Transmission system comprising: - a main housing; - a first base portion which is rotatable relative to the main housing about a first rotation axis (A r1) which is stationary relative to the main housing; - a second base portion which is rotatable about a second rotation axis (A r2) and pivotal about a pivot point which is stationary relative to the main housing, the second rotation axis (A r2) maintaining a stationary orientation relative to the second base portion during pivoting of the second base portion about the pivot point; - a coupling arrangement coupled to the first base portion and to the second base portion such as to convert a rotation of the first base portion about the first rotation axis (A r1) into a rotation of the second base portion about the second rotation axis (A r2); wherein: - the coupling arrangement comprises N coupling portions which are each coupled to the first base portion, at least in a tangential direction relative to the first rotation axis (A r1), in a respective one of N first coupling positions (C 1) on the first base portion, and which are each coupled to the second base portion, at least in a tangential direction relative to the second rotation axis (A r2), in a respective one of N second coupling positions (C 2) on the second base portion, wherein N is at least two; - the N first coupling positions (C 1) have equal axial positions in a direction parallel to the first rotation axis (A r1), a first center point (B c1) of the first base portion being located on the first rotation axis (A r1) in a position corresponding to said axial positions of the N first coupling positions (C 1); - the N second coupling positions (C 2) have equal axial positions in a direction parallel to the second rotation axis (A r2), a second center point (B c2) of the second base portion being located on the second rotation axis (A r2) in a position corresponding to said axial positions of the N second coupling positions (C 2); - a central axis (A c) of the coupling arrangement extends through the first and second center points (B c1, B c2); and - the coupling portions are mutually coupled such that the coupling portions are displaceable relative to each other only in an axial direction of the central axis (A c). - a main housing; - a first base portion which is rotatable relative to the main housing about a first rotation axis (A r1) which is stationary relative to the main housing; - a second base portion which is rotatable about a second rotation axis (A r2) and pivotal about a pivot point which is stationary relative to the main housing, the second rotation axis (A r2) maintaining a stationary orientation relative to the second base portion during pivoting of the second base portion about the pivot point; - a coupling arrangement coupled to the first base portion and to the second base portion such as to convert a rotation of the first base portion about the first rotation axis (A r1) into a rotation of the second base portion about the second rotation axis (A r2); - the coupling arrangement comprises N coupling portions which are each coupled to the first base portion, at least in a tangential direction relative to the first rotation axis (A r1), in a respective one of N first coupling positions (C 1) on the first base portion, and which are each coupled to the second base portion, at least in a tangential direction relative to the second rotation axis (A r2), in a respective one of N second coupling positions (C 2) on the second base portion, wherein N is at least two; - the N first coupling positions (C 1) have equal axial positions in a direction parallel to the first rotation axis (A r1), a first center point (B c1) of the first base portion being located on the first rotation axis (A r1) in a position corresponding to said axial positions of the N first coupling positions (C 1); - the N second coupling positions (C 2) have equal axial positions in a direction parallel to the second rotation axis (A r2), a second center point (B c2) of the second base portion being located on the second rotation axis (A r2) in a position corresponding to said axial positions of the N second coupling positions (C 2); - a central axis (A c) of the coupling arrangement extends through the first and second center points (B c1, B c2); and - the coupling portions are mutually coupled such that the coupling portions are displaceable relative to each other only in an axial direction of the central axis (A c).