Patent Application
20240060249
The present disclosure relates to a dual motor drive system for a milling attachment for a work machine. The milling attachment may be used to mill a ground surface.
The prior art includes milling attachments having dual drive motors. In such a system two separate hydraulic motors drive opposite ends of the milling drum of the milling attachment. In prior art designs both of the drive motors are connected to the milling drum by threaded connectors, thus requiring a complex mechanical arrangement to allow for the assembly and disassembly of the milling drum with the milling attachment and to allow for thermal expansion of the milling drum during milling operation.
There is a need for improved assembly arrangements allowing for faster and less labor intensive procedures for removing and replacing the milling drum of a milling attachment having dual drives.
In one embodiment a milling attachment for a work machine includes a frame including first and second frame side walls A motor mounting plate is removably mounted on the second frame side wall. A milling drum includes first and second mounting flanges. A first drive motor is mounted on the first frame side wall and includes a drive end connected to the first drum mounting flange by a plurality of threaded fasteners. A second drive motor is mounted on the motor mounting plate and connected to the second drum mounting flange by a stab-in non-threaded connector.
The second drum mounting flange may include a central opening and a plurality of radially offset openings. The stab-in non-threaded connector may include a center hub mounted on the second drive motor and configured to be received in the central opening, and a plurality of radially offset pins configured to be received in the plurality of radially offset openings.
The plurality of radially offset pins may include at least three radially offset pins. The pins may be equally spaced circumferentially around the center hub.
In any of the above embodiments, the center hub may include a cylindrical outer bearing surface configured to be closely received in the central opening, and the center hub may include a tapered axial end configured to guide the cylindrical outer bearing surface into the central opening.
In any of the above embodiments, the center hub may include an inside diameter equal to at least 40% of an inside diameter of a drum casing of the milling drum to allow access through the center hub to a plurality of fasteners connecting the center hub to the second drive motor.
In any of the above embodiments, the center hub may have an open axial end to allow access through the center hub to a plurality of fasteners connecting the center hub to the second drive motor.
In any of the above embodiments, the stab-in non-threaded connector may include a base plate having a generally circular mid-portion with three protruding lobes, and the plurality of radially offset pins may include three radially offset pins one of which is mounted on each of the lobes.
In any of the above embodiments, the central opening of the second drum mounting flange may have a diameter equal to at least 40% of an inside diameter of a drum casing of the milling drum to allow access to the fasteners connecting the first drive motor to the first drum mounting flange.
In any of the above embodiments, the first and second drive motors may be hydraulic motors.
In any of the above embodiments, the first and second hydraulic motors may be completely received between the first frame side wall and the motor mounting plate.
In any of the above embodiments, the milling attachment frame may include a back plate configured to be mounted on the work machine.
In another embodiment a method of removing a milling drum from a milling attachment of a work machine, may include steps of:
In the above method the motors may be hydraulic motors, and the method may be performed without disconnecting any hydraulic hoses from the hydraulic motors.
Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a review of following description in conjunction with the accompanying drawings.
Referring now to the drawings
The work machine 20 may include a machine frame 24 supported from a ground surface 28 by a plurality of ground engaging units 26 so that the work machine 20 is a self-propelled work machine. The ground engaging units 26 are shown as wheels but tracked ground engaging units may also be used. An operator's station 30 is carried on the machine frame 24. A boom 32 is pivotally connected to the machine frame 24 at 34 and can be raised and lowered relative to the machine frame 24 by lift cylinders such as 36. The boom 32 carries an attachment mounting frame 38 which may also be referred to as a manipulation frame 38. An implement actuator cylinder 40 can pivot the attachment mounting frame 38 relative to the boom 32. It will be understood that the attachment mounting frame 38 is a standard part of a work machine that is designed to allow various tool attachments to be mounted on the work machine 20 and manipulated relative to the machine frame 24 by operation of the actuators 36 and 40.
The milling attachment 22 includes a milling attachment frame 42 including first and second integral frame side walls 44 and 46, a frame back wall 48 and a frame top 50. The first and second integral frame side walls 44 and 46, the frame back wall 48 and the frame top 50 collectively form a milling drum housing 52 within which is received a milling drum 54. A motor mounting plate 56 (see
As best seen in
As further seen in
The second drive motor 62 is mounted on the motor mounting plate 56 via an adapter 47 by a plurality of threaded connectors such as 80. A stab-in non-threaded connector 82 is mounted on a drive end 84 of second motor 62 by a plurality of threaded connectors 86. As can be seen in
As best seen in
The stab-in non-threaded connector 82 is shown in isolation in
The stab-in non-threaded connector 82 includes a base plate 96 to which the center hub 92 is welded as indicated at 98. As best seen in
The hub 92 may have a cylindrical outer bearing surface 116 formed thereon and configured to be closely received in the central opening 88 of the second drum mounting flange 74. Adjacent the cylindrical outer bearing surface 116 may be a reduced diameter guide surface 117 and then a tapered axial end 120 configured to guide the cylindrical outer bearing surface 116 into the central opening 88 during the stab-in procedure. The hub 92 has an open axial end 118 defining an inner access opening to provide access to the threaded fasteners 86. Access opening 118 may be defined by an inside diameter 120 of hub which is preferably equal to at least 40% of an inside diameter of the drum casing 70.
As seen in
The arrangement described above for the mounting of the hydraulic motors 60 and 62 provides for an improved method of installing and/or removing the milling drum 54 in the milling attachment 22, especially as compared to prior art dual motor milling attachment designs. In prior art designs both of the drive motors are connected to the milling drum by threaded connectors, thus requiring a complex mechanical arrangement to allow for the assembly and disassembly of the milling drum with the milling attachment and to allow for thermal expansion of the milling drum 54 during milling operation.
With the arrangement of the present disclosure the milling drum 54 may be removed by a method including steps of:
With this arrangement the milling drum 54 may be removed without disconnecting any hydraulic hoses such as 122 and 124 (see
In the above procedure the milling drum 54 may be rested on a wooden pallet or the like prior to step (a) so that the milling drum 54 is temporarily supported during steps (a) and (b). Then step (c) may be performed with the aid of a fork lift or the like engaging the wooden pallet to remove the milling drum 54.
Installation of the milling drum may be performed by a reversal of the steps described above. To install the milling drum 54 it is first moved into position adjacent the first drive motor 60 and the first set of threaded fasteners 68 are installed to connect the milling drum to the first drive motor 60. Then the stab-in non-threaded connector 82, which is attached to the motor mounting plate 56 is stabbed into the milling drum 54 by an axial sliding motion so that the center hub 92 is received in the center opening 88 of second drum mounting flange 74 and the pins 94 are received in the radially offset openings 90. Then the motor mounting plate 56 is attached to the second frame side wall 46 by threaded fasteners 58 to complete the installation.
As best seen in
First and second adjustable side plates 134 and 136 are mounted on the first and second frame side walls 44 and 46, respectively. Each side plate has a ground engaging portion 138 which is configured for engaging the ground surface 28. Ground engaging portions 138 may be in the form of a skid. The details of construction of the first adjustable side plate 134, and further details of the mounting of milling attachment 22 on the work machine 20 are seen in
A three-dimensional reference system is shown in
As is further schematically shown in
In the illustrated embodiment the first adjustable side plate 134 is formed in two parts, namely an upper first lift component 150 and a lower first swivel component 152 supported on the first lift component 150 to be swivel able about a first swivel axis 154. The ground engaging portion or skid 138 is integrally formed on the first swivel component 152. The skid 138 may also be a replaceable wear part that is attached to the side plate in a replaceable manner.
A first actuator 156 is operably associated with the first adjustable side plate 134 for raising and lowering the first adjustable side plate 134 relative to the first frame side wall 44 to adjust the height of the first frame side wall 44 and the milling drum 54 relative to the ground surface 28. Similarly, a second actuator 158 is operably associated with the second adjustable side plate 136 for raising and lowering the second adjustable side plate 136 relative to the second frame side wall 46 to adjust the height of the second frame side wall 46 and the milling drum 54 relative to the ground surface 28. The first and second actuators 156 and 158 are independently operable so that a milling depth of the milling drum 54 can be adjusted on either side of the milling attachment 22.
The first actuator 156 includes a first pivot arm 160 and a first hydraulic cylinder 164. The first pivot arm 160 is mounted on the milling attachment frame 42 and operably connected to the first adjustable side plate 134 at connection 162. The first pivot arm 160 is a three-dimensional structure including an axially inner arm member 160.1, an axially outer arm member 160.2 and a bridge 160.3 rigidly connecting the axially inner and outer arm members 160.1 and 160.2. A pivot shaft 163 extends between projections 165 and 167 of the milling attachment frame 42. The axially inner and outer arm members 160.1 and 160.2 are mounted on the shaft 163 so that the entire pivot arm 160 is pivotable about axis 174 of shaft 163. An arcuate shaped scale 171 is fixed to and pivots with pivot arm 160. A pointer 173 (see
First actuator 156 further includes the first hydraulic cylinder 164 (see
The axially outer arm member 160.2 is connected to the first adjustable side plate 134 at the previously mentioned connection 162.
The first pivot arm 160 pivots relative to milling attachment frame 42 about pivot axis 174. As the pivot arm 160 pivots the interaction of connector 162 with the first adjustable side plate 134 raises or lowers the first adjustable side plate 134. The forward end 170 of hydraulic cylinder 164 is retracted to raise the first adjustable side plate 134 and extended to lower the first adjustable side plate 134.
The second actuator 158 is constructed substantially the same as the first actuator 156, including a hydraulic cylinder and a pivot arm, like the hydraulic cylinder 164 and the pivot arm 160.
As can be appreciated from
It will be appreciated that in addition to raising and lowering the milling attachment frame 42 relative to the ground surface 28 to adjust the milling depth 29 of milling drum 54, the adjustable side plates 134 and 136 in combination with the first and second frame side walls 44 and 46 function to enclose the milling drum 54 so as to capture the milled material created by the operation of the milling drum. Similarly, the movable front cover portion 126 can tilt up and down to enclose the front of the milling drum housing 52.
In prior art milling attachments such tiltable front cover portions typically operated just by the force of gravity pushing them down and engagement with the ground surface 28 pushing them up. The present disclosure provides an improved arrangement whereby the first actuator 156 is connected to the movable front cover portion 126 by a first actuator extension 176 configured such that the movable front cover portion 126 is raised or lowered when the first adjustable side plate 134 is raised or lowered relative to the milling attachment frame 42. Similarly, the second actuator 158 is connected to the movable front cover portion 126 by a second actuator extension 178.
The first and second actuator extensions 176 and 178 may be in the form of cables 176 and 178 connected between the pivotable front cover portion 126 and the forward ends 170 of their respective actuator hydraulic cylinders such as 164. The cables 176 and 178 are configured such that when the forward end 170 of the hydraulic cylinder 164 is retracted the cable pivots the front cover portion 126 upwards. In other embodiments the actuator extensions 176 and 178 may take other forms, such as for example linkages connecting the actuators to the front cover portion 126.
First hydraulic cylinder 164 is shown in
As can best be seen in
As previously noted, the actuators 156 and 158 are independently operable. Thus, if either hydraulic cylinder such as 164 is retracted the pivotable front cover portion 126 will be pulled upward. When the actuator or actuators that have pulled the pivoted front cover portion 126 upward are extended, then the pivoted front cover portion will be lowered by gravitational force.
As seen in
By the arrangement described above the actuators 156 and 158 of the present disclosure provide a dual function to control the raising and lowering of both the side plates 134, 136 and of the pivoted front cover portion 126. As compared to the prior art gravity operated front cover portions, this reduces wear and tear on the front cover portion 126 and provides for a more reliable sealing of the milling drum housing 52.
It is noted that in another embodiment, not shown, the kinematic arrangement of the hydraulic cylinders with the side plates could be reversed so that the cylinders are extended to raise the side plates and retracted to lower the side plates. In such an arrangement a redirecting device such as a deflection pulley could be used to reverse the operation of the cables 176 and 178 so that the extension of the cylinders would raise the movable front cover portion 126 and the retraction of the cylinders would lower the movable front cover portion 126.
As described above with reference to
As schematically shown in
Flow of hydraulic fluid to and from the lines 202 and 204 is controlled by a valve 206 which has at least three positions.
In a first position 208 hydraulic fluid from sump 210 is provided under pressure by pump 212 to the first hydraulic line 202 to retract the hydraulic tilt cylinder 148. Simultaneously return fluid passes through the second line 204 to return line 214 and to the sump 210.
In a second position 216 hydraulic fluid from sump 210 is provided under pressure by pump 212 to the second hydraulic line 204 to extend the hydraulic tilt cylinder 148. Simultaneously return fluid passes through the first line 202 to return line 214 and to the sump 210.
The first and second positions 208 and 216 may be referred to as active tilt modes wherein hydraulic fluid under pressure is applied to the hydraulic tilt cylinder 148 to tilt the milling attachment 22.
In a third position 218 the two hydraulic lines 202 and 204 are connected together in a closed loop and the hydraulic cylinder 148 is free to float in either direction under the forces imposed by the milling attachment 22. The third position 218 may be referred to as a floating mode in which the hydraulic tilt cylinder 148 does not apply any tilting force to the milling attachment 22.
By the present disclosure a tilt control 220 is placed within the operator's station 30 so that the tilt control 220 may be conveniently manipulated by the operator to switch the hydraulic circuit 200 between the active tilt mode 208 or 216 and the floating mode 218 during the milling operation. The tilt control 220 may be provided in various embodiments.
In one embodiment the valve 206 may be an electro-mechanical control valve and the tilt control 220 may be a switch, knob or other input to an electrical controller which sends a control signal via control line 222 to the valve 206 to switch the position of the valve 206.
In another embodiment the valve 206 may be a manually operated valve and the valve 206 itself may be placed in the operator's station 30. This will require the hydraulic lines 202 and 204 to be run into the operator's station 30. Then the tilt control 220 may be embodied as a handle 220 for manual operation of the valve 206 located within the operator's station 30.
In one method of using the tilt control 220 the operator may start a milling operation with both adjustable side plates 134 and 136 engaging an asphalt surface 28 which is to be milled. The milling operation may start with the valve 206 in the free-floating position 218. The milling operation may continue until one of the adjustable side plates 134 or 136 reaches a different surface, such as for example a soft shoulder of the street. At that point the operator may engage the tilt control 220 to switch the valve 206 to either position 208 or 216 to actively tilt the milling attachment 22 relative to work machine 20 to prevent the one side plate from digging into the soft ground surface. With the present system this can be performed without interrupting the milling operation.
A master control valve 306 controls flow of hydraulic fluid from pump 308 and return of hydraulic fluid to tank 310. Master control valve 306 is a three position valve and it controls flow to and from other valves associated with each hydraulically powered component.
The tilt cylinder 148 has associated there with two tilt control valves 312 and 314. Each of the tilt control valves 312 and 314 is a two-position valve that either permits or blocks flow from the master control valve 306 to the hydraulic lines 302 and 304 and thus to the two pressure chambers 316 and 318 of the tilt cylinder 148 to tilt the milling attachment 22 to the right or left.
The master control valve 306 has two active positions 320 and 322 which can direct pressurized hydraulic fluid to either of the intermediate lines 326 or 328. A third position 324 is a neutral position which communicates both lines 326 and 328 to the tank 310. Thus, with the master control valve in either position 320 or 322 and with the tilt control valves 312 and 314 in their open positions the milling attachment 22 is actively tilted to the right or left.
With the embodiment of
The tilt control 220 is again placed within the operator's station 30 so that the tilt control 220 may be conveniently manipulated by the operator to switch the hydraulic circuit 300 between the active tilt mode and the floating mode during the milling operation. The tilt control 220 may be a switch, knob or other input to an electrical controller 340 which sends control signals via control lines 342, 344 to the valves 306, 312, 314, 330 and 332.
Thus, it is seen that the apparatus and methods of the present disclosure readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the disclosure have been illustrated and described for present purposes, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present disclosure as defined by the appended claims. Each disclosed feature or embodiment may be combined with any of the other disclosed features or embodiments.
