |
| WO2004072463A1 (en) | Vibration dampening arrangement for internal combustion engines | |
| EP1707769B1 (en) | Engine balancer | |
| JP2587209B2 (en) | Swash plate machines, especially internal combustion engines | |
| JPS5936759Y2 (en) | Primary paransor device for 4-stroke in-line 2-cylinder engine | |
| JPH0633989A (en) | Engine equipped with balancer shaft | |
| EP2514993A1 (en) | Coupling device | |
| CN219587957U (en) | Gasket assembled crankshaft | |
| JP2000186746A (en) | Balancer shaft | |
| CN219388417U (en) | Split type bent axle of outboard engine double-cylinder | |
| JP3730557B2 (en) | Balancer shaft for engine balancing device | |
| JP2540109B2 (en) | Engine balancer | |
| JPH087158Y2 (en) | Bearing structure of engine rotating shaft |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |