Sander

Abstract

A sander includes an airflow element rotatable about a central axis along a preset direction of rotation to generate a dust removal airflow; an electric motor for providing a power source for the airflow element; and a battery pack for providing an energy source for the electric motor. When the sander is in a load-free state, the working duration of the sander when the battery pack consumes 10 WH of energy is defined as the functional time T of the sander; and the product of the load-free rotational speed N of the electric motor and the functional time T of the sander is greater than or equal to 63000 rpm·min and less than or equal to 120000 rpm·min.

What is claimed is: 
     
         1 . A sander, comprising:
 an airflow element rotatable about a central axis along a preset direction of rotation to generate a dust removal airflow;   an electric motor for providing a power source for the airflow element; and   a battery pack for providing an energy source for the electric motor;   wherein, when the sander is in a load-free state, a working duration of the sander when the battery pack consumes 10 W·h of energy is defined as a functional time T of the sander and a product of a load-free rotational speed N of the electric motor and the functional time T of the sander is greater than or equal to 63000 rpm·min and less than or equal to 120000 rpm·min.   
     
     
         2 . The sander of  claim 1 , wherein the product of the load-free rotational speed N of the electric motor and the functional time T of the sander is greater than or equal to 77000 rpm·min and less than or equal to 110000 rpm·min. 
     
     
         3 . The sander of  claim 1 , further comprising a housing configured to accommodate the airflow element and guide the dust removal airflow generated by the airflow element, wherein the housing comprises an upper sidewall and a lower sidewall opposite to the upper sidewall, a distance from the lower sidewall to the upper sidewall along a direction of the central axis is defined as a third distance D3, and the third distance D3 gradually increases along the preset direction of rotation. 
     
     
         4 . The sander of  claim 3 , wherein the upper sidewall comprises at least one connecting section that satisfies an Archimedean spiral direction. 
     
     
         5 . The sander of  claim 4 , wherein a guide wall is formed on an inner wall of the housing, a distance from the guide wall to the central axis is defined as a first distance D1, the first distance D1 gradually increases along the preset direction of rotation, and the inner wall comprises at least a structural section that satisfies an Archimedean spiral equation along a plane perpendicular to the central axis. 
     
     
         6 . The sander of  claim 4 , wherein a farthest end of the airflow element from the central axis forms a circle when the airflow element rotates about the central axis along the preset direction of rotation, a guide wall is formed on an inner wall of the housing, a distance from the guide wall to the circle is defined as a second distance D2, the second distance D2 gradually increases along the preset direction of rotation, and the inner wall comprises at least a structural section that satisfies an Archimedean spiral equation along a plane perpendicular to the central axis. 
     
     
         7 . The sander of  claim 4 , wherein the airflow element comprises a bottom plate rotatable around the central axis and a plurality of fan blade portions fixedly connected to or integrally formed with the bottom plate, wherein a fan blade portion of the plurality of fan blade portions extends along a curve, and an extension direction of the curve is opposite to the preset direction of rotation of the airflow element. 
     
     
         8 . The sander of  claim 7 , wherein the airflow element comprises the bottom plate rotatable around the central axis, the plurality of fan blade portions are fixedly connected to or integrally formed with the bottom plate, a first fan blade surface and a second fan blade surface of the fan blade portion are defined, the first fan blade surface is disposed on a front side of the second fan blade surface along the preset direction of rotation, two opposite ends of the first fan blade surface and two opposite ends of the second fan blade surface separately merge into a front edge and a rear edge, the front edge is away from the central axis relative to the rear edge, and an outer edge of the bottom plate at least partially contact with the front edge. 
     
     
         9 . The sander of  claim 8 , further comprising an eccentric element driven by the electric motor, wherein the eccentric element has an axis deviating from the central axis and a base plate drivable by the electric motor, a coordinate system is established with a certain point on the central axis as an origin with a direction of a line between the central axis and the axis as an X-axis and with a direction perpendicular to the direction of the line between the central axis and the axis as a Y-axis, a projection of the first fan blade surface on a plane formed by the X-axis and the Y-axis is defined as a first projection line, a tangent line at a position of the first projection line farthest from the central axis is defined as a first tangent line, in the plane formed by the X-axis and the Y-axis, a tangent line at an intersection of the outer edge of the bottom plate and the first projection line is defined as a second tangent line, and an included angle between the first tangent line and the second tangent line is greater than or equal to 20 degrees and less than or equal to 45 degrees. 
     
     
         10 . The sander of  claim 9 , wherein, in the plane formed by the X-axis and the Y-axis, an endpoint of the first projection line near the outer edge of the bottom plate is defined as A, an endpoint of the first projection line near the central axis is defined as B, and a ratio of a radius of the airflow element to a distance L1 between the endpoint A and the endpoint B of the first projection line is greater than or equal to 4 and less than or equal to 7.5. 
     
     
         11 . A sander, comprising:
 an airflow element rotatable about a central axis along a preset direction of rotation to generate a dust removal airflow;   an electric motor for providing a power source for the airflow element;   a battery pack for providing an energy source for the electric motor; and   a housing configured to accommodate the airflow element and guide the dust removal airflow generated by the airflow element;   wherein a guide wall is formed on a back of the housing, a distance from the guide wall to the central axis is defined as a first distance D1, the first distance D1 gradually increases along the preset direction of rotation, an inner wall comprises a first end and a second end along a plane perpendicular to the central axis, the guide wall connects the first end to the second end, and a distance from the first end to the central axis is greater than or equal to 40 mm and less than or equal to 60 mm.   
     
     
         12 . The sander of  claim 11 , wherein the first end and the second end are provided with air outlets for dust removal and air exhaust and a ratio of a distance between the air outlets along the plane perpendicular to the central axis to a distance from the central axis to a farthest end of the airflow element is greater than or equal to 1 and less than or equal to 1.5. 
     
     
         13 . The sander of  claim 12 , wherein the housing comprises an upper sidewall and a lower sidewall opposite to the upper sidewall, a distance from the lower sidewall to the upper sidewall along a direction of the central axis is defined as a third distance D3, the third distance D3 gradually increases along the preset direction of rotation, and the upper sidewall comprises at least one connecting section that satisfies an Archimedean spiral direction. 
     
     
         14 . The sander of  claim 11 , wherein a range of a product of weight of the airflow element and a square of an outer diameter of a centrifugal fan is greater than or equal to 3000 g·mm 2  and less than or equal to 10000 g·mm 2 . 
     
     
         15 . A sander, comprising:
 an airflow element rotatable about a central axis along a preset direction of rotation to generate a dust removal airflow;   an electric motor for providing a power source for the airflow element;   a battery pack for providing an energy source for the electric motor; and   a housing configured to accommodate the airflow element and guide the dust removal airflow generated by the airflow element;   wherein the housing comprises an upper sidewall and a lower sidewall opposite to the upper sidewall, a distance from the lower sidewall to the upper sidewall along a direction of the central axis is defined as a third distance D3, and the third distance D3 gradually increases along the preset direction of rotation.