System and Method for Controlling Rotor Assembly

The present disclosure relates to a rotor assembly for a rotary mixer, and more particularly, to a system and a method for controlling the rotor assembly for the rotary mixer.

Rotary mixers are often used for repairing or stabilization of various surfaces, and typically includes a rotor assembly. The rotor assembly includes a rotor and a gearbox that transfers power from a power source through a rotor drive train to drive the rotor at a predetermined speed. The rotor includes a number of cutting tools that engage with the surface being worked. The gearbox includes a number of shift components that cause rotation of the rotor when engaged. The rotor drive train may include a main clutch that is operatively coupled to the gearbox. Specifically, the main clutch may transmit power from the power source of the rotary mixer to the rotor via the gearbox.

Generally, rotary mixers use an unsynchronized shift mechanism in the gearbox. It is essential that the shift components of the gearbox are fully engaged before rotation of the rotor. If the rotor is rotated without the shift components being fully engaged, the shift components may get damaged. There are several methods of synchronizing the shift mechanism. However, such methods may cause undesirable wear of the main clutch.

U.S. Pat. No. 9,016,800 describe a cold planer that may have a frame, a drum rotatably mounted to the frame, and a gear box connected to the drum. The cold planer may also have a drive pulley connected to the gear box, a primary motor, and a drive belt connecting the primary motor to the drive pulley. The cold planer may further have a service pulley connected to the gear box, a service motor, and a service belt that connects the service motor to the service pulley. The cold planer may additionally have the gear box being configured to transfer motion from the drive pulley and the service pulley to the drum.

In an aspect of the present disclosure, a system for controlling a rotor assembly for a rotary mixer is provided. The rotor assembly includes a rotor. The system includes a gearbox operatively coupled to the rotor. The gearbox includes a plurality of shift components. The system also includes an auxiliary motor operatively coupled to the rotor via the gearbox. The auxiliary motor is adapted to selectively rotate the rotor via the gearbox. The system further includes a speed sensor configured to generate a speed signal indicative of a current speed of the rotor. The system includes a controller including one or more memories and one or more processors. The one or more processors are communicably coupled with the one or more memories and the speed sensor. The one or more processors are configured to determine whether the plurality of shift components of the gearbox are in an engaged position. The one or more processors are also configured to engage the auxiliary motor with the rotor to rotate the rotor if the plurality of shift components are not in the engaged position. The one or more processors are further configured to receive the speed signal indicative of the current speed of the rotor from the speed sensor after the auxiliary motor is engaged with the rotor. The one or more processors are configured to compare the current speed of the rotor with a threshold speed of the rotor. The threshold speed of the rotor is stored in the one or more memories. The one or more processors are also configured to maintain the engagement of the auxiliary motor with the rotor to rotate the rotor if the current speed of the rotor is below the threshold speed of the rotor.

In another aspect of the present disclosure, a rotor assembly for a rotary mixer is provided. The rotor assembly includes a rotor including a plurality of cutting tools. The rotor assembly also includes a system for controlling the rotor. The system includes a gearbox operatively coupled to the rotor. The gearbox includes a plurality of shift components. The system also includes an auxiliary motor operatively coupled to the rotor via the gearbox. The auxiliary motor is adapted to selectively rotate the rotor via the gearbox. The system further includes a speed sensor configured to generate a speed signal indicative of a current speed of the rotor. The system includes a controller including one or more memories and one or more processors. The one or more processors are communicably coupled with the one or more memories and the speed sensor. The one or more processors are configured to determine whether the plurality of shift components of the gearbox are in an engaged position. The one or more processors are configured to engage the auxiliary motor with the rotor to rotate the rotor if the plurality of shift components are not in the engaged position. The one or more processors are configured to receive the speed signal indicative of the current speed of the rotor from the speed sensor after the auxiliary motor is engaged with the rotor. The one or more processors are configured to compare the current speed of the rotor with a threshold speed of the rotor. The threshold speed of the rotor is stored in the one or more memories. The one or more processors are configured to maintain the engagement of the auxiliary motor with the rotor to rotate the rotor if the current speed of the rotor is below the threshold speed of the rotor.

In yet another aspect of the present disclosure, a method of controlling a rotor assembly for a rotary mixer is provided. The rotor assembly includes a rotor and a gearbox operatively coupled to the rotor. The method includes determining, by one or more processors of a controller, whether a plurality of shift components of the gearbox are in an engaged position. The method also includes engaging, by the one or more processors, an auxiliary motor of the rotor assembly with the rotor to rotate the rotor if the plurality of shift components are not in the engaged position. The auxiliary motor is operatively coupled with the rotor via the gearbox. The method further includes receiving, by the one or more processors, a speed signal indicative of a current speed of the rotor from a speed sensor after the auxiliary motor is engaged with the rotor. The method includes comparing, by the one or more processors, the current speed of the rotor with a threshold speed of the rotor. The threshold speed of the rotor is stored in one or more memories of the controller. The one or more memories are communicably coupled with the one or more processors. The method also includes maintaining, by the one or more processors, the engagement of the auxiliary motor with the rotor to rotate the rotor if the current speed of the rotor is below the threshold speed of the rotor.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

is a schematic side view of an exemplary rotary mixer. The rotary mixermay be used to grind off or otherwise mill a portion of a ground surface, such as, roads, pavements, or other surfaces. It should be noted that the present disclosure is not limited to the rotary mixerand alternatively may include other types of work machines such as, but not limited to, milling machines, paving machines, cold planers, and the like, that includes a rotor.

The rotary mixerincludes a frame, a front end, and a rear endopposite to the front end. The framesupports various components of the rotary mixerthereon. The framedefines an enclosureproximate to the front end. The rotary mixeralso includes a power sourcedisposed within the enclosure. Various components of the rotary mixerare operated by the power source. The power sourcemay be an engine, such as, an internal combustion engine, a fuel cell, or a battery system, without any limitations.

The rotary mixerincludes an operator cabin. An operator may be seated within the operator cabinto perform and/or observe work operations. The rotary mixerfurther includes a pair of front wheelsand a pair of rear wheelsthat are mounted to the frame. Particularly, the pair of front wheelsare disposed at the front endof the rotary mixerand the pair of rear wheelsare disposed at the rear endof the rotary mixer. The front and rear wheels,support the frameof the rotary mixerand allow the rotary mixerto travel over the ground surface.

The rotary mixerfurther includes a mixing chamberdisposed between the pair of front wheelsand the pair of rear wheels. However, it will be understood the mixing chambermay be positioned at an alternative location on the rotary mixer. The mixing chamberdefines a housing or other such enclosure for accommodating a rotor assembly(shown in).

As shown in, the rotor assemblyincludes a rotor. The rotorincludes a number of cutting tools (not shown herein). The number of cutting tools radially extend from an outer surface of the rotorand may engage the ground surface being worked. Specifically, the cutting tools may allow the rotor assemblyto remove and/or mix materials during work operations.also illustrates a systemfor controlling the rotor assemblyfor the rotary mixer(see). Specifically, the rotor assemblyincludes the systemfor controlling the rotor. The systemincludes a gearboxoperatively coupled to the rotor. In an example, the rotormay be a hollow structure that defines an interior cavitythat may partially house the gearbox. The gearboxincludes a number of shift components(schematically shown in). The shift componentsmay embody a planetary gear arrangement arranged inside the gearbox. It should be noted that the gearboxmay rotate the rotorat a predetermined speed that can be achieved through different gear ratios obtainable through the gearbox. The rotor assemblyalso includes a bearing assembly. As such, the gearboxand the bearing assemblymay be, at least partially, housed or otherwise contained within the interior cavityof the rotor. The rotor assemblyfurther includes a drivetrain housingthat is disposed adjacent to the rotor.

Referring to, the rotor assemblyincludes a primary drivetrainoperatively coupled to the rotorvia the gearbox. The primary drivetrainis disposed within the drivetrain housing. In some examples, the primary drivetrainmay include a main clutchcoupled to the power source(see), a drive belt, and one or more pulleys. In some examples, the one or more pulleysmay include a drive pulley attached to the main clutchand a driven pulley attached to the gearboxand operably coupled with the drive pulley. The main clutchis operably coupled to the power sourceby an input drive shaft (not shown). The main clutchand the pulleysare operably coupled by the drive beltto transfer power generated by the power sourcethrough the main clutchto the pulleysand to the rotor.

Referring now to, the systemalso includes an auxiliary motoroperatively coupled to the rotor(see) via the gearbox. The auxiliary motorselectively rotates the rotorvia the gearbox. In some examples, the auxiliary motorincludes a hydraulic motor or an electric motor. In an example, the auxiliary motormay include a clutched hydraulic motor.

The systemalso includes an auxiliary clutch mechanism, an auxiliary belt, and an auxiliary pulley. The auxiliary motoris operatively coupled to the gearboxvia the auxiliary clutch mechanism, the auxiliary belt, and the auxiliary pulley. The auxiliary clutch mechanismselectively couples and decouples the auxiliary motorfrom the auxiliary beltand the auxiliary pulley. In other words, the auxiliary clutch mechanismselectively couples and decouples the auxiliary motorfrom the auxiliary beltand the auxiliary pulleyto rotate the rotorvia the gearbox. Further, the pulleysmay be concentric with the auxiliary pulley.

When the auxiliary clutch mechanismis disengaged, the auxiliary clutch mechanismmay allow the auxiliary pulleyand the auxiliary beltto rotate somewhat independently of the auxiliary motor. In this state, the main clutch(see) may power the rotation of the rotorwithout interference by the auxiliary motor. Further, when the auxiliary clutch mechanismis engaged, the auxiliary motormay rotate with the auxiliary pulley. When the auxiliary motoris energized to rotate the rotor, the auxiliary clutch mechanismmay be engaged automatically to couple the auxiliary motorto the auxiliary pulleyvia the auxiliary belt. In some examples, the auxiliary beltmay be v-shaped, flat, corrugated, cog-type, or even a chain, based on application attributes. In some examples, the auxiliary pulleymay have corresponding geometry that meshes with the auxiliary beltto transfer torque with little or no slipping.

Referring now to, a block diagram of the systemfor controlling the rotor assembly(see) for the rotary mixerofis illustrated. The systemincludes a speed sensor. The speed sensorgenerates a speed signal Sindicative of a current speed of the rotor(see). In an example, the speed sensormeasures a rotational speed of the gearboxto generate the speed signal S. Alternatively, the speed sensormay measure a rotational speed of the rotor. In some examples the speed sensormay include a tachometer, an encoder, a magnetic sensor, a hall effect sensor, and the like. The present disclosure is not limited by a type of the speed sensoror a technique of measuring the speed of the rotor.

The systemalso includes a controllerincluding one or more memoriesand one or more processors. The one or more processorsare communicably coupled with the one or more memoriesand the speed sensor. The one or more memoriesstore a threshold speed Tof the rotor. The “threshold speed T” of the rotoris a speed at which it is known to be safe to operate the rotary mixer. The one or more memoriesmay include any means of storing information, including a hard disk, an optical disk, a floppy disk, ROM (read only memory), RAM (random access memory), PROM (programmable ROM), EEPROM (electrically erasable PROM), or other computer-readable memory media.

It should be noted that the one or more processorsmay embody a single microprocessor or multiple microprocessors for receiving various input signals and generating output signals. Numerous commercially available microprocessors may perform the functions of the one or more processors. Each processormay further include a general processor, a central processing unit, an application specific integrated circuit (ASIC), a digital signal processor, a field programmable gate array (FPGA), a digital circuit, an analog circuit, a microcontroller, any other type of processor, or any combination thereof. Each processormay include one or more components that may be operable to execute computer executable instructions or computer code that may be stored and retrieved from the one or more memories.

The systemfurther includes one or more position sensors. The one or more position sensorsgenerate a position signal Sindicative of an engaged position of the number of shift componentsof the gearbox. The one or more position sensorsare communicably coupled with the one or more processors. In some examples, the one or more position sensorsmay include at least one of an inductive position sensor, a linear position sensor, an ultrasonic sensor, a laser sensor, a radio detection and ranging (RADAR) sensor, a light detection and ranging (LIDAR) sensor, a rotary position sensor, and the like.

The one or more processorsdetermine whether the number of shift componentsof the gearboxare in the engaged position. Particularly, the one or more processorsdetermine whether the number of shift componentsare in the engaged position based on the position signal Sreceived from the one or more position sensors. The one or more processorsengage the auxiliary motorwith the rotorto rotate the rotorif the number of shift componentsare not in the engaged position. Specifically, the one or more processorsmay engage the auxiliary clutch mechanism(see), such that the auxiliary pulley(see) may transmit the rotation of the auxiliary motorthrough the gearboxto the rotor. When the auxiliary motoris engaged with the rotor, the auxiliary motorrotates the rotorvia the gearboxat a starting speed or a slower speed. It should be noted that, when the auxiliary motoris engaged with the rotor, the primary drivetrain(see) is disengaged from the gearbox.

However, the one or more processorsoperate the rotorvia the primary drivetrainif the number of shift componentsare in the engaged position. Specifically, based on the receipt of the position signal S, if the processorsdetermine that the shift componentsare fully engaged, the processorscontrol the primary drivetrainto operate the rotorvia the primary drivetrain. It should be noted that, when the primary drivetrainis engaged with the rotor, the auxiliary motoris disengaged from the gearbox.

Further, the one or more processorsreceive the speed signal Sindicative of the current speed of the rotorfrom the speed sensorafter the auxiliary motoris engaged with the rotor. The one or more processorscompare the current speed of the rotorwith the threshold speed Tof the rotor. Specifically, the processorretrieve the threshold speed Tof the rotorfrom the memoriesto compare the current speed of the rotorwith the threshold speed T. The one or more processorsmaintain the engagement of the auxiliary motorwith the rotorto rotate the rotorif the current speed of the rotoris below the threshold speed Tof the rotor. Further, the one or more processorsdisengage the auxiliary motorfrom the rotorif the current speed of the rotoris above the threshold speed Tof the rotor. Thus, the rotoris operated by the auxiliary motoruntil the current speed of the rotoris equal to the threshold speed T. Once the current speed of the rotoris above the threshold speed Tof the rotor, the processorsdisengage the auxiliary motorfrom the rotor.

illustrates a process (or an algorithm) flowchartfor controlling the rotor assemblyfor the rotary mixer of. The processis an implementation of the systemdescribed in relation to. Referring to, the processmay be stored in the one or more memoriesof the controllerand retrieved for execution by the one or more processorsof the controller.

The processstarts at a blockat which the one or more processorsdetermine whether the number of shift componentsof the gearboxare in the engaged position based on receipt of the position signal Sfrom the position sensor.

At the block, if the one or more processorsdetermine that the shift componentsare in the engaged position, the processmoves to a block, at which the one or more processorsoperate the rotorvia the primary drivetrain.

However, at the block, if the one or more processorsdetermine that the shift componentsare not in the engaged position, the processmoves to a block, at which the one or more processorsengage the auxiliary motorwith the rotorto rotate the rotor.

From the block, the processmoves to a block, at which the one or more processorsreceive the speed signal Sindicative of the current speed of the rotorfrom the speed sensor. The speed signal Sis received after the auxiliary motoris engaged with the rotor.

From the block, the processmoves to a block, at which the one or more processorscompare the current speed of the rotorwith the threshold speed Tof the rotorto determine if the current speed of the rotoris below the threshold speed Tof the rotor.

At the block, if the one or more processorsdetermine that the current speed of the rotoris below the threshold speed Tof the rotor, the processmoves to a block, at which the one or more processorskeep the auxiliary motorin operation, in order to maintain the engagement of the auxiliary motorwith the rotorto rotate the rotor. Further, from the blockthe processreverts back to the block, at which the one or more processorsagain compare the current speed of the rotorwith the threshold speed Tof the rotor, thereby forming a closed-loop.

However, at the block, if the one or more processorsdetermine that the current speed of the rotoris above the threshold speed Tof the rotor, the processmoves to a block, at which the one or more processorsdisengage the auxiliary motorfrom the rotor.

From the block, the processreverts back to the block, thereby forming a closed-loop.

It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The above described implementation does not in any way limit the scope of the present disclosure. Therefore, it is to be understood although some features are shown or described to illustrate the use of the present disclosure in the context of functional segments, such features may be omitted from the scope of the present disclosure without departing from the spirit of the present disclosure as defined in the appended claims.

The present disclosure describes the systemfor controlling the rotor assemblyfor the rotary mixer. As one specific example, the teachings of the present disclosure can be used in the design and manufacturing of rotary mixers, and specifically the start-up of rotary mixers in a safe and reliable manner that does not cause damage thereto. The systemincludes the auxiliary motoroperatively coupled to the rotorvia the gearbox. The auxiliary motorselectively rotates the rotorvia the gearbox, when the shift componentsof the gearboxare not fully engaged. The auxiliary motormay rotate the rotorat a slower speed and at a much lower torque, when compared to a normal rotor operation. The normal rotor operation may be defined as an operation of the rotorvia the primary drivetrain.

Further, the one or more processorsoperate the rotorvia the primary drivetrainif the number of shift componentsare in the engaged position. Thus, the one or more processorsmay prevent rotation of the rotorvia the primary drivetrainif the number of shift componentsare not fully engaged, thereby preventing damage of the shift components. In other words, the systemdescribed herein overcomes the problem of starting the rotorwithout the gearbox, the main clutch, and the shift componentsbeing fully engaged to prevent wear and damage to the rotary mixer. Use of the auxiliary motormay eliminate wear of the main clutchthat may happen if conventional methods are used to align and engage the shift components. Further, the auxiliary motormay simplify the process of aligning the shift componentsduring start-up of the rotor. Furthermore, the systemof the present disclosure may solve the problem of misalignments of the shift componentsduring the start-up of the rotorusing a simple arrangement of components.

Moreover, the systemmay reduce servicing and maintenance costs associated with the rotary mixerand may improve performance of the rotary mixer. The systemdescribed herein may be cost-effective, may be retrofitted in existing rotary mixers, and may improve operating time of the rotary mixer.

is a flowchart of a methodof controlling the rotor assemblyfor the rotary mixer. With reference to, the rotor assemblyincludes the rotorand the gearboxoperatively coupled to the rotor. The rotor assemblyfurther includes the primary drivetrainoperatively coupled to the rotorvia the gearbox. At step, the one or more processorsof the controllerdetermine whether the number of shift componentsof the gearboxare in the engaged position.

At step, the one or more processorsengage the auxiliary motorof the rotor assemblywith the rotorto rotate the rotorif the number of shift componentsare not in the engaged position. The auxiliary motoris operatively coupled with the rotorvia the gearbox.

The methodfurther includes a step at which the speed sensorgenerates the speed signal Sindicative of the current speed of the rotor. The speed sensormeasures the rotational speed of the gearboxto generate the speed signal S.

At step, the one or more processorsreceive the speed signal Sindicative of the current speed of the rotorfrom the speed sensorafter the auxiliary motoris engaged with the rotor.

At step, the one or more processorscompare the current speed of the rotorwith the threshold speed Tof the rotor. The threshold speed Tof the rotoris stored in the one or more memoriesof the controller. The one or more memoriesare communicably coupled with the one or more processors.

At step, the one or more processorsmaintain the engagement of the auxiliary motorwith the rotorto rotate the rotorif the current speed of the rotoris below the threshold speed Tof the rotor.

The methodfurther includes a step at which the one or more processorsdisengage the auxiliary motorfrom the rotorif the current speed of the rotoris above the threshold speed Tof the rotor.

The methodfurther includes a step at which the one or more processorsoperate the rotorvia the primary drivetrainif the number of shift componentsare in the engaged position.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed work machine, systems and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.