CA1129378A - Drive assembly for power shovels and the like - Google Patents

Abstract

DRIVE ASSEMBLY FOR POWER SHOVELS AND THE LIKE

Abstract of the Disclosure In an earth working machine having a frame subject to loads resulting in frame deflections, an assembly for effecting a work function on the machine comprising a drive unit supported on the frame, a driven unit supported on the frame, a gear train set, flexible coupling means drivingly interconnecting the drive unit and the gear train set and flexible coupling means drivingly interconnecting the gear train set and the driven unit whereby the gear train set is isolated from the frame deflections of the machine during operating conditions.

Description

DRIVE ASSEMBLY ~OR POWER SHOVELS AND THE LIKE
Technical Field This invention relates to a drive assembly and more particularly to a drive assembly mountable on a machine for performing a work function. This invention specifically contemplates a drive assembly for a power shovel for perform-ing a work function such as crowding, hoisting, swinging and propelling.
Background of the Invention Large, heavy-duty mining shovels of the type dis-closed in U.S. Patents Nos. 3,50~,034 and 3,648,863 general ly are provided with crowd, hoist, swing and propel systems which are operated to produce the various work functions of the machine. Each of such systems basically includes a drive assembly mounted on the machine, operatively connected to a working component of the machine. In the case of the crowd system of a rope type, the drive assembly is operative-ly connected to a rope drum for paying out and taking in a ;, crowd rope. In a hoist system of the rope type, the drive assembly is operatively connected to a hoist drum for paying out and taking in hoist line. In the case of a swing system, the drive assembly usually is mounted on an upper rotatable frame and i9 provided with a depending shaft having a pinion ' drivingly engaged with a ring gear mounted on a lower frame of the machine. In a typical propel system of the crawler type, the drive assembly is operatively connected to a drive sprocket journaled in a crawler frame which is drivingly con-nected to a crawler tread.
In each application, the drive assembly for a par-~- 30 ticular work function is mounted on the machine and generally - . ... .. , .: i .
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consists of a drive means such as an electric or hydraulic motor, a driven means such as a drum, rack, rotatable frame or a drive sprocket and a gear train drivingly interconnecting the drive means and the driven means for effecting torque transmission and speed reduction.
During the normal operation of a large, heavy-duty mining shovel, as when the machine is crowding or retracting its dipper, hoisting or lowering its dipper, swinging its upper frame or propelling the entire machine, the machine is subjected to a multitude of loads in tension, compression, bending and torsion, in a variety of magnitudes, which are transmitted to the upper and lower frames of the machine.
Such loads result in deflections of the upper and lower frames of the machine on which the drive assemblies for the crowd, hoist, swing and propulsion systems are mounted. In-evitably, such frame deflections are imposed on the drive and driven components of such assemblies which are translated to misalignments of the gear trains thereof. Such misalignments produce non-uniform bearing contact of the gear teeth which '~ 20 results in inefficient torque transmission, undue tooth wear and often tooth breakage. It thus has been found to be desirable to provide drive assemblies mounted on machines of the type described which are capable of withstanding the adverse effects of loads being imposed on the machines during normal operating conditions.
Summary of the Invention Accordingly, it is the principal object of the present invention to provide an improved drive assembly for a system mounted on a machine for performing a work function.
Another object of the present invention is to pro-vide an improved drive assembly for a system mounted on a machine for performing a work function, in which the machine is subjected to various applied loads during normal opera-ting conditions.
A further object of the present invention is to provide an improved drive assembly for a system mounted on a machine for performing a work function which is capable of counteracting the adverse effects of loads applied to the machine during normal operating conditions.

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1~2~378 The above objects are met by the present invention which broadly provides in an earth working machine having a frame subject to loads resulting in frame deflections, an assembly for effecting a work function on the machine comprising a drive unit supported on the frame, a driven unit supported on the frame, a gear train set, flexible coupling means drivingly interconnecting the drive unit and the gear train set and flexible coupling means drivingly interconnecting the gear train set and the driven unit whereby the gear train set is isolated from the frame deflections.
Other objects and features of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains, from the following description taken in conjunction with the accompanying drawings, wherein:
Description of the Drawings Figure 1 is a side elevational view of a power shovel incorporating several embodiments of the present invention;

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Figure 2 is an enlarged top plan view of an upper cleck of the machine show in Figure 1, illustrating the arran~ement of various drive assemblies thereon;
Figure 3 is an enlarged, rear elevational view of 5 the crowd drive assembly shown in Figure l;
Figure 4 is an enlarged cross-sectional view taken along line 4-4 in Figure l;
Figure 5 is a rear elevational view of another crowd drive assembly embodying the invention, shown partially in section;
Figure 6 is a rear elevational view of a further crowd drive assembly embodying the invention, shown partially in section;
Figure 7 is a rear elevational view of a still further crowd drive assembly embodying the present invention, shown partially in section;
Figure 8 is an enlarged cross-sectional view taken along line 8-8 in Figure l;
Figure 9 is a rear elevational view of another ;~ 20 hoist drive assembly embodying the present invention, shown partially in section;
~: Figure 10 is an enlarged cross-sectional view taken along line 10-10 in Figure 2; and Figure 11 is an enlarged cross-sectional view taken along line 11-11 in Figure 1.
Detailed Description -Referring to Figures 1 and 2 of the drawings, there is illustrated a power shovel utilizing several embodiments of the present invention which generally includes a main support unit 20 mounted on a pair of crawler units 21, a front end assembly 22 mounted on the front end of the main support unit, a crowd system 23 mounted on the main support unit and operatively connected to the front end assembly, a hoist system 24 mounted on the main support unit and opera-tively connected to the front end assembly, a swing system 25 ; mounted on the main support unit, crawler drive assemblies 26 and 27 mounted on the rear end of the main support unit and the rear ends of crawler units 21, and appropriate power supplies and controls mounted on the main support unit for . .

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operating such various systems and assemblies.
The crawler units are substantially similar in con-struction and operation. Each of such units includes a crawler frame 28, a drive sprocket 29 mounted on the rear end thereof, a driven sprocket 30 mounted on the front end there-of, a crawler tread 3~, a plurality of support rollers 32 mounted on the lower side of the crawler frame and supported on the lower flight of the tread, and a plurality of guide rollers 33 mounted on the upper side of the crawler frame and supporting the upper flight of the tread. Each of the crawler units functions in the conventional manner to propel the machine.
As best seen in Figures 1, 2 and 10, main support unit 20 generally consists of a lower frame 34, a live roller circle 35 and an upper frame 36. Lower frame 34 is supported on crawler frames 28 of the crawler units and is provided with a ring gear 37. Live roller circle 35 consists of a lower circular rail 38 mounted on the lower frame, an upper circular rail 39 mounted on the underside of upper frame 36 and a pluality of rollers 40. The rollers are supported on shafts carried by a cage structure 41. As best illustrated in Figure 10, rollers 40 are supported on lower rail 38 and upper rail 39 is supported on the rollers so that the upper frame can be rotated or swung relative to the lower frame ~ 25 about the vertical center line of the live roller circle.
; The upper frame also is provided with a pair of mounting brackets 42 and 43 on the front end thereof for mounting the front end assembly to the front end of the upper frame.
Front end assembly 22 generally includes a stiffleg - 30 44, a hoist frame 45, a dipper handle 46, a dipper 47 and a hoist link 48. Stiffleg 44 consists of a structural member pivotally connected at its lower end to mounting lugs 42 and 43 by means of a pair of foot pins, and is provided at its ` upper end with a head shaft 49. Hoist frame 45 is pivotally mounted on head shaft 49. Handle 19 consists of a suitable structural member and is provided with upper and lower bi-furcated ends. The upper bifurcated end is connected to the hoist frame by means of a pair of connecting pins. The lower bifurcated end of the stiffleg is pivotally connected to the ,. , ~ .

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37~3 upper rear end of dipper 47 by means of a pair of axially aligned pins 50. The forwardly disposed head section of the hoist frame and the upper end of dipper 47 are connected by hoist link 48. The upper end of the hoist link is bifurcated and connected to the head section of the hoist frame by means of a connecting pin 51. The lower bifurcated end of the hoist link is connected to the dipper by means of a pair of axially aligned pins 52. It thus will be seen that hoist frame 45, handle 46, dipper 47 and hoist link 48 are pivotal-ly connected together to provide a four-bar linkage with the link comprising the hoist frame being pivotally connected to the upper end of the stiffleg by means of head shaft 49.
To provide a substantially flat pass of the dipper when it is crowded into a bank of material being excavated or loaded, there is provided on the front end assembly a pitch control system 53, the construction and operation of which is fully described in U.S. Patents Nos. 3,501,034 and 3,648,863. In addition, the front end assembly is provided with a pitch stop assembly 54, the construction and operation of which is fully described in U.S. Patent No. 4,085,854.
Crowd syst0m 23 consists of a gantry 55 mounted on upper frame 36 of the machine, a crowd drive assembly 56 mounted on the upper end of the gantry, above housing structure 57 supported on the upper frame, a mast 58 provided with sheaves 59, a crowd link 60 and a crowd rope 61. Mast 58 consists of a structural member pivotally connected at its lower end to a pair of brackets 62 and 63 rigidly secured to the upper frame 36, forwardly of the vertical center line of live roller circle 35. The upper end of mast 58 is provided with a shaft 64 on whic~ sheaves 59 are mounted. Crowd link ~` 60 is pivotally connected at the ends thereof to hoist frame 45 and mounting shaft 64 at the upper end of the mast so that pivotal motion of mast 58 in a vertical plane will be trans-mitted by crowd link 60 to the front end assembly of the machine. Crowd rope 61 is operatively connected to crowd drive assembly 56 and extendsforwardly and around sheaves 59, and rearwardly where it is connected to a bail 65 mounted on the head portion of the gantry.

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~2~3378 Referring to Figures 3 and 4, crowd drive assembly 56 consists of a rope drum 66 and a drive unit 67. The rope drum is trunnionmounted in a set of bearings 67 and 68 mounted in the upper end of gantry 55. It is provided with a pair of transversely spaced bull gears 69 and 70 and an intermediate drum portion 71 provided with suitable guide grooves for winding crowd rope 61 thereon. Drum portion 71 is disposed substantially in longitudinal alignment with ; mast 58. Drive unit 67 generally consists of a gear case 72, a pinion shaft 73, a motor 74, a drive shaft 75 and planetary gear sets 76 and 77. Gear case 72 is formed with an annular portion 78 which is journaled in a bearing 79 mounted in a bearing block 80 supported in an opening of gantry 55, for mounting the gear case on one side of the gantry.
15The axial opening of annular portion 78 is provided with a pair of bearings 81 and 82 for supporting one end of pinion shaft 73. Aligned axially with bearings 81 and 82 is a bearing 83 mounted in a bearing block 84 provided in an i-opening in gantry 55, for supporting the other end of the pinion shaft.
Pinion shaft 73 is provided with an axially dis-posed passageway and a pair of integrally formed pinions 85 and 86 which mesh with bull gears 69 and 70 of crowd drum 66 when the drum is trunnion mounted on bearings 67 and 68 and pinion shaft 73 is journaled in bearings 81, 82 and 83. The pinion shaft is also provided with a pair of brake drums 87 and 88 which are adapted to be frictionally engaged by brake bands to arrest the rotation of the pinion shaft. Motor 74 may consist of either an electrical or hydraulic motor and is rigidly mounted on gantry 55 on a side opposite ~rom gear !case 72. Drive shaft 75 is drivingly connected to the output shaft of motor 74 and extends through the entire length of the axial opening in the pinion shaft, into gear case 72.
The free end of shaft 75 abuts a stop 89 mounted on the end wall 9~ of the gear case.
Planetary gear set 76 consists of a sun gear 91, a ring gear 92 and a plurality of planetary gears 93. Sun gear 91 is formed integrally with the end of drive shaft 75. Ring gear 92 is formed as an outer wall section of gear case 72.
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Each of planetary gears 93 is provided with a shaft 94 mounted on a planetary gear carrier 95.
Planetary gear set 77 consists of a sun gear 96, a ring gear 97 and a plurality of planetary gears 98. Sun gear 96 is provided with an axial opening, receiving drive shaft 75 therethrough, and is drivingly connected to plane-tary gear carrier 9S of gear set 7Ç. Ring gear 97 is formed as a component of gear case 72. Each of planetary gears 98 is provided with a shaft 99 mounted on a rotatable carrier 100. Planetary gear carrier 100 is provided with an annular portion 101 which extends into an enlarged section of the opening in pinion shaft 73 and which receives drive shaft 75 therethrough. The outer end of annular carrier portion 101 is provided with crowned, external splines which engage with a set of internal splines on the end of the pinion shaft to drivingly connect the planetary gear carrier of gear set 77 to the pinion shaft.
In the operation of the drive unit shown in Figure 4, whenever motor 74 is operated, drive will be transmitted through drive shaft 75, planetary gear set 76, planetary gear set 77 and pinion shaft 73 to drum 66. Under such circum-stances, the drive will undergo a first stage spe~d reduction by planetary gear set 76, a second stage speed reduction by planetary gear set 77 and a third stage reduction by the parallel pinion and bull gears transmitting drive from the pinion shaft to the rope drum. Whenever it is desired to brake the unit, a suitable mechanism is operated to cause the brake bands cooperating with brake drums 87 and 88 to fric-tionally engage such drums to arrest the rotation of the pinion shaft. The rotation of gear case 72 can be restrained by any suitable means including a linkage, such as torque arm 102, operatively interconnecting the gear case and the gantry.
Loads imposed on the shovel resulting in structural deflections of the gantry are prevented from being transmit-ted to planetary gear sets 76 and 77 by means of several structural features of the crowd assembly including the link-age provided with torque arm 102, the length of drive shaft 75 which permits it to deflect, the crowned spline connection ., ~, ,, - ~
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~2~3'78 between the planetary gear carrier of gear set 77 and the pinion shaft, and the length of the pinion shaft which allows limited deflection. In essence, gear sets 76 and 77 are isolated from the loads imposed on the machine and the re-sulting structural deflections of the machine thus minimizingif not eliminating misalignment of the gear components there-of.
Referring to Eigure 5, there is shown another em-bodiment of the present invention. In particular, Figure 5 illus~rates a crowd drive assembly 103 generally consisting of a rope drum 104, a gear case 105, a motor 105, a drive shaft 107, a first planetary gear set 108 and a secondary planetary gear set 109 Rope drum 104 is adapted to be trunnion mounted in a set of bearings 110 and 111 provided in 15 gantry 55. Gear case 105 is adapted to be mounted on gantry 55 at one end of rope drum 104. Mounted on the gantry at the opposite side of rope drum 104 is motor 106 which is provided with an output shaft coupled to drive shaft 107. Drive shaft 107 is disposed axially relative to rope drum 104 and extends 20 into gear case 105. Planetary gear set 108 consists of a sun gear 112 formed on the end of drive shaft 107, a ring gear 113 formed on gear case 105 and a plurality of planetary ~
gears 114. Each of the planetary gears is provided with a shaft 115 mounted on a planetary gear carrier 116.
Planetary gear set 109 consists of a sun gear 117 connected with a spline connection with planetary gear carrier 116 and having an axially disposed opening therein for receiving the drive shaft therethrough, a ring gear 118 and a plurality of planetary gears 119. Each of the planet-ary gears is provided with a shaft 120 mounted on a planetary gear carrier 121. Carrier 121 is spline connected to a quill shaft 122 which receives a portion of the drive shaft there-through and is provided with crowned, e~ternal splines at the free end thereof which are received within an end of rope drum 104 and engage a set of internal splines thereon. Alter-natively, quill shaft 122 may be drivingly connected to the other side of the drum through a crowned spline connection.
In the operation of crowd drive assembly 103, when motor 106 is operated, drive will be transmitted through J
, 313'7~3 drive shaft 107, planetary gear set 108 and planetary gear set 109 to rope drum 104. As drive is transmitted through planetary gear sets 108 and 109, it will undergo first and second stage speed reductions. As stated with respect to the embodiment shown in Figure 4, planetary gear sets 108 and 109 will be isolated from the structural deflections of the machinP to prevent misalignment of the gears thereof. The elongated lengths of drive shaft 107 and quill shaft 122, allowing a certain amount of deflection, and the crowned spline connection of quill shaft 122 with the rope drum principally assure the isolation of the gear sets from the structural deflections of the machine.
Figure 6 illustrates another embodiment of the present invention which is similar in construction and opera-tion to the embodiment shown in Figure 5 except that it pro-vides for an additional speed reduction stage. Figure 6 illustrates a crowd drive assembly 123 generally consisting of a rope drum 124 trunnion mounted on gantry 55, a first gear case 125 mounted on gantry 55 at one end of drum 124, a second gear case 126 mounted on the gantry at an opposite end of drum 124, a motor 127 mounted on gear case 125, a first planetary gear set 128 mounted in gear case 125 and drivingly connected to the output shaft of motor 127, a drive shaft 129 drivingly connected to planetary gear set 128 and extending through drum 124 into gear case 126, a second planetary gear set 130 mounted in gear case 126 and drivingly connected to drive shaft 129 and a third planetary gear set 131 drivingly interconnecting planetary gear set 130 and drum 124. The planetary gear carrier of gear set 131 is drivingly connected to a quill shaft 132 which is drivingly connected to drum 124 through a spline connection at the free end thereof. Also, the output shaft of motor 127 is drivingly connected to the sun gear of gear set 128 through a crowned spline connection.
Alternatively, the output shaft of the motor can be drivingly connected to the sun gear shaft of gear set 128 through a flexible coupling of any suitable type.
In the operation of the drive assembly shown in Figure 6, it will be appreciated that when motor 127 is operated, drive will be transmitted through gear set 128 , ' ' '~'~,,',: ' ;
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where it will undergo a first stage speed reduction, drive shaft 129, gear train 130 where it will undergo a second stage speed reduction, gear set 131 where it will undergo a third stage speed reduction and through quill shaft 132 to drum 124. In this arrangement, the elongated lengths of drive shaft 129 and quill shaft 132 and the crowned spline connections between the output shaft of the motor and the sun gear of gear set 128, and quill shaft 132 and drum 124 function to isolate gear sets 128, 130 and 131 from the structural deflections of the machine frame.
Figure 7 illustrates another embodiment of the invention as applied to a crowd system utilizing a crowd handle in lieu of a rope and sheave arrangement as illustra-ted in Figure 1. The embodiment consists of a crowd drive assembly 133 including a drive unit 134 mounted on gantry 55 and a crowd handle 135 also mounted on the gantry for fore and aft reciprocal movement, above the drive unit. The c~owd handle is guided on the upper end of the gantry by sets of rollers 136 and 137, and is provided with a rack portion 138 on the underside thereof which is drivingly engaged by a pin-ion portion 139 of a quill shaft 140 journaled in the gantry.
The crowd unit generally consists of a gear case 141 flange mounted on one side of the gantry, a gear case 142 flange mounted on an opposite side of the gantry, a motor 143 flange mounted on gear case 141, a first planetary gear set 144, second and third planetary gear sets 145 and 146, a drive shaft 147 and a quill shaft 148.
Planetary gear set 144 is mounted in gear case 141.
Gear sets 145 and 146 are mounted in gear case 142 and are disposed in axial alignment with gear set 144. The output shaft of motor 143 is drivingly connected to the sun gear shaft of gear set 144 by means of a coupling 149. Coupling 149 is connected to the sun gear shaft by means of a crowned spline connection to provide a flexible coupling between the output shaft of motor 143 and gear set 144. The output of gear set 144 is connected to the input of gear set 145 by means of elongated drive shaft 147. Shaft 147 is connected to the planetary gear carrier of gear set 144 through a c~Dwned spline connection. The planetary carrier of gear set , ~.

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146 is drivingly connected to pinion shaft 140 through elongated quill shaft 148. As shown in Figure 7, the plane-tary gear carrier of gear set 146 is drivingly connected to _ one end of quill shaft 140 through a crowned spline connec-tion and the opposite end of ~uill shaft 140 is drivinglyconnected to pinion shaft 140 through a crowned spline connec-tion.
In the operation of the assembly shown in Figure 7, when motor 143 is operated, drive is transmitted to planetary gear set 144 where it undergoes a first stage speed reduction, through drive shaft 147 to planetary gear set 145 where it undergoes a second stage speed reduction, to planetary gear set 146 where it undergoes a third stage speed reduction and through quill shaft 148 to pinion shaft 140. It will be appreciated that upon rotation of pinion shaft 140, pinion portion 139 thereof will engage the rack portion of crowd handle 135 to drive the crowd handle in either a fore or aft direction. It further will be seen that gear sets 144, 145 and 146 will be isolated from the frame deflections of the machine caused by loads imposed upon the machine by means of the elongated lengths of drive shaft 147 and quill shaft 148 and the various crowned spline connections in the drive train providing flexible couplings between the gear sets and the other drive components of the drive train.
Hoist system 24 generally includes a hoist drive assembly 150, sheaves 151 and 152 and a hoist line 153.
Hoist drive assembly 150 is mounted on the upper frame of the i machinel rearwardly of the swing axis of the machine, as best illustrated in Figure 2. Sheave 151 is mounted on the lower 30 end of stiffleg 44 and sheave 152 is mounted on an upper, rear end of hoist frame 45. As illustrated in Figure 1, hoist line 153 is operatively connected to hoist drive assem-bly 150, extends forwardly and around sheave 151, extends upwardly and around sheave 152 and extends downwardly and is connected to a bail 154 mounted on the mounting shaft of sheave 151. It further will be seen that by operating the ; hoist drive assembly to pay out or take in hoist line 153, hoist frame 45, handle 46 and hoist link 48 will be caused to pivot about head shaft 49 to correspondingly hoist and lower ' ,: ' ~ , 7~3 the dipper.
The hoist drive assembly consists of a hoist drum 155 disposed substantially in longitudinal alignment with the stiffleg and a pair of substantially identical drive units 156 and 157 mounted on opposite ends of the hoist drum and being drivingly connected thereto.
Referring to Figure 8, it will be seen that hoist drum 155 is trunnion mounted on a support frame 158 connected to the upper frame of the machine. Drive unit 157 consists of a gear case 159 mounted on the support frame, a first planetary gear set 160 mounted in gear case 159, a secondary planetary gear set 161 also mounted in gear case 159, a motor 162 supported on the upper deck of the machine, a flexible mechanical coupling 163 drivingly interconnecting the output shaft of motor 162 and first planetary gear set 160 and a drive shaft 164 drivingly interconnecting the output of gear set 161 and hoist drum 155. Flexible mechanical coupling 163 may be of any suitable type which is capable of transmitting torque while allowing angular and parallel displacement of the input and output components thereof. One of such coup-lings which can be used with the invention and which is com-mercially available consists of a housing, a pair of axially spaced hubs rotatably mounted in the housing and connectable to input and output shafts and a steel spring element inter-connecting the hubs which functions to transmit torquebetween the hubs yet has sufficient flexibility to allow the axes of the hubs and, correspondingly, of the input and out-put shafts to become displaced both angularly and radially.
Gear set 160 consists of a sun gear 165, a ring gear 166 and a plurality of planetary gears 167. Sun gear 165 is formed on a shaft which is drivingly connected to the output shaft of coupling 163. Ring gear 166 is formed as a component part of gear case 159. Each of planetary gears 167 is pro-vided with a shaft 168 mounted on a planetary carrier 169.
Gear set 161 consists of a sun gear 170, a ring gear 172 and a plurality of planetary gears 173. Sun gear 170 is formed on a shaft drivingly connected to the planetary gear carrier 169 of gear set 160 through a spline connection. Ring gear 172 is formed as part of gear case 159. Each of planetary . ~

~3.~ 7~3 gears 173 is provided with a shaft 174 mounted on a carrie.r 175. Drive is transmitted from planetary gear carrier 175 to hoist drum 155 by means of drive shaft 164. The outer end of shaft 164 is drivingly connected to planetary gear carrier 175 through a crowned spline connection 176. The inner end of shaft 164 is drivingly connected to a trunnion of hoist drum 155 through a crowned spline connection 178.
In the operation of the hoist drive assembly shown in Figure 8, when motor 162 is operated, drive is transmitted through flexible coupling 163, planetary gear set 160 where it undergoes a first stage speed reduction, planetary gear set 161 where it undergoes a second stage speed reduction and drive shaft 164 to rotate hoist drum 155. Because of the flexible coupling between motor 162 and planetary gear set 160 as provided by flexible mechanical coupling 163, and the flexible coupling between planetary gear set 161 and hoist drum 155 as provided by the crowned spline connections of drive shaft 164 with carrier 175 and the trunnion of the hoist drum, gear sets 160 and 161 will be isolated from the struc-tural deflections of the machine and particularly deflectionsin the upper frame. Figure 9 illustrates an alternative hoist drive assembly 179 which consists of a hoist drum 180 and a drive unit 181. In such embodiment, hoist drum 180 is provided with annular trunnions 182 and 183 which are journaled in a set of bearings 184 and 185 mounted in a support frame 186.
~he drive assembly consists of a motor 187, a gear case 180, a drive shaft 189, a flexible mechanical coupling 190, a first planetary gear set 192 and a second planetary gear set 193.
Motor 187 is mounted on one side of the hoist drum and is supported on the upper deck of the machine. Gear case 188 is mounted on the opposite side of the hoist drum and is support-ed on a frame mounted on the deck. Drive is transmitted frommotor 187 to gear case 188 by drive shaft 189 which extends through trunnions 182 and 183. Flexible mechanical coupling190 is similar in construction and function to.¢oupling 163 described in connection with the embodiment shown in Figure 8 to transmit torque from the motor output shaft to drive shaft 189 while permit~ngangular and parallel displacement of such ;
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~2~37~3 shafts.
Planetary gear sets 192 and 193 are mounted in gear case 188. ~ear set 182 consists of a sun gear 194, a ring gear 195 and a plurality of planetary gears 196. Sun gear 194 is formed on the free end of drive shaft 189. Ring gear 195 is formed as a component of the gear case. Each of planetary gears 196 is provided with a shaft 197 mounted on a rotatable carrier 198. Gear set 193 similarly consists of a sun gear 199, a ring gear 200 and a plurality of planetary gears 201. Sun gear 199 is spline connected with planetary gear carrier 198 and is provided with an axial passageway for receiving the end of drive shaft 189 therethrough. Ring gear 200 is formed as a component of the gear case. Each of plane-tary gears 201 is provided with a shaft 202 mounted on a rotatable carrier 203. Gear carrier 203 is drivingly connec-ted to trunnion 183 of the hoist drum by means of a crowned ; spline connection 204. It further will be noted that trunnion 183 is drivingly connected to the main body of the drum through a spline connection 205.
In the operation of the hoist drive assembly shown in Figure 9, when motor 187 is operated, drive is transmitted through flexible coupling 190, drive shaft 189, planetary gear sets 192 and 193 and trunnion 183 to hoist drum 180. As in the previously described embodiments, it will be seen that the effect of flexible mechanical coupling 190, the elongated length of drive shaft 189 and crowned spline connection 204 will be to isolate gear sets 192 and 193 from the adverse effects of the frame deflections of the machine.
The system for swinging the upper frame relative to the lower frame on the live roller circle consists of a number of swing assemblies 206. Each of the swing assemblies is mounted on the upper frame and is provided with a pinion ; drivingly engaging ring gear 37 on the lower frame. Any suit-able number of such assemblies can be used although an even number of such assemblies symmetrically positioned should be used. In the machine shown in the drawings, four of such assemblies are used, arranged symmetrically to provide a uni-form load on the machine.
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l~Z~37~3 Referring to Figure 10, there is illustrated a swing drive assembly 206. Basically, the assembly consists of a pinion shaft 207 drivingly connected to ring gear 37 and a drive unit 208 drivingly connected to the pinion shaft.
Pinion shaft 207 is disposed vertically and is journaled in a pair of bearings 209 and 208 mounted on a support frame 210 rigidly secured to a portion of upper frame 36. The lower free end of the pinion shaft is provided with a pinion 211 having crowned teeth drivingly engaged with ring gear 37.
The drive unit of the assembly consists of a gear case 212 mounted on support frame 210, first and second planetary gear sets 213 and 214 mounted in the gear case and a motor 215 mounted on the gear case and drivingly connected to the first planetary gear set through a flexible mechanical coupling 216. Planetary gear set 213 consists of a sun gear 217, a ring gear 218 and a plurality of planetary gears 219.
Sun gear 217 is drivingly connected to an output shaft of flexible mechanical coupling 216 which is similar in construc-tion and operation to couplings 163 and 190 of the embodiments of the invention described in connection with Figures 8 and 9.
Ring gear 218 is formed as a component of the gear case. Each of planetary gears 218 is provided with a shaft 220 mounted on a rotatable carrier 221. Planetary gear set 214 consists of a sun gear 222, a rin~ gear 223 and a plurality of planetary gears 224. Sun gear 222 is mounted on a sun gear shaft 225 which is drivingly connected to planetary gear carrier 221 through a spline connection. Ring gear 223 is formed as a component of the gear case. Each of planetary gears 224 is provided with a shaft 226 which is mounted on a rotatable carrier 227. Carrier 227 is drivingly connected to the upper end of pinion shaft 207 by means of a crowned spline connec-tion 228.
In the operation of the assembly shown in Figure 10, when motor 215 is operated, drive will be transmitted through coupling 216, gear sets 213 and 214 to pinion shaft 207. As the pinion shaft is rotated, the interaction of pinion 211 with ring gear 37 will cause support frame 210 and corres-pondingly upper frame 36 to rotate or swing relative to lower frame 34 about live roller circle 35. As in previous embodi-- ' .

1~L2~3!37~3 ments of the invention, it will be noted that flexible coup-ling 216, crowned spline connection 228 and the crowned teeth of pinion 211 will function to isolate gear sets 213 and 214 from the deflections of the upper and lower frames of the machine.
Crawler drive assemblies 26 and 27 mounted on the rear end of the main support unit and the rear ends of craw-ler units 21 are substantially similar in construction and operation. Crawler drive assembly 27 consists of a drive sprocket 29 and a drive unit 229. Sprocket 29 is drivingly mounted on a quill shaft 230 through a spline connection.
Shaft 230 is journaled in the rear end of crawler frame 28.
Drive unit 229 consists of a gear case 231 mounted on the outboard side of the crawler frame, a gear case 232 mounted on the inboard side of the crawler frame, a parallel gear set 233 and planetary gear sets 234 and 235 mounted in gear case 232, a drive shaft 236 extending from year case 232 into gear case 231, a planetary gear set 237 mounted in gear case 231, a quill shaft 238 mounted concentrically with drive shaft 236 and quill shaft 230 and a motor 239 mounted on the rear end of the lower frame and drivingly connected to parallel gear set 233 through a flexible mechanical coupling 240.
Parallel gear set 233 consists of a pair of gears 241 and 242 journaled in year case 232. Gear 241 is driving-ly connected to coupling 240 which is substantially similar in construction and function to couplings 163, 190 and 216 described in connection with the embodiments shown in Figures 8 through 10. Gear 242 is drivingly connected to a sun gear shaft 243.
Planetary gear set 234 consists of a sun gear 244, a ring gear 245 and a plurality of planetary gears 246. Sun gear 244 is formed on one end of shaft 243. Ring gear 245 is formed as a component of gear case 232. Each of planetary gears 246 is provided with a shaft 248 mounted on a rotatable 35 carrier 249. Planetary gear set 235 consists of a sun gear 250,a ring gear 251 and a plurality of planetary gears 252.
Sun gear 250 is formed on a sun gear shaft 253 drivingly connected to rotatable carrier 249 through a spline connec-tion. Ring gear 251 is formed as a component of gear case ~.

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f~3~7~3 232. Each of planetary gears 252 is provided witll a shaft 254 which is mounted on a rotatable carrier 255.
Planetary gear set 237 consists of a sun gear 256, a ring gear 257 and a plurality of planetary gears 258. Sun gear 256 is formed integrally with the outer end of drive shaft 236 which is drivingly connected at the inner end thereof to rotatable carrier 255 through a spline connection.
Ring gear 257 is mounted on gear case 231. Each of planetary gears 258 is provided with a shaft 259 mounted on a carrier 260. Quill shaft 238 is drivingly connected at the outer end thereof through a crowned spline connection 261 with rotatable carrier 260. At the inner end, shaft 238 is drivingly con-nected to quill shaft 230 by means of a crowned spline con-nection 262.
In the operation of the crawler drive assembly shown in Figure 11, whenever motor 239 is operated, drive will be transmitted through flexible coupling 240, parallel gear set 233, planetary gear sets 234 and 235, drive shaft 236, planetary gear set 237 and quill shaft 238 to drive sprocket 29 through shaft 230. As drive is transmitted from the motor to the sprocket, it will undergo a first stage speed reduction by parallel gear set 233, a second stage speed reduction by planetary ~ear set 234, a third stage speed reduction by planetary gear set 235 and a fourth stage speed reduction by planetary gear set 237. The various gear sets further will be isolated from loads applied to the craw-ler frame and lower frame resulting in structural deflections by means of flexible coupling 240, the elongated lengths of shaft 236 and quill shaft 238 and crown spline connections . 30 261 and 262.
At the beginning of each digging cycle of the machine as described, the crowd system is operated to fully retract the front end assembly and the hoist system is opera-ted to lower the dipper so that the dipper is positioned adjacent the lower end of the stiffleg. Suitable resilient pads are provided at the lower end of the stiffleg to prevent damage to the stiffleg by the dipper. To commence the opera-ting cycle of the machine, the operator manipulates appropri-ate controls at the operator's station on the machine to ; .
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i~.2937~3 permit the crowd rope to pay out. Under such conditions, the weight of the front end assembly will cause the stiffleg to pivot forwardly, simultaneously crowding the dipper into the material being excavated or loaded. Simultaneously with the commencement of the crowding action of the dipper, appropri-ate controls are operated on the machine to effect limited hoisting motion of the dipper. This is accomplished by operating hoist drum 155 to take up hoist line 153. As the dipper is crowded into the bank of material being excavated or loaded, the combined crowding and hoisting action causes it to make a flat pass. At the same time, pitch control system 53 causes the pitch of the dipper to remain constant relative to the ground. At the end of the crowd phase of the cycle, the pitch control mechanism is released to cause the dipper to pitch upwardly and thus assure a full load of material in the dipper. The upward pitch of the dipper is restricted by the pitch stop system 54 in a manner as described in the aforementioned patent relating to such system.
After the dipper has been pitched upwardly, controls for the crowd and hoist systems and the swing machinery are operated to position the dipper above the dump body of a hauling vehicle or another suitable repository for the material, where the door of the dipper is tripped to cause the door to open and the material to be unloaded. The de-sired retracting motion of the front end assembly is effected by operating crowd motor 74 to rotate crowd drum 71 and take in crowd rope 61. Under such conditions, mast 58 will be caused to pivot rearwardly and such motion will be transmitted to the front end assembly 22 causing stiffleg 44 to pivot up-wardly.
As soon as the material has been dumped, the swing machinery can be operated to rotate the front end of the machine back to the embankment, the crowd system can be operated to continue to retract the front end assembly and the hoist system can be operated to permit the dipper handle to swing downwardly at a controlled rate until it again is positioned at the lower end of a stiffleg, ready to begin another operating cycle. To re-position the machine, the '1~.2~37~3 propel system is operated in the conventional manner to move the machine.
It will be appreciated that during the corwding, retracting, hoisting or lowering of the dipper, the swinging of the upper frame and the propelling of the entire machine, the machine will be subjected to a multitude of loads which result in structural deflections of the frames of the machine.
In conventional shovels of the type described, such deflec-tions would be transmitted to the various gear trains for the various machinery on the machine, resulting in misalignment of the gear train components thereof. In the present inven-tion, the transmission of such deflection to the various gear trains of the machine is at least substantially minimized, thus assuring full contact between mating gear teeth during the various work functions of the machine. The result of such consistent and uniform gear tooth contact is more efficient torque transmission and less tooth wear and break-age.
From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention which fall within the province of those persons having ordinary skill in the art to which the present invention pertains. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof as limited solely by the appended claims.

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Claims (90)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. In an earth working machine having a frame subject to loads resulting in frame deflections, an assembly for effecting a work function on said machine comprising a drive unit supported on said frame, a driven unit supported on said frame, a gear train set, flexible coupling means drivingly interconnecting said drive unit and said gear train set and flexible coupling means drivingly interconnecting said gear train set and said driven unit whereby said gear train set is isolated from said frame deflections.

2. An assembly according to claim 1 wherein at least one of said flexible coupling means comprises a drive shaft having sufficient allowable deflection to accommodate axial misalignment.

3. An assembly according to claim 1 wherein at least one of said flexible coupling means comprises a crowned spline connection.

4. An assembly according to claim 1 wherein at least one of said flexible coupling means comprises a mechani-cal coupling device accommodating angular and parallel mis-alignment of input and output components thereof.

5. An assembly according to claim 1 including at least an additional gear train set drivingly connected in series with said first-mentioned gear train set, providing a multiple-stage gear reduction.

6. An assembly according to claim 1 wherein said gear train set includes a planetary gear set.

7. An assembly according to claim 6 including at least one additional gear train set drivingly connected in series with said first-mentioned gear train set, providing a multiple-stage gear reduction.

8. An assembly according to claim 6 wherein said planetary gear set includes a first component being drivingly connected through a flexible coupling to said drive unit, a second component drivingly connected through a flexible coupling to said drive unit and a third component being restrained from rotation.

9. An assembly according to claim 1 wherein said drive unit comprises a motor and said driven unit comprises a rope drum of a rope crowd system for a power shovel.

10. An assembly according to claim 1 wherein said drive unit comprises a motor and said driven means comprises a rope drum of a rope hoist system for a power shovel.

11. An assembly according to claim 1 wherein said driven unit comprises and upper frame structure rotatably mounted on a lower frame structure, said drive unit comprises a motor rigidly mounted on said upper drive structure and said gear train set is mounted on said upper frame structure having a gear drivingly connected to a ring gear on said lower frame structure whereby upon operation of said motor, said gear train will cooperate with said ring gear to rotate said upper frame structure relative to said lower frame structure.

12. An assembly according to claim 1 wherein said drive unit comprises a motor and said driven unit comprises a sprocket of a crawler drive assembly.

13. An assembly according to claim 1 wherein said assembly is yieldingly mounted on said machine frame whereby said assembly is further isolated from said frame deflection.

14. An assembly according to claim 1 wherein said assembly is mounted on a support frame yieldingly connected to said machine frame.

15. An assembly according to claim 1 wherein said assembly comprises a crowd drive assembly mounted on a gantry pin connected to said machine frame.

16. An assembly according to claim 15 wherein said crowd drive assembly is mounted on a head portion of said gantry.

17. An assembly according to claim 1 wherein said gear train is mounted in a housing yieldingly mounted on said machine frame.

18. An assembly according to claim 1 wherein said gear train is mounted in a housing mounted on a support frame yieldingly connected to said machine frame.

19. An assembly according to claim 1 wherein said gear train is mounted in a housing mounted on a gantry pin connected to said machine frame.

20. An assembly according to claim 19 wherein said gear set housing is mounted on a head portion of said gantry.

21. In a power shovel having a main frame subject to loads resulting in structural deflections of said frame, a front end assembly including an earth working implement, operatively connected to said main frame and a rope crowd system mounted on said main frame and operatively connected to said front end assembly, a crowd drive assembly comprising a rope drum rotatably supported on said main frame, a drive motor supported on said main frame, a planetary gear set supported on said main frame including a sun gear, a ring gear and a plurality of planetary gears mounted on a rotatable carrier, one of said gear set components being drivingly connected through a flexible coupling to said drive motor, another of said gear set components being drivingly connected through a flexible coupling to said rope drum, and means for restraining the rotation of a further one of said gear set components whereby said gear train is isolated from said structural deflections of said main frame.

22. A crowd drive assembly according to claim 21 wherein said planetary gear carrier is drivingly connected through a flexible coupling to said rope drum.

23. A crowd drive assembly according to claim 21 wherein said sun gear is drivingly connected through a flexi-ble coupling to said drive motor.

24. A crowd drive assembly according to claim 21 wherein said ring gear is mounted on a casing linked to said main frame by means of a torque arm.

25. A crowd drive assembly according to claim 21 including a second planetary gear set operatively connected in series with said first planetary gear set providing first and second gear reduction stages.

26. A crowd drive assembly according to claim 21 including means for braking a component of said planetary gear set drivingly connected to said rope drum.

27. In a power shovel having a main frame subject to loads resulting in structural deflections of said main frame, a front end assembly including a working implement, operatively connected to said main frame and a rope crowd system mounted on said main frame and operatively connected to said front end assembly, a crowd drive assembly comprising a support frame mounted on said main frame, a rope drum rotatably mounted on said support frame, and a drive unit comprising a gear case mounted on said support frame, a shaft journaled in said gear case and said support frame, said shaft having a pair of pinions formed integrally therewith drivingly engaged with gears provided on said rope drum, a motor having a drive shaft including a flexible coupling portion mounted on said support frame and a planetary gear set disposed in said gear case, said gear set including a sun gear mounted on the free end of said drive shaft, a ring gear mounted on said gear case and a plurality of planetary gears mounted on a rotatable carrier operatively connected through a flexible coupling to said pinion shaft, and means for restraining the rotation of said gear case.

28. A crowd drive assembly according to claim 27 wherein said pinion shaft comprises a quill shaft and said gear case and said motor are disposed at opposite ends of said quill shaft and said motor drive shaft extends through the axially disposed opening in said quill shaft.

29. A crowd drive assembly according to claim 27 including a second planetary gear set disposed in said gear case, said second gear set including a sun gear drivingly connected to the planetary gear carrier of said first gear set, a ring gear mounted on said gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said pinion shaft.

30. A crowd drive assembly according to claim 29 wherein said pinion shaft comprises a quill shaft and said gear case and motor are disposed at opposite ends of said quill shaft and said motor drive shaft extends through the axially disposed opening in said quill shaft.

31. A crowd drive assembly according to claim 27 including at least one brake drum mounted on said pinion shaft.

32. A crowd drive assembly according to claim 27 wherein said means for restraining the rotation of said gear case comprises a torque arm operatively interconnecting said mounting frame and said gear case.

33. A crowd drive assembly according to claim 27 wherein said support frame comprises a ganty pin connected to said main frame.

34. A unit for driving the rope drum of a rope crowd system in a power shovel subject to loads resulting in structural deflections comprising a gear case mountable on a support frame of the power shovel, a shaft journaled in said gear case and rotatably mountable on said support frame, said shaft having a pair of pinions formed integrally therewith drivingly engageable with gears provided on said rope drum, a motor having a drive shaft including a flexible coupling portion, mountable on said support frame and a planetary gear set disposed in said gear case, said gear set including a sun gear mounted on said drive shaft, a ring gear mounted on said gear case and a plurality of planetary gears mounted on a rotatable carrier operatively connected through a flexible coupling to said pinion shaft.

35. A crowd drive unit according to claim 34 wherein said pinion shaft comprises a quill shaft and said gear case and motor are disposed at opposite ends of said quill shaft and said drive shaft extends through the axially disposed opening in said quill shaft.

36. A crowd drive unit according to claim 34 in-cluding a second planetary gear set disposed in said gear case, said second gear set including a sun gear drivingly connected to said rotatable carrier of said first planetary gear set, a ring gear mounted on said gear case and a plural-ity of planetary gears mounted on said rotatable carrier drivingly connected through a flexible coupling to said pin-ion shaft to provide first and second gear reduction stages.

37. A crowd drive unit according to claim 36 where-in said pinion shaft comprises a quill shaft and said gear case and drive motor are disposed at opposite ends of said quill shaft and said drive shaft extends through the axially disposed opening in said quill shaft.

38. A crowd drive unit according to claim 34 in-cluding at least one brake drum mounted on said pinion shaft.

39. A crowd drive unit according to claim 34 in-cluding a torque arm operatively connected to said gear case, connectable to said support frame.

40. A crowd drive assembly for a rope crowd system of a power shovel comprising a rope drum rotatably mountable on a support frame of a power shovel subject to loads result-ing in structural deflections, a motor mountable on said support frame at one end of said rope drum, having an elong-ated drive shaft extending thorugh said rope drum, a gear case mountable on said support frame at an opposite end of said rope drum, a planetary gear set disposed in said gear case, said gear set including a sun gear mounted on a free end of said shaft, a ring gear mounted on said gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said rope drum.

41. A crowd drive assembly according to claim 40 including a second planetary gear set disposed in said gear case having a sun gear drivingly connected to the planetary gear carrier of said first gear set, a ring gear mounted on said gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said rope drum.

42. A drive assembly for a rope crowd system of a power shovel comprising a rope drum rotatably mountable on a support frame of a power shovel subject to loads resulting in structural deflections, a first gear case mountable on said support frame at one end of said rope drum, a second gear case mountable on said support frame at an opposite end of said rope drum, an elongated drive shaft disposed in said first gear case, said rope drum and second gear case, a first planetary gear set mounted in said first gear case, said first gear set including a sun gear drivingly connectable through a flexible coupling to a drive input shaft, a ring gear mounted on said first gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected to said drive shaft, providing a first stage gear reduction, and a secondary planetary gear set disposed in said second gear case including a sun gear mounted on an end of said drive shaft, a ring gear mounted on said second gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said rope drum, providing a second stage gear reduction.

43. A crowd drive unit according to claim 42 in-cluding a motor mounted on said first gear case having an output shaft drivingly connected through a flexible coupling to the sun gear of said first planetary gear set.

44. A crowd drive unit according to claim 42 in-cluding a third planetary gear set disposed in said second gear case, said third planetary gear set including a sun gear drivingly connected to the planetary gear carrier of said second gear set, a ring gear mounted on said second gear case and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said rope drum, providing a third stage gear reduction.

45. A crowd drive unit according to claim 43 in-cluding a motor mounted on said first gear case having an output shaft drivingly connected thorugh a flexible coupling to the sun gear of said first planetary gear set.

46. In a power shovel having a main frame subject to loads resulting in structural deflections of said frame, a front end assembly including an earth working implement, operatively connected to said main frame and a crowd system mounted on said main frame and operatively connected to said front end assembly, said crowd system including a reciprocable crowd handle having a rack portion, a crowd drive assembly comprising a pinion shaft journaled on said support frame and operatively engageable with the rack portion of said crowd handle, a drive motor supported on said main frame, a plane-tary gear set supported on said main frame including a sun gear, a ring gear and a plurality of planetary gears mounted on a rotatable carrier, one of said gear set components being drivingly connected through a flexible coupling to said drive motor, another of said gear set components being drivingly connected through a flexible coupling to said pinion shaft, and means for restraining the rotation of a further one of said gear set components whereby said gear train is isolated from said structural deflections os said main frame.

47. A crowd drive assembly according to claim 46 including at least one additional planetary gear set opera-tively connected in series with said first-mentioned plane-tary gear set providing multiple gear reduction stages.

48. In a power shovel having a main frame subject to loads resulting in structural deflections of said main frame, a front end assembly including a working implement, operatively connected to said main frame and a crowd system mounted on said support frame and operatively connected to said front end assembly, a crowd drive assembly comprising a support frame mounted on said main frame, a crowd handle having a rack portion mounted on said support frame for reciprocable movement, a pinion shaft journaled in said sup-port frame and drivingly connected to the rack portion of said crowd handle, and a drive unit comprising a motor and a planetary gear set mounted on said support frame, said planetary gear set including a sun gear drivingly connected through a flexible coupling with a drive shaft of said motor, a ring gear mounted on said support frame and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said pinion shaft, and means for restraining the rotation of said ring gear.

49. A crowd drive assembly according to claim 48 wherein said motor and planetary gear set are mounted at one end of said pinion shaft.

50. A crowd drive assembly according to claim 49 wherein said pinion shaft comprises a quill shaft and includ-ing a second planetary gear set mounted on an opposite side of said pinion shaft, said second planetary gear set including a sun gear drivingly connected to the planetary gear carrier of said first planetary gear set by a drive shaft extending through said pinion shaft, a ring gear mounted on said support frame and a plurality of planetary gears mounted on a rotata-ble carrier drivingly connected thorugh a flexible coupling to said pinion shaft.

51. A crowd drive assembly according to claim 50 including a third planetary gear set mounted on said opposite side of said pinion shaft including a sun gear drivingly con-nected to the planetary gear carrier of said second planetary gear set, a ring gear mounted on said support frame and a plurality of planetary gears mounted on a rotatable carrier drivingly connected to said pinion shaft through a flexible coupling.

52. In a power shovel having a main frame subject to loads resulting in structural deflections of said frame, a front end assembly including an earth working implement, operatively connected to said main frame and a rope hoist system mounted on said main frame and operatively connected to said front end assembly, a hoist drive assembly comprising a hoist drum rotatably mounted on said main frame, a drive motor supported on said main frame, a planetary gear set supported on said main frame including a sun gear, a ring gear and a plurality of planetary gears mounted on a rotatable carrier, one of said gear set components being drivingly con-nected through a flexible coupling to said drive motor, another of said gear set components being drivingly connected through a flexible coupling to said drive motor, another of said gear set components being drivingly connected through a flexible couping to said hoist drum, and a further one of said gear set components being restrained from rotation where-by said gear train is isolated from said structural deflec-tions of said main frame.

53. A hoist drive assembly according to claim 52 wherein said planetary gear carrier is drivingly connected through a flexible coupling to said hoist drum.

54. A hoist drive assembly according to claim 52 wherein said sun gear is drivingly connected thorugh a flexible coupling to said drive motor.

55. A crowd drive assembly according to claim 52 wherein said ring gear is mounted on a casing linked to said main frame by means of a torque arm.

56. A hoist drive assembly according to claim 52 including a second planetary gear set operatively connected in series with said first planetary gear set providing first and second gear reduction stages.

57. In a power shovel having a main frame subject to loads resulting in structural deflections of said main frame, a front end assembly including a working implement, operatively connected to said main frame, and a rope hoist system mounted on said main frame and operatively connected to said front end assembly, a hoist drive assembly comprising a support frame mounted on said main frame, a hoist drum rotatably mounted on said support frame, and a drive unit comprising a motor supported on said main frame and a plane-tary gear set mounted on said support frame, said planetary gear set including a sun gear drivingly connected through a flexible coupling to said motor, a ring gear mounted on said support frame and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said hoist drum.

58. A hoist drive assembly according to claim 57 wherein said motor and gear set are mounted on one side of said hoist drum.

59. A hoist drive assembly according to claim 57 wherein said motor is mounted on one side of said hoist drum and said planetary gear set is mounted on an opposite side of said hoist drum.

60. A hoist drive assembly according to claim 57 including a second planetary gear set operatively connected in series with said first-mentioned planetary gear set.

61. A hoist drive assembly according to claim 60 wherein said second planetary gear set includes a sun gear drivingly connected to the planetary carrier of said first planetary gear set, a ring gear mounted on said support frame and a plurality of planetary gears mounted on a rotatable carrier drivingly connected to said hoist drum through a flexible coupling.

62. A hoist drive assembly according to claim 60 including a third planetary gear set drivingly connected in series with said first and second-mentioned gear sets.

63. A hoist drive assembly according to claim 62 wherein said third planetary gear set includes a sun gear drivingly connected to the planetary carrier of said second planetary gear set, a ring gear mounted on said support frame and a plurality of planetary gears mounted in a rotatable carrier drivingly connected through a flexible coupling with said hoist drum.

64. In a power shovel having a support unit in-cluding an upper frame rotatably mounted on a lower frame, subject to loads resulting in structural deflections of said frames, an assembly for swinging said upper frame relative to said lower frame comprising a motor mounted on said upper frame, a shaft journaled in said upper frame having a pinion drivingly engaged with a ring gear mounted on said lower frame, and a gear train set supported on said upper frame having a component thereof drivingly connected through a flexible coupling to said motor and another component thereof drivingly connected through a flexible coupling to said pinion shaft.

65. A swing assembly according to claim 64 wherein said gear train set comprises a planetary gear set including a sun gear, a ring gear and a plurality of planetary gears mounted on a rotatable carrier, and wherein one of said gear train components is drivingly connected to said motor through a flexible coupling, another of said gear train components is drivingly connected through a flexible coupling to said pinion shaft and a further gear train component is restrained from rotation.

66. A swing assembly according to claim 65 in-cluding a second planetary gear set operatively connected in series with said first-mentioned planetary gear set.

67. A swing assembly according to claim 65 wherein said sun gear is drivingly connected through a flexible coupling to said motor, said planetary gear carrier is drivingly connected through a flexible coupling to said pinion shaft and said ring gear is mounted on said upper frame.

68. A swing assembly according to claim 67 in-cluding a second planetary gear set operatively connected in series with said first-mentioned planetary gear set.

69. A swing assembly for a power shovel comprising a shaft having a pinion drivingly engageable with a ring gear mounted on a lower frame of a power shovel, a motor mounted on an upper frame of said power shovel rotatable on said lower frame, and a gear train set including a gear component drivingly connected through a flexible coupling to said motor and another gear component drivingly connected through a flexible coupling with said pinion shaft.

70. In a power shovel having a propel unit in-cluding a rotary drive member, subject to loads resulting in structural deflections of said propel unit, a propel drive assembly comprising a drive motor mounted on said propel unit and a gear train set, one of said gear set components being drivingly connected through a flexible coupling to said motor and another of said gear train components being drivingly connected through a flexible coupling to said rotary drive member.

71. In a power shovel having a propel unit in-cluding a rotary drive member, subject to loads resulting in structural deflections, a prople drive assembly comprising a motor mounted on said propel unit and a planetary gear set mounted on said propel unit including a sun gear, a ring gear and a plurality of planetary gears mounted on a rotatable carrier, one of said gear set components being drivingly connected through a flexible coupling to said drive motor, another of said gear set components being drivingly connected through a flexible coupling to said rotary drive member and a further one of said gear set components being restrained from rotation whereby said gear train is isolated from said structural deflections of said propel unit.

72. A propel drive assembly according to claim 71 wherein said planetary gear carrier is drivingly connected through a flexible coupling to said rotary drive member.

73. A propel drive assembly according to claim 71 wherein said sun gear is drivingly connected through a flexible coupling to said drive motor.

74. A propel drive assembly according to claim 71 including a second planetary gear set operatively connected in series with said first planetary gear set providing first and second gear reduction stages.

75. A propel drive assembly according to claim 71 wherein said motor and gear set are mounted on one side of said rotary drive member.

76. A propel drive assembly according to claim 71 wherein said motor is mounted on one side of said rotary drive member and said gear set is mounted on an opposite side of said rotary drive member.

77. A propel drive assembly according to claim 71 wherein said motor and gear set are mounted on one side of said rotary drive member and including a second gear train set mounted on said one side of said rotary member drivingly connected in series with said first gear train set and a third gear train set mounted on an opposite side of said rotary drive member, drivingly interconnecting said third gear train set and said rotary drive member.

78. A power shovel having a propel unit including a rotary drive member, subject to loads resulting in structur-al deflections, a propel drive assembly comprising a drive motor mounted on said propel unit and a planetary gear set mounted on said propel unit, said planetary gear set including a sun gear drivingly connected through a flexible coupling to said motor, a ring gear mounted on said propel unit and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling to said rotary drive member.

79. A propel drive assembly according to claim 78 wherein said motor and gear set are mounted on one side of said rotary drive member.

80. A propel drive assembly according to claim 78 wherein said motor is mounted on one side of said rotary drive member and said planetary gear set is mounted on an opposite side of said rotary drive member.

81. A propel drive assembly according to claim 78 including a second planetary gear set operatively connected in series with said first-mentioned planetary gear set.

82. A propel drive assembly according to claim 81 wherein said second planetary gear set includes a sun gear drivingly connected to the planetary gear set of said first planetary gear set, a ring gear mounted on said propel unit and a plurality of planetary gears mounted on a rotatable carrier drivingly connected through a flexible coupling with said rotary drive member.

83. A propel drive assembly according to claim 81 including a third planetary gear set drivingly connected in series with said first and second-mentioned planetary gear sets.

84. A propel drive assembly according to claim 83 wherein said third planetary gear set includes a sun gear drivingly connected to the planetary carrier of said second planetary gear set, a ring gear mounted on said propel unit and a plurality of planetary gears mounted in a rotatable carrier drivingly connected through a flexible coupling with said rotary drive member.

85. A propel drive assembly according to claim 84 wherein said motor and said first and second planetary gear sets are mounted on one side of said rotary drive member and said third planetary gear set is mounted on an opposite side of said rotary drive member.

86. A drive assembly for a rotatable member mounted on a frame subject to loads resulting in frame deflections comprising an elongated quill shaft rotatably mountable on said frame, means disposed at one end of said quill shaft for drivingly connecting said quill shaft to said rotatable member, a motor mountable on said frame having an elongated shaft projecting through said quill shaft and a gear train set mountable on said frame drivingly interconnecting the free end of said drive shaft and an end of said quill shaft disposed opposite the end thereof having said means for drivingly connecting said quill shaft to said rotatable member.

87. A drive assembly according to claim 86 wherein said gear train set comprises a planetary gear set.

88. A drive assembly according to claim 87 inclu-ding a second gear set drivingly interconnecting said motor and said drive shaft and further including flexible coupling means operatively interconnecting said motor and said second planetary gear set.

89. A drive assembly according to claim 87 inclu-ding a second planetary gear set drivingly interconnecting said first planetary gear set and said quill shaft to pro-vide a multiple gear reduction.

90. A drive assembly according to claim 87 inclu-ding a second planetary gear set drivingly interconnecting said drive shaft and said motor, flexible coupling means operatively interconnecting said second planetary gear set and said motor and a third planetary gear set drivingly interconnecting said first planetary gear set and said quill shaft.