Power transmission apparatus and power control apparatus of washing machine

Abstract

A washing machine includes a power transmission apparatus and a power control apparatus. The power transmission apparatus includes a driving unit, a gear mechanism including an input shaft connected to the driving unit, a reduction assembly coupled to the input shaft to reduce its rotational speed to a preset gear ratio, a washing shaft coupled to the reduction assembly that rotates at the gear ratio, and a water removal assembly selectively connected to the driving unit in a water removal mode for independently rotating from the washing shaft, a coupling unit selectively transmitting a power of the driving unit to the water removal assembly in the water removal mode, and a brake unit selectively forcing the water removal assembly to stop in the water removal mode.

What is claimed is: 
     
         1 . An apparatus for a washing machine, the apparatus comprising:
 a driving unit;   a gear mechanism comprising:
 an input shaft coupled to the driving unit; 
 a reduction assembly coupled to the input shaft and configured to reduce a rotational speed to a preset gear ratio; 
 a washing shaft coupled to the reduction assembly and configured to rotate at the gear ratio; and 
 a water removal assembly selectively connected to the driving unit in a water removal mode and configured to rotating independently from the washing shaft; 
   a coupling unit configured to selectively transfer power from the driving unit to the water removal assembly in the water removal mode; and   a brake unit configured to selectively force the water removal assembly to stop in the water removal mode.   
     
     
         2 . The apparatus of  claim 1 , wherein the driving unit is a direct drive motor configured to transmit the power to the input shaft. 
     
     
         3 . The apparatus of  claim 1 , wherein the driving unit comprises:
 a first rotor configured to transfer power to the input shaft; and   a second rotor installed on the same axis as the first rotor and configured to transfer power to the water removal assembly.   
     
     
         4 . The apparatus of  claim 1 , wherein the reduction assembly comprises:
 a sun gear formed on one end of the input shaft;   a planetary pinion capable of meshing with the sun gear; and   a ring gear capable of meshing with the planetary pinion.   
     
     
         5 . The apparatus of  claim 4 , wherein one end of the washing shaft is coupled to a carrier coupled to the planetary pinion, while another end of the washing shaft is coupled to a pulsator. 
     
     
         6 . The apparatus of  claim 4 , wherein the water removal assembly comprises:
 a water removal rotational body configured to receive power from the driving unit through the coupling unit;   a drum coupled to the water removal rotational body; and   a water removal shaft having one end coupled to the drum and another end coupled to a washing tub and configured to rotate the washing tub.   
     
     
         7 . The apparatus of  claim 6 , wherein the water removal rotational body comprises:
 a first gear coupled with the coupling unit; and   a flange coupled to the first gear and to the drum.   
     
     
         8 . The apparatus of  claim 7 , wherein the coupling unit comprises:
 a sliding coupler on an outer circumferential surface of the water removal rotational body and capable of moving up and down while being coupled with the first gear and selectively coupled with the driving unit;   an elastic member coupled to the sliding coupler and configured to provide an elastic force toward the driving unit to couple the sliding coupler with the driving unit; and   a push lever coupled to the sliding coupler and configured to provide a force opposing the elastic force to separate the sliding coupler from the driving unit.   
     
     
         9 . The apparatus of  claim 8 , wherein the sliding coupler comprises:
 a first spline portion coupled to the second rotor of the driving unit; and   a second spline portion coupled to the first gear of the water removal rotational body.   
     
     
         10 . The apparatus of  claim 9 , wherein the coupling unit further comprises a stopper unit configured to restrain rotation of the sliding coupler when the sliding coupler is separated from the driving unit. 
     
     
         11 . The apparatus of  claim 10 , wherein the gear mechanism comprises a case containing the water removal rotational body and the drum, wherein the case is fixed in place relative to the water removal rotational body and the drum. 
     
     
         12 . The apparatus of  claim 11 , wherein the stopper unit comprises:
 a first stopper coupled to the sliding coupler and having a plurality of protrusions formed along its circumference and separated from one another; and   a second stopper coupled to a stop flange coupled with the case and configured to engage with the first stopper to limit rotation of the first stopper.   
     
     
         13 . The apparatus of  claim 12 , wherein the push lever is pivotably coupled to the case or to the stop flange. 
     
     
         14 . An apparatus for a washing machine, the apparatus comprising:
 a driving unit comprising:
 a first rotor provided on a central axis; and 
 a second rotor installed on the central axis; 
   a gear mechanism comprising:
 an input shaft coupled to the driving unit; 
 a reduction assembly coupled to the input shaft and configured to reducing a rotational speed according to a preset gear ratio; 
 a washing shaft coupled to the reduction assembly and configured to rotate at the gear ratio, and 
 a water removal assembly selectively coupled to the driving unit in a water removal mode and configured to rotating independently from the washing shaft; 
   a coupling unit configured to selectively transferring power from the driving unit to the water removal assembly in a water removal mode;   a brake unit;   a sensing unit for sensing opening of a door of the washing machine; and   a control unit configured to determining when the washing machine is operating in a washing mode and when the washing machine is operating in the water removal mode, for cutting off power between the coupling unit and the second rotor in the washing mode, for connecting power between the coupling unit and the second rotor in the water removal mode, and for forcibly stopping the water removal assembly by controlling the brake unit in response to a signal from the door opening sensing unit indicating the door is open.   
     
     
         15 . The apparatus of  claim 14 , wherein the reduction assembly comprises:
 a sun gear formed on one end of the input shaft;   a planetary pinion meshed with the sun gear; and   a ring gear meshed with the planetary pinion.   
     
     
         16 . The apparatus of  claim 15 , wherein the water removal assembly comprises:
 a water removal rotational body configured to receiving power from the driving unit through the coupling unit;   a drum coupled to the water removal rotational body; and   a water removal shaft having one end coupled to the drum and another end coupled to a washing tub.   
     
     
         17 . The apparatus of  claim 16 , wherein the water removal rotational body comprises:
 a first gear coupled to the coupling unit; and   a flange coupled to the drum.   
     
     
         18 . The apparatus of  claim 17 , wherein the coupling unit comprises:
 a sliding coupler on an outer circumferential surface of the water removal rotational body and capable of moving up and down while coupled with the first gear and coupled with the second rotor;   an elastic member coupled to the sliding coupler and providing an elastic force toward the second rotor to couple the sliding coupler with the second rotor; and   a push lever coupled to the sliding coupler and providing an external force opposing the elastic force of the elastic member to release the sliding coupler from the second rotor.   
     
     
         19 . The apparatus of  claim 18 , wherein the sliding coupler comprises:
 a first spline portion coupled to the second rotor; and   a second spline portion capable of coupling with the first gear of the water removal rotational body.   
     
     
         20 . The apparatus of  claim 19 , wherein the coupling unit further comprises a stopper unit configured to limit rotation of the sliding coupler when the sliding coupler is separated from the second rotor in the washing mode.