Drum type washing machine and method for controlling the same

Abstract

A drum type washing machine has an access hole and a drum door for closing the access hole provided on the cylindrical sidewall of the drum. The enclosure of the washing machine includes an access opening that aligns with the assess hole of the drum. A motor of the washing machine is coupled to both the drum door and the drum itself. Thus, the motor can be used to rotate the drum and the door during washing operations. A clutch unit selectively couples and decouples the motor from the drum so that the drum door can be rotated with respect to the drum to open and close the access hole of the drum.

1 . A washing machine, comprising:
 an enclosure including an access opening formed thereon;   a tub mounted in the enclosure;   a drum rotatably mounted inside the tub and including an access hole provided on a circumferential cylindrical surface of the drum;   a drum door that moves to open and close the access hole;   a motor mounted on the enclosure, wherein a rotor of the motor is rotationally fixed to one of the drum and the drum door; and   a clutch unit that selectively rotationally couples the rotor to the other of the drum and the drum door.   
   
   
       2 . The washing machine of  claim 1 , wherein the drum door moves relative to the drum in a direction substantially parallel to the circumferential cylindrical surface of the drum to open and close the access hole. 
   
   
       3 . The washing machine of  claim 1 , wherein the drum door is positioned within the drum, and wherein the drum door is pushed against the inner cylindrical surface of the drum by centrifugal force during rotation of the drum. 
   
   
       4 . The washing machine of  claim 1 , wherein when the clutch unit rotationally couples the rotor to the other of the drum and the drum door the drum and the drum door rotate together with the rotor. 
   
   
       5 . The washing machine of  claim 4 , wherein when the clutch unit decouples the rotor from the other of the drum and the drum door, rotation of the rotor causes the drum door to move with respect to the drum to open and close the access hole. 
   
   
       6 . The washing machine of  claim 5 , wherein when the clutch unit decouples the rotor from the other of the drum and the drum door, the clutch unit also couples the other of the drum and the drum door to a fixed part of the washing machine. 
   
   
       7 . The washing machine of  claim 6 , wherein the fixed part comprises the tub. 
   
   
       8 . The washing machine of  claim 1 , further comprising:
 a first sensor part mounted on the drum; and   a second sensor part mounted on a fixed part of the washing machine such that the first sensor will pass by the second sensor as the drum rotates, and wherein at least one of the first and second sensor parts generate a signal when the first and second sensor parts are adjacent one another.   
   
   
       9 . The washing machine of  claim 1 , further comprising:
 a hollow drum shaft having a first end that is coupled to the drum and a second end that passes through and extends from the tub; and   a door shaft that is rotationally coupled to the rotor, wherein the door shaft passes through the hollow drum shaft and is attached to the drum door.   
   
   
       10 . The washing machine of  claim 9 , wherein the clutch unit comprises:
 a clutch member that is rotationally coupled to the hollow drum shaft and that is movably mounted between the rotor and the hollow drum shaft, wherein the clutch member can move along a longitudinal direction of the hollow drum shaft, and wherein the clutch member can be selectively rotationally coupled to the rotor; and   an actuator for moving the clutch member in the longitudinal direction of the hollow drum shaft.   
   
   
       11 . The washing machine of  claim 10 , wherein a first serration on the rotor can selectively engage a second serration on the clutch member to rotationally couple the clutch member to the rotor. 
   
   
       12 . The washing machine of  claim 11 , wherein the actuator can operate to move the clutch member in a longitudinal direction such that the second serration on the clutch member disengages from the first serration on the rotor. 
   
   
       13 . The washing machine of  claim 12 , wherein when the clutch member is moved to a position where the second serration on the clutch member is disengaged from the first serration on the rotor, the clutch member is rotationally fixed to a stationary part of the washing machine. 
   
   
       14 . The washing machine of  claim 12 , wherein when the clutch member is moved to a position where the second serration on the clutch member is disengaged from the first serration on the rotor, a third serration on the clutch member engages with a fourth serration on a fixed portion of the washing machine to rotationally fix the clutch member to the fixed portion of the washing machine. 
   
   
       15 . The washing machine of  claim 12 , wherein the actuator can also operate to move the clutch member in a longitudinal direction such that the second serration on the clutch member engages the first serration on the rotor. 
   
   
       16 . The washing machine of  claim 12 , further comprising a biasing member that biases the clutch member into a position at which the second serration on the clutch member engages the first serration on the rotor. 
   
   
       17 . A method for controlling a washing machine having a cylindrical drum and a drum door that moves substantially parallel to the cylindrical surface of the drum to open and close an access hole on the cylindrical surface of the drum, comprising:
 rotationally coupling a rotor of a motor of the washing machine to both the drum and the drum door so that the motor rotates the drum and the drum door together;   disconnecting one of the drum and the drum door from the rotor; and   rotating the rotor and the other of the drum and the drum door to move the drum door with respect to the drum to open and close the access hole of the drum.   
   
   
       18 . The method of  claim 17 , further comprising rotationally fixing the one of the drum and the drum door that is disconnected from the rotor to a fixed part of the washing machine before performing the rotating step. 
   
   
       19 . A method for controlling a washing machine having a cylindrical drum and a drum door that moves substantially parallel to the cylindrical surface of the drum to open and close an access hole on the cylindrical surface of the drum, wherein the washing machine also includes an enclosure with an access opening, the method comprising:
 rotating both the drum and the drum door together with a motor until the access hole is aligned with the access opening;   disconnecting the drum from the motor such that the drum door is still rotationally coupled to the motor; and   moving the drum door with respect to the drum with the motor to open the access hole of the drum.   
   
   
       20 . The method of  claim 19 , further comprising rotationally fixing the drum to a fixed part of the washing machine before performing the moving step.