In the existing withdrawable switchgear, in order to enable a breaker to implement an advancement and withdrawal function conveniently (the advancement refers to advancement from a testing position to a work position, and the withdrawal refers to withdrawal from the work position to the testing position), a chassis is typically used for carrying elements, such as a breaker and the like, and moves forwards and backwards on a track within the switchgear by wheels mounted on the chassis.
In order to move the chassis within the switchgear, a manual operation mechanism is used in most of the current common chassis, i.e., a lead screw is provided on the chassis, a nut fixed on a chassis bracket is arranged on the lead screw, an end of which is sleeved with a handle, the handle is used to drive the lead screw to rotate, such that the screw nut drives the chassis to move forwards and backwards, thereby implementing advancement and withdrawal of the breaker chassis. Due to a manual manner of operating the handle manually, the manual chassis has deficiencies, such as a low work efficiency, laborious operations, inconvenience for a remote operation and the like, which cannot tally with the development of the power automation.
An electric chassis is developed to reduce the operation workload of the substation operation workload, improve the unattended ability of the power system, and implement the advancement and withdrawal of the breaker electrically and remotely. In the existing electric chassis, a motor, a transmission device, a clutch and a lead screw are mounted on the chassis, the motor and the transmission device are connected to the clutch, and the other end of the clutch is connected to the lead screw. The advancement and withdrawal of the chassis are controlled by positive and reversal rotation of the motor, so as to implement motorization and automation of the movement of the chassis. In the prior art, a worm gear mechanism is typically used in a transmission device to drive a sprocket shaft to rotate and further drive the lead screw to rotate. Such transmission manner using a worm gear leads to that the axis of the motor is necessarily perpendicular to the axis of the sprocket shaft. In addition, due to a limited volume of the switchgear, the transmission and clutch device of the electric chassis cannot be designed with an exceedingly large size. However, the existing electric and manual transmission and clutch devices can hardly be modularized and standardized due to a great number of parts, a complicated structure, a strict requirement on processing precision, a large occupancy space, and complicated mounting maintenance.
Hence, for the breaker electric chassis, there arises a problem to be solved in the art, i.e., how to reliably implement transmission and clutch while satisfying the space requirements.