How to install the drive shaft

Abstract

To provide an assembling method of a drive shaft which can suppress the impairment of a bellows shape caused by the expansion of a boot in a vacuum environment.SOLUTION: An assembling method of a drive shaft of the present invention has: a step for connecting a grease filling device to a filling port arranged at a constant velocity joint so as to communicate with the inside of an outer race; a step for bringing a boot and a periphery of the boot into a vacuum state in a state that a bleeding port for bleeding air from the inside of the boot to the constant velocity joint is opened; a step for filling grease into the boot from the filling port by the grease filling device; a step for blocking the air bleeding port; a step for returning the peripheral pressure of the boot to atmospheric pressure, and releasing the connection of the filling port and the grease filling device; and a step for blocking the filling port.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for assembling a drive shaft. [Background technology]

[0002] Patent Document 1 discloses a technique for assembling a boot to a shaft and an outer race of a constant velocity joint using a boot assembling jig. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-122414 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology disclosed in Patent Document 1, when grease is filled into the boot, air is sealed in along with the grease, so in a vacuum environment such as the lunar surface, the boot will expand together with the air, which could damage the bellows shape of the boot.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a method for assembling a drive shaft that can prevent the boot from expanding in a vacuum environment and damaging the bellows shape. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a method of assembling a drive shaft according to the present invention is a method of assembling a drive shaft including a constant velocity joint having an outer race and an inner race housed within the outer race, a shaft having the inner race attached to an end thereof, and a boot having a small diameter end fastened to the shaft, a large diameter end fastened to an outer periphery of the outer race, and a bellows-shaped portion provided between the small diameter end and the large diameter end, the method comprising the steps of: connecting a grease filling device to a filling port provided in the constant velocity joint so as to communicate with an inside of the outer race; creating a vacuum state in the boot and the surroundings of the boot with an air vent port of the constant velocity joint open for venting air from within the boot; filling grease into the boot through the filling port by the grease filling device; closing the air vent port; returning the surroundings of the boot to atmospheric pressure and disconnecting the filling port from the grease filling device; and closing the filling port. Effect of the Invention

[0007] The drive shaft assembly method according to the present invention has an effect of suppressing the boot from expanding in a vacuum environment and damaging the bellows shape. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a constant velocity joint according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of a step of connecting a grease filling device to a filling port of a constant velocity joint. [Diagram 3] FIG. 3 is an explanatory diagram of the step of creating a vacuum in the boot and around the boot. [Figure 4] FIG. 4 is an explanatory diagram of the step of filling the boot with grease. [Diagram 5] FIG. 5 is an explanatory diagram of the step of closing the air vent hole. [Figure 6] FIG. 6 is an explanatory diagram of the step of returning the pressure around the boot to atmospheric pressure and disconnecting the grease filling device. [Figure 7] FIG. 7 is an explanatory diagram of the step of closing the filling port. [Figure 8] FIG. 8 is an explanatory diagram of another example of the filling port and the air vent port. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the drive shaft assembling method according to the present invention will be described below. In this embodiment, an example will be described in which the drive shaft assembling method according to the present invention is applied to the assembling of a drive shaft provided in a vehicle that runs in a vacuum environment, such as on the surface of the moon. Note that the present invention is not limited to this embodiment.

[0010] 1 is a diagram showing a schematic configuration of a constant velocity joint 10 according to an embodiment. The constant velocity joint 10 includes an outer race 12 having integrally therewith a hollow outer shaft 11 to which power is transmitted from a differential gear of a vehicle, an inner race 13 housed within the outer race 12, a plurality of balls 14 serving as torque transmission members interposed between the outer race 12 and the inner race 13, and a boot 30.

[0011] The outer race 12 has an open end on the side where the inner shaft 20 is inserted, and the other end communicates with and is integrally connected to the hollow outer shaft 11. On the inner peripheral surface of the outer race 12, a plurality of ball rolling grooves are formed in the axial direction of the outer race 12 at predetermined intervals in the circumferential direction.

[0012] A plurality of ball rolling grooves are formed at predetermined intervals in the circumferential direction on the outer circumferential surface of the inner race 13. The inner race 13 is configured to be connected to one end of the inner shaft 20 so as to rotate integrally with the inner shaft 20 about a common rotation center line.

[0013] A plurality of balls 14 are rollably fitted in the space between a ball rolling groove formed on the inner circumferential surface of the outer race 12 and a ball rolling groove formed on the outer circumferential surface of the inner race 13 .

[0014] The boot 30 is made of an elastic material such as rubber, and includes a large diameter end provided on the outer race 12 side, a small diameter end provided on the inner shaft 20 side, and a bellows-shaped portion provided between these two ends. The large diameter end of the boot 30 is fastened to the outer periphery of the end on the opening side of the outer race 12 by being fastened by a large diameter clamp 31. The small diameter end of the boot 30 is fastened to the outer periphery of the inner shaft 20 by being fastened by a small diameter clamp 32. In FIG. 1, the small diameter end of the boot 30 is not fastened by the small diameter clamp 32, and an air vent hole 33 for venting air from inside the boot 30 before filling the constant velocity joint 10 (the outer race 12 and the boot 30) with grease is opened in the constant velocity joint 10 (between the outer periphery of the inner shaft 20 and the inner periphery of the boot 30).

[0015] The inner shaft 20 is, for example, a drive shaft for transmitting power to a wheel. One end of the inner shaft 20 is inserted into the small diameter end of the boot 30, passes through the boot 30, protrudes from the large diameter end of the boot 30, and is connected to the inner race 13.

[0016] A filling port 15 for filling the constant velocity joint 10 (the outer race 12 and the boot 30) with grease is provided on the end face of the hollow outer shaft 11 opposite to the outer race 12 side.

[0017] The method of assembling the drive shaft according to the embodiment includes the steps of connecting a grease filling device 80 (see Figure 2) to a filling port 15 provided in a constant velocity joint 10 (hollow outer shaft 11) so as to communicate with the inside of the outer race 12, creating a vacuum state in the boot 30 and the area around the boot 30 while an air vent port 33 for venting air from inside the boot 30 is open in the constant velocity joint 10, filling the boot 30 with grease 84 (see Figure 4) through the filling port 15 using the grease filling device 80, blocking the air vent port 33, returning the area around the boot 30 to atmospheric pressure and disconnecting the filling port 15 from the grease filling device 80, and blocking the filling port 15.

[0018] Specifically, in the method of assembling the drive shaft according to the embodiment, first, as shown in FIG. 2, the constant velocity joint 10 with the boot 30 attached to the outer race 12 is stored in the vacuum tank 40. At this time, the end of the hollow outer shaft 11 on the filling port 15 side is inserted into the opening 41 provided in the vacuum tank 40 via the seal material 42 and exposed to the outside of the vacuum tank 40. Then, the end of the hollow outer shaft 11 exposed to the outside of the vacuum tank 40 is connected to the nozzle part 82 of the grease filling device 80 via the joint 70, so that the grease filling device 80 is attached to the constant velocity joint 10. In addition, the filling port 15 of the hollow outer shaft 11 and the discharge port 83 of the grease filling device 80 are communicated with each other via the communication port 71 provided in the joint 70. Note that the grease 84 accommodated in the accommodation part 81 of the grease filling device 80 has been previously subjected to defoaming and deaeration (removal of gas dissolved in oil).

[0019] Next, in the method of assembling the drive shaft according to the embodiment, as shown in Fig. 3, the air in the vacuum chamber 40 is exhausted using an exhaust device that sucks in air from an exhaust port 43 that is provided in an openable and closable manner in the vacuum chamber 40. At this time, the air in the constant velocity joint 10 (inside the outer race 12 and the boot 30) is exhausted from the exhaust port 43 of the vacuum chamber 40 through the air vent port 33 of the constant velocity joint 10. This creates a vacuum state in the vacuum chamber 40 (around the boot 30) and in the constant velocity joint 10 (inside the outer race 12 and the boot 30).

[0020] 4, in the method of assembling the drive shaft according to the embodiment, grease 84 stored in a storage portion 81 of a grease filling device 80 is discharged from an outlet 83 of a nozzle portion 82, and the grease 84 is filled into the constant velocity joint 10 (inside the outer race 12 and the boot 30) from the filling port 15 of the hollow outer shaft 11 via the communication port 71 of the joint 70. Note that at this time, it is not necessary that the grease 84 can be filled into the boot 30 without leaving any gaps.

[0021] Next, in the method of assembling the drive shaft according to the embodiment, as shown in FIG. 5, a tool is inserted from outside the vacuum chamber 40 through an openable / closable tool insertion opening 44 provided in the wall of the vacuum chamber 40 at a position opposite the small diameter clamp 32, via a sealing material 45, and while the vacuum state within the vacuum chamber 40 is maintained, the small diameter clamp 32 is tightened using the tool, and the air vent opening 33 is closed.

[0022] Next, in the method of assembling the drive shaft according to the embodiment, as shown in FIG. 6, exhaust from the exhaust port 43 of the vacuum chamber 40 is stopped, and the inside of the vacuum chamber 40 (around the boot 30) is returned to atmospheric pressure, and then the grease filling device 80 is removed from the constant velocity joint 10 (hollow outer shaft 11) together with the joint 70. In this manner, after the grease filling device 80 is disconnected from the constant velocity joint 10 (hollow outer shaft 11), the constant velocity joint 10 is taken out from the vacuum chamber 40. At this point, the vacuum gap in the boot 30 is crushed by the atmospheric pressure, and the inside of the boot 30 is filled with grease 84 without any gaps. At this time, since the pressure inside and outside the boot 30 is equal, the grease 84 does not spurt out from inside the boot 30.

[0023] Next, in the method of assembling the drive shaft according to the embodiment, as shown in FIG. 7, a plug 16 that is a stopper for blocking the filling port 15 is attached to the filling port 15 of the constant velocity joint 10 (hollow outer shaft 11) to close the filling port 15, thereby completing the series of drive shaft assembly steps.

[0024] If the amount of grease 84 in the boot 30 decreases due to the grease 84 evaporating under vacuum due to insufficient sealing of the boot 30, it is possible to replenish the grease 84 in the boot 30 through the filling port 15 using a grease filling device 80 with the constant velocity joint 10 mounted on the vehicle by removing the plug 16 from the filling port 15.

[0025] Here, in the method for assembling the drive shaft according to the embodiment, the filling port 17 and the air vent port 18 may be provided in other locations, such as the outer periphery of the outer race 12 of the constant velocity joint 10, as shown in Fig. 8. That is, in the method for assembling the drive shaft according to the embodiment, the filling port and the air vent port for filling grease are provided in the constant velocity joint 10 in which the boot 30 is attached to the outer race 12, and grease is filled into the boot 30 through the filling port while the boot 30 is evacuated through the air vent port, and then the air vent port is closed, and the pressure around the boot 30 is returned to atmospheric pressure, and the filling port can be closed with a plug or the like. In the method for assembling the drive shaft according to the embodiment, as shown in Figs. 1 to 7, the filling port and the air vent port are provided at both ends in the axial direction of the constant velocity joint 10, making it easier to fill every corner of the boot 30 with grease and reducing the number of parts. [Explanation of symbols]

[0026] 10 Constant velocity joint 11 Hollow outer shaft 12 Outer Race 13 Inner Race 14 Ball 15 Filling port 16 Plug 20 Inner shaft 30 Boots 31 Large diameter clamp 32 Small diameter clamp 33 Air vent 40 Vacuum chamber 41 Opening 42 Sealing material 43 Exhaust port 44 Tool insertion port 45 Sealing material 70 Joint 71 Connecting port 80 Grease filling device 81 Storage unit 82 Nozzle section 83 Discharge port 84 Grease

Claims

[Claim 1] a constant velocity joint having an outer race and an inner race housed within the outer race; a shaft having the inner race attached to an end thereof; a boot including a small diameter end portion fastenable to the shaft, a large diameter end portion fastenable to an outer periphery of the outer race, and a bellows-shaped portion provided between the small diameter end portion and the large diameter end portion; A method for assembling a drive shaft comprising: connecting a grease filling device to a filling port provided in the constant velocity joint so as to communicate with the inside of the outer race; creating a vacuum state in the boot and around the boot while an air vent port for venting air from inside the boot is open in the constant velocity joint; filling the boot with grease through the filling port by the grease filling device; A step of closing the air vent hole; returning the pressure around the boot to atmospheric pressure and disconnecting the filling port from the grease filling device; blocking the filling port; A method for assembling a drive shaft, comprising the steps of:

Images