A ball-hinged transmission shaft with a straight shaft includes a socket, a ball, and a straight shaft. A rolling element is further coaxially provided on a straight shaft. The rolling element is a rotator with an axis of the straight shaft as a center of rotation. An upper portion of the rolling element is connected to a bearing. A mouth-shaped surface is further respectively provided at two ends of a transmission hole of a ball. The mouth-shaped surface is a curved surface matching the shape of the rolling element. The rolling element is fit and provided in the mouth-shaped surface at the two ends of the transmission hole of the ball. The ball is restricted by an inner positioning spherical surface of a socket, the straight shaft, and the rolling element at the same time.

A ball-hinged transmission shaft with a straight shaft includes a socket, a ball, and a straight shaft. A rolling element is further coaxially provided on a straight shaft. The rolling element is a rotator with an axis of the straight shaft as a center of rotation. An upper portion of the rolling element is connected to a bearing. A mouth-shaped surface is further respectively provided at two ends of a transmission hole of a ball. The mouth-shaped surface is a curved surface matching the shape of the rolling element. The rolling element is fit and provided in the mouth-shaped surface at the two ends of the transmission hole of the ball. The ball is restricted by an inner positioning spherical surface of a socket, the straight shaft, and the rolling element at the same time.

A coupling (1,2) has an inner member (111) and an outer annular member (131) and an intermediate annular member (121) which when aligned share a common axis and have a common centre on the common axis. The inner and the intermediate annular member are constrained to rotate, one with respect to the other about a second axis perpendicular to the common axis. The intermediate annular member and the outer annular member are constrained to rotate, one with respect to the other about a third axis (Z) perpendicular to the common axis (X) and the second axis (Y). The members are spaced apart to leave a gap (103) between each of the members.

A coupling (1,2) has an inner member (111) and an outer annular member (131) and an intermediate annular member (121) which when aligned share a common axis and have a common centre on the common axis. The inner and the intermediate annular member are constrained to rotate, one with respect to the other about a second axis perpendicular to the common axis. The intermediate annular member and the outer annular member are constrained to rotate, one with respect to the other about a third axis (Z) perpendicular to the common axis (X) and the second axis (Y). The members are spaced apart to leave a gap (103) between each of the members.

A drive transmission device includes a first rotary body coupled to a drive source, a second rotary body that receives a drive force transmitted from the drive source, a coupling that couples the first rotary body and the second rotary body, and a spring that presses the coupling toward the second rotary body. Each of the first rotary body and the second rotary body includes a plurality of grooves. The coupling has axially opposed first end and second end coupled to the first rotary body and the second rotary body, respectively. The coupling includes a plurality of couplers on a circumferential surface of each of the first end and the second end. The plurality of couplers are axially movable into and out of the plurality of grooves of each of the first rotary body and the second rotary body. The coupling has a spherical end face at the second end.

A ball-type constant velocity joint may include: an outer race part installed on a shaft and having a plurality of first grooves formed axially in the inner surface thereof; a first inner race part including: a first inner race rotatably installed in the outer race part, having a plurality of second grooves formed on the outer surface thereof, and having a plurality of third grooves formed axially on the inner surface thereof; and a plurality of first balls installed between the first grooves and the second grooves; and a second inner race part including: a second inner race rotatably installed in the first inner race, and having a plurality of fourth grooves formed on the outer surface thereof and facing the third grooves; and a plurality of second balls installed between the third grooves and the fourth grooves.

A connecting arrangement for connecting two parts (1, 5) by way of two connected sockets (2, 4), wherein parts and sockets have rotationally symmetrical engagement regions, not exceeding 180°, about engagement axes (11, 15 or 12, 14), which engagement regions are complementary between one part and one socket each, wherein one socket is rotated into one part each, and the complementary engagement regions hold the part on its socket so as to be pivotable about the respective aligned engagement axes and so as to withstand tensions in the direction of a zenith axis of the parts (10 or 16), and in that, after the parts and socket pairs are rotated into engagement and positioned with respect to each other, the sockets (2, 4) are connected to each other, the connection being rotationally and tensionally stiff with respect to the direction of the zenith axes.

A ball-hinged transmission shaft with a straight shaft includes a socket, a ball, and a straight shaft. A rolling element is further coaxially provided on a straight shaft. The rolling element is a rotator with an axis of the straight shaft as a center of rotation. An upper portion of the rolling element is connected to a bearing. A mouth-shaped surface is further respectively provided at two ends of a transmission hole of a ball. The mouth-shaped surface is a curved surface matching the shape of the rolling element. The rolling element is fit and provided in the mouth-shaped surface at the two ends of the transmission hole of the ball. The ball is restricted by an inner positioning spherical surface of a socket, the straight shaft, and the rolling element at the same time.

A ball-hinged transmission shaft with a straight shaft includes a socket, a ball, and a straight shaft. A rolling element is further coaxially provided on a straight shaft. The rolling element is a rotator with an axis of the straight shaft as a center of rotation. An upper portion of the rolling element is connected to a bearing. A mouth-shaped surface is further respectively provided at two ends of a transmission hole of a ball. The mouth-shaped surface is a curved surface matching the shape of the rolling element. The rolling element is fit and provided in the mouth-shaped surface at the two ends of the transmission hole of the ball. The ball is restricted by an inner positioning spherical surface of a socket, the straight shaft, and the rolling element at the same time.

The torque transmission shaft has a shaft having a hollow tubular shape and a clamp. The shaft has a connecting portion integral with the shaft at one axial end portion, a slit extending in the axial direction in a portion on the other axial end side and opens on the other side in the axial direction, and a female serration on the inner circumferential surface of the other axial end portion. The clamp is separate from the shaft and has a non-continuous portion at one location in the circumferential direction, a pair of flange portions on both sides of the non-continuous portion, and a connecting portion connecting the pair of flange portions in the circumferential direction. The clamp is externally fitted and fixed to the other axial end portion of the shaft and reduces the diameter of the other axial end side portion of the shaft.