JP2019011786A - Drive shaft structure for vehicle - Google Patents

Abstract

To provide a drive shaft structure for a vehicle which can reduce operation resistance at a posture change or the like of a drive shaft more than before by using means which is simple in a constitution.SOLUTION: A drive shaft structure for a vehicle comprises a drive shaft D in which a differential-side constant velocity universal joint 4A which is drive-connected to a differential device 1 is connected to one end part of an intermediate shaft 3, and a wheel-side constant velocity universal joint 4B connected to a wheel 2 is connected to the other end part of the intermediate shaft 3. The drive shaft structure also comprises oil passages 61, 62a and 62b for making a lubricant in the differential device 1 flow to at least either of internal space parts 43a, 43b of the differential-side/wheel-side constant velocity universal joints 4A, 4B, and the lubricant is used for the lubrication of at least either of movable connecting part 44A, 44B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle drive shaft structure for transmitting engine power from a differential device to wheels in a vehicle such as an automobile.

An example of a vehicle drive shaft structure is disclosed in Patent Document 1.
In the structure described in the document, the drive shaft includes an intermediate shaft and a pair of constant velocity universal joints connected to both ends of the intermediate shaft. Of the pair of constant velocity universal joints, one is drivingly connected to the differential device and the other is drivingly connected to the wheels. As a connecting means between each constant velocity universal joint and the intermediate shaft, an end portion of the intermediate shaft is made to enter the internal space of the joint body member, and these are used as a movable connecting portion using a rolling element such as a roller or a ball. Thus, a means for connecting is adopted. The movable connecting portion enables relative swinging of the joint body member and the intermediate shaft, displacement in the axial length direction, and the like when the wheel moves up and down or the direction is changed. One end opening side of the internal space portion of the joint body member is closed by a boot, and grease is enclosed in the internal space portion as a lubricant for lubricating the movable connecting portion.

  However, in the prior art, there is still room for improvement as described below.

That is, conventionally, grease is used as a lubricant for lubricating the movable connecting portion of the constant velocity universal joint, but grease has a relatively high viscosity. Therefore, it is difficult to sufficiently reduce the operating resistance generated in the movable connecting portion when the posture of the drive shaft changes with the raising and lowering of the wheels and the change in direction. Such operation resistance is a factor that deteriorates the fuel efficiency of the vehicle.
Such a problem can theoretically be solved by using a lubricating oil having a low viscosity as the lubricant. However, conventionally, when assembling the drive shaft, the boot is attached so that the lubricant is not leaked to the outside after the lubricant is put into the internal space of the joint body member. In the procedure, it is substantially difficult to use a lubricating oil having a low viscosity other than grease as a lubricant.

JP, 2014-31804, A

  The present invention has been conceived under the circumstances as described above, and for a vehicle in which the operating resistance at the time of a change in the attitude of the drive shaft or the like can be made smaller than before by means of a simple configuration. The challenge is to provide a drive shaft structure.

  In order to solve the above problems, the present invention takes the following technical means.

In the vehicle drive shaft structure provided by the present invention, a differential constant velocity universal joint connected to a differential device is connected to one end of the intermediate shaft, and the other end of the intermediate shaft is connected to a wheel. A drive shaft to which a drive-connected constant velocity universal joint is connected, and each of the differential-side and wheel-side constant velocity universal joints is an internal space portion into which an end of the intermediate shaft enters. A drive shaft structure for a vehicle, comprising: a joint main body member having a movable connecting portion that is provided in the internal space portion and is connected to the joint main body member so as to be relatively displaceable. And an oil passage that allows the lubricating oil in the differential device to flow into the internal space of at least one of the differential-side and wheel-side constant velocity universal joints, Namerayu is characterized by being used for lubrication of the movable coupling part.

According to such a configuration, the following effects can be obtained.
First, lubricating oil in the differential device is used as a lubricant for at least one of the constant velocity universal joints on the differential side and the wheel side. For this reason, it is not necessary to use a grease having a relatively high viscosity as the lubricant, and it is possible to lubricate the movable connecting portion of the constant velocity universal joint using a lubricating oil having a viscosity lower than that of the grease. As a result, it is possible to reduce the operating resistance when the attitude of the drive shaft changes with the raising and lowering of the wheels and the change of the direction, and to improve the fuel efficiency of the vehicle.
Secondly, since the lubricating oil flows from the differential device into the internal space of the constant velocity universal joint through the oil passage, the drive shaft is assembled into the internal space of the constant velocity universal joint when the drive shaft is assembled. It becomes possible to eliminate the need for a dedicated work for filling the lubricating oil. Therefore, the assembly work of the drive shaft can be facilitated and the productivity can be increased.
Thirdly, the lubricating oil in the differential device becomes relatively hot during operation of the differential device, but can be expected to be cooled when it flows into the internal space of the constant velocity universal joint. Therefore, it is possible to cool the lubricating oil in the differential device by moving the lubricating oil back and forth between the differential device and the internal space of the constant velocity universal joint.

  In the present invention, preferably, the oil passage is provided in the constant-velocity universal joint on the differential side and communicates the internal space of the constant-velocity universal joint on the differential side with the inside of the differential device. A plurality of second oil passages that are provided on the intermediate shaft and communicate with each other between a pair of internal space portions of the constant velocity universal joint on the differential side and the wheel side, At least one of the pair of internal space portions is provided with a pump member that generates a pumping action by being deformed as the drive shaft rotates, swings, or expands and contracts. By the pumping action of the pump member, The lubricating oil is configured to be circulated through the plurality of second oil passages between the pair of internal space portions.

According to such a configuration, the following effects can be obtained.
That is, by using the first oil passage, the lubricating oil in the differential device can be allowed to flow into the internal space of the differential constant velocity universal joint, and by using the second oil passage, Lubricating oil in the internal space portion of the constant velocity universal joint on the differential side can flow into the internal space portion of the constant velocity universal joint on the wheel side. As a result, it is possible to appropriately use the lubricating oil in the differential device as the lubricant for the constant velocity universal joint on both the differential side and the wheel side.
Further, between the pair of internal space portions of the constant velocity universal joint on the differential side and the wheel side, the lubricating oil can be actively circulated using the pump member, so that the lubricating performance is further improved. It is possible. Since the pump member generates a pumping action by being deformed as the drive shaft rotates, swings, or expands and contracts, it is not necessary to separately provide a drive source for operating the pump member.
Further, the lubricating oil can be cooled when it passes through the second oil passage provided on the intermediate shaft.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is a partially broken principal part sectional view showing an example of the drive shaft structure for vehicles concerning the present invention. It is II-II sectional drawing of FIG. (a) is a principal part expanded sectional view of FIG. 1, (b) is a schematic perspective view of the pump member shown to (a). (A), (b) is sectional drawing which simplifies and shows the operation state of the pump member shown in FIG. It is principal part sectional drawing which shows the other example of this invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  In the vehicle drive shaft structure A shown in FIG. 1, a vehicle differential device (differential gear device) 1 and a wheel 2 are drivingly connected using a drive shaft D.

  The differential device 1 is connected to a terminal of a transmission (not shown) that changes the engine output of the vehicle, and its basic configuration is the same as that conventionally known. Briefly, in the differential apparatus 1, a differential case 11 is connected to a ring gear 10 that rotates by receiving a driving force from a transmission, and a pair of pinion gears 13a and 13b coupled to a pin 12 is provided in the differential case 11. , And side gears 14a and 14b that mesh with these. Of these side gears 14a and 14b, the rotational torque of the side gear 14a on the right side of the drawing is transmitted to the drive shaft D. The rotational torque of the side gear 14b on the left side of the drawing is transmitted to the drive shaft Da. In FIG. 1, only a part of the drive shaft Da is shown, but the configuration of the drive shaft Da is the same as that of the drive shaft D, and the description thereof is omitted. Each component described above of the differential device 1 is disposed in the housing 15, and lubricating oil is stored in the housing 15. The liquid level of the lubricating oil is higher than that of a first oil passage 61 described later.

  Although only a part of the wheel 2 is shown in FIG. 1, the structure relating to the wheel 2 is the same as that conventionally known and is fixedly connected to the hub 20. The hub 20 is rotatably held by a knuckle 21 via a bearing 22.

The drive shaft D includes an intermediate shaft 3 and constant-velocity universal joints 4A and 4B on the differential side and the wheel side connected to both ends of the intermediate shaft 3. A pump member 5 is provided in the constant velocity universal joint 4B on the wheel side.
The differential-side constant velocity universal joint 4A is a so-called triport type, and includes a joint body member 40A having an outer race portion 41a forming an internal space portion 43a and an input shaft portion 42a connected to one side thereof. . The input shaft portion 42a is drivingly connected to the side gear 14a of the differential device 1 using means such as spline coupling. As a result, the entire joint body member 40A can rotate in conjunction with the side gear 14a. The end portion of the intermediate shaft 3 is coupled to the joint body member 40A via the movable coupling portion 44A so as to be able to swing with respect to the joint body member 40A and slide in the axial length direction. The movable connecting portion 44 </ b> A includes a plurality of rollers 45 attached to the end portion of the intermediate shaft 3, an inner race portion 46 externally fitted to the end portion of the intermediate shaft 3, and the like. These components are the same as those of the conventional tripport type, and the description thereof is omitted. One end opening side of the internal space 43a is closed by a boot 9a, and a lubricating oil described later can be enclosed inside the boot 9a.

  The constant velocity universal joint 4B on the wheel side is a so-called Rzeppa type, and includes a joint main body member 40B having an outer race part 41b forming an internal space part 43b and an output shaft part 42b connected to one side thereof. . The output shaft portion 42b and the hub 20 are drivingly connected to each other through means such as spline coupling. As a result, the intermediate shaft 3 and the joint body member 40B can rotate together. The end portion of the intermediate shaft 3 is coupled to the joint body member 40B via the movable coupling portion 44B so as to be able to swing with respect to the joint body member 40B. The movable connecting portion 44B includes an inner race portion 47 that is externally fitted to the end portion of the intermediate shaft 3, a plurality of balls 49 that are held by the cage 48, and the like. These components are the same as those of the conventional Zepper type, and the description thereof is omitted. One end opening side of the internal space portion 43b is closed by a boot 9b, and lubricating oil to be described later can be enclosed inside these.

  The drive shaft D is provided with a first oil passage 61 and a pair of second oil passages 62a and 62b.

More specifically, the first oil passage 61 is a part for allowing the lubricating oil in the differential device 1 to flow into the internal space 43a, and allows the internal space 43a and the differential device 1 to communicate with each other. Thus, it is configured as a hole provided in the joint body member 40A.
Preferably, the first oil passage 61 has an inner diameter that allows the lubricating oil to flow in and out (go back and forth) between the differential device 1 and the internal space 43a. When the vehicle is traveling, the temperature of the internal space 43a is generally lower than that in the differential device 1, and the lubricating oil in the differential device 1 and the lubricating oil in the internal space 43a are: A temperature difference is produced, and a specific gravity difference is generated. By utilizing such a specific gravity difference, it is possible to cause the lubricating oil to flow in and out.

  The second oil passages 62a and 62b are portions for allowing the internal space portions 43a and 43b to communicate with each other and to circulate the lubricating oil between them, both located inside the intermediate shaft 3, and The intermediate shaft 3 extends in the longitudinal direction. Both end openings of the second oil passage 62a are located on both end faces of the intermediate shaft 3, whereas both end openings of the second oil passage 62b are located on the intermediate shaft 3 rather than the movable connecting portions 44A and 44B. It is located near the center in the longitudinal direction. On the other hand, as described later, the second oil passage 62a is a portion that receives the pump discharge pressure of the pump member 5, whereas the second oil passage 62b is a portion that receives the suction negative pressure of the pump member 5. is there. According to such a configuration, in the differential-side constant velocity universal joint 4A, the lubricating oil that has flowed out from the one end of the second oil passage 62a into the internal space portion 43a passes through the movable connecting portion 44A and then is second. Into one end of the oil passage 62b. In the constant velocity universal joint 4B on the wheel side, the lubricating oil that has flowed out from the other end of the second oil passage 62b to the internal space 43b side is sucked into the pump member 5 after passing through the movable connecting portion 44B. The Rukoto. Accordingly, it is possible to appropriately supply the lubricating oil to the movable connecting portions 44A and 44B.

  As a means for forming the second oil passages 62a and 62b, in the present embodiment, for example, a means as shown in FIG. 2 is adopted. That is, inside the hollow intermediate shaft 3, the two tubular bodies 30, 31 are arranged in a state of being fitted to each other, and a part 30 a of the inner tubular body 30 is formed on the outer tubular body 31. The shape is separated from the inner peripheral surface. According to such a configuration, even if the intermediate shaft 3 and the second oil passages 62a and 62b have a relatively long size, the intermediate shaft 3 is relatively reduced without significantly impairing the strength of the intermediate shaft 3. It can be easily manufactured. However, different from this, a double pipe having a different structure from the above may be used, or a means for forming a hole in the intermediate shaft 3 may be employed.

The pump member 5 has a drive shaft D rotating or swinging (joint body members 40A, 4
The pumping operation for circulating the lubricating oil between the pair of internal space portions 43a and 43b is caused when the 0B and the intermediate shaft 3 are relatively swung. The pump member 5 has a hollow shape having an external form as shown in FIG. 3B, for example, and can be expanded and contracted in the axial length direction (front-rear thickness direction). Preferably, the expansion / contraction deformation is elastic deformation, and the material of the pump member 5 is a material excellent in durability against repeated deformation.

  3 (a) and 3 (b), the pump member 5 is located behind the end of the intermediate shaft 3 in the internal space 43b of the joint body member 40B. The surface portion is fixed to the joint body member 40B. A substantially disc-shaped contact plate 7 attached to the end of the intermediate shaft 3 is in contact with the front surface of the pump member 5. The pump member 5 and the contact plate 7 are rotatable in conjunction with the intermediate shaft 3 and the joint body member 40B. The abutting plate 7 is a member for appropriately performing compressive deformation or the like of the pump member 5. For example, the end surface of the inner race portion 47 is disposed on the front surface of the pump member 5 without using the abutting plate 7. You may make it contact | abut.

  Inside the pump member 5, a plurality of chambers C partitioned by a plurality of partition walls 50 are provided side by side in the circumferential direction. Each chamber C has a suction port 51 and a discharge port 52 for lubricating oil, In addition, a valve 53 composed of a pair of tongue pieces is provided. The discharge port 52 of each chamber C faces the end opening of the second oil passage 62a. The suction port 51 is open to the internal space 43b. As a means for realizing this, the contact plate 7 is provided with a hole communicating with the suction port 51, and an inner race portion. 47 also has a hole 47 b communicating with the suction port 51.

  As described above, since the rear surface portion of the pump member 5 is fixed to the joint body member 40B, the central axis of the pump member 5 is always horizontal during normal times when the vehicle is not inclined. On the other hand, in this embodiment, the heights of the constant velocity universal joints 4A and 4B on the differential side and the wheel side are different, and the intermediate shaft 3 is inclined at an appropriate angle α in the normal state. For this reason, the contact plate 7 rotates in a posture inclined with respect to the vertical direction. As a result, the pump member 5 has the following effects.

  That is, in FIG. 4A, the upper region of the pump member 5 is pressed and deformed by being pressed by the contact plate 7, and the inner chamber Ca is reduced in volume and its internal pressure is increased, so that the valve 53 Opens. As a result, the lubricating oil present in the chamber Ca is discharged from the discharge port 52 to the second oil passage 62a. On the other hand, since the lower region of the pump member 5 is not pressed by the contact plate 7, the volume is larger than that of the upper region, and the volume of the inner chamber Cb is in an expanded state. For this reason, the lubricating oil in the internal space 43b is sucked into the chamber Cb from the suction port 51. The valve 53 of the chamber Cb is closed.

  Next, when the drive shaft D is rotated by 180 ° compared to the case described above, the chamber Cb that has been in an expanded state is positioned in the upper region of the pump member 5, and the contact plate 7. Compressed by Therefore, in the chamber Cb, the lubricating oil is discharged from the discharge port 52 on the same principle as the chamber Ca shown in FIG. On the other hand, the chamber Ca is located in the lower region of the pump member 5 in FIG. Therefore, in the chamber Ca, the lubricating oil is sucked from the suction port 51 on the same principle as the chamber Cb shown in FIG. As a result, in each chamber C of the pump member 5, as a result of repeated compression and expansion as the drive shaft D rotates, the pumping action of feeding the lubricating oil in the internal space 43b into the second oil passage 62a. Is obtained. Even when the intermediate shaft 3 swings relative to the joint body member 40B, the pump member 5 is compressed and deformed, so that the pumping action as described above can be obtained. .

  Next, the operation of the vehicle drive shaft structure A will be described.

  First, the lubricating oil in the differential device 1 flows into the pair of internal space portions 43a and 43b of the constant velocity universal joints 4A and 4B on the differential side and the wheel side, and this lubricating oil lubricates the movable connecting portions 44A and 44B. Used for. Here, as this lubricating oil, for example, oil whose viscosity is considerably lower than that of grease is used. For this reason, the intermediate shaft 3 and the joint body members 40A and 40B swing relative to each other as the wheel 2 moves up and down, changes its orientation, and the like, and the intermediate shaft 3 is pivoted relative to the joint body member 40A. It is possible to reduce the operating resistance of the movable connecting portions 44A and 44B when sliding and displacing in the long direction, and to improve the fuel consumption performance of the vehicle.

  Between the pair of internal space portions 43a and 43b, since the lubricating oil can be actively circulated using the pump member 5, more suitable lubrication is possible. In particular, according to the present embodiment, as described above, in the process in which the lubricating oil circulates and flows between the pair of internal space portions 43a and 43b through the second oil passages 62a and 62b, Since the lubricating oil passes through the positions of the movable connecting portions 44A and 44B, it is possible to further improve the lubrication of the movable connecting portions 44A and 44B.

  The lubricating oil in the differential device 1 becomes relatively hot when the vehicle is running, but this lubricating oil flows into the internal space portions 43a and 43b of the constant velocity universal joints 4A and 4B located outside the differential device 1. By doing so, an effect of cooling the lubricating oil is also obtained. Further, since the second oil passages 62a and 62b are provided on the intermediate shaft 3, when the lubricating oil passes through the second oil passages 62a and 62b, the lubricating oil is cooled more effectively. It is also possible.

Since the pump member 5 generates a pumping action by the rotation and swinging of the drive shaft D, it is not necessary to separately provide a drive source for operating the pump member 5, and an increase in manufacturing cost is suppressed. Is possible. Further, the operation of filling the pair of internal space portions 43a and 43b with the lubricating oil is performed after the drive shaft D is connected to the differential device 1 and the wheel 2. Therefore, when the drive shaft D is assembled and manufactured, it is not necessary to perform a dedicated operation for filling the pair of internal space portions 43a and 43b with the lubricating oil. As a result, the assembly work of the drive shaft can be facilitated and the productivity can be increased.
By providing the second oil passages 62a and 62b in the intermediate shaft 3 and making the intermediate shaft 3 hollow, the natural frequency of the intermediate shaft 3 can be set to a numerical value away from a predetermined resonance frequency. In this way, it is possible to eliminate the need to provide a vibration-proof mass 95 (shown in phantom lines in FIG. 1) on the intermediate shaft 3.

  FIG. 5 shows another embodiment of the present invention. In the figure, the same or similar elements as those of the above embodiment are denoted by the same reference numerals as those of the above embodiment, and redundant description is omitted.

In the embodiment shown in FIG. 5, the joint body member 40A is provided with a plurality of first oil passages 61a and 61b. Among these, the first oil passage 61a is in a position closest to the one end opening 62a ′ of the second oil passage 62a when the drive shaft D is in the most general posture (swing angle). The other first oil passage 61b is located farther from the one end opening 62a ′ of the second oil passage 62a than the first oil passage 61a.
According to the present embodiment, the pump discharge pressure + P by the pump member 5 acts on the internal space 43a from the one end opening 62a ′ of the second oil passage 62a, but part of the pressure is the first oil passage 61a. Also works. As a result, part of the lubricating oil in the internal space 43a flows through the first oil passage 61a into the differential device 1. On the other hand, the pump suction pressure -P acts on the internal space 43a via the second oil passage 62b, and this pressure -P acts on the first oil passage 61b. For this reason, the lubricating oil in the differential device 1 passes through the first oil passage 61b and flows into the internal space 43a.
In the present invention, the pumping action of the pump member 5 can be used as described above, so that the lubricating oil can flow in and out between the differential device 1 and the internal space 43a.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the vehicle drive shaft structure according to the present invention can be modified in various ways within the scope of the present invention.

  In the above-described embodiment, the lubricating oil of the differential device is caused to flow into the internal spaces of both the differential side and the constant velocity universal joints on the wheel side, but the present invention is not limited to this, and the differential side and the wheel The lubricating oil may be allowed to flow into only one of the internal space portions of the constant velocity universal joint on the side. Even with such a configuration, it is possible to reduce the operating resistance when the attitude of the drive shaft is changed as compared with the conventional case where grease is used as the lubricant. Therefore, as an oil path, it can also be set as the structure provided only with the 1st oil path, without providing the 2nd oil path of the above-mentioned embodiment, for example.

  The constant velocity universal joint on the differential side and the wheel side is not necessarily limited to a combination of the tripod type and the Zepper type. The movable connecting portion referred to in the present invention only needs to have a structure for connecting the joint body member and the intermediate shaft so as to be capable of relative displacement. The joint main body member may have an internal space portion into which the end portion of the intermediate shaft enters and a movable connecting portion is provided in the internal space portion.

  The pump member only needs to have a structure that generates a pumping action by being deformed along with rotation, swinging, or expansion / contraction of the drive shaft, and can have a configuration other than the above-described embodiment. As a means for smoothly changing the volume of the pump member, a means for forming a part of the pump member in a bellows shape may be employed.

A Vehicle drive shaft structure D Drive shaft 1 Differential device 2 Wheel 3 Intermediate shaft 4A Differential side constant velocity universal joint 4B Wheel side constant velocity universal joint 40A, 40B Joint body members 43a, 43b Internal space portions 44A, 44B Movable connection Part 5 Pump member 61 First oil passage (oil passage)
62a, 62b Second oil passage (oil passage)

Claims (2)

A differential constant velocity universal joint that is drivingly connected to a differential device is connected to one end of the intermediate shaft, and a constant velocity universal joint that is driven and connected to a wheel is connected to the other end of the intermediate shaft. Has a drive shaft that is
Each of the differential-side and wheel-side constant velocity universal joints includes a joint body member having an internal space portion into which an end portion of the intermediate shaft enters, and an end portion of the intermediate shaft provided in the internal space portion. A movable connecting portion that is connected to the joint body member so as to be relatively displaceable, and a vehicle drive shaft structure,
An oil path that allows the lubricating oil in the differential device to flow into the internal space of at least one of the differential-side and wheel-side constant velocity universal joints;
A drive shaft structure for a vehicle, wherein the lubricating oil is used for lubricating the movable connecting portion. The vehicle drive shaft structure according to claim 1,
As the oil passage,
A first oil passage that is provided in the constant velocity universal joint on the differential side and communicates the internal space portion of the constant velocity universal joint on the differential side with the inside of the differential device;
A plurality of second oil passages provided on the intermediate shaft and for communicating with each other a pair of internal space portions of the constant velocity universal joint on the differential side and the wheel side;
With
At least one of the pair of internal space portions is provided with a pump member that generates a pumping action by being deformed as the drive shaft rotates, swings, or expands and contracts,
A drive shaft structure for a vehicle in which the lubricating oil can be circulated through the plurality of second oil passages between the pair of internal space portions by the pumping action of the pump member.

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