Washing machine having ball balancers

A drum type washing machine comprising:

• a housing;
• a drum to receive laundry to be washed, the drum including a front cover with an opening provided at a front side of a drum body to receive laundry and a rear cover provided at a rear side of the drum body, an annular recess formed in the front cover such that the annular recess is located immediately adjacent to a wall of the drum body;
• and
• a ball balancer coupled to the drum to compensate for a dynamic imbalance during rotation of the drum, the ball balancer including an annular-shaped racer having a closed internal space in which a plurality of balls and viscous oil are accommodated, the annular-shaped racer including a first injection molded member and a second injection molded member joined to each other to form the closed internal space, the first injection molded member including a first side wall, a second side wall and a connecting wall between the first side wall and the second side wall, the first injection molded member having an open side opposite to the connecting wall, and the second injection molded member is adapted to cover the open side of the first injection molded member,
• wherein the ball balancer is supported by the annular recess formed in the front cover of the drum, the ball balancer is configured to be attachable to the drum with the viscous oil and the plurality of balls already in the ball balancer.