| 摘要 |
PURPOSE:To aim at enhancing the durability of seal members, by forming a communication hole for communicating between a fluid pressure source and a tire pneumatic chamber, in an axle, and by sealing up the opening end of the communication hole at the outer peripheral surface of the axle with the use of a fluid pressure seal member which is extended and retracted by the internal fluid pressure. CONSTITUTION:When the pressure 39 in a tire pneumatic chamber is at an appropruate value during stoppage of an engine, a solenoid changeover valve 38 closes an air pipe 24, and a solenoid changeover valve 40 communicates a fluid pipe line 23. Accordingly, the pressure in a tire pneumatic pressure chamber 7 acts upon fluid chambers 19 in fluid pressure seal members 17, 18 through a peircing hole 8, a through-hole 9, an air-gap 25, an air pipe line 24 and a fluid pipe line 23 to inflate the seal members 17, 18 so that they fasten an axle 2 to seal up the same. When the engine is driven, the solenoid changeover switch communicates the fluid pipe line 23 to the discharge side to allow a fluid chamber 19 to open to the atmospheric air, and therefore, the seal members 17, 18 deflate to decrease their fastening force. With this arrangement, the abrasion of the seal members may be reduced thereby it is possible to enhance the durability thereof. |
