A pressure reducer valve includes a first chamber having a first spring and a first volume for receiving an output fluid having an actual output pressure that equals the desired output pressure in response to the pressure reducer valve achieving equilibrium and a second chamber having a second spring and a second volume for receiving a return fluid having a return pressure that is less than the desired output pressure and the input pressure of an input fluid. The pressure reducer valve further includes a main shaft exposed to the first spring and the output fluid from the first chamber and the second spring and the return fluid from the second chamber such that the main shaft may move relative to the first chamber and the second chamber based on forces applied by the first spring, the output fluid, the second spring, and the return fluid.

An outboard wheel half has an axis and includes an outboard wheel structure configured to receive at least a portion of a tire. The outboard wheel half also includes a structure defining an alignment hole usable to align a hubcap relative to the structure. The structure defines a pocket circumferentially aligned with the alignment hole to reduce an amount of stress at a location of the alignment hole.

An improved structure of an energy-saving precision pressure adjusting valve includes a main body in an interior of which a main membrane and a balance membrane are arranged. The main membrane is operable by an overflow tube and the balance membrane is operable by a pressure-adjusting stein, so that when pneumatic fluid enters the main body, through a channel, a feedback channel and a pressure regulation channel that communicate with each other, together with a feedback channel flow regulation hole and a steel ball arranged in the feedback channel, the pneumatic fluid is allowed to flow in one direction, in combination with stein covering rubber provided on the pressure-adjusting stein and membrane covering rubber provided on the main membrane, the flowing of the pneumatic fluid is made faster and the purpose of fast increase and decrease of pressure and high precision pressure output can be achieved.