Patent Publication Number: US-2023157511-A1

Title: Mop unit lifting device and cleaning machine

Description:
CROSS REFERENCE 
     The present application is a Continuation Application of PCT Application No. PCT/CN2021/102876, filed on Jun. 28, 2021, which claims the priority of Chinese Patent Application No. 202021226406.9, filed on Jun. 29, 2020, the entire contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to the technical field of cleaning equipment, in particular to a mop unit lifting device and a cleaning machine. 
     DESCRIPTION OF THE PRIOR ART 
     Cleaning machines have important market value due to the functions thereof such as automatically rotating to clean the floor. However, in the existing cleaning machines, the rotatable mop units are usually lifted and lowered integrally. In other words, the frame or the housing in which the mop units are mounted is lifted and lowered as a whole. The driving mechanisms are required to be mounted in the frame or the housing for driving the mop units to rotate to clean. That is, the mop units are lifted indirectly. This results in a heavy machine. The applicant has found that the technical features of the integral lifting lead to an easy change of the center of gravity, which has an adverse effect on the stable operation of the cleaning machine. Therefore, in the process of design, production and manufacturing, it is necessary to pay special attention to the matching of the center of gravity under different conditions. The existing cleaning machines are not only complicated in structure, but also complicated in design, production and manufacturing, and relatively high in cost. 
     SUMMARY OF THE DISCLOSURE 
     In view of the above problems existing in the prior art, the present invention provides a mop unit lifting device, the mop unit can be directly and separately, solving the problem that the weight of the lifted portion is heavy. A cleaning machine is further provided which uses the aforementioned mop unit lifting device. 
     The specific technical scheme is as follows: 
     A mop unit lifting device, comprising:
         a mop unit,   a lifting mechanism for lifting the mop unit; and   a driving mechanism for driving the mop unit to rotate; wherein   the driving mechanism is a first driving mechanism that is configured not to be lifted together with the mop unit, and the lifting mechanism and the mop unit are formed in one piece or separate pieces; or   the driving mechanism is a second driving mechanism that is configured to be lifted together with the mop unit, and the lifting mechanism and the mop unit are formed in separate pieces.       

     The advantages of the above technical scheme are as follows: 
     In the first case, the mop unit can be directly lifted, the driving mechanism adopts the first driving mechanism which would not be lifted together with the mop unit, and the lifting mechanism and the mop unit are formed in one or separate pieces. Therefore, the weight of the lifted portion of the mop unit is reduced. Especially for the lifting mechanism and the mop unit formed in separate pieces, the weight can be further reduced, the center of gravity of the whole machine can be designed conveniently, and the problem of heavy weight of the lifted portion is overcome. 
     In the second case, the mop unit can be directly lifted, the driving mechanism adopts the second driving mechanism which would be lifted together with the mop unit, and the lifting mechanism and the mop unit are separate pieces. Therefore, the lifting mechanism needs not to be directly mounted on the mop unit, otherwise, the mop unit would have a heavy weight at the lifted portion. Although the driving mechanism employs the second driving mechanism which is lifted together with the mop unit, compared with the prior art, the weight distributed to the mop unit is still effectively reduced, so that the center of gravity of the whole machine can be designed conveniently, and the problem of heavy weight of the lifted portion is overcome. 
     Preferably, the lifting mechanism is a rack-and-pinion lifting mechanism, a screw lifting mechanism, a cam lifting mechanism, a swing link lifting mechanism or an electromagnetic lifting mechanism. These structures are all applicable to the present invention, and can be flexibly selected according to the design requirement for the center of gravity of the whole machine. 
     Preferably, the lifting mechanism and the mop unit are formed in one piece, in which a telescopic end of the lifting mechanism is connected with the mop unit, and the above structure is adaptable for the lifting mechanism and the mop unit formed in one piece. For example, a linear motor can be adopted, which is arranged coaxially with the mop unit and directly drives the mop unit to move up and down. The structure is compact and high in efficiency, but the overall profile is high, and each mop unit needs to be provided with a linear motor, with a high cost. Alternatively, the lifting mechanism and the mop unit are formed in separate pieces, in which the lifting mechanism is provided with a lifting member which is movable upward and downward, and is connected with a rotatable shaft of the mop unit, and the lifting mechanism is configured to indirectly drive the rotatable shaft to lift through the lifting member, and the above structure is adaptable for the lifting mechanism and the mop unit formed in separate pieces. The height of the profile of the whole structure can be controlled conveniently, and it is not necessary to provide a power unit for each mop unit. Further, the components of the lifting mechanism can be arranged more flexibly. 
     Preferably, the lifting member is configured as a beam which connects mop units, and a driving part of the lifting mechanism is arranged between the mop units for lifting the beam. The structure is compact, simple and reliable. In addition, the synchronization of the elevation of the mop units is good. In addition, it is convenient to arrange the components of the lifting mechanism and to arrange the driving part in the middle of the beam. If the driving part is arranged in the middle of the beam, the mechanical property of lifting is better. 
     Preferably, the mop unit comprises a mop, a turntable and a rotatable shaft, wherein the mop is connected with the turntable, and the rotatable shaft is connected with the turntable; and the rotatable shaft functions to lift the turntable and drive the turntable to rotate. 
     Preferably, the rotatable shaft comprises an inner shaft and an outer shaft surrounding the inner shaft; a limiting structure is arranged between the inner shaft and the outer shaft so that the inner shaft and the outer shaft are movable relative to each other in an axial direction but are limited in a circumferential direction; the outer shaft is configured to rotate to drive the inner shaft to rotate synchronously through the limiting structure, and the inner shaft is connected with the turntable and functions to drive the turntable to lift and rotate synchronously, or the inner shaft is configured to rotate to drive the outer shaft to rotate synchronously through the limiting structure, and the outer shaft is connected with the turntable and functions to drive the turntable to lift and rotate synchronously. The structure is simple, compact, stable and reliable. 
     Preferably, the outer shaft is connected with the first driving mechanism in a transmission manner, the outer shaft is configured to drive the inner shaft to rotate synchronously by the limiting structure, the limiting structure is provided with a connecting portion which is connected with the lifting mechanism, the lifting mechanism and the mop unit are formed in separate pieces, and the lifting mechanism is configured to drive the inner shaft to move axially with respect to the outer shaft through the connecting portion. This structure can greatly simplify the arrangement and layout of the first driving mechanism and the lifting mechanism, reduce the weight of the lifted portion of the mop unit, and make the center of gravity of the whole machine more optimized. 
     Preferably, the mop unit lifting device further includes a spring member for resiliently supporting the inner shaft and/or the turntable downward in the case where the inner shaft is connected with the turntable, or for resiliently supporting the outer shaft and/or the turntable downward in the case where the outer shaft is connected with the turntable. In either case, the arrangement and distribution of the lifting mechanism can be simplified. Due to the spring member which provides a downwardly resilient support force, the lifting mechanism only needs to lift the mop unit upwardly. When the mop unit needs to be lowered, the lifting mechanism releases the mop unit, under the gravity of the mop unit, the mop unit descends spontaneously. Under the action of the spring member, the mop is resiliently attached to the surface to be mopped. Due to the unevenness of the surface to be mopped, the mop will ascend and descend adaptively under the action of the spring member, so that the mop can clean the surface to be mopped better. 
     Preferably, the mop unit lifting device further includes a position detection mechanism for controlling the lifting position of the mop, so that the position of the mop unit can be well controlled to allow a stable lifting, providing a good use experience. 
     The present invention further provides a cleaning machine, which is provided with the aforementioned mop unit lifting device. 
     The advantageous effects of the above technical solution are: 
     In the present invention, the mop unit is directly lifted and lowered, so that the problem of heavy weight of the lifted portion is overcome, and the lifting function of the mop unit is relatively reliable in the long-term use process of the cleaning machine, so the reliability of the clean machine is greatly improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of a mop unit lifting device of the present invention; 
         FIG.  2    is another perspective view of the mop unit lifting device of the present invention, with the outer shaft omitted; and 
         FIG.  3    is a further perspective view of the mop unit lifting device of the present invention, with the screw omitted. 
     
    
    
     List of the reference numerals:  1 , mop unit,  2 , lifting member,  3 , outer shaft,  4 , inner shaft,  5 , bearing,  6 , connecting portion,  7 , gear,  8 , first worm gear,  9 , second worm gear,  10 , first motor,  11 , first worm,  12 , second motor,  13 , second worm,  14 , guide rod,  15 , groove,  16 , spring member,  17 , screw. 
     DESCRIPTION OF EMBODIMENTS 
     The following description is a disclosure of the invention intended to enable those skilled in the art to implement the invention. The preferred embodiments in the following description are merely for example. Those skilled in the art can conceive other obvious alternatives accordingly. The basic principles of the invention described in the following description can be applied to other embodiments, modifications, improvements, alternatives, and others without departing from the spirit and scope of the invention. 
     It will be understood by those skilled in the art that in the present disclosure, the terms such as “longitudinal”, “transversal”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, and “outer” refer to orientations or positional relationships shown in the drawings, which are merely for convenience of description and simplification of description, rather than indicating or implying that the means or elements referred to must have a particular orientation, or be constructed and operated in a particular orientation. Therefore, the above terms are not to be construed as limiting the invention. 
     A mop unit lifting device of the present invention includes two rotatable mop units  1  for cleaning arranged in a substantially left-and-right symmetrical distribution, a lifting mechanism for lifting the mop unit  1 , and a driving mechanism for driving the mop unit  1  to rotate. The driving mechanism is a first driving mechanism which would not be lifted together with the mop unit  1 . The lifting mechanism and the mop unit  1  are formed in one piece or separate pieces. Alternatively, the driving mechanism is a second driving mechanism which would be lifted together with the mop unit  1 , while the lifting mechanism and the mop unit  1  are formed in separate pieces. 
     The lifting mechanism and the mop unit  1  are formed in one piece, in which the telescopic end of the lifting mechanism is connected with the mop unit  1 . The aforementioned structure is suitable for the lifting mechanism and the mop unit  1  formed in one piece. Alternatively, the lifting mechanism and the mop unit  1  are formed in separate pieces, and the lifting mechanism is provided with a lifting member  2 , and the lifting member  2  is connected with the mop unit  1 . The lifting mechanism indirectly drives the mop unit  1  to lift through the lifting member  2 . The aforementioned structure is suitable for separating the lifting mechanism from the mop unit  1 . In this embodiment, the lifting mechanism and the mop unit  1  are formed in separate pieces. 
     The lifting mechanism can use a rack-and-pinion lifting mechanism or a screw lifting mechanism or a cam lifting mechanism or a swing link lifting mechanism or an electromagnetic lifting mechanism. The swing link lifting mechanism can be, for example, a shift fork lifting mechanism which shifts the fork to realize lifting. The electromagnetic lifting mechanism can be, for example, an electromagnetic valve lifting mechanism which realizes lifting by moving the valve core of the electromagnetic valve, or an electromagnet lifting mechanism which realizes lifting by attracting the electromagnet. For example, an iron piece can be arranged at the upper end of the mop unit  1 , and an electromagnet can be arranged above the iron piece. When the electromagnet is energized, the electromagnet attracts the iron piece, thereby lifting the mop unit  1 . When the electromagnet is de-energized, the attraction force disappears, and the mop unit  1  is lowered. In this embodiment, the screw lifting mechanism is used. 
     The screw lifting mechanism is provided separately from the mop unit  1 . The screw lifting mechanism is provided with a lifting member  2 . The lifting member  2  is connected with the mop unit  1 . The screw lifting mechanism indirectly drives the mop unit  1  to lift through the lifting member  2 . This structure allows the lifting mechanism to be provided separately from the mop unit  1 . 
     The lifting member  2  is configured as a beam, which is connected to each mop unit  1 . A driving part of the lifting mechanism is arranged between the mop units  1 , and the driving part is used for driving the beam to lift. 
     In this embodiment, two mop units  1  are provided, and the beam can be provided as a striped beam. Two ends of the beam are respectively connected with one mop unit  1 . A screw  17  is arranged between the two mop units  1 . The screw  17  is screwed to the beam, and the screw  17  rotates to drive the beam to lift. The screw  17  is located in the middle of the beam. In this embodiment, the portion between the two ends of the beam is concaved for height control. 
     The mop unit  1  includes a mop, a turntable and a rotatable shaft. The mop is connected with the turntable, the rotatable shaft is connected with the turntable, and the rotatable shaft is used for lifting the turntable and driving the turntable to rotate. 
     The rotatable shaft includes an inner shaft  4  and an outer shaft  3  surrounding the former. A limiting structure is arranged between the inner shaft  4  and the outer shaft  3  which allows the axial movements of the inner shaft  4  and the outer shaft  3  relative to each other but limits the circumferential movements of the inner shaft  4  and the outer shaft  3  relative to each other. The outer shaft  3  rotates to drive the inner shaft  4  to rotate synchronously through the limiting structure. The inner shaft  4  is connected with the turntable for driving the turntable to lift and rotate synchronously. Alternatively, the inner shaft  4  rotates to drive the outer shaft  3  to rotate synchronously through the limiting structure. The outer shaft  3  is connected with the turntable, and the outer shaft  3  is used to lift and rotate the turntable synchronously. 
     In this embodiment, the outer shaft  3  is connected with a first driving mechanism in a transmission manner. The outer shaft  3  rotates to drive the inner shaft  4  to rotate synchronously through the limiting structure. The limiting structure is provided with a connecting portion  6  connected with the lifting mechanism. The lifting mechanism is provided separately from the mop unit  1 , and drives the inner shaft  4  to move axially relative to the outer shaft  3  via the connecting portion  6 . 
     The screw lifting mechanism employed in this embodiment includes a second motor  12 , a second worm  13  connected to the second motor  12 , a second worm gear  9  connected to the second worm  13 , and a screw  17  connected to the second worm gear  9 . The screw  17  is screwed with the lifting member  2 . The second motor  12  rotates to drive the screw  17  to rotate through the worm and worm gear transmission, and the screw  17  rotates to lift the lifting member  2 . 
     Two ends of the lifting member  2  respectively surround the outer shafts  3  and can move up and down relative to the outer shafts  3 . In this embodiment, the connecting portion  6  is configured as a crossbar arranged on the periphery of the inner shaft  4 . The crossbar passes through the groove  15  defined in the outer shaft  3  and can move upward and downward along the groove  15 . In order to obtain more uniform force, two crossbars are evenly distributed on the periphery. The lifting member  2  drives the inner shaft  4  upward through the crossbar, and the inner shaft  4  moves upward relative to the outer shaft  3 . In turn, when the lifting member  2  descends, the inner shaft  4  is moved downward relative to the outer shaft  3 . 
     The crossbar also serves as a circumferential driving component. That is, when the outer shaft  3  rotates, the crossbar is driven to rotate through the groove  15 , thereby driving the inner shaft  4  to rotate, and the inner shaft  4  rotates to drive the turntable to rotate, thereby driving the mop to rotate. 
     In this embodiment, the first driving mechanism includes a first motor  10 , first worms  11 , and first worm wheels  8 . The first motor  10  is a dual-output motor, and two rotatable ends of the dual-output motor are respectively connected with one first worm  11 . Accordingly, two first worm wheels  8  are used. The first motor  10  drives the shafts for the respective first worm gears  8  to rotate, and the shafts for the respective first worm gears  8  drive the respective gears  7  connected to the outer shafts  3  to rotate through gear transmission, thereby driving the respective outer shafts  3  for the two mop units  1  to rotate by a single first motor  10 . This configuration greatly facilitates a compact structure and the reduction of the space occupied by the cleaning machine, so that this configuration is more suitable for the cleaning machine which involves space requirements such as a floor-sweeping robot. 
     Further, a spring member  16  is provided. In the case where the inner shaft  4  is connected with the turntable, the spring member  16  is used to resiliently support the inner shaft  4  or/and the turntable downwardly. In the case where the outer shaft  3  is connected with the turntable, the spring member  16  is used to resiliently support the outer shaft  3  and/or the turntable downwardly. In this embodiment, it is the inner shaft  4  that is connected to the turntable. 
     The spring member  16  is a compression spring, which is disposed between the inner shaft  4  and the upper end of the outer shaft  3 , with a very compact structure. The outer shaft  3  is provided with bearings  5  at the upper and lower ends thereof and is disposed between the two bearings  5 . 
     When the lifting member  2  ascends, the inner shaft  4  ascends and the compression spring is compressed. When the lifting member  2  descends, the compression spring resiliently supports the inner shaft  4  downward. In this embodiment, in order to allow the mop to attach the surface to be cleaned better, the compression spring is set to be in the compressed state when the mop attaches the surface to be cleaned, so that a self-adaptive cleaning on the uneven surface to be cleaned can be realized, and the cleaning effect is better as a certain pressure is applied to the mop when cleaning. 
     A position detection mechanism is further provided for controlling the lifting position of the mop unit  1 . For example, a code disc for position detection is provided to the second motor  12 , and the position of rotation of the second motor  12  is detected by the code disc, thereby controlling the lifting position of the mop unit  1 . Such a design can avoid the lifting abnormality caused by power failure, program operation error, etc. When an accident occurs, as long as the code disc is detected to return to zero, the control portion can know that the mop unit  1  has returned to the initial position, so that the second motor  12  can be stopped in time, avoiding a continuing rotation of the motor having reached the position. The reliability of the lifting function is thus significantly improved. 
     In this embodiment, the overall distribution of the mop unit lifting device is as follows: two mop units  1  are arranged left and right, respectively, the lifting member  2  is located between two axes of the two mop units  1 , the first driving mechanism is located at the front side of the lifting member  2 , the first motor  10  is centrally disposed, the screw lifting mechanism is located at the rear side of the lifting member  2 , and the screw  17  is centrally disposed. A guide rod  14  is further provided for stably lifting the lifting member  2 . This distribution is compact, with a low profile, and space saving. In terms of the performance, the lifting function can be well realized, and the lifting motion is stable and accurate, with stable and reliable performance. 
     A cleaning machine is provided with the mop unit lifting device, that is, the mop unit lifting device is installed in a cabinet of the cleaning machine, and the motor and the code disc are connected with the control portion of the cleaning machine for control. 
     The operation principle of the present invention may be referred to as follows: when it is necessary to lift the mop unit  1 , the first motor  10  remains stopped, the second motor  12  rotates to lift the lifting member  2 , the lifting member  2  lifts the inner shaft  4 , thereby lifting the mop unit  1 . In case of lowering the mop unit  1 , when the mop unit  1  is lowered into position, the first motor  10  is restarted, so that cleaning can continue. 
     In the present invention, the mop unit  1  is directly lifted and lowered, the problem that the lifted portion is heavy can be solved. In addition, the embodiment of the invention has the advantage of simple and compact structure, good durability, stability, reliability and low cost, and has strong practicability, promoting the upgrading of the lift of the mop unit, making the cleaning machine more user friendly. 
     The above description is only illustration of the invention, but is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof can be modified. Various modifications made within the scope of the independent claims of the present invention are within the scope of the present invention.