Reduction unit, arm joint provided with two or three reduction units respectively, and a robot arm

A robot arm comprising:

• a first arm joint;
• a second arm joint;
• a third arm joint;
• a coupling arm part connected to an external object;
• an upper arm part;
• a lower arm part;
• the first arm joint comprising:
• a first coupling part connected in a manner rotatable around a first axis with the coupling arm part;
• a second coupling part connectable in a manner rotatable around a second axis or fixedly with a first end of the upper arm part;
• a third coupling part connected in a manner rotatable around a third axis with the first coupling part, wherein the third axis includes an angle with the first axis in the range of 30-60 degrees, wherein the third coupling part is connected in a manner rotatable around a fourth axis with the second coupling part, wherein the fourth axis includes an angle with the second axis in the range of 30-60 degrees, and wherein the third and the fourth axis mutually include an angle in the range of 60-120 degrees;
• and
• a first drive assembly configured to energize the rotation of the first coupling part around the third axis with respect to the third coupling part, the first drive assembly being configured to energize the rotation of the second coupling part around the fourth axis with respect to the third coupling part,
• wherein the first drive assembly is configured such that the rotations of the first and the second coupling part with respect to the third coupling part are energizable independently of each other;
• the second arm joint comprising:
• a fourth coupling part connected in a manner rotatable around a fifth axis with a second end of the upper arm part;
• a fifth coupling part connectable in a manner rotatable around a sixth axis or fixedly with a first end of the lower arm part;
• a sixth coupling part connected in a manner rotatable around a seventh axis with the fourth coupling part, wherein the seventh axis includes an angle with the fifth axis in the range of 30-60 degrees, wherein the sixth coupling part is connected in a manner rotatable around a eighth axis with the fifth coupling part, wherein the eighth axis includes an angle with the sixth axis in the range of 30-60 degrees, and wherein the seventh and the eighth axis mutually include an angle in the range of 60-120 degrees;
• and
• a second drive assembly configured to energize the rotation of the fourth coupling part around the seventh axis with respect to the sixth coupling part, the second drive assembly being configured to energize the rotation of the fifth coupling part around the eighth axis with respect to the sixth coupling part,
• wherein the second drive assembly is configured such that the rotations of the fourth and the fifth coupling part with respect to the sixth coupling part are energizable independently of each other;
• the third arm joint comprising:
• a seventh coupling part connected in a manner rotatable around an ninth axis with a second end of the lower arm part;
• an eighth coupling part connectable in a manner rotatable around a tenth axis or fixedly with a first end of a gripper;
• a ninth coupling part connected in a manner rotatable around a eleventh axis with the seventh coupling part, wherein the eleventh axis includes an angle with the ninth axis in the range of 30-60 degrees, wherein the ninth coupling part is connected in a manner rotatable around a twelfth axis with the eighth coupling part, wherein the twelfth axis includes an angle with the tenth axis in the range of 30-60 degrees, and wherein the eleventh and the twelfth axis mutually include an angle in the range of 60-120 degrees;
• and
• a third drive assembly configured to energize the rotation of the seventh coupling part around the eleventh axis with respect to the ninth coupling part, the second drive assembly being configured to energize the rotation of the eighth coupling part around the twelfth axis with respect to the ninth coupling part,
• wherein the third drive assembly is configured such that the rotations of the seventh and the eighth coupling part with respect to the ninth coupling part are energizable independently of each other.