CA1204001A - Speed changing device - Google Patents
Speed changing deviceInfo
- Publication number
- CA1204001A CA1204001A CA000435059A CA435059A CA1204001A CA 1204001 A CA1204001 A CA 1204001A CA 000435059 A CA000435059 A CA 000435059A CA 435059 A CA435059 A CA 435059A CA 1204001 A CA1204001 A CA 1204001A
- Authority
- CA
- Canada
- Prior art keywords
- speed
- discs
- gear
- plates
- brake
- 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.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
- F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
- F16H3/72—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion with a secondary drive, e.g. regulating motor, in order to vary speed continuously
- F16H3/721—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion with a secondary drive, e.g. regulating motor, in order to vary speed continuously with an energy dissipating device, e.g. regulating brake or fluid throttle, in order to vary speed continuously
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Details Of Gearings (AREA)
- Braking Arrangements (AREA)
- Retarders (AREA)
Abstract
Abstract of the Disclosure A speed changing device having a first section preferably of a parallel axis gear set and a second section of a planetary gear set, the two sets being connected to one another, with the parallel gear set normally connected to the input shaft and the planetary gear set to the output shaft. A brake assembly, consisting of a plurality of alternately arranged reaction and opposing annularly shaped plates, controls the rotation of the ring gear and hence the speed and torque of the output shaft. The plates are cooled and lubricated to permit continued use of the brake assembly to control the speed of the output shaft and to provide a soft start for accelerating the equipment driven by the speed changing device. The faces of the brake plates contain radially extending intersecting grooves forming a series of diamond shaped lands throughout the faces of the plates, and the grooves supply a cooling and lubricating fluid to the plate faces to facilitate optimum performance of the brake assembly over extended periods of time.
Description
v~
SPEED CHANGING_DEVICE
Backqround of the Invention Generally in industrial applications, conventional gear reducers are of the single speed type consisting essentially of an input shaft on one side, an output shaft on the other side, and a fixed housing containing xeduction gears interconnecting the two shafts.
The housing, which encloses and supports the gearing between the shafts, is normally securecl to a rigid base and forms the reaction member ~or the torque transmitted between the two sha~ts. Multiple speed power trans-missions, which o~ten include gear reducexs, are extensively used in the vehicular field, and are specially designed and constructed for that particular application.
They are fxequently of the gear shift typel ei-thex manual or automatic; however, clutch operation reaction types have been extensively used ln the vehicular field to vary the ra~io between the engine and drive shaft. The foregoing vehicular types of speed changing mechanisms have not been utilized in most instances in industrial installation, primarily because they are unduly complex, laxge and expensive, and/or are unreliable ~or extended pexiods of operation for driving machinery and other equipment under heavy loads. Instead, variable speed changiny involving gear reducers has principally been accomplished in the industrial field by using variable speed electric motors to drive the equipment through single gear ratio reducers.
It is sometimes necessary or desirable to control variable speed reducers and other mechanical power transmission drives in response to the load on -the driven :1.
equipment, and to vary the accelera-tion and deceleration rates of the drive even though the drive normally operates at a constant speed when in full operation. An example of this type of application and operation is in drives for belt conveyors used for handliny heavy materials such as ore, coal, rock and similar material. This type of conveyor equipment is often driven hy an electric motor th.rough a speed reduce.r connected to the shaft of one of the pulleys on which the conveyor belt is trained. The motor and speed reducer may be installed a-t the end of the driven pulley, or the motor may be installed at the end of the pulley with the speed reducer moun-ted in the driven pulley as an inteyral installation. In the latter type of installation, the motor drives the speed reducer through a shaft axially disposed in the main pulley shaft, and the speed reducer reacts directly on the pulley to pro~ide the drive torque therefor.
In belt conveyors, sudden starts with no load or only liyht loads may result in damage to the conveyor system or cause the conveyor belt to loosen to the extent that the conveyor fails to operate or operates in efficiently. Variable acceleration of a speed reducer has been effectively accomplished by a brake mechanism used in conjunction with the reaction shaft of the speed reducer operating the driven pulley of the conveyor system. Such mechanisms and installations are disclosed and claimed in U.S~ Patents Nos~ 4,047,452 to ~ddy, 4,168,611 to Woyton and Meredith, 4,189r962 to Chung, and 4,231,565 to Lower.
While these patents disclose drives intended for conveyor systems and the like/ these controlled start speed chanying devices have a much more ye:neral field of use and broader applications, and may be used in a wide varie~y of installa-tions. In ~-he soft start concept of the foregoiny patents, -the power drive is responsive to the load on the power output element at the time of starting to provide the required torque and effect a soft start, and thereafter controls the acceleration rate until the conveyor system has reached normal operating speed, regardless of the load on th^-~system, thus avoiding a quick start, normally invoiving a sudden jerk when the system is unloaded or has only a light load~ This soft start concept has a distinct advantage in the opexation of various types oE equipment other than belt conveyors. It is also sometimes desirable to operate the equipment at slower than normal speed. In the past this could not be accomplished using the braking mechanism, since the friction created sufficient heat to destroy the braking ~echanism in a relatively short period of time, and long soft start and acceleration periods could create sufficient heat to seriously damage the mechanism.
Sur~mary of_the Invention One of the principal objects of the present invention is to provide a speed changing device having an acceleration and deceleration control system which is hlghly reliable and efficient~ and which can be operated for prolonged periods of time under adverse conditions and/or at less than full speed, without attention or adjustment by an operator once the desired rate of acceleration and deceleration and/or speed has been se:lected for the various operating parameters, and without subjecting the device to conditions which would be likely to cause serious damage to the device or equipment driven thereby.
A further object oE the inventiorl is to provide a system for controlling the acceleration and deceleration rate of a mechanical power drive which normally operates at a substantially constant speed, and which may be driven by a constant speed motor and yet be capable of providing a soft start and slow acceleration of the equipment with any gear ratio selected.
Still another object is to provide a dual type speed changing device which is relatively simple in operation and construction~ which can be installed and operated under adverse environmental and operating conditions, and which is capable of easily beiny modified by changing a pinion and gear combination to adapt it to different applications and types of installations.
The foregoing objects, and other objects,and advantages which will become apparent from the following description of the present invention, are accomplished by a speed changing device having a planetary gear reducer, the reaction element of which is controlled by an oil cooled ~reaction brake, normally responsive to the load Gn the equip~nent being started and driven by the speed changing device. The reaction brake is of the multiple disc type, actuated by a hydraulic piston, and the cooling fluid is forced under pressure between the discs which preferably have surfaces with a special configuration to provide optimum flow of fluid between the discs~ The discs of the actuating brake are, in effect/ in a floating arrangement with the ring gear and the reaction member on the housing to permit effective centering of the various parts without interference of the brake discs. The fluid nlay be forced between the discs throughout the operation of the speed ~2~
changing device, and the cooling and lubricating effect of the fluid will permit some slippage to vary or regulate the output speed of the device to something less than maximum speed. The reaction brake is preferably disposed on the output side of the reducer and reacts between the ring gear and the housing~ One of the features of the concept disclosed in the application is the combination of a single stage, parallel axis gear reducer section involving a pinion and gear, with the pinion preferably on the input shaft, and the planetary reducer section on the output side of the device. In the event a change in the gear ratio is desired, the pinion and the driven gear of the gear section can be relatively easily changed without disassembling the more complicated planetary gear section. This dual section can be reversed so that the planetary gear section i5 on the input side of the speed changiny device and the parallel axis/ gear reducing section is on the output side.
II1 either of these two arrangements, the selection of the desired gear reduction can be made by changing the pinion and driven gear reducer section.
Brief Descrlption of_the Drawings Figure 1 is a perspective view of the speed chanying device er~odying the present invention;
Figure 2 is a horizontal cross-sectional view taken on horizontal line 2 of Figure 1;
Figure 3 is an enlarged fragmentary cross~
sectional view of the speed changing device, the view being indicated on Figure 2 by the broken circle identified by the numexal 3;
Figure 4 is a perspective view of a brake element used in the present device;
Figure 5 is an exploded view of a portion of the planetary gear sec-tion and reaction element used in the present speed changing device; and Fiyure 6 is an enlarged fragmentary view of one of the plates of the disc pack of the reaction brake used in the pr~sent speed changing device.
Detai ~ ion oE the Preferred Embodiment Referring more specifically to the drawings, and to Figures l and 2 in particular, numeral 10 indicates generally a speed changing device embodying the present invention, having a housing 12~ an input shaft 14 and an output shaft 16 journaled in the opposite side walls 18 and 20 of the houslng. In the embodiment illustrated in the drawings, the present speed changiny device has two basic sections consisting of a parallel axis gear reduction section indicated generally by numeral 22, and a planetary gear section indicated ~enerally by numeral 24. These two sections interconnect the input shaft 14 and the output shaft 16. Arrangements of these two sections other than that shown in the drawings may be used if desired.
The gear section 22 consists of input shaEt 14 journaled in bearings 30 and 32 supported by external side wall 18 of the housing 12, and an inner wall 34 in the housing. A pinion 36 is disposed Oll or Eormed integrally with input shaEt 14 and meshes~with a gear 38 mounted on a shaft 40 and keyed thereto for rotation therewith, the shaft 40 being journaled in bearings 42 in side wall 18 and be~ring 44 in inner wall 34. The pinion 36 and gear 38 are lubricated by the lubricant in the lower portiorl of the housing in which gear 38 is partially submerged. Different reductions in speed can be selected by varying the ratio between pinion 36 and year 38. Since these two parts can be relatively easily changed, the desired speed reduction can conveniently be varied from one installation to another to satisfy requirements.
The planetary reduction section 24 consists of sun gear 62 and three planetary gears 64, 66 and 68 having shafts journaled in the planetary gear carrier, indicated generally by the numeral 70, having flanges 72 and 74 in which the shafts of the planetary gears are journaled and an extension 75 journaled in bearing 76 supported by an annular extension on internal wall 34. The sun gear 62 and shaft 40 are interconnected by a spline coupling 78 in extension 75 so that sun gear 62 and shaft 40 rotate together and relative to the planetary gear carrier.
Hence, rotation of shaft 40 and sun gear 62 rotates the three planetary gears in ring gear 60 as in a conventional planetary gear reducer. Each of three planetary gears 64, ~6 and 68 is mounted on a shaft 80 seated in holes in flanges 72 and 74, and bearings 82 and 84 are disposed on the shaft and the respective planetary gears are journaled on the two bearings for relative rotation wlth respect to shaft 80.
The planetary gear is controlled by a reaction brake, indicated generally by the numeral 90, having a plurality of interleaved friction plates 92 connected to annular housing insert 94 by spline part 95 and opposing plates 96 connected to extension 98 of riny gear 60 by sp'ine part 99. Plates 92 are prevented from rotation by the spline formed by interlocking ribs and grooves on the plates and on the perlphery of annular member 94, and plates 96 are prevented from relative rotation wi.th respect ~26~
to one another by the spline formed by interlocking ribs and grooves on the opposing plates and on the internal surface of extension 98 of ring gear 60; thus, the friction and opposing plates move relative to one another during operation of the planetary gear section until the brake is fully applied. The braking is achieved by ring shaped piston 100 disposed in a ring shaped cylinder 102, the latter being connected to a hydraulic control pressure source through port 104, the piston being sealed at the cylinder walls by O-ring gaskets 106 and 108 in the side wall of the cylinder. When hydraulic fluid is admitted into cylinder 102, the piston 100 moves laterally to the left, thereby compressing the friction and opposing plates together to create a resistance to the rotatlon of the ring gear 60, thus causing the planetary gears to rotate relative thereto and to rotate carrier 70 to which output shaft 16, journaled in bearing 109, is joined integrally.
One of the important features of the present speed changing device is the use of a reaction brake which is lubricated and cooled by fluid forced under pressure between the plates. The fluid is admitted into an annular channel 110 in the external surface of member 94 under pressure through port 112 and flows outwardly between the friction and opposing brake plates, where it lubricates and cools the plates while they are under compression from piston 100.
As the pressure is applied by piston 100 to the stack of plates, the friction or drag produced thereby on the ring gear produces the desired gear reduction accomplished by the planetary section.
Most brake systems under the opera-ting conditions to which the present speed changing device is subjected :L2~
wi]l become excessively hot if operated for any extended period of time. Consequently, brake systems in planetary reducers have not permitted prolonged or indefinite operation as a means of accomplishing desired speed reduction and/or prolonged soft start operations. The present system has overcome this diffic~lty by the utilization of a particular surface configuration on the two sides of the fric-tion plates. This surface con-struction and configuration are illustrated in Figure 6, and consist of a plurality of generally radially disposed, though somewhat diagonal, grooves 12~ and 122 extending from the internal edge to the external edge of the plates.
The grooves which form diamond shaped lands 124 throughout the opposite side surfaces of the plates, and permit the oil to flow continually through grooves 120 and 122 from annular groove 110 to the external surface of the brake plates, and the configuration formed thereby, permit the plates to be lubricated relative to one another to reduce friction and to maintain a satisfactory operatiny temperature in the stack of plates so that the brake can be operated an indefinite period of time at any preselected speed. The pressure on the plates can be varied infinitely between virtually no drag or friction to fully engaged plates, where the stack of plates and the ring gear are stationary, to obtain an infinitely variable speed reduction in the planetary section. The piston 100 is returned to its withdrawn position by a plurality of springs 130 mounted on pins 132, each spriny reacting against a tab 134 on each pin and forcing the tab to the right, as viewed in Figures 2 and 3, to return piston 100 to its withdrawn position, thereby permitting the friction and opposing plates to separate~
The lubricating and cooliny fluid flows inwardly through holes 112 into aIInular space 110 and thence axially in the longitudinal grooves of splined part 95 into which the inner edges of the friction plates are disposed. The pins and springs are seated in grooves 136 and extend into holes in ring 138 secured to the inner end of member 90.
The brake assembly is held in operative position in the ring by member 140 secured to member 138 by a plurality of bolts 142, the member 140 extending into and loosely seating in a slot 144, forming a structural arrangement which permits a floa~ing relationship between the brake assembly and the ring gear to permit the ring gear to center itself in -the final assembly.
A lubrication pump 150 for the bearings is mounted on inner wall 34 and connected to and driven by input shaft 14. Oil is pumped fl^om the sump in the bottom of the housing through various channels, most of which are not shown, to the bearings for the shafts.
In the operation of the present speed changing devic~, a motor is connected to input shaft 14, and a drive sprocket, coupling, gear, or pulley is mounted on output shaft 16 for connection to the equipment to be driven by the device. As shaft 14 is driven, it rotates pinion 36, which in turn rotates gear 38 and shaft 40. Since shaft 40 is connected by coupling 78 to sun gear 62, the planetary gears 64l Z6 and 68 and ring gear 60 are rotated at substantially the same rate as shaft 40, before the reaction brake has been applied, and the planetary gear carrier xemains stationary. To obtain the desired speed from the gear section 22 to the ou-tput shaft 16, the Q~
reaction brake 90 i5 applied by the introduction of hydraulic fluid into cylinder 102, which forces the ring piston 100 against the brake plates, thereby forcing the brake plates into partial or full contact with one ano-ther.
This either slows or stops the rotation of ring gear 60 t the amount of decrease in speed achieved depending upon the pressure applied by the brake piston. As the speed of rotation of the ring gear is reduced, the speed of rotation from the gear section 22 to the output shaf~ 16 is increased, and the maximum speed is reached when the ring gear is fully stopped by the application of reaction brake 90 ~
In many installations, a speed between the full speed of gear section 22 and the full reduction obtained by zero rotation of ring gear 60 may be desired. In order to obtain this, the brake 90 is applied with a preselected pressure, which permits the opposing plates to rotate relative to the friction plates, thereby permitting the ring gear to rotate; but at a reduced speed. This type of operation is particularly effective for obta:Lning a so~t start for driving conveyors and other equipment where a rapid start-up would result in a shock to the equipment, which might cause serious and irreparable damage to the equipment. The equipment is accelerated by the application of further force of the brake, which causes a still slower rotation of ring gear 60 until the desired speed is reached.
If it is less than the full zero rotation of the ring gear, the opposing plates continue to rotate relative to the friction plates while -the cooling fluid is applied through port 112 lnto annular passage 110, and thence to ~.2~
th~ grooves of part 95 orming a splined relationship with the inner edges of the frictlon plates 92. The cooling fluid then flows outwardly between the plates through grooves 122 and 124 and is discharged from the outer ends of the grooves from where it drips into the sump of the housing. The continual flow of fluid through the grooves prevents the plates from increasing in temperature to the point where damage occurs, and hence permits the continual use of the gear reducer at any chosen speed up to full speed reduction achieved by the planetary gear section with the ~ero rotation of the ring gear. When the brake is released, pressure o the ~luid delivered to cylinder 102 lS decreased and springs 130 reacting against tabs 134 on pins 132 release the pack o~ friction and opposing plates so that the opposing plates can rotate freely relative to the friction plates, and the ring gear is ree to rotate without interference from the brake.
It is seen ~rom the foregoing, that the present speed changing device provides a variable speed output covering a broad range of selected speeds by the output shaft while the speed changing device can be driven by a constant speed motor. Regardless of whether or no-t the device is used for a preselected constant speed, it can effectively be used or a soft start operation which permits slow acceleration to avoid shock on the driven equipment. The range o~ applications o~ the device can be extended by changing the gear ratio in the parallel axis gear section, and this change can be made without any major or difficult operation being required to make the changes.
~'urther, while the device is shown with the parallel axls gear section on the input side and the planetary section on ~g~
the output side, the two sections can be reversed if desired, so that the planetary section would be on the input side of the device and the parallel axis gear reducer would be on the output side of the device.
While only one embodiment of the present speed changing device has beerl described herein in detail, various changes and modifications can be made without departing from the scope of the invention.
SPEED CHANGING_DEVICE
Backqround of the Invention Generally in industrial applications, conventional gear reducers are of the single speed type consisting essentially of an input shaft on one side, an output shaft on the other side, and a fixed housing containing xeduction gears interconnecting the two shafts.
The housing, which encloses and supports the gearing between the shafts, is normally securecl to a rigid base and forms the reaction member ~or the torque transmitted between the two sha~ts. Multiple speed power trans-missions, which o~ten include gear reducexs, are extensively used in the vehicular field, and are specially designed and constructed for that particular application.
They are fxequently of the gear shift typel ei-thex manual or automatic; however, clutch operation reaction types have been extensively used ln the vehicular field to vary the ra~io between the engine and drive shaft. The foregoing vehicular types of speed changing mechanisms have not been utilized in most instances in industrial installation, primarily because they are unduly complex, laxge and expensive, and/or are unreliable ~or extended pexiods of operation for driving machinery and other equipment under heavy loads. Instead, variable speed changiny involving gear reducers has principally been accomplished in the industrial field by using variable speed electric motors to drive the equipment through single gear ratio reducers.
It is sometimes necessary or desirable to control variable speed reducers and other mechanical power transmission drives in response to the load on -the driven :1.
equipment, and to vary the accelera-tion and deceleration rates of the drive even though the drive normally operates at a constant speed when in full operation. An example of this type of application and operation is in drives for belt conveyors used for handliny heavy materials such as ore, coal, rock and similar material. This type of conveyor equipment is often driven hy an electric motor th.rough a speed reduce.r connected to the shaft of one of the pulleys on which the conveyor belt is trained. The motor and speed reducer may be installed a-t the end of the driven pulley, or the motor may be installed at the end of the pulley with the speed reducer moun-ted in the driven pulley as an inteyral installation. In the latter type of installation, the motor drives the speed reducer through a shaft axially disposed in the main pulley shaft, and the speed reducer reacts directly on the pulley to pro~ide the drive torque therefor.
In belt conveyors, sudden starts with no load or only liyht loads may result in damage to the conveyor system or cause the conveyor belt to loosen to the extent that the conveyor fails to operate or operates in efficiently. Variable acceleration of a speed reducer has been effectively accomplished by a brake mechanism used in conjunction with the reaction shaft of the speed reducer operating the driven pulley of the conveyor system. Such mechanisms and installations are disclosed and claimed in U.S~ Patents Nos~ 4,047,452 to ~ddy, 4,168,611 to Woyton and Meredith, 4,189r962 to Chung, and 4,231,565 to Lower.
While these patents disclose drives intended for conveyor systems and the like/ these controlled start speed chanying devices have a much more ye:neral field of use and broader applications, and may be used in a wide varie~y of installa-tions. In ~-he soft start concept of the foregoiny patents, -the power drive is responsive to the load on the power output element at the time of starting to provide the required torque and effect a soft start, and thereafter controls the acceleration rate until the conveyor system has reached normal operating speed, regardless of the load on th^-~system, thus avoiding a quick start, normally invoiving a sudden jerk when the system is unloaded or has only a light load~ This soft start concept has a distinct advantage in the opexation of various types oE equipment other than belt conveyors. It is also sometimes desirable to operate the equipment at slower than normal speed. In the past this could not be accomplished using the braking mechanism, since the friction created sufficient heat to destroy the braking ~echanism in a relatively short period of time, and long soft start and acceleration periods could create sufficient heat to seriously damage the mechanism.
Sur~mary of_the Invention One of the principal objects of the present invention is to provide a speed changing device having an acceleration and deceleration control system which is hlghly reliable and efficient~ and which can be operated for prolonged periods of time under adverse conditions and/or at less than full speed, without attention or adjustment by an operator once the desired rate of acceleration and deceleration and/or speed has been se:lected for the various operating parameters, and without subjecting the device to conditions which would be likely to cause serious damage to the device or equipment driven thereby.
A further object oE the inventiorl is to provide a system for controlling the acceleration and deceleration rate of a mechanical power drive which normally operates at a substantially constant speed, and which may be driven by a constant speed motor and yet be capable of providing a soft start and slow acceleration of the equipment with any gear ratio selected.
Still another object is to provide a dual type speed changing device which is relatively simple in operation and construction~ which can be installed and operated under adverse environmental and operating conditions, and which is capable of easily beiny modified by changing a pinion and gear combination to adapt it to different applications and types of installations.
The foregoing objects, and other objects,and advantages which will become apparent from the following description of the present invention, are accomplished by a speed changing device having a planetary gear reducer, the reaction element of which is controlled by an oil cooled ~reaction brake, normally responsive to the load Gn the equip~nent being started and driven by the speed changing device. The reaction brake is of the multiple disc type, actuated by a hydraulic piston, and the cooling fluid is forced under pressure between the discs which preferably have surfaces with a special configuration to provide optimum flow of fluid between the discs~ The discs of the actuating brake are, in effect/ in a floating arrangement with the ring gear and the reaction member on the housing to permit effective centering of the various parts without interference of the brake discs. The fluid nlay be forced between the discs throughout the operation of the speed ~2~
changing device, and the cooling and lubricating effect of the fluid will permit some slippage to vary or regulate the output speed of the device to something less than maximum speed. The reaction brake is preferably disposed on the output side of the reducer and reacts between the ring gear and the housing~ One of the features of the concept disclosed in the application is the combination of a single stage, parallel axis gear reducer section involving a pinion and gear, with the pinion preferably on the input shaft, and the planetary reducer section on the output side of the device. In the event a change in the gear ratio is desired, the pinion and the driven gear of the gear section can be relatively easily changed without disassembling the more complicated planetary gear section. This dual section can be reversed so that the planetary gear section i5 on the input side of the speed changiny device and the parallel axis/ gear reducing section is on the output side.
II1 either of these two arrangements, the selection of the desired gear reduction can be made by changing the pinion and driven gear reducer section.
Brief Descrlption of_the Drawings Figure 1 is a perspective view of the speed chanying device er~odying the present invention;
Figure 2 is a horizontal cross-sectional view taken on horizontal line 2 of Figure 1;
Figure 3 is an enlarged fragmentary cross~
sectional view of the speed changing device, the view being indicated on Figure 2 by the broken circle identified by the numexal 3;
Figure 4 is a perspective view of a brake element used in the present device;
Figure 5 is an exploded view of a portion of the planetary gear sec-tion and reaction element used in the present speed changing device; and Fiyure 6 is an enlarged fragmentary view of one of the plates of the disc pack of the reaction brake used in the pr~sent speed changing device.
Detai ~ ion oE the Preferred Embodiment Referring more specifically to the drawings, and to Figures l and 2 in particular, numeral 10 indicates generally a speed changing device embodying the present invention, having a housing 12~ an input shaft 14 and an output shaft 16 journaled in the opposite side walls 18 and 20 of the houslng. In the embodiment illustrated in the drawings, the present speed changiny device has two basic sections consisting of a parallel axis gear reduction section indicated generally by numeral 22, and a planetary gear section indicated ~enerally by numeral 24. These two sections interconnect the input shaft 14 and the output shaft 16. Arrangements of these two sections other than that shown in the drawings may be used if desired.
The gear section 22 consists of input shaEt 14 journaled in bearings 30 and 32 supported by external side wall 18 of the housing 12, and an inner wall 34 in the housing. A pinion 36 is disposed Oll or Eormed integrally with input shaEt 14 and meshes~with a gear 38 mounted on a shaft 40 and keyed thereto for rotation therewith, the shaft 40 being journaled in bearings 42 in side wall 18 and be~ring 44 in inner wall 34. The pinion 36 and gear 38 are lubricated by the lubricant in the lower portiorl of the housing in which gear 38 is partially submerged. Different reductions in speed can be selected by varying the ratio between pinion 36 and year 38. Since these two parts can be relatively easily changed, the desired speed reduction can conveniently be varied from one installation to another to satisfy requirements.
The planetary reduction section 24 consists of sun gear 62 and three planetary gears 64, 66 and 68 having shafts journaled in the planetary gear carrier, indicated generally by the numeral 70, having flanges 72 and 74 in which the shafts of the planetary gears are journaled and an extension 75 journaled in bearing 76 supported by an annular extension on internal wall 34. The sun gear 62 and shaft 40 are interconnected by a spline coupling 78 in extension 75 so that sun gear 62 and shaft 40 rotate together and relative to the planetary gear carrier.
Hence, rotation of shaft 40 and sun gear 62 rotates the three planetary gears in ring gear 60 as in a conventional planetary gear reducer. Each of three planetary gears 64, ~6 and 68 is mounted on a shaft 80 seated in holes in flanges 72 and 74, and bearings 82 and 84 are disposed on the shaft and the respective planetary gears are journaled on the two bearings for relative rotation wlth respect to shaft 80.
The planetary gear is controlled by a reaction brake, indicated generally by the numeral 90, having a plurality of interleaved friction plates 92 connected to annular housing insert 94 by spline part 95 and opposing plates 96 connected to extension 98 of riny gear 60 by sp'ine part 99. Plates 92 are prevented from rotation by the spline formed by interlocking ribs and grooves on the plates and on the perlphery of annular member 94, and plates 96 are prevented from relative rotation wi.th respect ~26~
to one another by the spline formed by interlocking ribs and grooves on the opposing plates and on the internal surface of extension 98 of ring gear 60; thus, the friction and opposing plates move relative to one another during operation of the planetary gear section until the brake is fully applied. The braking is achieved by ring shaped piston 100 disposed in a ring shaped cylinder 102, the latter being connected to a hydraulic control pressure source through port 104, the piston being sealed at the cylinder walls by O-ring gaskets 106 and 108 in the side wall of the cylinder. When hydraulic fluid is admitted into cylinder 102, the piston 100 moves laterally to the left, thereby compressing the friction and opposing plates together to create a resistance to the rotatlon of the ring gear 60, thus causing the planetary gears to rotate relative thereto and to rotate carrier 70 to which output shaft 16, journaled in bearing 109, is joined integrally.
One of the important features of the present speed changing device is the use of a reaction brake which is lubricated and cooled by fluid forced under pressure between the plates. The fluid is admitted into an annular channel 110 in the external surface of member 94 under pressure through port 112 and flows outwardly between the friction and opposing brake plates, where it lubricates and cools the plates while they are under compression from piston 100.
As the pressure is applied by piston 100 to the stack of plates, the friction or drag produced thereby on the ring gear produces the desired gear reduction accomplished by the planetary section.
Most brake systems under the opera-ting conditions to which the present speed changing device is subjected :L2~
wi]l become excessively hot if operated for any extended period of time. Consequently, brake systems in planetary reducers have not permitted prolonged or indefinite operation as a means of accomplishing desired speed reduction and/or prolonged soft start operations. The present system has overcome this diffic~lty by the utilization of a particular surface configuration on the two sides of the fric-tion plates. This surface con-struction and configuration are illustrated in Figure 6, and consist of a plurality of generally radially disposed, though somewhat diagonal, grooves 12~ and 122 extending from the internal edge to the external edge of the plates.
The grooves which form diamond shaped lands 124 throughout the opposite side surfaces of the plates, and permit the oil to flow continually through grooves 120 and 122 from annular groove 110 to the external surface of the brake plates, and the configuration formed thereby, permit the plates to be lubricated relative to one another to reduce friction and to maintain a satisfactory operatiny temperature in the stack of plates so that the brake can be operated an indefinite period of time at any preselected speed. The pressure on the plates can be varied infinitely between virtually no drag or friction to fully engaged plates, where the stack of plates and the ring gear are stationary, to obtain an infinitely variable speed reduction in the planetary section. The piston 100 is returned to its withdrawn position by a plurality of springs 130 mounted on pins 132, each spriny reacting against a tab 134 on each pin and forcing the tab to the right, as viewed in Figures 2 and 3, to return piston 100 to its withdrawn position, thereby permitting the friction and opposing plates to separate~
The lubricating and cooliny fluid flows inwardly through holes 112 into aIInular space 110 and thence axially in the longitudinal grooves of splined part 95 into which the inner edges of the friction plates are disposed. The pins and springs are seated in grooves 136 and extend into holes in ring 138 secured to the inner end of member 90.
The brake assembly is held in operative position in the ring by member 140 secured to member 138 by a plurality of bolts 142, the member 140 extending into and loosely seating in a slot 144, forming a structural arrangement which permits a floa~ing relationship between the brake assembly and the ring gear to permit the ring gear to center itself in -the final assembly.
A lubrication pump 150 for the bearings is mounted on inner wall 34 and connected to and driven by input shaft 14. Oil is pumped fl^om the sump in the bottom of the housing through various channels, most of which are not shown, to the bearings for the shafts.
In the operation of the present speed changing devic~, a motor is connected to input shaft 14, and a drive sprocket, coupling, gear, or pulley is mounted on output shaft 16 for connection to the equipment to be driven by the device. As shaft 14 is driven, it rotates pinion 36, which in turn rotates gear 38 and shaft 40. Since shaft 40 is connected by coupling 78 to sun gear 62, the planetary gears 64l Z6 and 68 and ring gear 60 are rotated at substantially the same rate as shaft 40, before the reaction brake has been applied, and the planetary gear carrier xemains stationary. To obtain the desired speed from the gear section 22 to the ou-tput shaft 16, the Q~
reaction brake 90 i5 applied by the introduction of hydraulic fluid into cylinder 102, which forces the ring piston 100 against the brake plates, thereby forcing the brake plates into partial or full contact with one ano-ther.
This either slows or stops the rotation of ring gear 60 t the amount of decrease in speed achieved depending upon the pressure applied by the brake piston. As the speed of rotation of the ring gear is reduced, the speed of rotation from the gear section 22 to the output shaf~ 16 is increased, and the maximum speed is reached when the ring gear is fully stopped by the application of reaction brake 90 ~
In many installations, a speed between the full speed of gear section 22 and the full reduction obtained by zero rotation of ring gear 60 may be desired. In order to obtain this, the brake 90 is applied with a preselected pressure, which permits the opposing plates to rotate relative to the friction plates, thereby permitting the ring gear to rotate; but at a reduced speed. This type of operation is particularly effective for obta:Lning a so~t start for driving conveyors and other equipment where a rapid start-up would result in a shock to the equipment, which might cause serious and irreparable damage to the equipment. The equipment is accelerated by the application of further force of the brake, which causes a still slower rotation of ring gear 60 until the desired speed is reached.
If it is less than the full zero rotation of the ring gear, the opposing plates continue to rotate relative to the friction plates while -the cooling fluid is applied through port 112 lnto annular passage 110, and thence to ~.2~
th~ grooves of part 95 orming a splined relationship with the inner edges of the frictlon plates 92. The cooling fluid then flows outwardly between the plates through grooves 122 and 124 and is discharged from the outer ends of the grooves from where it drips into the sump of the housing. The continual flow of fluid through the grooves prevents the plates from increasing in temperature to the point where damage occurs, and hence permits the continual use of the gear reducer at any chosen speed up to full speed reduction achieved by the planetary gear section with the ~ero rotation of the ring gear. When the brake is released, pressure o the ~luid delivered to cylinder 102 lS decreased and springs 130 reacting against tabs 134 on pins 132 release the pack o~ friction and opposing plates so that the opposing plates can rotate freely relative to the friction plates, and the ring gear is ree to rotate without interference from the brake.
It is seen ~rom the foregoing, that the present speed changing device provides a variable speed output covering a broad range of selected speeds by the output shaft while the speed changing device can be driven by a constant speed motor. Regardless of whether or no-t the device is used for a preselected constant speed, it can effectively be used or a soft start operation which permits slow acceleration to avoid shock on the driven equipment. The range o~ applications o~ the device can be extended by changing the gear ratio in the parallel axis gear section, and this change can be made without any major or difficult operation being required to make the changes.
~'urther, while the device is shown with the parallel axls gear section on the input side and the planetary section on ~g~
the output side, the two sections can be reversed if desired, so that the planetary section would be on the input side of the device and the parallel axis gear reducer would be on the output side of the device.
While only one embodiment of the present speed changing device has beerl described herein in detail, various changes and modifications can be made without departing from the scope of the invention.
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A speed changing device comprising:
a housing;
a main input shaft and a main output shaft;
a parallel axis gear section disposed in said housing and having a rotatable output element and a pinion connected to and rotatable with said main input shaft and gear means operatively connecting said pinion to said output element;
a planetary gear section disposed in said housing and having a sun gear connected to the rotatable output element of said parallel axis gear section;
a plurality of planetary gears meshing with said sun gear and having a carrier connected to said main output shaft;
a ring gear surrounding said planetary gears and meshing therewith; and a reaction brake connected to said housing and to said ring gear for controlling the speed and torque of said main output shaft, said reaction brake includ-ing a plurality of annular friction and opposing discs alternately arranged in side-by-side rela-tionship, means connecting said friction discs to said housing in a nonrotatable position, means connecting said opposing discs to said ring gear, a hydraulically operated piston for actuating said brake by urging said friction and opposing discs toward one another, a channel being provided adjacent the inner edges of said friction and opposing discs to supply cooling and lubri-cating fluid to said discs, and generally radially extending grooves in the faces of said discs for facilitating the flow of said fluid between said discs.
a housing;
a main input shaft and a main output shaft;
a parallel axis gear section disposed in said housing and having a rotatable output element and a pinion connected to and rotatable with said main input shaft and gear means operatively connecting said pinion to said output element;
a planetary gear section disposed in said housing and having a sun gear connected to the rotatable output element of said parallel axis gear section;
a plurality of planetary gears meshing with said sun gear and having a carrier connected to said main output shaft;
a ring gear surrounding said planetary gears and meshing therewith; and a reaction brake connected to said housing and to said ring gear for controlling the speed and torque of said main output shaft, said reaction brake includ-ing a plurality of annular friction and opposing discs alternately arranged in side-by-side rela-tionship, means connecting said friction discs to said housing in a nonrotatable position, means connecting said opposing discs to said ring gear, a hydraulically operated piston for actuating said brake by urging said friction and opposing discs toward one another, a channel being provided adjacent the inner edges of said friction and opposing discs to supply cooling and lubri-cating fluid to said discs, and generally radially extending grooves in the faces of said discs for facilitating the flow of said fluid between said discs.
2. A speed changing device as defined in Claim 1 in which said grooves in the faces of each of said discs inter-sect one another and form a generally diamond shaped land con-figuration throughout the surfaces of said discs.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US41536782A | 1982-09-07 | 1982-09-07 | |
| US415,367 | 1982-09-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1204001A true CA1204001A (en) | 1986-05-06 |
Family
ID=23645406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000435059A Expired CA1204001A (en) | 1982-09-07 | 1983-08-22 | Speed changing device |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU552238B2 (en) |
| BR (1) | BR8304758A (en) |
| CA (1) | CA1204001A (en) |
| DE (1) | DE3330147A1 (en) |
| FR (1) | FR2532707B1 (en) |
| GB (1) | GB2126292B (en) |
| ZA (1) | ZA836418B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2139715A (en) * | 1983-05-14 | 1984-11-14 | Peter Harold Goss | Variable transmission system |
| DE3331039C2 (en) * | 1983-08-29 | 1995-01-19 | Dorstener Maschf Ag | Branching gear with built-in clutch |
| AT389577B (en) * | 1985-09-13 | 1989-12-27 | Steyr Daimler Puch Ag | TRANSMISSION UNIT, ESPECIALLY DIFFERENTIAL GEARBOX BETWEEN THE DRIVEN AXLES OF A MOTOR VEHICLE |
| US4858493A (en) * | 1987-05-04 | 1989-08-22 | Sundstrand Corporation | Multi-range, dissipative, infinitely variable ratio transmission |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR745303A (en) * | 1933-05-09 | |||
| FR367268A (en) * | 1906-06-19 | 1906-10-25 | Henri Arsene Benjamin Prosper | Gradual shifting, differential motion, for automobiles |
| GB247540A (en) * | 1925-02-10 | 1926-11-04 | William Beardmore | Improvements in or relating to internal combustion engine locomotives |
| US2939346A (en) * | 1957-11-01 | 1960-06-07 | Caterpillar Tractor Co | Two-step gear reduction mechanism |
| US3020990A (en) * | 1958-07-07 | 1962-02-13 | Us Industries Inc | Transmissions |
| DE2055087A1 (en) * | 1970-11-10 | 1972-05-18 | Klöckner-Humboldt-Deutz AG, 5000 Köln | Engine for motor vehicles, in particular commercial motor vehicles |
| DE2249774A1 (en) * | 1972-10-11 | 1974-04-18 | Heinz Knebel | CONTINUOUSLY CONTROLLED GEAR REVERSING GEAR |
| US4075910A (en) * | 1976-08-20 | 1978-02-28 | Caterpillar Tractor Co. | Overload safety device for gas turbine engines |
| US4114477A (en) * | 1976-10-18 | 1978-09-19 | Iverson Roger A | Reversible power transmission |
| GB2060115A (en) * | 1980-09-22 | 1981-04-29 | Pitcraft Summit Ltd | Power Transmission for Scraper Chain Conveyor |
-
1983
- 1983-08-20 DE DE19833330147 patent/DE3330147A1/en active Granted
- 1983-08-22 CA CA000435059A patent/CA1204001A/en not_active Expired
- 1983-08-25 AU AU18408/83A patent/AU552238B2/en not_active Expired
- 1983-08-30 ZA ZA836418A patent/ZA836418B/en unknown
- 1983-08-30 GB GB08323217A patent/GB2126292B/en not_active Expired
- 1983-08-31 BR BR8304758A patent/BR8304758A/en not_active IP Right Cessation
- 1983-09-02 FR FR838314103A patent/FR2532707B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| BR8304758A (en) | 1984-04-10 |
| DE3330147C2 (en) | 1988-07-21 |
| GB2126292A (en) | 1984-03-21 |
| FR2532707B1 (en) | 1989-06-16 |
| FR2532707A1 (en) | 1984-03-09 |
| AU1840883A (en) | 1984-03-15 |
| GB2126292B (en) | 1985-09-11 |
| AU552238B2 (en) | 1986-05-22 |
| GB8323217D0 (en) | 1983-09-28 |
| DE3330147A1 (en) | 1984-03-08 |
| ZA836418B (en) | 1984-11-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |