JP2005133784A - Protecting device of propeller shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protecting device of a propeller shaft which can simplify a structure and improve the degree of freedoms of designing the propeller shaft and its circumference. <P>SOLUTION: The protecting device of the propeller shaft transmits a rotary torque outputted from a drive shaft 2 to a differential gear side through a center shaft 5, and includes a uniform velocity joint provided between the respective shafts. A stub shaft 16 of the central shaft is inserted and disposed in an outer wheel member 12 of the uniform velocity joint, serration coupled to an inner wheel member 15. An annular groove-like fragile part 24 to be broken at the distal end of the stub shaft from a radial direction when an excessive rotary torque more than a predetermined value or more is inputted to the central shaft at the base end side of the torque transmission route of the distal end 16a of the stub shaft, is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a protection device for a propeller shaft that transmits power from, for example, a transmission of a vehicle to drive wheels, and relates to a protection device that has a simple structure and can be safely held when the propeller shaft is broken.

  As is well known, the propeller shaft disposed between the transmission of the vehicle and the differential gear generates excessive torque, for example, more than a predetermined value during rotational driving, and the input shaft and the output shaft are twisted from a predetermined position. In the case of breaking from almost the radial direction, various holding devices for safely holding the broken propeller shaft are provided, and one of them is described in Patent Document 1 below.

  Briefly, this propeller shaft protection device is composed of a chassis frame extending along the propeller shaft, a beam material bent in a loop shape, and intersected with a gap that exceeds the outer diameter of the propeller shaft. And a protection member that protects the propeller shaft by attaching both ends to the chassis frame with the loop-shaped portion surrounding the propeller shaft.

Thereby, the simplification of the structure is achieved, and the attachment work of the protection member is facilitated.
Japanese Utility Model Publication No. 7-31453

  However, in this conventional protective device, as described above, the beam material is bent into a loop shape and crossed with a gap exceeding the outer diameter of the propeller shaft. By this loop-shaped portion, Both ends are attached to the chassis frame in a state of surrounding the propeller shaft, that is, the structure around the propeller shaft is enlarged because it is surrounded by the loop portion from the outside of the propeller shaft, The degree of freedom in designing the propeller shaft and its surroundings is limited.

  That is, since various parts such as an exhaust pipe and a fuel tank are arranged around the propeller shaft at the lower part of the vehicle body floor, it is constrained from the space that the protective device is attached around the propeller shaft. As a result, the degree of freedom in overall design is restricted.

  In addition, mounting means such as a loop-shaped part and bolts for mounting the same are required, the structure becomes relatively complicated, and the number of parts increases, so the efficiency of manufacturing and assembling work decreases and the cost increases. Has been forced.

  The present invention has been devised in view of the above-described conventional technical problems, and has a simpler structure and uses existing members to protect the propeller shaft. It is an object of the present invention to provide a propeller shaft protection device capable of improving efficiency and reducing costs.

  According to the first aspect of the present invention, in particular, one end portion of one transmission shaft is inserted and arranged in the housing of the joint mechanism, and is linked to the housing in the drive transmission path of the one end portion. When an excessive rotational torque is input, a weakened portion that breaks the one end portion from the substantially radial direction is provided.

  According to the present invention, since the weak portion is provided at a predetermined portion of the one end portion of the transmission shaft, when an excessive rotational torque bending torque or the like exceeding a predetermined value acts on the propeller shaft, the one end portion is broken from the weak portion, One end of the transmission shaft that has been broken and dropped is placed and held in the housing as it is.

  As described above, the weakened portion is simply provided at one end of the transmission shaft, and the one end of the transmission shaft that has been broken and dropped from the weakened portion is held in the housing as it is, so that the transmission shaft is detached from the housing. Therefore, safety is ensured and no member is required on the outer peripheral side of the propeller shaft, so that the degree of freedom in designing the propeller shaft and the propeller shaft is improved.

  Moreover, since the structure of the protective device is greatly simplified as compared with the conventional structure, a decrease in manufacturing work and assembly work efficiency is prevented, and an increase in cost can be suppressed.

  In the invention according to claim 2, the joint mechanism is arranged so as to be able to roll between the housing, the inner ring housed in the housing, the inner ring and the housing, and transmitted from the housing. A rolling element that transmits the generated power to one end of the transmission shaft, and a snap ring that positions the inner ring in the housing in the axial direction is fitted to the weakened portion.

  According to this invention, since the fragile portion is also used as the fitting groove of the snap ring, it is possible to further suppress an increase in manufacturing cost.

  The invention according to claim 3 is characterized in that an axial positioning flange portion is formed at one end portion of the transmission shaft, and the fragile portion is formed in the vicinity of the flange portion.

  According to the present invention, by forming the flange portion together when forming the transmission shaft, the snap ring for axial positioning described in claim 2 is not necessary, so the number of parts can be reduced, The manufacturing cost can be further reduced.

  Embodiments of a propeller shaft protection device according to the present invention will be described below in detail with reference to the drawings.

  A propeller shaft 1 provided for this embodiment is for a vehicle, and as shown in FIG. 3, a transmission-side drive shaft 3 connected to a transmission 2 and a joint mechanism for the drive shaft 3. It is mainly composed of a center shaft 5 connected in the axial direction through a constant velocity joint 4 and a driven shaft 8 on the differential gear 7 side connected to the center shaft 5 through a cross-shaped universal joint 6. A protective device is provided between the constant velocity joint 4 and the center shaft 5.

  Further, the propeller shaft 1 is disposed substantially in parallel with the lower surface 9a of the cross member 9 that is a floor member of the vehicle body as a whole. The shafts 2, 5, and 8 constitute transmission shafts.

  The protective device will be described in detail. First, as shown in FIG. 1, the constant velocity joint 4 includes a plurality of flange-like mounting brackets 10 integrally provided on the outer end portion of the drive shaft 3. A substantially cylindrical outer ring member 12 which is a housing connected in the axial direction by bolts 11a and nuts 11b, and a plurality of torque transmitting balls 13 which are housed in the outer ring member 12 and which are rolling elements, are center shafts. An outer spherical spherical cage 14 that is rotatably held on a bisecting surface 5 and an inner circumferential side of each of the balls 13 that are arranged on the inner circumferential side of the cage 14 and that are rotatable. An inner ring member 15 having an annular shape, and a distal end portion 16a of a stub shaft 16 which is one end portion of the center shaft 5 is accommodated and disposed in the outer ring member 12 from the axial direction. It fitted and coupled via the serration portion 17 on the inner peripheral surface of the.

  The outer ring member 12 is integrally formed with a flange-like bracket portion 12a that is bolted to the mounting bracket 10 on the outer periphery of one end, and a holding groove 12b that holds the balls 13 on the inner peripheral surface is axial. It is formed along. In addition, a substantially disc-shaped closing member 18 is accommodated in the end portion on the drive shaft 3 side inside the outer ring member 12, and the axial direction of each ball 13 is disposed on the end portion on the stub shaft 16 side. A stopper ring 19 for restricting the slipping out is fixedly fitted.

  The inner ring member 15 is formed with a holding groove 15a on the spherical outer peripheral surface along the axial direction for holding the balls 13 in a freely rolling manner.

  A seal boot 20 is disposed between the outer peripheral surface of the outer ring member 12 on the stub shaft 16 side and the stub shaft 16, and the seal boot 20 has a rubber boot portion 20a, a metal retainer 20b, and small diameters of the rubber boot 20a. The clamp 20c is configured to hold the end portion on the outer periphery of the stub shaft 16.

  The center shaft 5 is integrally provided with the stub shaft 16 at one end portion of the cylindrical main body 5a, and is integrally provided with a yoke portion 21 constituting a part of the universal joint 6 at the other end portion. Yes.

  As shown in FIG. 2, the stub shaft 16 has an annular fitting groove 23 that fits and holds the first snap ring 22 that restricts the withdrawal from the inner ring member 15 on the outer periphery of the tip end portion 16 a. Is formed, and a thin annular fragile portion 24 is formed on the outer periphery on the proximal end side of the distal end portion 16a.

  That is, the weakened portion 24 is formed in the outer ring member 12 and the rotational torque from the drive shaft 3 is transmitted to the stub shaft 16 via the outer ring member 12, the ball 13 and the inner ring member 15. It is formed on the base end side of the distal end portion 16a in the middle of the path (arrow in FIG. 1), and its depth d is set so that the fragile portion 24 of the stub shaft 16 has a minimum diameter, for example, When an excessive rotational torque exceeding a predetermined rotational torque is applied, it is set so as to break almost from the radial direction. Even if the outer ring member 12 and the inner ring member 15 of the constant velocity joint 4 are relatively moved in the axial direction, the fragile portion 24 is positioned in the outer ring member 12.

  The weakened portion 24 is also used as a fitting groove for fitting the second snap ring 25 for positioning in the axial direction of the stub shaft 16 in cooperation with the first snap ring 22. Yes. As shown in FIG. 2, the radial width of the second snap ring 25 is set larger than that of the first snap ring 22 in accordance with the depth of the fragile portion 24.

  Therefore, according to this embodiment, since the weakened portion 24 is provided at the distal end portion 16a of the stub shaft 16 of the center shaft 5, an excessive rotational torque acts on the center shaft 5 during driving of the vehicle and exceeds a predetermined value. Then, as shown in FIG. 4, the tip end portion 16a of the stub shaft 16 is broken along the radial direction from the fragile portion 24, and the stub shaft 16 side of the center shaft 5 that has fallen and dropped is on the ground E. Without being dropped, it is placed and held on the inner periphery of the stopper member 19 inside the outer ring member 12 as it is.

  Therefore, the center shaft 5 is prevented from falling out of the outer ring member 12, and safety can be ensured.

  In addition, since the dropped center shaft 1 is slightly tilted but is held in a relatively horizontal state, the center shaft 5 is prevented from swinging and the safety is further improved.

  Further, when the stub shaft 16 of the center shaft 5 falls, as shown in FIG. 4, the rubber boot 20a of the seal boot 20 can be bent and deformed to interfere with the impact of the fall. Moreover, since the support state by the rubber boot 20a is maintained, even if the center shaft 5 moves slightly in the axial direction, an inadvertent drop to the ground E is prevented.

  Further, in this protection device, no member is required on the outer peripheral side of the propeller shaft 1 as in the conventional protection device, and only the existing stub shaft 16 and the outer ring member 12 are used. Therefore, the degree of freedom in the radial direction of the propeller shaft 1 is not restricted at all, and the degree of freedom in designing the propeller shaft 1 and its surroundings is improved.

  In addition, as described above, since only the existing members are used, the overall structure of the protective device is greatly simplified, and therefore, a reduction in manufacturing work and assembly work efficiency is prevented, thereby suppressing an increase in cost. it can.

  Further, since the fragile portion 24 is also used as the fitting groove of the second snap ring 25, it is possible to further suppress an increase in manufacturing cost.

  FIG. 5 shows the second embodiment, and the basic structure is the same as that of the first embodiment. However, the second snap ring 25 is abolished and the second end of the stub shaft 16 on the proximal end side of the distal end portion 16a is second. A flange portion 26 for positioning in the axial direction instead of the snap ring is formed, and the fragile portion 24 is formed on the outer side portion of the flange portion 26.

  Therefore, the same effect as the first embodiment can be obtained, and the second snap ring can be eliminated by forming the flange portion 26 together when forming the stub shaft 16. Therefore, the number of parts can be reduced and the manufacturing cost can be kept low.

  The present invention is not limited to the configuration of each of the embodiments described above, and the propeller shaft may be applied to a ship other than a vehicle, and the specification of the propeller shaft 1 or the magnitude of excessive torque may be used. The shape of the fragile portion 24 can be further changed accordingly.

It is a fragmentary sectional view which expands and shows the constant velocity joint provided to 1st Embodiment of this invention. It is a front view which decomposes | disassembles and shows the stub axis | shaft and inner ring member which are provided to this embodiment. It is a whole block diagram of the propeller shaft of this embodiment. It is a longitudinal cross-sectional view of the principal part of 2nd Embodiment. It is a fragmentary sectional view which expands and shows the constant velocity joint provided for the 2nd Embodiment of this invention. It is a front view which decomposes | disassembles and shows the stub axis | shaft and inner ring member which are provided to this embodiment.

Explanation of symbols

1 ... Propeller shaft 3 ... Drive shaft (transmission shaft)
4 ... Constant velocity joint 5 ... Center shaft (transmission shaft)
8 ... driven shaft (transmission shaft)
12 ... Outer ring member (housing)
13 ... Torque transmission ball 14 ... Cage 15 ... Inner ring member 16 ... Stub shaft (one end)
16a ... Tip 24 ... Fragile 26 ... Flange

Claims (3)

In the propeller shaft protection device in which the power output from the drive source is transmitted to the driven body via a plurality of transmission shafts, and a joint mechanism is provided between the transmission shafts.
When one end of the one transmission shaft is inserted and arranged in the housing of the joint mechanism and linked, and when an excessive torque exceeding a predetermined value is input to the housing in the drive transmission path of the one end A propeller shaft protection device comprising a weakened portion that breaks the one end portion from substantially the radial direction. The joint mechanism is rotatably disposed between the housing, an inner ring accommodated in the housing, and the inner ring and the housing, and transmits power transmitted from the housing to one end of the transmission shaft. Rolling elements to
2. The propeller shaft protection device according to claim 1, wherein a snap ring for positioning the inner ring in the axial direction in the housing is fitted to the weakened portion. The propeller shaft protection device according to claim 1, wherein a flange portion for positioning in the axial direction is formed at one end portion of the transmission shaft, and the fragile portion is formed in the vicinity of the flange portion.

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