Provided are a maintenance-free gas density relay and a mutual check method therefor. The maintenance-free gas density relay includes a gas density relay body and first gas density detection sensors which are in communication on gas paths, and an intelligent control unit connected to the gas density relay body and the first gas density detection sensors separately, where the intelligent control unit compares and checks a first pressure value and a second pressure value acquired at the same gas pressure, and/or compares and checks a first temperature value and a second temperature value acquired at the same gas temperature, or compares and checks a first density value and a second density value acquired at the same gas density, and can further upload received data to a background for data comparison by the background. The present disclosure further completes online self-check or mutual check of the gas density relay while being used for monitoring gas density of a gas-insulated or arc-control electrical apparatus, thereby improving efficiency, avoiding maintenance, reducing cost, and ensuring safe operation of a power grid.

An inhibitor switch is provided. The inhibitor switch includes a housing having a rotor accommodation space and a Hall element accommodation space, a rotor disposed in the rotor accommodation space, and a magnet disposed on an outer circumferential surface of the rotor. A Hall element is disposed in the Hall element accommodation space and spaced apart horizontally from the magnet with a sensing surface facing an outer circumferential surface of the magnet. Further, the inhibitor switch include a cover configured to block an opening of the rotor accommodation space to prevent the rotor from being released.

A preassembled gear shift module is adapted to be connected to a substructure. The preassembled gear shift module includes a cover assembly, a circuit board, and a function button. The circuit board is attached to the cover assembly, and includes a switch. The function button is exposed through the cover assembly, and is operably connected to the switch.

An inhibitor switch is attached to a manual shaft with a jig. The jig includes a fitting part and an engagement pin. The fitting part is spline-fitted to an outer periphery of the manual shaft. The engagement pin engages in a positioning hole of the inhibitor switch. The outer periphery of the manual shaft includes a tooth-omitted part formed by omitting at least one of spline teeth. The fitting part includes an insertion hole. The insertion hole includes an inner periphery including internal teeth and an engaging part, wherein the internal teeth meshes with the spline teeth, and wherein the engaging part engages with the tooth-omitted part. The jig is attached to the manual shaft with the engaging part engaged with the tooth-omitted part. The inhibitor switch is rotated about the rotation axis to a position allowing engagement of the positioning hole with the engagement pin.

A transmission shifter includes a base defining P, R, N, D gear positions; four electrical dome switches associated with each of the P, R, N, D gear positions, and analog and digital circuits operably connected to the electrical switches, respectively, and associated with the P, R, N, D gear positions. The dome switches are arranged in different patterns in each of the different gear positions, and in combination with pushbutton actuators operate with different actuator motions and with different closure distances and forces to cause reliable ad confirmed intentional actuation, including redundancy. The switches are operably connected to analog and digital circuits, which provides additional functional advantage, reliability, and certainty of intentional operation.

A switch may include a movable board and a pole board having an inner surface on which a fixed contact point is exposed, the inner surface facing the movable board. A movable contact point may be supported by the movable board and may include a plurality of contact pieces making resilient contact with the inner surface of the pole board. The switch may also include an output terminal corresponding to the fixed contact point. The movable contact point and the fixed contact point may come in contact with each other when a position of the movable contact point is changed via a displacement of the movable board. The fixed contact point and the output terminal may be connected via a board having a disconnection detection circuit. The board may be enclosed in an insulating seal material.

An inhibitor switch is attached to a manual shaft with a jig. The jig includes a fitting part and an engagement pin. The fitting part is spline-fitted to an outer periphery of the manual shaft. The engagement pin engages in a positioning hole of the inhibitor switch. The outer periphery of the manual shaft includes a tooth-omitted part formed by omitting at least one of spline teeth. The fitting part includes an insertion hole. The insertion hole includes an inner periphery including internal teeth and an engaging part, wherein the internal teeth meshes with the spline teeth, and wherein the engaging part engages with the tooth-omitted part. The jig is attached to the manual shaft with the engaging part engaged with the tooth-omitted part. The inhibitor switch is rotated about the rotation axis to a position allowing engagement of the positioning hole with the engagement pin.

A preassembled gear shift module is adapted to be connected to a substructure. The preassembled gear shift module includes a cover assembly, a circuit board, and a function button. The circuit board is attached to the cover assembly, and includes a switch. The function button is exposed through the cover assembly, and is operably connected to the switch.

A transmission shifter includes a base defining P, R, N, D gear positions; four electrical dome switches associated with each of the P, R, N, D gear positions, and analog and digital circuits operably connected to the electrical switches, respectively, and associated with the P, R, N, D gear positions. The dome switches are arranged in different patterns in each of the different gear positions, and in combination with pushbutton actuators operate with different actuator motions and with different closure distances and forces to cause reliable ad confirmed intentional actuation, including redundancy. The switches are operably connected to analog and digital circuits, which provides additional functional advantage, reliability, and certainty of intentional operation.

An inhibitor switch is provided. The inhibitor switch includes a housing having a rotor accommodation space and a Hall element accommodation space, a rotor disposed in the rotor accommodation space, and a magnet disposed on an outer circumferential surface of the rotor. A Hall element is disposed in the Hall element accommodation space and spaced apart horizontally from the magnet with a sensing surface facing an outer circumferential surface of the magnet. Further, the inhibitor switch include a cover configured to block an opening of the rotor accommodation space to prevent the rotor from being released.