A compressor comprising: a shell; a first compression mechanism disposed within the shell and including a first compression member that is rotatable relative to the shell about a first rotational axis and a second compression member that is rotatable relative to the shell about a second rotational axis that is parallel to and offset from the first rotational axis; a first bearing housing fixed relative to the shell and rotatably supporting a first hub of the first compression member; a second bearing housing fixed relative to the shell and rotatably supporting a second hub of the second compression member; a first motor assembly disposed between the first and second bearing housings (14, 16) and including a first rotor attached to the first compression member; characterised by: a second compression mechanism disposed within the shell and including a third compression member that is rotatable relative to the shell about a third rotational axis and a fourth compression member that is rotatable relative to the shell about a fourth rotational axis that is parallel to and offset from the third rotational axis, the fourth compression member including a fourth hub that is rotatably supported by the second bearing housing; a third bearing housing fixed relative to the shell and rotatably supporting a third hub of the third compression member; and a second motor assembly disposed between the second and third bearing housings (16, 21) and including a second rotor attached to the third compression member. a shell; a first compression mechanism disposed within the shell and including a first compression member that is rotatable relative to the shell about a first rotational axis and a second compression member that is rotatable relative to the shell about a second rotational axis that is parallel to and offset from the first rotational axis; a first bearing housing fixed relative to the shell and rotatably supporting a first hub of the first compression member; a second bearing housing fixed relative to the shell and rotatably supporting a second hub of the second compression member; a first motor assembly disposed between the first and second bearing housings (14, 16) and including a first rotor attached to the first compression member; characterised by: a second compression mechanism disposed within the shell and including a third compression member that is rotatable relative to the shell about a third rotational axis and a fourth compression member that is rotatable relative to the shell about a fourth rotational axis that is parallel to and offset from the third rotational axis, the fourth compression member including a fourth hub that is rotatably supported by the second bearing housing; a third bearing housing fixed relative to the shell and rotatably supporting a third hub of the third compression member; and a second motor assembly disposed between the second and third bearing housings (16, 21) and including a second rotor attached to the third compression member. a second compression mechanism disposed within the shell and including a third compression member that is rotatable relative to the shell about a third rotational axis and a fourth compression member that is rotatable relative to the shell about a fourth rotational axis that is parallel to and offset from the third rotational axis, the fourth compression member including a fourth hub that is rotatably supported by the second bearing housing; a third bearing housing fixed relative to the shell and rotatably supporting a third hub of the third compression member; and a second motor assembly disposed between the second and third bearing housings (16, 21) and including a second rotor attached to the third compression member.