A robot comprising: an articulated arm ; and a base unit to which the articulated arm is operably coupled, the base unit comprising: a base ; a rotating portion ; an actuator configured to rotate the rotating portion about a first axis (Ax1), wherein the actuator comprises a body attached to the rotating portion and an output shaft protruding from the body , wherein the body comprises a motor and a speed reducer configured to transmit a rotation of the motor to the output shaft to rotate the output shaft about the first axis (Ax1), wherein the output shaft , the speed reducer , and the motor are aligned along the first axis (Ax1), and wherein the output shaft passes through the rotating portion and is attached to the base ; an arm connector located at a first portion (P1) of the rotating portion , wherein the articulated arm is connected to the arm connector to swing about a second axis (Ax2); and a rib straddling the actuator in a plane including the first axis (Ax1) and connecting the arm connector to a second portion (P2) of the rotating portion , wherein the actuator is located between the first portion (P1) and the second portion (P2) of the rotating portion . an articulated arm ; and a base unit to which the articulated arm is operably coupled, the base unit comprising: a base ; a rotating portion ; an actuator configured to rotate the rotating portion about a first axis (Ax1), wherein the actuator comprises a body attached to the rotating portion and an output shaft protruding from the body , wherein the body comprises a motor and a speed reducer configured to transmit a rotation of the motor to the output shaft to rotate the output shaft about the first axis (Ax1), wherein the output shaft , the speed reducer , and the motor are aligned along the first axis (Ax1), and wherein the output shaft passes through the rotating portion and is attached to the base ; an arm connector located at a first portion (P1) of the rotating portion , wherein the articulated arm is connected to the arm connector to swing about a second axis (Ax2); and a rib straddling the actuator in a plane including the first axis (Ax1) and connecting the arm connector to a second portion (P2) of the rotating portion , wherein the actuator is located between the first portion (P1) and the second portion (P2) of the rotating portion . a base ; a rotating portion ; an actuator configured to rotate the rotating portion about a first axis (Ax1), wherein the actuator comprises a body attached to the rotating portion and an output shaft protruding from the body , wherein the body comprises a motor and a speed reducer configured to transmit a rotation of the motor to the output shaft to rotate the output shaft about the first axis (Ax1), wherein the output shaft , the speed reducer , and the motor are aligned along the first axis (Ax1), and wherein the output shaft passes through the rotating portion and is attached to the base ; an arm connector located at a first portion (P1) of the rotating portion , wherein the articulated arm is connected to the arm connector to swing about a second axis (Ax2); and a rib straddling the actuator in a plane including the first axis (Ax1) and connecting the arm connector to a second portion (P2) of the rotating portion , wherein the actuator is located between the first portion (P1) and the second portion (P2) of the rotating portion . <EOS>