A motor assembly comprising: a motor comprising: a stator including a coil holding portion and a doughnut-shaped first portion , the coil holding portion holding a coil , the doughnut-shaped first portion extending radially outward from the coil holding portion; and a rotor including a magnet and a magnet holding portion that holds the magnet, wherein the magnet holding portion is located in a first space (S11) having an annular shape and located radially outside the coil holding portion, the doughnut-shaped first portion has a first surface that is in contact with the first space (S11), and a second surface , opposite to the first surface in a rotation axis direction (CA1), that is not in contact with the first surface, and in the first portion, a through hole penetrating from the first surface to the second surface is formed, a sealing member disposed on a side of the stator opposite to the rotor in the rotation axis direction (CA1); and a frame to which the motor and the sealing member are fixed, wherein the sealing member is fixed to the frame in such a way that a second space (S12) between the sealing member and the stator does not communicate with an external space (S3) other than the first space (S11). a motor comprising: a stator including a coil holding portion and a doughnut-shaped first portion , the coil holding portion holding a coil , the doughnut-shaped first portion extending radially outward from the coil holding portion; and a rotor including a magnet and a magnet holding portion that holds the magnet, wherein the magnet holding portion is located in a first space (S11) having an annular shape and located radially outside the coil holding portion, the doughnut-shaped first portion has a first surface that is in contact with the first space (S11), and a second surface , opposite to the first surface in a rotation axis direction (CA1), that is not in contact with the first surface, and in the first portion, a through hole penetrating from the first surface to the second surface is formed, a stator including a coil holding portion and a doughnut-shaped first portion , the coil holding portion holding a coil , the doughnut-shaped first portion extending radially outward from the coil holding portion; and a rotor including a magnet and a magnet holding portion that holds the magnet, wherein the magnet holding portion is located in a first space (S11) having an annular shape and located radially outside the coil holding portion, the doughnut-shaped first portion has a first surface that is in contact with the first space (S11), and a second surface , opposite to the first surface in a rotation axis direction (CA1), that is not in contact with the first surface, and in the first portion, a through hole penetrating from the first surface to the second surface is formed, a sealing member disposed on a side of the stator opposite to the rotor in the rotation axis direction (CA1); and a frame to which the motor and the sealing member are fixed, wherein the sealing member is fixed to the frame in such a way that a second space (S12) between the sealing member and the stator does not communicate with an external space (S3) other than the first space (S11). <EOS>