Robotic arm

A robotic arm, comprising:

• a first arm unit having a first end portion and a second end portion;
• a second arm unit having a first end portion and a second end portion;
• wherein the first end portion of the second arm unit and the second end portion of the first arm unit are pivotally connected to each other;
• a first screw rod rotatably arranged within the first arm unit and extending from the first end portion of the first arm unit and along a lengthwise direction of the first arm unit;
• a first guider screwed at the first screw rod;
• a first drive plate rotatably disposed within the first arm unit and adjacent to the first end portion of the first arm unit;
• a second drive plate fixedly connected to the first end portion of the second arm unit and pivotally connected to the second end portion of the first arm unit;
• a first transmission component connecting to the first guider, the first drive plate and the second drive plate;
• wherein the first guider moves along the first screw rod when the first screw rod is rotated;
• and wherein a linear motion of the first guider drives the first transmission component and then a motion of the first transmission component drives the first and second drive plates to be rotated such that the second arm unit rotates relative to the first arm unit;
• wherein the second arm unit further comprises a stem, wherein a first end of the stem passes through a shaft hole of the first end portion of the second arm unit and extends into the first end portion of the second arm unit and a second end of the stem is connected to the second end portion of the second arm unit, and wherein the stem axially rotates relative the first end portion of the second arm unit;
• a second screw rod rotatably arranged within the first arm unit and extending from the first end portion of the first arm unit and along the lengthwise direction of the first arm unit;
• a second guider screwed at the second screw rod;
• a third drive plate rotatably disposed within the first arm unit and adjacent to the first end portion of the first arm unit;
• a fourth drive plate rotatably pivotally connected to the second end portion of the first arm unit and first end portion of the second arm unit;
• a first gear integrated with the fourth drive plate;
• a second gear connecting to the first end of the stem, which is arranged within the first end portion of the second arm unit, and engaging with the first gear;
• a second transmission component connecting to the second guider, the third drive plate and the fourth drive plate;
• wherein the second guider moves along the second screw rod when the second screw rod is rotated;
• and wherein a linear motion of the second guider drives the second transmission component and then a motion of the second transmission component drives the third and fourth drive plates to be rotated such that the first gear integrated with the fourth drive plate drives the second gear connected to the first end of the stem of the second arm unit to be rotated and the second arm unit axially rotates relative to the first arm unit;
• a third arm unit, wherein one end portion of the third unit and the second end portion of the second arm unit are pivotally connected to each other;
• a third screw rod rotatably arranged within the first arm unit and extending from the first end portion of the first arm unit and along a lengthwise direction of the first arm unit;
• a third guider screwed at the third screw rod;
• a fifth drive plate rotatably disposed within the first arm unit and adjacent to the first end portion of the first arm unit;
• a sixth drive plate fixedly connected to the first end portion of the third arm unit and pivotally connected to the second end portion of the first arm unit;
• and
• a third transmission component connecting to the third guider, the fifth drive plate and the sixth drive plate;
• wherein the third guider moves along the third screw rod when the third screw rod is rotated;
• and wherein a linear motion of the third guider drives the third transmission component and then a motion of the third transmission component drives the fifth and sixth drive plates to be rotated such that the third arm unit pivotally rotates relative to the second arm unit.