JP2008002476A - Method and structure for lubricating final drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent lubrication from becoming insufficient by sufficiently lubricating a bearing part on the drive pinion shaft side and a bearing part on the differential case side during the high-speed rotation. <P>SOLUTION: A guide plate 16 rotatingly displaceable by the action of a temperature sensitive actuator 18 is installed on a carrier 2. In the low temperature state where a ring gear 7 is rotated at a relatively low speed, the guide plate 16 is held in a retreated position P2, and the lubricating oil scraped off by the ring gear 7 is circulated as indicated by the arrows B1 to B3 to lubricate bearings 5, 6 on the drive pinion shaft 4 side. In the high temperature state where the ring gear is rotated at a high speed, the guide plate 16 is positioned in a projecting position P2, and a part of the lubricating oil scraped off by the ring gear 7 is directed just downward as indicated by the arrow C1 to sufficiently lubricate even a bearing 9 on the differential case 10 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a final drive lubrication method and lubrication structure in an automobile drive system, and particularly supports a differential device (differential device) having a ring gear and a drive pinion shaft with a drive pinion gear meshing with the ring gear. The present invention relates to a final drive lubrication method and a lubrication structure in which a bearing portion inside a carrier (also referred to as a housing) is forcibly lubricated.

  In this type of final drive lubrication method or lubrication structure, a drive pinion shaft with a drive pinion gear such as a hypoid pinion gear that meshes with the ring gear as well as a differential device in which the ring gear is fixed, as described in Patent Document 1, is provided. Lubricating oil is stored in the carrier that supports each bearing, and the lubricating oil is basically swept up and circulated to the upper space inside the carrier by rotation of the ring gear etc. Like to do.

More specifically, for example, in the case of a final drive for an FR type vehicle and the type in which the rotation center (axial center) of the drive pinion gear is offset downward by a predetermined amount from that of the ring gear, A portion of the lubricating oil that has been scraped up to the internal upper space is transmitted to the inner surface of the carrier to lubricate the meshing part of the gear inside the differential case and the side bearing that supports the differential case itself. After the front and rear bearings that support the drive pinion shaft are lubricated by the lubricating oil in each part, the respective lubricating oil returns to the bottom of the carrier again, so that a lubricating action is performed by so-called lubricating oil circulation. It has come to be.
Japanese Utility Model Publication No. 5-12829

  In the final drive for an FR type vehicle as described above, especially in a situation where the drive pinion gear and the ring gear continue to rotate at a high speed, a part of the lubricating oil originally scraped up by the ring gear falls directly below the differential. The side bearings that support the interior of the case or the side of the case should be lubricated, but the lubricating oil that has been scraped up by the ring gear and the like does not lubricate the differential case, etc. due to centrifugal force. Tend to be collected. Also, the lubricating oil collected on the drive pinion shaft side is scraped again by the drive pinion gear rotating at high speed before returning to the lubricating oil reservoir at the bottom of the carrier, resulting in a so-called local circulation lubrication form. As a result, the lubricating oil is not evenly distributed throughout the interior of the carrier. As a result, a situation in which the lubricating oil does not circulate, particularly in the meshing portion between the ring gear and the drive pinion gear and the side bearing supporting the differential case, may lead to insufficient lubrication at high speed rotation.

  In addition, as a countermeasure against the above-mentioned insufficient lubrication, the amount of lubricating oil in the carrier is reduced to a level at which the side bearing is immersed in the lubricating oil so that the side bearing can be sufficiently lubricated even if high-speed rotation of the ring gear or the like continues. Although it is possible to increase it, in that case, the agitation resistance of the lubricating oil by the drive pinion gear increases, which is not preferable because the fuel efficiency of the vehicle deteriorates as the power transmission efficiency decreases.

  The present invention has been made paying attention to such problems, and in particular, even if the drive pinion gear and the ring gear are continuously rotated at a high temperature and become a high temperature state, the lubrication form is caused by the local circulation due to the centrifugal force. In particular, an attempt is made to provide a lubrication method and a lubrication structure that can uniformly lubricate the meshing portion of the ring gear and the drive pinion gear, the side bearing that supports the differential case, and the entire interior of the differential case. To do.

  According to the first aspect of the present invention, in addition to the differential device in which the ring gear is fixed to the differential case, the drive pinion shaft having the drive pinion gear meshing with the ring gear stores the lubricating oil in the respective carriers supported by the bearings. , A final drive lubrication method in which each bearing support is lubricated while circulating the lubricating oil by the scraping action accompanying the meshing rotation of the ring gear and the drive pinion gear, and is described above at high and low temperatures. The direction in which the lubricating oil circulates is changed.

  The invention described in claim 2 is the one in which the technique described in claim 1 is grasped as a lubrication structure, and in addition to a differential device having a ring gear fixed to a differential case, a drive pin having a drive pinion gear meshing with the ring gear. Lubricating oil is stored in a carrier in which each two-on shaft is supported by a bearing, and each bearing support portion is lubricated while circulating the lubricating oil by a scraping action accompanying the meshing rotation of the ring gear and the drive pinion gear. On the premise of the final drive lubrication structure, a direction changing means for changing the direction in which the lubricating oil circulates at a high temperature and a low temperature is provided at the upper part of the inner surface of the carrier.

  The direction changing means, as described in claim 3, changes the direction in which the lubricating oil circulates according to the degree of protrusion from the carrier inner surface, and specifically, as described in claim 4, It is assumed that the amount of protrusion from the inner surface of the carrier is larger at high temperatures than at low temperatures. More specifically, as described in claim 5, the direction changing means is a movable guide plate that changes the direction in which the lubricating oil circulates between a high temperature and a low temperature. The direction in which the lubricating oil circulates is changed by being driven by a warm type actuator.

  As the temperature-sensitive actuator, for example, a spring having a shape memory alloy, a bimetal, or the like is used as a main element.

  Therefore, in the inventions described in at least claims 1 and 2, especially when the drive pinion gear and the ring gear continue to rotate at a high speed, the carrier is in a high temperature state due to heat generated from the gears and the bearings. Due to the centrifugal force, the lubricating oil scraped up by the oil tends to circulate intensively toward the drive pinion shaft. On the other hand, if the direction changing means is switched to the high temperature side on the condition that the carrier has become hot, a part of the lubricating oil circulated by centrifugal force collides with the direction changing means provided on the upper surface of the carrier, for example. This forcibly changes the circulation direction of some of the lubricating oil.

  This is due to the fact that a part of the lubricating oil scraped upward by the ring gear is dropped directly or directly below by the collision with the direction changing means. However, in addition to the meshing portion between the ring gear and the drive pinion gear, the inside of the differential case and the side bearings supporting the differential case itself can be sufficiently lubricated.

  According to the first and second aspects of the invention, not only the drive pinion shaft side but also the meshing portion of the ring gear and the drive pinion gear, the inside of the differential case and the differential case itself are supported even under high temperature conditions accompanying high-speed rotation. The side bearings that are used can be sufficiently lubricated, so that it is possible not only to prevent insufficient lubrication especially during high-speed rotation, but also because there is no need to increase the amount of lubricating oil stored in the carrier. There will be no deterioration.

  1 to 3 are views showing a more specific first embodiment of a final drive lubrication structure according to the present invention, and show an example of a final drive for an FR type vehicle. 1A is a sectional view of the final drive 1, FIG. 1B is a left side view of FIG. 1A, and FIG. 2 is a line aa in FIG. The cross-sectional explanatory drawing which follows is shown, respectively.

  As shown in FIGS. 1 and 2, a drive pinion shaft 4 integral with a drive pinion gear (hypoid pinion gear) 3 is provided via a front bearing 5 and a rear bearing 6 in a carrier (housing) 2 that forms the base of the final drive 1. A differential device (differential device) 8 having a ring gear (hypoid ring gear) 7 meshing with the drive pinion gear 3 on the outer periphery thereof is rotatably supported via a pair of side bearings 9. The carrier 2 is composed of a carrier body 2A and a rear cover 2B, and both are connected by a bolt or the like (not shown).

  The differential device 8 includes a differential case 10 in which a pair of pinion mate gears 12 sharing a pinion mate shaft 11 and a pair of side gears 13 meshing with the pinion mate gears 12 are rotatably accommodated. Each side gear 13 is connected to an axle shaft 14. The pinion mate gear 12 can revolve together with the differential case 10 and can rotate around the axis of the pinion mate gear 12 itself. The ring gear 7 is fixed to the differential case 10 with bolts 15.

  Here, when paying attention to the relationship between the drive pinion shaft 4 and the ring gear 7, the drive pinion shaft 4 has a predetermined amount with respect to the axis (rotation center) of the ring gear 7 as is apparent from FIG. It is offset downward. As a result, the meshing portion between the drive pinion gear 3 and the ring gear 7 is located below the axis of the ring gear 7, while the meshing portion between the drive pinion gear 3 and the ring gear 7 is immersed in the carrier 2. Predetermined lubricating oil has been stored.

  As is clear from FIGS. 1 and 3, a part of the carrier body 2 </ b> A contains lubricating oil flowing from the direction of arrow B <b> 3 as will be described later in addition to the drive pinion shaft 4 and the front bearing 5 and rear bearing 6 sides. An opening 20 is formed for the purpose of positive introduction.

  In such a final drive 1 structure, when the drive pinion shaft 3 is rotationally driven as is well known, both axle shafts 14 are rotationally driven with a differential in the differential device 8 as is well known. At that time, the drive pinion gear 3 and the ring gear 7 immersed in the stored lubricating oil scoop up the lubricating oil and circulate it, so that not only the meshing part of both, but also the bearings 5, 6, 9 in the carrier 2. Etc., each part is lubricated.

  Here, as shown in FIG. 3 in addition to FIG. 1, the direction of the upper inner wall surface 2 a of the carrier body 2 </ b> A is changed in order to positively change the circulation direction of the lubricating oil between the high temperature and low temperature of the carrier 2. A movable guide plate 16 that functions as changing means is arranged along the upper inner wall surface 2a of the carrier body 2A. As shown in FIG. 4, the guide plate 16 is supported on the carrier body 2A by a hinge pin 17 so as to be swingable or rotatable. Even when the carrier 2 is at a low temperature, the carrier plate 2A is in the state of FIG. 2 is protruded further inward than the upper inner wall surface 2a of the carrier main body 2A as shown in FIG. 3B, and the carrier main body 2A as shown in FIG. 3A and FIG. Depending on the degree of protrusion of the guide plate 16 from the upper inner wall surface 2a, the circulation direction of the lubricating oil is positively changed or variably controlled at high temperature and low temperature.

  As shown in FIG. 4, a temperature-sensitive actuator 18 having, for example, a shape memory alloy spring 20 as a main element is disposed outside the carrier body 2A, and the guide plate 16 is rotated by the expansion / contraction operation of the actuator 18. It is intended to move or infest. The temperature-sensitive actuator 18 has a compression coil spring 20 made of a shape memory alloy and a normal compression coil spring 21 arranged in series around a rod 19 having a spring seat 19a as shown in FIG. Both springs 20 and 21 are supported by a substantially U-shaped holder 22 together with the rod 19, and the holder 22 is fixedly supported by the carrier body 2A and the tip of the rod 19 is guided by the guide plate 16. It is connected or brought into contact with the back of the.

  In other words, the temperature-sensitive actuator 18 uses the property of the material itself of the shape memory alloy compression coil spring 20 that is soft at low temperatures and hard at high temperatures. In addition, a compression coil spring 21 is used in combination as a bias spring.

  The behavior of this temperature-sensitive actuator 18 is that when the carrier 2 is at a low temperature, the spring force (restoring force) of the compression coil spring 21 is the same as that of the compression coil spring 20 made of shape memory alloy, as shown in FIG. Overcoming this, the compression coil spring 20 made of shape memory alloy is in a compressed state, and therefore the guide plate 16 stands by at a retracted position P1 so as not to obstruct the flow of the lubricating oil due to the centrifugal force of the ring gear 7.

  On the other hand, when the carrier 2 is at a high temperature, the spring force of the compression coil spring 20 made of a shape memory alloy overcomes that of the compression coil spring 21 and restrains the compression coil spring 21 in a compressed state as shown in FIG. Therefore, the guide plate 16 is pivotally displaced to the protruding position P2 so as to positively inhibit the flow of the lubricating oil accompanying the centrifugal force of the ring gear 7, and greatly protrudes inside the carrier body 2A. .

  Therefore, according to the lubrication structure of the final drive 1 as described above, in the state where the rotation speed of the ring gear 7 is in a so-called low speed rotation range where the speed is relatively low, as shown in FIGS. The ring gear 7 that rotates while meshing with the pinion gear 3 scoops up the lubricating oil stored at the bottom of the carrier 2 at its teeth as shown by arrows B1 and B2, so that it reaches the upper space in the carrier 2 The lubricating oil is directed in the direction of the drive pinion shaft 3 as indicated by an arrow B3 due to centrifugal force, and finally circulates as indicated by arrows B4 and B5 to mainly drive the drive pinion shaft 3 The front bearing 5 and the rear bearing 6 that support the bearing are lubricated. At the same time, the drive pinion gear 3 also scoops up the lubricating oil as indicated by the arrow B6. Therefore, the drive pinion gear 3 merges with the lubricating oil oriented in the direction of the arrow B3, and mainly lubricates the front bearing 5 and the rear bearing 6 as described above. Will do.

  In this case, as long as the carrier 2 is in a low temperature state, the guide plate 16 is at the retracted position P1 as shown in FIG. 4A, and the flow of the lubricating oil accompanying the centrifugal force of the ring gear 7 is not actively changed. .

  On the other hand, when the high-speed rotation state of the ring gear 7 and the drive pinion gear 3 continues and the carrier 2 becomes a high temperature state higher than a predetermined temperature, the temperature-sensitive actuator 18 extends as shown in FIG. By operating, the guide plate 16 is rotationally displaced to the protruding position P2, and greatly protrudes inside the carrier body 2A. In this state, as described above, the guide plate 16 positively changes the flow of the lubricating oil accompanying the centrifugal force of the ring gear 7.

  That is, the circulation and lubrication action of the lubricating oil that the ring gear 7 and the drive pinion gear 3 scoop up are basically the same as those at the low temperature shown in FIGS. 1 (A) and 1 (B). A part of the lubricating oil that has been scraped up collides with the guide plate 16 so that the circulation direction of a part of the lubricating oil is forcibly changed. The lubricating oil that has collided with the guide plate 16 is directed almost directly below as shown by the arrow C1, and as a result, in addition to the meshing portion with the ring gear 7 and the drive pinion gear 3, the inside of the differential case 10, The side bearing 9 supporting the differential case 10 is positively and sufficiently lubricated.

  In other words, even if the ring gear 7 and the drive pinion gear 3 continue to rotate at a high speed and the carrier 2 is in a high temperature state due to heat generated by the gears 3 and 7 and the side bearings 9 and the like, The protruding guide plate 16 forcibly changes the direction in which the lubricating oil is circulated, so that the inside of the differential case 10 and the side bearings 9 that support the differential case 10 itself are sufficiently lubricated. Insufficient lubrication of the bearing 9 can be prevented beforehand.

  Here, the number of guide plates 16 provided as direction changing means for controlling the circulation direction of the lubricating oil is not necessarily one. For example, two guide plates 16 are arranged in parallel and are alternately or The same effect can be obtained even if they are simultaneously rotated and displaced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows preferable embodiment of the final drive based on this invention, (A) is sectional explanatory drawing which shows the retraction | saving state of the guide plate provided as direction change means, (B) is description of the left side surface of the figure (A) Figure. Cross-sectional explanatory drawing along the aa line of FIG. (A) is sectional explanatory drawing which shows the state which the guide plate rotated and displaced from the state of FIG. 1, and (B) is left side explanatory drawing of the figure (A). FIGS. 4A and 4B are enlarged explanatory views showing the behavior of the guide plate shown in FIGS. 1 and 3, wherein FIG. 4A is an explanatory view showing a retracted state, and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Final drive 2 ... Carrier 2A ... Carrier body 2B ... Rear cover 2a ... Upper inner wall surface 3 ... Drive pinion gear 4 ... Drive pinion shaft 5 ... Front bearing 6 ... Rear bearing 7 ... Ring gear 8 ... Differential device 9 ... Side bearing 10 ... Differential Case 16: guide plate (direction changing means)
DESCRIPTION OF SYMBOLS 17 ... Hinge pin 18 ... Temperature sensitive actuator 19 ... Rod 20 ... Compression coil spring 21 made of shape memory alloy 21 ... Compression coil spring 22 ... Holder P1 ... Retraction position P2 ... Projection position

Claims (6)

In addition to the differential device in which the ring gear is fixed to the differential case, the drive pinion shaft having the drive pinion gear meshing with the ring gear stores lubricant oil in a carrier that is supported by the bearing, and the ring gear and the drive pinion gear mesh with each other. It is a final drive lubrication method in which each bearing support portion is lubricated while circulating lubricating oil by a scraping action accompanying rotation,
A final drive lubrication method characterized by changing a direction in which the lubricating oil circulates between a high temperature and a low temperature. In addition to the differential device in which the ring gear is fixed to the differential case, the drive pinion shaft having the drive pinion gear meshing with the ring gear stores lubricant oil in a carrier that is supported by the bearing, and the ring gear and the drive pinion gear mesh with each other. It is a final drive lubrication structure that lubricates each bearing support part while circulating the lubricating oil by a scraping action accompanying rotation,
A lubrication structure for a final drive, characterized in that direction changing means for changing the direction in which the lubricating oil circulates between the high temperature and the low temperature is provided on the inner surface of the carrier.   3. The final drive lubrication structure according to claim 2, wherein the direction changing means changes a direction in which the lubricating oil circulates in accordance with a degree of protrusion from the inner surface of the carrier.   4. The final drive lubrication structure according to claim 3, wherein the direction changing means is set so that the amount of protrusion from the inner surface of the carrier is larger at a higher temperature than at a lower temperature.   The direction changing means is a movable guide plate that changes the direction in which the lubricating oil circulates between a high temperature and a low temperature, and this guide plate is driven by a temperature-sensitive actuator to change the direction in which the lubricating oil circulates. 5. The final drive lubricating structure according to claim 4, wherein the lubricating structure is changed.   6. The final drive lubricating structure according to claim 5, wherein the actuator has a spring or bimetal made of a shape memory alloy as a main element.

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