JP2008196555A - Shaft supporting structure of transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration of durability of a bearing for supporting a transmission shaft and a retaining portion for retaining the bearing. <P>SOLUTION: When a radial reaction force of gear engagement works on the transmission shaft 1, a load due to this reaction force works on every ball 4c of a ball bearing 4 of supporting the shaft 1 and a retaining portion 3 of holding the bearing 4.To average a load on each ball 4c due to the operation of the reaction force and loads that the retaining portion 3 receives from the balls, a rigidity adjuster 6 for adjusting the peripheral rigidity of the bearing 4 in the retaining portion 3 so that the rigidity of a portion on which the reaction force works becomes lower than the rigidity of the other portions.This can prevent concentration of loads onto balls 4c and portions of the retaining portion 3 in the direction of operation of the reaction force and consequently suppress deterioration of durability of the bearing 4 and the retainer 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shaft support structure for a transmission.

  Conventionally, on a rotation transmission path between a prime mover and wheels in a vehicle such as an automobile, a transmission for changing the speed of rotation transmitted through the path is provided.

  In such a transmission, a plurality of shafts to which various gears for shifting are fixed are connected so as to be able to transmit rotation through meshing of these gears, and the input rotational speed and the output rotational speed of the transmission are switched by switching the meshed gears. A speed change operation for changing the speed ratio, which is the ratio, is performed. By performing the speed change operation of the transmission in this way, the speed of rotation transmitted through the route is changed on the rotation transmission route between the prime mover and the wheels in the vehicle.

A plurality of shafts provided in the transmission are rotatably supported on the case of the transmission by a bearing shown in Patent Document 1, for example. In Patent Document 1, the bearing is held in the transmission case by fixing the coaxial receiver to the case with a bolt. Alternatively, it may be possible to form a holding portion into which the bearing is fitted in the transmission case, and hold the bearing with the entire outer peripheral surface of the coaxial bearing inscribed by the holding portion. In this case, it is possible to more reliably hold the bearing in the case.
JP 2002-188710 (paragraph [0018], FIG. 2, FIG. 3)

  By the way, in the transmission, when rotation is transmitted between the shafts by the gears meshing with each other, a large force called a gear meshing reaction force acts on the shafts in the radial direction, and the holding portion that supports the shafts via the bearings. Thus, a load based on the reaction force is applied. Here, when a load is applied to the bearing and the holding portion in accordance with the reaction force, a portion of the bearing and the holding portion that is located in the direction in which the reaction force acts has a larger load than the other portions. work. In other words, the load accompanying the action of the reaction force is concentrated on the portion of the bearing and the holding portion that is located in the direction in which the reaction force acts. And the durability of a bearing and a holding | maintenance part deteriorates because such concentration of load arises.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shaft for a transmission that can suppress deterioration in durability of a bearing that supports the shaft of the transmission and a holding portion that holds the bearing. It is to provide a support structure.

In the following, means for achieving the above object and its effects are described.
To achieve the above object, according to the first aspect of the present invention, there is provided a bearing for rotatably supporting a shaft on which a gear meshing reaction force acts in the radial direction when the transmission is driven, and a case of the transmission for holding the bearing. In the shaft support structure of the transmission in which the bearing is held in a state in which the entire circumferential direction of the outer peripheral surface thereof is inscribed in the holding portion, the reaction force of the holding portion A rigidity adjusting portion is provided for adjusting the rigidity of the holding portion around the circumferential direction of the bearing so that the rigidity of the portion located in the direction in which the bearing acts is lower than the rigidity of the other portions.

  When a gear meshing reaction force acts on the transmission shaft in the radial direction, a load based on the reaction force is applied to the bearing that supports the shaft and the holding portion that holds the bearing. According to the above configuration, the load received by the bearing and the holding unit in accordance with the action of the reaction force by setting the rigidity of the part located in the action direction of the reaction force in the holding part to be lower than the rigidity of the other part. Is averaged. That is, among the loads received by the bearing and the holding part due to the action of the reaction force, the load received by the part located in the direction in which the reaction force acts is suppressed low, and the load of other parts is reduced by the amount that the load is suppressed low. The load received is increased. In this way, the load received by the bearing and the holding part with the action of the reaction force is averaged, and the concentration of the load on the part located in the reaction direction of the reaction force in the bearing and the holding part is suppressed. Deterioration of the durability of the bearing and the holding part due to the concentration of the load is suppressed.

  According to a second aspect of the present invention, in the first aspect of the present invention, the bearing is a rolling bearing in which a large number of rolling elements capable of rolling between an inner ring and an outer ring are arranged in the circumferential direction of the shaft. It is a summary.

  When the meshing reaction force of the gear acts on the shaft, a load based on the reaction force is applied to the holding portion via each rolling element of the bearing. Here, among the rolling elements of the bearing, a larger load is applied to the rolling elements positioned in the direction in which the meshing reaction force acts than the other rolling elements. Therefore, among the loads received by the holding portion via the rolling elements in response to the reaction force, the loads received via the rolling elements located in the direction in which the reaction force acts are loads received via the other rolling elements. It becomes big compared with. Further, during the rotation of the shaft, each rolling element of the bearing rotates in the circumferential direction while rolling between the inner ring and the outer ring, and a portion corresponding to the portion located in the direction in which the reaction force acts on the holding portion pass. As for the rolling elements passing through this portion, the load acting on the rolling elements increases rapidly and then decreases rapidly. If the load acting on the rolling element changes suddenly in this way, the rolling element may be damaged or damaged between the inner ring and the outer ring, and the durability of the bearing will be deteriorated.

  However, according to the above configuration, the rigidity of the portion of the holding portion that is located in the reaction direction of the reaction force is lower than the rigidity of the other portions. The load received through the moving body can be averaged. That is, among the loads received by the holding portion via the rolling elements in response to the reaction force, the load received via the rolling elements located in the direction in which the reaction force acts is kept low, and the load is kept low. As much as possible, the load received through the other rolling elements increases. For this reason, when each rolling element of the bearing rotates in the circumferential direction between the inner ring and the outer ring in accordance with the rotation of the shaft, it passes through a portion corresponding to the portion located in the direction in which the reaction force acts in the holding portion. A sudden change in the load acting on the rolling elements, that is, a rapid increase and a rapid decrease thereafter is suppressed. Accordingly, it is possible to suppress the rolling element from being damaged or damaged between the inner ring and the outer ring due to a sudden change in the load caused by the reaction force acting on the rolling element, thereby suppressing the deterioration of the durability of the bearing. it can.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the rigidity adjusting portion reduces the rigidity of a portion of the holding portion located in the direction in which the reaction force acts.
According to the above configuration, the rigidity adjusting portion reduces the rigidity of the portion of the holding portion located in the direction in which the reaction force acts, thereby accurately creating a state where the rigidity of the portion is lower than the rigidity of the other portions. be able to.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the rigidity adjusting portion may have a thickness in the radial direction of the shaft at a portion located in a direction in which the reaction force acts on the holding portion. The gist is that it is formed by making it thinner than the thickness in the same diameter direction in the part.

  According to the above configuration, since it is easy to form the rigidity adjusting portion with respect to the holding portion, the rigidity of the portion located in the direction in which the reaction force acts on the holding portion can be easily made lower than the rigidity of the other portions. .

  The invention according to claim 5 is the invention according to claim 4, wherein the rigidity adjusting portion is formed by cutting a portion of the holding portion corresponding to the outer peripheral surface of the bearing.

  There are other parts such as gear around the holding part of the transmission, and ribs and grooves are formed on the outer surface of the holding part, so it is not possible to provide a rigidity adjustment part on the outer surface side of the holding part difficult. However, according to the above configuration, the rigidity adjusting portion is formed by cutting the portion of the holding portion corresponding to the outer peripheral surface of the bearing, in other words, the portion on the inner surface side of the holding portion. This can be carried out without being obstructed by other parts around the holding part and ribs and grooves formed on the outer surface side of the holding part. Accordingly, the degree of freedom in forming the rigidity adjusting portion in the holding portion increases.

  The invention according to claim 6 is the invention according to claim 5, wherein the bearing is a rolling bearing in which a large number of rolling elements that can roll between an inner ring and an outer ring are arranged in a circumferential direction of the shaft, In the holding part, one side in the axial direction of the shaft is opened and the other side is closed, and the rigidity adjusting part is the other side of the part corresponding to the outer peripheral surface of the bearing in the holding part. The gist of the present invention is that it is formed by cutting this part and extends to a position closer to the one side than the rolling element of the bearing.

  According to the above configuration, when the meshing reaction force of the gear acts on the rolling element of the bearing, the rigidity adjusting part side formed by cutting the portion corresponding to the outer peripheral surface of the coaxial receiver in the holding part. Pressed. When the rolling element is pushed to the rigidity adjusting portion side in this way, the bearing (outer ring or the like) is deformed to the rigidity adjusting portion side, so that it is difficult for the holding portion of the coaxial receiver to come off from one side.

Hereinafter, an embodiment in which the present invention is applied to a transmission provided on a rotation transmission path between a prime mover and wheels in a vehicle such as an automobile will be described.
In the above transmission, a plurality of fixed shafts of various gears for shifting are connected so as to be able to transmit rotation through meshing of these gears, and the input rotational speed and output rotational speed of the transmission are switched by switching the meshing gears. A speed change operation for changing the speed ratio, which is the ratio, is performed. By performing the speed change operation of the transmission in this manner, the speed of rotation transmitted through the route on the rotation transmission route between the prime mover and the wheels in the vehicle is changed.

  FIG. 1 is a partial sectional view showing a shaft support structure of a transmission, more specifically, a support structure of a predetermined shaft 1 in the transmission. As shown in the figure, the transmission case 2 is formed with a holding portion 3 for supporting the shaft 1, and the rolling bearing 4 attached to the shaft 1 has an entire outer peripheral surface thereof. Is held in an inscribed state. The holding portion 3 includes a hole 5 that opens toward the right side in the drawing, and holds the bearing 4 in the hole 5. In the holding part 3, the formation of such a hole 5 opens one side (right side in the figure) and closes the other side (left side in the figure).

  The bearing 4 is arranged in the circumferential direction between an inner ring 4a fitted on the outer circumferential surface of the shaft 1, an outer ring 4b fitted on the inner circumferential surface of the hole 5 of the holding portion 3, and the inner ring 4a and the outer ring 4b. And a large number of balls 4c that can be rolled. When the shaft 1 rotates, the balls 4c provided between the inner ring 4a and the outer ring 4b of the bearing 4 rotate in the circumferential direction of the shaft 1 while rolling, and the shaft 1 moves to the holding portion 3 by the movement of the bearing 4. It will be supported rotatably.

  By the way, in a transmission, when rotation is transmitted between shafts by meshing gears, a large force called a gear meshing reaction force acts on these shafts in the radial direction. Here, for example, when the vehicle moves forward, the meshing reaction force of the gear acts on the shaft 1 in the direction of the arrow Y1 in the figure. Further, when the vehicle is moving backward, the rotation direction of each shaft in the transmission is opposite to that when moving forward, so that the direction of action of the gear meshing reaction force with respect to the shaft 1 is also opposite to the arrow Y1 direction. And when the said reaction force acts with respect to the axis | shaft 1, the load based on the effect | action of the said reaction force is applied with respect to many ball | bowl 4c provided between the inner ring | wheel 4a and the outer ring | wheel 4b in the bearing 4 which supports the axis | shaft 1. A load based on the action of the reaction force is applied to the holding portion 3 that holds the bearing 4 through the balls 4c.

  In this embodiment, in order to average the load received by each ball 4c of the bearing 4 based on the reaction force and the load received by the holding unit 3 via the ball 4c based on the reaction force, A rigidity adjusting unit 6 that adjusts the rigidity of the bearing 4 around the circumferential direction of the bearing 4 is provided in the holding unit 3. More specifically, the rigidity adjusting portion 6 is provided in the holding portion 3 so that the rigidity of the portion of the holding portion 3 located in the direction in which the reaction force acts is lower than the rigidity of the other portions. The rigidity adjusting portion 6 is a portion that is located in the direction in which the reaction force of the holding portion 3 acts (the direction of the arrow Y1 and the direction opposite to the arrow Y1) and that corresponds to the outer peripheral surface of the bearing 4 by cutting. Is formed. By forming the rigidity adjusting portion 6, the thickness of the portion of the holding portion 3 located in the direction in which the reaction force acts is made thinner than the thickness of the other portions. As a result, the rigidity of the portion located in the direction in which the reaction force acts on the holding portion 3 is made lower than the rigidity of the other portions.

  Next, the detailed shape of the rigidity adjusting unit 6 will be described with reference to FIGS. 2 is a front view of the shaft 1, the holding portion 3, and the bearing 4 of FIG. 1 viewed from the right side in the drawing, and FIG. 3 is a cross-sectional view of the holding portion 3 of FIG. FIG.

  The rigidity adjusting portion 6 is formed by cutting a portion on the other side (left side in FIG. 1) of portions corresponding to the outer peripheral surface of the bearing 4 in the holding portion 3, and is one than the ball 4 c of the bearing 4. It extends to the side (right side in FIG. 1).

  Further, regarding the inner shape of the rigidity adjusting portion 6, the cutting depth of the rigidity adjusting portion 6 and the cross-sectional area in the radial direction of the shaft 1 in the internal space of the rigidity adjusting portion 6 are from the other side of the holding portion 3. It is formed so as to gradually become smaller toward one side. Further, the cutting depth of the rigidity adjusting portion 6 is maximized in a portion located in the direction in which the gear meshing reaction force acts, and gradually decreases as the distance from the portion in the circumferential direction of the shaft 1 increases. Therefore, the contact length in the axial direction of the shaft 1 between the bearing 4 (outer ring 4b) and the hole 5 of the holding portion 3 is minimum at the portion located in the direction in which the reaction force acts, and the shaft 1 The longer it is, the longer it becomes.

  FIG. 4 is a cross-sectional view of the shaft 1, the holding unit 3, and the bearing 4 of FIG. 2 as viewed from the direction of the arrow BB. As can be seen from the figure, in the holding portion 3, the position farthest in the circumferential direction of the shaft 1 from the portion located in the direction in which the reaction force acts is over the entire axial direction of the shaft 1 on the outer peripheral surface of the bearing 4. The length in the axial direction of the outer peripheral surface of the bearing 4 and the inner peripheral surface of the hole 5 is maximum.

  Next, when the rigidity adjusting portion 6 is formed on the holding portion 3, the load received by each ball 4c of the bearing 4 and the load received by the holding portion 3 via each ball 4c based on the action of the reaction force. This will be described with reference to FIGS. In these figures, the magnitude of the load received by each ball 4c based on the action of the reaction force and the magnitude of the load received by the holding portion 3 via each ball 4c are indicated by the length of the thin arrow. The thin arrow in FIG. 5 represents the magnitude of the load when the rigidity adjusting portion 6 is not formed, and the thin arrow in FIG. 6 represents the magnitude of the load when the rigidity adjusting portion 6 is formed.

  When the rigidity adjusting portion 6 is not formed in the holding portion 3, as shown in FIG. 5, when the reaction force acts on the shaft 1 in the direction indicated by the arrow Y1, the bearing 4 supporting the shaft 1 Of each ball 4c, a larger load is applied to the ball 4c located in the direction of the reaction force than the other balls 4c. Therefore, among the loads received by the holding unit 3 via the balls 4c due to the reaction force, the loads received via the ball 4c located in the direction in which the reaction force acts (in this example, the direction of the arrow Y1) The load is larger than the load received through the other balls 4c. In other words, the load associated with the reaction force is concentrated on the ball 4c positioned in the reaction direction of the reaction force in the bearing 4 and the portion of the holding portion 3 positioned in the reaction direction of the reaction force. And the durability of the bearing 4 and the holding | maintenance part 3 deteriorates because such concentration of load arises.

  When the shaft 1 rotates, the balls 4c of the bearing 4 rotate in the circumferential direction while rolling between the inner ring 4a and the outer ring 4b, and the direction in which the reaction force acts on the holding portion 3 (the direction of the arrow Y1) Passes through the part corresponding to the part located at. Regarding the ball 4c passing through this portion, the load acting on the ball 4c increases rapidly and then decreases rapidly. When the load acting on the ball 4c changes abruptly in this manner, the ball 4c may be damaged or damaged between the inner ring 4a and the outer ring 4b, and the durability of the bearing 4 will be deteriorated.

  On the other hand, when the rigidity adjusting part 6 is formed in the holding part 3, the rigidity of the part located in the action direction (arrow Y1 direction) of the reaction force in the holding part 3 is lower than the rigidity of the other parts. . As a result, as shown in FIG. 6, the load received by each ball 4c of the bearing 4 as a result of the reaction force and the load received by the holding portion 3 via the ball 4c as a result of the reaction force. Averaging is achieved. That is, among the loads received by the respective balls 4c of the bearing 4 due to the reaction force, the load received by the ball 4c located in the direction in which the reaction force acts (the direction of the arrow Y1) is suppressed to a low level. The load received by the other balls 4c increases by the amount that can be suppressed. In addition, among the loads received by the holding unit 3 through the balls 4c in response to the reaction force, the loads received through the balls 4c located in the direction in which the reaction force acts (the direction of the arrow Y1) are kept low. The load received through the other balls 4c is increased by the amount that the load is kept low.

  Thus, by averaging the load received by each ball 4c of the bearing 4 with the action of the reaction force and the load received by the holding portion 3 through the ball 4c with the action of the reaction force, Concentration of the load on the ball 4c located in the reaction direction of the reaction force in the bearing 4 and the portion of the holding portion 3 located in the action direction of the reaction force is suppressed. Therefore, deterioration of the durability of the bearing 4 and the holding part 3 due to the concentration of the load is suppressed.

  Further, when each ball 4c of the bearing 4 rotates in the circumferential direction between the inner ring 4a and the outer ring 4b as the shaft 1 rotates, it is positioned in the direction in which the reaction force acts on the holding portion 3 (arrow Y1 direction). It is suppressed that the load acting on the ball 4c passing through the portion corresponding to the portion to be changed suddenly increases, that is, rapidly increases and then decreases rapidly. Therefore, it is possible to prevent the ball 4c from being damaged or damaged between the inner ring 4a and the outer ring 4b due to a sudden change in the load caused by the reaction force acting on the ball 4c, thereby suppressing deterioration of the durability of the bearing 4. can do.

According to the embodiment described in detail above, the following effects can be obtained.
(1) By providing the rigidity adjusting portion 6 in the holding portion 3, the load received by each ball 4c of the bearing 4 with the action of the meshing reaction force of the gear with respect to the shaft 1, and the holding portion 3 with the action of the reaction force. Is averaged through the balls 4c. Thereby, the load concentrates on the ball 4c located in the reaction direction of the reaction force in the bearing 4 and the portion located in the reaction direction of the reaction force in the holding portion 3, and the load acting on them increases. It is suppressed. Therefore, deterioration of the durability of the bearing 4 and the holding part 3 due to the concentration of the load is suppressed.

  (2) Since the rigidity adjusting portion 6 is provided in the holding portion 3, the load received by each ball 4 c of the bearing 4 due to the action of the reaction force is averaged, so that each ball of the bearing 4 is rotated when the shaft 1 is rotated. When 4c passes through a portion of the holding portion 3 that corresponds to the portion where the gear meshing reaction force acts, the load acting on the ball 4c does not change suddenly. Therefore, it is possible to suppress the ball 4c from being damaged or damaged between the inner ring 4a and the outer ring 4b due to a sudden change in the load acting on the ball 4c, and thereby suppressing the deterioration of the durability of the bearing 4. Will be able to.

  (3) The rigidity adjusting portion 6 is configured so that the rigidity of the portion of the holding portion 3 located in the direction in which the reaction force acts is lower than the rigidity of the other portion. This adjusts the rigidity around the direction. Specifically, the rigidity adjusting unit 6 is provided so as to reduce the rigidity of the portion of the holding unit 3 located in the direction in which the reaction force acts. Thereby, the state mentioned above, ie, the state in which the rigidity of the part located in the direction in which the reaction force of the holding part 3 acts can be accurately created.

  (4) Moreover, the rigidity adjustment part 6 makes the thickness about the radial direction of the axis | shaft 1 in the part located in the direction where the said reaction force acts in the holding | maintenance part 3 rather than the thickness about the same radial direction in another part. It is formed by thinning. For this reason, it is possible to easily form the rigidity adjusting portion 6 with respect to the holding portion 3. Accordingly, the rigidity of the portion of the holding portion 3 located in the direction in which the reaction force acts can be easily made lower than the rigidity of the other portions.

  (5) As a specific method of forming the rigidity adjusting portion 6, a portion of the holding portion 3 located in the direction in which the reaction force acts and a portion corresponding to the outer peripheral surface of the bearing 4 (the inner periphery of the hole 5 The method of cutting the surface) is employed. Here, since other parts such as gears are provided around the holding part 3 of the transmission or ribs and grooves are formed on the outer surface of the holding part 3, the rigidity adjustment is performed on the outer surface side of the holding part. It is difficult to provide a part. However, as described above, the rigidity adjusting portion 6 is formed by cutting the inner peripheral surface of the hole 5 in the holding portion 3, thereby forming the formation on other parts around the holding portion 3 or on the outer surface side of the holding portion 3. This can be done without being interrupted by the ribs and grooves formed. Accordingly, the degree of freedom in forming the rigidity adjusting portion 6 in the holding portion 3 is increased.

  (6) The cutting depth of the rigidity adjusting portion 6 is maximized at the portion located in the direction in which the gear meshing reaction force acts, and gradually decreases as the distance from the portion in the circumferential direction of the shaft 1 increases. Accordingly, the thickness in the radial direction of the shaft 1 in the holding portion 3 of the portion where the rigidity adjusting portion 6 is formed is the smallest in the portion located in the direction in which the reaction force acts, and the circumference of the coaxial 1 from that portion. The larger the distance, the larger the distance. For this reason, the rigidity of the portion of the holding portion 3 where the rigidity adjusting portion 6 is formed is also the lowest in the portion located in the direction in which the reaction force acts, and gradually increases as the distance from the portion in the circumferential direction of the coaxial 1 increases. Become. In this way, by gradually changing the rigidity of the portion where the rigidity adjusting portion 6 is formed in the holding portion 3 in the circumferential direction, each ball 4c of the bearing 4 acts in the direction in which the gear meshing reaction force acts on the holding portion 3. When passing through a portion corresponding to the portion located at, the sudden change in the load acting on the ball 4c can be more accurately suppressed.

  (7) As shown in FIG. 7, the rigidity adjusting portion 6 is the other side (left side in the drawing) of the portion corresponding to the outer peripheral surface of the bearing 4 in the holding portion 3, in other words, the portion on the closed side of the hole 5. It is formed by cutting. Furthermore, the rigidity adjusting portion 6 extends to one side (right side in the figure) of the ball 4 c of the bearing 4, in other words, to a position closer to the opening side of the hole 5. Therefore, when the meshing reaction force of the gear indicated by the arrow Y1 acts on the ball 4c of the bearing 4, the ball 4c is pushed to the rigidity adjusting portion 6 side. Thus, when the ball 4c is pushed to the rigidity adjusting portion 6 side, the deformation of the bearing 4 (outer ring 4b) toward the rigidity adjusting portion 6 side by the deformation shown by the two-dot chain line in the figure causes the holding portion 3 of the coaxial receiver 4 to move. Dropping off from one side (open side) is less likely to occur.

In addition, the said embodiment can also be changed as follows, for example.
The rigidity adjusting portion 6 is not necessarily formed so as to extend closer to the opening side of the hole 5 than the ball 4c of the bearing 4, for example, as shown in FIG. 8, the closed side of the hole 5 rather than the ball 4c. You may form so that it may stay to the position of a near side.

  As shown in FIG. 9, the rigidity adjusting portion 6 is formed in the portion of the holding portion 3 corresponding to the outer peripheral surface of the bearing 4 (inner peripheral surface of the hole 5) on the open side portion of the hole 5. It is also possible to do. In this case, since the rigidity adjusting portion 6 is formed in the vicinity of the opening portion of the hole 5, an operation for forming the rigidity adjusting portion 6 is facilitated. In forming the rigidity adjusting portion 6 in this manner, from the viewpoint of suppressing the dropout of the bearing 4 from the hole 5, the rigidity adjusting portion 6 is located closer to the opening side of the hole 5 than the ball 4 c of the bearing 4. It is preferable to form so that it may remain.

The rigidity adjusting unit 6 may be formed on the outer surface side of the holding unit 3.
The rigidity adjusting unit 6 may be formed by assembling a separate part made of a material softer than the other part in a part located in the direction in which the gear meshing reaction force acts in the holding part 3. . In this case, it is not necessary to make the thickness in the radial direction of the shaft 1 thinner than the thickness in the same radial direction in the other portions of the holding portion 3 that is located in the direction in which the reaction force acts.

  -The rigidity adjustment part 6 may raise the rigidity of parts other than the part located in the direction in which the said reaction force acts in the holding | maintenance part 3. FIG. For example, it is conceivable that the rigidity adjusting portion 6 is formed in a portion of the holding portion 3 other than the portion positioned in the direction in which the reaction force acts by providing a rib. Moreover, you may make it form the said rigidity adjustment part 6 by assembling | attaching another part which consists of material harder than the part located in the direction where the said reaction force acts in the holding | maintenance part 3 to parts other than the part. When the rigidity adjusting portion 6 is provided as described above, the rigidity of the portion located in the direction in which the reaction force acts in the holding portion 3 is relatively lower than the rigidity of the other portions, and thereby the holding portion 3 The state where the rigidity of the part located in the direction in which the reaction force acts is lower than the rigidity of the other part is created.

-As the rolling bearing 4, you may employ | adopt the rolling bearing which uses a cylindrical roller or a cone roller as a rolling element.
A sliding bearing may be used in place of the rolling bearing 4.

The fragmentary sectional view which shows the shaft support structure of the transmission in this embodiment. The front view which looked at the axis | shaft, holding | maintenance part, and bearing of FIG. 1 from the right side in a figure. Sectional drawing which looked at the holding | maintenance part of FIG. 1 from the arrow AA direction. Sectional drawing which looked at the axis | shaft, holding | maintenance part, and bearing of FIG. 2 from the arrow BB direction. Explanatory drawing which shows the magnitude | size of the load which each ball | bowl of a bearing receives based on the effect | action of the meshing reaction force of the gear with respect to a shaft, and the load which a holding | maintenance part receives via each ball | bowl based on the effect | action of the said reaction force. Explanatory drawing which shows the magnitude | size of the load which each ball | bowl of a bearing receives based on the effect | action of the meshing reaction force of the gear with respect to a shaft, and the load which a holding | maintenance part receives via each ball | bowl based on the effect | action of the said reaction force. The expanded sectional view which shows the rigidity adjustment part periphery in the said holding | maintenance part. The expanded sectional view which shows the other example of formation of a rigidity adjustment part. The expanded sectional view which shows the other example of formation of a rigidity adjustment part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Shaft, 2 ... Case, 3 ... Holding part, 4 ... Bearing, 4a ... Inner ring, 4b ... Outer ring, 4c ... Ball, 5 ... Hole, 6 ... Stiffness adjustment part

Claims (6)

A bearing that rotatably supports a shaft on which a gear meshing reaction force acts in a radial direction when the transmission is driven, and a holding portion that is formed in the case of the transmission to hold the bearing, the holding portion includes In the shaft support structure of the transmission in which the bearing is held in a state where the entire circumferential direction of the outer peripheral surface is inscribed,
A stiffness adjusting unit that adjusts the stiffness of the holding portion around the circumferential direction of the bearing so that the stiffness of the portion located in the direction in which the reaction force acts is lower than the stiffness of the other portion; A transmission shaft support structure characterized by being provided. 2. The shaft support structure for a transmission according to claim 1, wherein the bearing is a rolling bearing in which a large number of rolling elements that can roll between an inner ring and an outer ring are arranged in a circumferential direction of the shaft. The transmission shaft support structure according to claim 1, wherein the rigidity adjusting unit is configured to reduce a rigidity of a portion of the holding unit positioned in a direction in which the reaction force acts. The rigidity adjusting portion is formed by making the thickness of the holding portion in the radial direction of the portion located in the direction in which the reaction force acts smaller than the thickness of the other portion in the same radial direction. The transmission shaft support structure according to claim 3. The transmission shaft support structure according to claim 4, wherein the rigidity adjusting portion is formed by cutting a portion of the holding portion corresponding to an outer peripheral surface of the bearing. The bearing is a rolling bearing in which a large number of rolling elements that can roll between an inner ring and an outer ring are arranged in the circumferential direction of the shaft,
In the holding portion, one side of the shaft in the axial direction is opened and the other side is closed,
The rigidity adjusting portion is formed by cutting the other side portion of the holding portion corresponding to the outer peripheral surface of the bearing, and is positioned closer to the one side than the rolling element of the bearing. The transmission shaft support structure according to claim 5, wherein

Images