Abstract:
Disclosed is a washing machine driver, comprising an electric motor, a washing axle ( 51 ), a dehydration axle sleeve ( 52 ) sheathed on the washing axle ( 51 ) and a gear reduction mechanism, wherein the washing axle ( 51 ) is coaxially mounted inside a motor rotor ( 23 ) of the electric motor and is fixed to an output gear ( 332 ) of the gear reduction mechanism, and an input gear shaft ( 31 ) of the gear reduction mechanism is inserted inside a shaft hole of the motor rotor ( 23 ). Since the input gear shaft ( 31 ) of the gear reduction mechanism is inserted inside the shaft hole of the motor rotor ( 23 ), the motor rotor acts as the gear carrier of the gear reduction mechanism, effectively combining the gear reduction mechanism and the electric motor in one, thereby reducing the axial size of the washing machine driver, making the structure of the washing machine driver simple and compact so as to occupy a small space. Furthermore, since the transmission ratio of the gear reduction mechanism has a large range, a large reduction ratio output can be achieved.

Description:
[0001]    This application claims the benefit of priority to Chinese Patent Application No. 201210165853.1 titled “WASHING MACHINE DRIVER”, filed with the Chinese State Intellectual Property Office on May 24, 2012, the entire disclosure of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present application relates to the technical field of drivers, and particularly to a driver for a washing machine. 
       BACKGROUND 
       [0003]    A washing machine is a common home appliance in daily life, and has two main operation conditions, which are a washing condition and a spinning condition. 
         [0004]    A conventional driving unit of an existing washing machine mainly consists of an electric motor and a speed reduction clutch mechanism. A common electric motor has a high rotating speed, and in order to obtain a suitable rotating speed for the washing condition, the rotating speed transmitted from the electric motor to the speed reduction clutch is reduced by a primary pulley. Common speed reduction clutch mechanisms mainly include a single-stage planetary reduction clutch mechanism, a pulley-type reduction clutch mechanism, and an electric motor direct-driven clutch mechanism. However, the single-stage planetary reduction clutch mechanism cannot output speed at a large reduction ratio, which reduces the washing efficiency, and imposes a high requirement on the electric motor, thus the cost is increased. When a multi-stage planetary reduction is employed, the cost is increased, and the mechanism becomes complex, incompact, and unstable. The pulley-type reduction clutch mechanism has a high cost and inaccurate belt transmission ratio, and the belt has a short life, which also reduces the washing efficiency. Further, a driver consisting of the electric motor and the speed reduction clutch mechanism has a large axial dimension, and an incompact structure. 
         [0005]    Another speed reduction clutch in the conventional technology uses a direct-driven electric motor instead of the original general indirect-driven electric motor. However, most of this kind of drive motors are brushless DC motors, and a control unit is required to realize rotation control and other functions, the control unit has a high cost, and this kind of drivers have a large axial dimension, thus are not suitable for long-term development. 
         [0006]    Therefore, a technical problem to be solved currently by those skilled in the art is to design a washing machine driver which has a small axial dimension and a compact structure, and is space saving. 
       SUMMARY 
       [0007]    An object of the present application is to provide a washing machine driver, which has a small axial dimension and a compact structure, and is space saving. 
         [0008]    To address the above technical issues, a washing machine driver is provided according to the present application, which includes an electric motor, a wash shaft, a spin tube sleeved on the wash shaft, and a gear reduction mechanism, the wash shaft is coaxially mounted in a motor rotor of the electric motor and is fixedly connected to an output gear of the gear reduction mechanism, and the gear reduction mechanism includes an input gear shaft inserted in a shaft hole of the motor rotor. 
         [0009]    Preferably, the gear reduction mechanism includes a first gear, a second gear, an intermediate gear and the output gear, the first gear and the second gear are fixedly installed at two ends of the input gear shaft respectively, the first gear engages with the intermediate gear, and the second gear engages with the output gear; and the intermediate gear is sleeved on the spin tube, and the output gear is fixedly connected to the wash shaft. 
         [0010]    Preferably, the gear reduction mechanism includes a dual gear, an intermediate gear and the output gear, the dual gear is sleeved on the input gear shaft, and the intermediate gear and the output gear engage with a first stage gear and a second stage gear of the dual gear respectively; and the intermediate gear is sleeved on the spin tube, and the output gear is fixedly connected to the wash shaft. 
         [0011]    Preferably, the intermediate gear is an external gear or an internal gear ring. 
         [0012]    Preferably, the output gear is an external gear or an internal gear ring. 
         [0013]    Preferably, the driver further includes a clutch device, and the clutch device is arranged between the spin tube and the motor rotor to realize a switching between a washing condition and a spinning condition. 
         [0014]    Preferably, a clutch toothed disc of the clutch device is connected to the spin tube via a splined sleeve, and the clutch toothed disc engages with the splined sleeve and is axially slidably connected to the splined sleeve. 
         [0015]    Preferably, in the washing condition, the clutch toothed disc is engaged with an upper end cover of the electric motor, and in the spinning condition, the clutch toothed disc is engaged with the motor rotor. 
         [0016]    Preferably, in the washing condition, the clutch toothed disc is not fixed; and in the spinning condition, the clutch toothed disc is engaged with the motor rotor. 
         [0017]    Preferably, the clutch device is an electromagnetic clutch device or a mechanical clutch device. 
         [0018]    Compared to the background technology, the driver of the impeller type washing machine according to the present application includes an electric motor, a wash shaft, a spin tube sleeved on the wash shaft, and a gear reduction mechanism, the wash shaft is coaxially mounted in a motor rotor of the electric motor and is fixedly connected to an output gear of the gear reduction mechanism, and the gear reduction mechanism includes an input gear shaft inserted in a shaft hole of the motor rotor. The input gear shaft of the gear reduction mechanism is inserted in the shaft hole of the motor rotor, thus the motor rotor functions as a gear carrier of the gear reduction mechanism, which effectively integrates the gear reduction mechanism and the electric motor, and reduces the axial dimension of the washing machine driver, thus the washing machine driver has a simple and compact structure and is space saving. Furthermore, the gear reduction mechanism has a large range of transmission ratio, thereby achieving an output at a large reduction ratio. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a front view of a washing machine driver according to an embodiment of the present application; 
           [0020]      FIG. 2  is a sectional view of the washing machine driver in  FIG. 1  taken along direction A-A; 
           [0021]      FIG. 3  is an exploded view of the washing machine driver in  FIG. 1 ; 
           [0022]      FIG. 4  is a schematic view showing the transmission of the washing machine driver according to a first embodiment of the present application; 
           [0023]      FIG. 5  is a schematic view showing the transmission of the washing machine driver according to a second embodiment of the present application; 
           [0024]      FIG. 6  is a schematic view showing the transmission of the washing machine driver according to a third embodiment of the present application; 
           [0025]      FIG. 7  is a schematic view showing the transmission of the washing machine driver according to a fourth embodiment of the present application; 
           [0026]      FIG. 8  is a schematic view showing the transmission of the washing machine driver according to a fifth embodiment of the present application; 
           [0027]      FIG. 9  is a schematic view showing the transmission of the washing machine driver according to a sixth embodiment of the present application; and 
           [0028]      FIG. 10  is a schematic view showing the transmission of the washing machine driver according to a seventh embodiment of the present application. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    An object of the present application is to provide a washing machine driver, which has a small axial dimension and a compact structure, and is space saving. 
         [0030]    For those skilled in the art to better understand technical solutions of the present application, the present application is described in detail in conjunction with drawings and embodiments hereinafter. 
         [0031]    It is to be noted that, locality terms, such as upper and lower, involved herein are defined by the positions of parts and the position relationship of the parts in  FIGS. 1 to 10 , and are only intended to clearly and conveniently describe the technical solutions. It should be appreciated that, the locality terms herein should not limit the scope of the present application as claimed. 
         [0032]    Reference is made to  FIGS. 1 ,  2  and  3 .  FIG. 1  is a front view of a washing machine driver according to an embodiment of the present application;  FIG. 2  is a sectional view of the washing machine driver in  FIG. 1  taken along direction A-A; and  FIG. 3  is an exploded view of the washing machine driver in  FIG. 1 . 
         [0033]    In an embodiment, the washing machine driver according to the present application includes an electric motor. The electric motor includes a motor housing  21 , a motor stator  22  and a motor rotor  23 . The motor stator  22  is arranged inside the motor housing  21 , the motor rotor  23  is coaxially arranged in the motor stator  22 , and the motor rotor  23  is provided with a shaft hole. An upper end cover  24  and a lower end cover  25  are respectively provided above and below the electric motor. The motor housing  21 , the motor stator  22 , the upper end cover  24  and the lower end cover  25  may be fixedly connected by bolts. 
         [0034]    The wash shaft  51  of the washing machine is coaxially mounted in the motor rotor  23 , and a rotor oil-containing bearing  81  is provided between the wash shaft  51  and the motor rotor  23 . The wash shaft  51  limits the motor rotor  23  in a radial direction, and a relative rotation between the wash shaft  51  and the motor rotor  23  is realized by the rotor oil-containing bearing  81 . 
         [0035]    A spin tube  52  of the washing machine is sleeved on the wash shaft  51 , and a wash shaft oil-containing bearing  82  is provided between the spin tube  52  and the wash shaft  51 , which realizes a relative rotation between the spin tube  52  and the wash shaft  51 . 
         [0036]    The washing machine driver further includes a gear reduction mechanism. The gear reduction mechanism includes an input gear shaft  31 , a first gear  321 , a second gear  322 , an intermediate gear  331  and an output gear  332 . The input gear shaft  31  is inserted in the shaft hole of the motor rotor  23 , an oil-containing bearing is provided between the input gear shaft  31  and the motor rotor  23 , and a relative rotation between the input gear shaft  31  and the motor rotor  23  is realized by the oil-containing bearing. The first gear  321  and the second gear  322  are fixedly installed at two ends of the input gear shaft  31  respectively. The first gear  321  engages with the intermediate gear  331 , and the second gear  322  engages with the output gear  332 . 
         [0037]    The intermediate gear  331  is sleeved on the spin tube  52 . The output gear  332  is fixedly connected to the washing wheel  51 , and the fixed connection may be achieved by a straight pin  84 . A distance ring  72  is provided between the wash shaft  51  and the output gear  332 , plane bearings are respectively provided at two ends of the motor rotor  23 , and an axial movement of the motor rotor  23  may be limited by the distance ring  72  and the plane bearings. 
         [0038]    It is to be noted that, the motor rotor may be provided with multiple shaft holes, that is, multiple input gear shafts, and first gears and second gears which cooperate with the multiple input gear shafts may be inserted in the motor rotor. Due to the multiple input gear shafts, the combination of the electric motor and the gear reduction mechanism may operate more stable and has a prolonged working life. 
         [0039]    A mounting plate  11  is fixedly provided above the upper end cover  24  of the electric motor, and the mounting plate  11  and the upper end cover  24  may be fixedly connected by bolts. The driver may be mounted in the washing machine via the mounting plate  11 . 
         [0040]    Reference is made to  FIG. 4 , which is a schematic view showing the transmission of an embodiment of the washing machine driver. In operation, after being energized, the electric motor drives the motor rotor  23  to rotate, and at the same time, drives the input gear shaft  31  connected to the motor rotor  23  and the first gear  321  and the second gear  322  fixedly connected to the input gear shaft  31  to orbit. Since the first gear  321  engages with the intermediate gear  331  and there is a difference between the numbers of teeth of the first gear  321  and the intermediate gear  331 , the input gear shaft  31  is driven to rotate on its own axis. Since the second gear  322  engages with the output gear  332 , the output gear  332  is driven to rotate, which further drives the wash shaft  51  fixedly connected to the output gear  332  to rotate. Since there is a relationship of difference of the numbers of teeth between the first gear  321 , the second gear  322 , the intermediate gear  331  and the output gear  332 , a rotation speed difference will be generated between the output gear  332  and the motor rotor  23 , thereby driving the wash shaft  51  to output at a low speed. Since the intermediate gear  331  is sleeved on the spin tube  52  and is in an unfixed state, the spin tube  52  also outputs at a low speed in a certain speed ratio while the wash shaft  51  outputs at a low speed. Therefore, in a washing condition, the electric motor may rotate at a high speed, and the wash shaft  51  may output at a low speed through the gear reduction mechanism, thereby increasing the use efficiency of the electric motor and also achieving a combined power output. 
         [0041]    It is to be noted that, the wash shaft  51  and the spin tube  52  may both output at a low speed in the same rotational direction or output in reverse rotational directions. Whether the rotational directions of the wash shaft  51  and the spin tube  52  are the same or opposite, is depending on whether the value of the tooth number difference ratio of the gear reduction mechanism is positive or negative. In practical application, the relationship of the tooth number differences of the gear reduction mechanism may be determined as desired. 
         [0042]    It is to be noted that, in this embodiment, the intermediate gear  331  and the output gear  332  are both internal gear rings. 
         [0043]    Reference is made to  FIG. 5 , in a second embodiment, the gear reduction mechanism includes a dual gear  32 , an intermediate gear  331  and an output gear  332 . The dual gear  32  is sleeved on an input gear shaft  31 ′, and the intermediate gear  331  and the output gear  332  respectively engage with a first stage gear  321  and a second stage gear  322  of the dual gear  32 . The intermediate gear  331  is sleeved on the spin tube  52 , and the output gear  332  is fixedly connected to the wash shaft  51 . The intermediate gear  331  and the output gear  332  are both external gear rings. 
         [0044]    In the second embodiment, the input gear shaft  31 ′ is fixedly connected to the motor rotor  23 , and the dual gear  32  and the input gear shaft  31 ′ may rotate with respect to each other. When the motor rotor  23  is driven to rotate, the dual gear  32  is driven to orbit and rotate on its own axis at the same time, and the low speed output of the wash shaft  51  may also be achieved due to the relationship of tooth number differences between the first stage gear  321  of the dual gear  32 , the second stage gear  322  of the dual gear  32 , the intermediate gear  331  and the output gear  332 . 
         [0045]    Certainly, the low speed output of the wash shaft  51  may also be achieved by rotatably connecting the input gear shaft  31 ′ to the motor rotor  23  and fixedly connecting the dual gear  32  to the input gear shaft  31 ′. 
         [0046]    In the second embodiment or in the first embodiment, the intermediate gear  331  may be an external gear, or an internal gear ring, and the output gear  332  may be an external gear, or an internal gear ring, thus the gear reduction mechanism may have the following several different embodiments. 
         [0047]    It is to be noted that, in various embodiments, structures or members having the same function or equivalent functions are indicated with the same reference numbers in the drawings. 
         [0048]    Reference is made to  FIG. 6 , in a third embodiment, the input gear shaft  31  is rotatably inserted in the motor rotor  23 , and the first gear  321  and the second gear  322  are fixedly installed at two ends of the input gear shaft  31 . The intermediate gear  331  and the output gear  332  are both external gears. 
         [0049]    Reference is made to  FIG. 7 , in a fourth embodiment, the input gear shaft  31  is rotatably inserted in the motor rotor  23 , and the first gear  321  and the second gear  322  are fixedly installed at two ends of the input gear shaft  31 . The intermediate gear  331  is an internal gear ring, and the output gear  332  is an external gear. 
         [0050]    Reference is made to  FIG. 8 , in a fifth embodiment, the input gear shaft  31  is rotatably inserted in the motor rotor  23 , and the first gear  321  and the second gear  322  are fixedly installed at two ends of the input gear shaft  31 . The intermediate gear  331  is an external gear, and the output gear  332  is an internal gear ring. 
         [0051]    Reference is made to  FIG. 9 , in a sixth embodiment, the input gear shaft  31 ′ is fixedly connected to the motor rotor  23 , the dual gear  32  and the input gear shaft  31 ′ may rotate with respect to each other, and the intermediate gear  331  and the output gear  332  engage with the first stage gear  321  and the second stage gear  322  of the dual gear  32  respectively. The intermediate gear  331  is an internal gear ring, and the output gear  332  is an external gear. 
         [0052]    Since the two stages of gears of the dual gear  32  have different tooth numbers, according to a seventh embodiment shown in  FIG. 10 , a first stage gear  321 ′ of the dual gear  32  may engage with the output gear  332 , and a second stage gear  322 ′ may engage with the intermediate gear  331 . The intermediate gear  331  is still an internal gear ring, and the output gear  332  is still an external gear. 
         [0053]    The principle of transmission of the several embodiments described above in operation are the same as that of the first embodiment, thus will not be described herein. 
         [0054]    It is to be noted that, in addition to the above several embodiments, the gear reduction mechanism may have other embodiments, as long as the differential reduction can be achieved and the output mechanism and the motor rotor may produce rotational speed difference. 
         [0055]    A further improvement may be made to the above washing machine driver. 
         [0056]    The washing machine driver may further include a clutch device  4 . The clutch device is arranged between the spin tube  52  and the motor rotor  23 , which may realize the switching between the washing condition and the spinning condition. 
         [0057]    The clutch device  4  may be an electromagnetic clutch device, or a mechanical clutch device. The electromagnetic clutch device is described as an example hereinafter. 
         [0058]    The electromagnetic clutch device includes a clutch cover plate  41 , a clutch fixing plate  42 , a clutch toothed disc  43  and a coil holder  44 . The coil holder  44  is located in an annular groove of the clutch fixing plate  42 , the clutch cover plate  41  is arranged above the coil holder  44 , and the clutch toothed disc  43  is located in an inner ring of the clutch fixing plate  42 . The clutch cover plate  41 , the clutch fixing plate  42  and the coil holder  44  are connected together first and then are fixedly connected to the upper end cover  24 , and the fixedly connection may be achieved by bolts. A pressure spring  45  may be further provided above the clutch toothed disc  43 . 
         [0059]    The clutch toothed disc  43  is sleeved on the spin tube  52  via a splined sleeve  71 , and the clutch toothed disc  43  engages with the splined sleeve  71  and is axially slidably connected to the splined sleeve  71 . It is to be noted that, the clutch toothed disc  43  and the splined sleeve  71  are engaged constantly in any operating conditions, and cannot rotate with respective to each other. The clutch toothed disc  43  and the splined sleeve  71  are located at an upper end of a first internal gear ring  331 . 
         [0060]    When the electromagnetic clutch device is energized to generate magnetic field, the clutch toothed disc  43  may slide upwards in an axial direction along external splines of the splined sleeve  71  against the spring force of the pressure spring  45 , which disengages the clutch toothed disc  43  from the motor rotor  23 . At this time, when the electric motor is energized, the low speed output of the wash shaft  51  may be achieved through the gear reduction mechanism, thereby realizing the washing function. 
         [0061]    It is to be noted that, a common output and a combined power output may be realized by changing the fixing manner of the clutch device  4 . 
         [0062]    When the clutch toothed disc  43  is disengaged from the motor rotor  23 , the clutch toothed disc  43  is allowed to be engaged with the upper end cover  24 , and at this time, the spin tube  52  connected to the clutch toothed disc  43  is in a fixed state, thus in the washing condition, only the wash shaft  51  outputs at a low speed, which is a normal washing output. When the clutch toothed disc  43  is disengaged from the motor rotor  23  and is unfixed, the wash shaft  51  outputs at a low speed, and the spin tube  52  also outputs at a low speed in a certain speed ratio, thereby realizing the combined power output. The meaning of the clutch toothed disc  43  being unfixed is that the clutch toothed disc  43  is not engaged with any components which are in a fixed state, i.e. the spin tube  52  connected to the clutch toothed disc  43  is also in an unfixed state. 
         [0063]    When the electromagnetic clutch device is de-energized, the magnetic field disappears, and under the spring force of the pressure spring  45 , the clutch toothed disc  43  slides downwards in the axial direction along the external splines of the splined sleeve  71 , which allows the clutch toothed disc  43  to be engaged with the motor rotor  23 . Since the clutch toothed disc  43  and the splined sleeve  71  cannot rotate with respect to each other, the spin tube  52  connected to the splined sleeve  71  and the intermediate gear  331  sleeved on the spin tube  52  are locked with respect to the motor rotor  23 , which results in a self-locking of the gear reduction mechanism. Thus, the motor rotor  23  and the wash shaft  51  rotate at the same speed, thereby achieving the spinning function. 
         [0064]    It is to be noted that, the clutch device may also achieve the switching between the washing condition and the spinning condition by driving other transmission parts of the gear reduction mechanism to be engaged with or disengaged from the motor rotor. In the common washing output of the washing condition, the clutch toothed disc of the clutch device may also be engaged with other fixed parts of the electric motor. There are many arrangements of the clutch device, as long as the switching between the washing condition and the spinning condition of the washing machine may be realized. 
         [0065]    In the spinning condition, the spin tube  52  is required to bear the weight of the clothes to be washed, thus in order to limit an axial movement of the spin tube  52 , a plane bearing, a flat gasket and an elastic retaining ring may be provided between the spin tube  52  and the intermediate gear  331  to limit the movement of the spin tube  52  in an axial direction thereof. 
         [0066]    To allow the wash shaft  51  and the spin tube  52  to rotate more stably in the spinning condition, a first bearing  831  is provided between the spin tube  52  and the mounting plate  11 , and a second bearing  832  is provided between the output gear  332  and the lower end cover  25 . 
         [0067]    Further, a first water seal member  61  is provided between the wash shaft  51  and the spin tube  52 , and a second water seal member  62  is provided between the spin tube  52  and the mounting plate  11 , so as to prevent the washing water from entering the interior of the driver during the operation of the washing machine. 
         [0068]    A washing machine driver according to the present application is described in detail hereinbefore. The principle and the embodiments of the present application are illustrated herein by specific examples. The above description of examples is only intended to help the understanding of the method and the spirit of the present application. It should be noted that, for the person skilled in the art, a few of modifications and improvements may be made to the present application without departing from the principle of the present application, and these modifications and improvements are also deemed to fall into the scope of the present application defined by the claims.