Abstract: The heat exchange module is used in the cabinet that includes a cabinet body. The cabinet body has a first space and a second space. A temperature of the first space is higher than a temperature of the second space. The heat exchange module has a first air circulation system and a second air circulation system, and heat exchange may be performed between the first air circulation system and the second air circulation system. Both an air intake vent and an air exhaust vent of the first air circulation system are configured to be connected to the first space. An air exhaust vent of the second air circulation system is connected to an external space, and an air intake vent of the second air circulation system can be configured to be selectively connected to the external space and/or the second space.

Abstract: A fan includes an impeller rotating on a central axis, an impeller housing, a motor located on one side in an axial direction of the impeller and driving the impeller to rotate, and a motor housing. The impeller housing is provided with an air inlet. The fan further includes a pre-pressing portion expanding radially inward from an edge of the air inlet. The pre-pressing portion includes a pressing portion located on another side in the axial direction of the impeller and pressing, from the another side in the axial direction, an end portion of the impeller on the another side in the axial direction, and at least two connection portions connected between an outer periphery of the pressing portion and the edge of the air inlet. The connection portions are disposed obliquely with respect to the axial direction.

Abstract: A fan includes an impeller rotating on a central axis, an impeller housing, a motor located on one side in an axial direction of the impeller and driving the impeller to rotate, and a motor housing. The impeller housing is provided with an air inlet. The fan further includes a pre-pressing portion expanding radially inward from an edge of the air inlet. The pre-pressing portion includes a pressing portion located on another side in the axial direction of the impeller and pressing, from the another side in the axial direction, an end portion of the impeller on the another side in the axial direction, and at least two connection portions connected between an outer periphery of the pressing portion and the edge of the air inlet. The connection portions are disposed obliquely with respect to the axial direction.

Abstract: A gear assembly includes an upper cover and a lower cover, a stator fixed to the lower cover, a rotor opposite to the stator and including a rotary shaft and magnet, a main gear fixed to the rotary shaft and rotating along with the rotary shaft, and a helical gear engaged with the main gear, the main gear and the helical gear being both received in the cover member, the upper cover including a boss portion with a recess receiving a tip of the rotary shaft. The rotor is axially movable and when the rotary shaft stops rotating, the tip of the rotary shaft is in the recess of the boss portion, and when the rotary shaft rotates, the helical gear applies a force on the main gear, and the tip of the rotary shaft is disengaged from the recess of the boss portion.

Abstract: A gear assembly includes an upper cover and a lower cover, a stator fixed to the lower cover, a rotor opposite to the stator and including a rotary shaft and magnet, a main gear fixed to the rotary shaft and rotating along with the rotary shaft, and a helical gear engaged with the main gear, the main gear and the helical gear being both received in the cover member, the upper cover including a boss portion with a recess receiving a tip of the rotary shaft. The rotor is axially movable and when the rotary shaft stops rotating, the tip of the rotary shaft is in the recess of the boss portion, and when the rotary shaft rotates, the helical gear applies a force on the main gear, and the tip of the rotary shaft is disengaged from the recess of the boss portion.

Abstract: The illuminating projectile and projectile tail includes housing, a battery, and a light and lights up upon impact with a target.

Abstract: The illuminating projectile and projectile tail includes housing, a battery, and a light and lights up upon impact with a target.