Input device assemblies for robotic surgical systems

A torque transducer for mounting a motor, comprising:

• a motor plate configured to be fixed to the motor;
• a mounting plate configured to be fixed to a fixed structure;
• and
• a flex ring interconnecting the motor plate and the mounting plate, the flex ring including:
• a first member having a first portion fixed to the motor plate and a second portion fixed to the mounting plate;
• a second member having a first segment fixed to the motor plate and a second segment fixed to the mounting plate;
• and
• an active strain gauge positioned on the first member between the first and second portions, the active strain gauge configured to measure flexation of the first member in response to the first portion moving relative to the second portion.

An drive unit comprising:

• a fixed structure;
• a first motor having a drive shaft passing through the fixed structure;
• and
• a first torque transducer mounting the first motor to the fixed structure, the first torque transducer including:
• a motor plate fixed to the first motor;
• a mounting plate fixed to fixed structure;
• and
• a flex ring interconnecting the motor plate and the mounting plate, the flex ring including:
• a first member having a first portion fixed to the motor plate and a second portion fixed to the mounting plate;
• a second member having a first segment fixed to the motor plate and a second segment fixed to the mounting plate;
• and
• an active strain gauge positioned on the first member between the first and second portions, the active strain gauge configured to measure flexation of the first member in response to the first portion moving relative to the second portion.

A torque transducer for mounting a motor, comprising:

• a motor ring configured to be fixed to the motor;
• a mounting ring configured to be fixed to a fixed structure;
• and
• a flex ring interconnecting the motor ring and the mounting ring, the flex ring disposed about a longitudinal axis of the torque transducer that extends through the motor ring, mounting ring, and the flex ring, the flex ring including:
• a first member extending in a direction parallel to the longitudinal axis from a first portion fixed to the motor ring to a second portion fixed to the mounting ring;
• and
• an active strain gauge positioned on the first member between the first and second portions, the active strain gauge configured to measure flexation of the first member in response to the first portion moving relative to the second portion.