Motor module and vacuum cleaner

Abstract

This motor module includes a motor, a fan, and a casing arranged to house the motor and the fan therein. The casing includes a tubular body portion arranged to extend in an axial direction, an air inlet, an air outlet, a flow passage, and a partitioning portion. The flow passage is a space arranged to join the air inlet and the air outlet to each other between the body portion and the motor. The partitioning portion is arranged in the flow passage to partition the flow passage. The flow passage includes a fan accommodating portion, a first silencing chamber arranged to be in communication with the fan accommodating portion through a first communicating passage, and a second silencing chamber arranged to be in communication with the first silencing chamber through a second communicating passage. The second silencing chamber is arranged to be in communication with the air outlet. The first silencing chamber is arranged to have a flow passage cross-sectional area greater than that of the first communicating passage. The second silencing chamber is arranged to have a flow passage cross-sectional area greater than that of the second communicating passage. Two expansion-type silencers, one defined by the first communicating passage and the first silencing chamber and the other defined by the second communicating passage and the second silencing chamber, are arranged between the fan and the air outlet, so that noise generated in the fan can be reduced with high efficiency.

What is claimed is: 
     
         1 . A motor module comprising:
 a motor including a rotating portion arranged to rotate about a rotation axis;   a fan arranged on a first axial side of the motor to rotate together with the rotating portion; and   a casing arranged to house the motor and the fan therein; wherein   the casing includes:
 a tubular body portion arranged to extend in an axial direction; 
 an air inlet arranged on the first axial side of the fan; 
 an air outlet arranged on a second axial side of the fan and radially outside of the motor; 
 a flow passage being a space arranged to join the air inlet and the air outlet to each other between the body portion and the motor; and 
 at least one partitioning portion arranged in the flow passage to partition the flow passage; 
   the flow passage includes:
 a fan accommodating portion arranged to have the fan accommodated therein, and arranged to be in direct communication with the air inlet; 
 a first silencing chamber arranged to be in communication with the fan accommodating portion through a first communicating passage; and 
 a second silencing chamber arranged to be in communication with the first silencing chamber through a second communicating passage, and arranged to be in direct or indirect communication with the air outlet; 
   the first silencing chamber is arranged to have a flow passage cross-sectional area greater than a flow passage cross-sectional area of the first communicating passage; and   the second silencing chamber is arranged to have a flow passage cross-sectional area greater than a flow passage cross-sectional area of the second communicating passage.   
     
     
         2 . The motor module according to  claim 1 , wherein the at least one partitioning portion includes:
 a plate-shaped first partitioning portion arranged between the fan accommodating portion and the first silencing chamber; and   a plate-shaped second partitioning portion arranged between the first and second silencing chambers.   
     
     
         3 . The motor module according to  claim 2 , wherein the first partitioning portion includes:
 a first plate portion arranged to extend substantially perpendicularly to the axial direction; and   a first bend portion arranged to extend from the first plate portion to the second axial side.   
     
     
         4 . The motor module according to  claim 2 , wherein the second partitioning portion includes:
 a second plate portion arranged to extend substantially perpendicularly to the axial direction; and   a second bend portion arranged to extend from the second plate portion to the second axial side.   
     
     
         5 . The motor module according to  claim 1 , wherein
 each of the first and second communicating passages is arranged along an inner wall of the body portion; and   the first and second communicating passages are arranged to overlap at least in part with each other when viewed in the axial direction.   
     
     
         6 . The motor module according to  claim 1 , wherein
 the first communicating passage is arranged along an inner wall of the body portion;   the second communicating passage is arranged along the motor; and   the first and second communicating passages are arranged at different positions when viewed in the axial direction.   
     
     
         7 . The motor module according to  claim 1 , wherein
 the casing further includes a motor covering portion arranged between the motor and the flow passage; and   at least a portion of the flow passage is surrounded by the motor covering portion and the body portion.   
     
     
         8 . The motor module according to  claim 1 , wherein the air outlet is a through hole defined in the body portion, and is arranged to be in direct communication with the second silencing chamber. 
     
     
         9 . The motor module according to  claim 8 , wherein the casing further includes a partition wall portion arranged to divide the second silencing chamber and a space on the second axial side of the second silencing chamber from each other on the second axial side of the air outlet. 
     
     
         10 . The motor module according to  claim 1 , wherein the casing includes:
 a first casing defined by a single monolithic member; and   a second casing defined by a single monolithic member; and   the first and second casings include contact surfaces arranged to be in contact with each other on a plane passing through the rotation axis.   
     
     
         11 . The motor module according to  claim 10 , wherein
 the first casing includes a projecting portion arranged to project from the plane toward the second casing;   the second casing includes a recessed portion recessed from the plane; and   the projecting portion is fitted into the recessed portion.   
     
     
         12 . A handy-type, upright-type, or stick-type vacuum cleaner comprising:
 a suction head;   a dust separation portion arranged to separate dust included in an air flow from the air flow; and   the motor module of  claim 10 ; wherein   the casing includes a handle portion arranged to be substantially symmetrical with respect to the plane; and   the motor module is arranged to cause gas to be sucked into the air inlet through the suction head and the dust separation portion and be discharged through the air outlet.   
     
     
         13 . A canister-type vacuum cleaner comprising:
 a suction head;   a dust separation portion arranged to separate dust included in an air flow from the air flow;   a hose portion arranged to join the suction head and the dust separation portion to each other; and   the motor module of  claim 1 ; wherein   the motor module is arranged to cause gas to be sucked into the air inlet through the suction head, the hose portion, and the dust separation portion and be discharged through the air outlet.