Drive transmission device

Abstract

To provide a drive transmission device capable of reducing a thrust load which occurs on a drive gear and a driven gear during the operation of parking lock while reducing the sizes and costs of a bearing, and thus those of the drive transmission device.SOLUTION: The drive transmission device according to the present invention includes gears (a driven gear 110, and a drive gear 120) each having an inclined tooth muscle, a parking lock gear 130 to be rotated integrally with the gears, and a lock lever 160 for engaging with the parking lock gear to suppress the rotation. The tooth muscle of the parking lock gear is inclined in the direction of mitigating the thrust load which occurs on the gears.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drivetrain equipped with a parking lock device. [Background technology]

[0002] Vehicles are equipped with drivetrains, such as transmissions and transaxles, that transmit driving force between multiple axles with different rotational speeds. These drivetrains may be equipped with a parking lock device. The parking lock device prevents the wheels from rotating unintentionally when the shift lever is shifted into park or when the parking button is manually operated.

[0003] For example, Patent Document 1 discloses a parking lock device for an electric vehicle that has a reducer that reduces the power from a drive motor. The reducer includes "an input shaft to which the rotational force of the drive motor is input, an input gear provided on the input shaft, a first intermediate gear that meshes with the input gear, an intermediate shaft on which the first intermediate gear is provided, a second intermediate gear that is provided on the intermediate shaft so as to be axially aligned with the first intermediate gear, and an output shaft on which an output gear that meshes with the second intermediate gear is provided."

[0004] Furthermore, the parking lock device of Patent Document 1 includes "a parking lock gear provided on the intermediate shaft so as to be aligned in the axial direction with the first intermediate gear and the second intermediate gear, a lock lever that can lock the parking lock gear by engaging with the upper teeth of the parking lock gear, and a parking lock actuator that is disposed on the top of the motor housing, is connected to the lock lever via an actuator rod, and drives the lock lever to switch the parking lock gear between a locked state and an unlocked state." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-92616 Summary of the Invention [Problem to be solved by the invention]

[0006] As disclosed in Patent Document 1, in a typical drive mechanism, the drive gear and driven gear (the first intermediate gear and second intermediate gear in Patent Document 1) are helical gears. Therefore, when the parking lock device is activated (when the parking lock is ON), a large thrust load is generated due to the twist angle of the tooth trace of the drive gear and driven gear.

[0007] This causes the rolling elements of the bearings supporting the rotating shafts of the drive gear and driven gear to ride up onto the shoulders of the outer and inner rings. To prevent this, the bearings' load-bearing capacity against thrust loads must be increased, necessitating the use of larger bearings. This results in increased bearing costs and larger drive transmission devices.

[0008] In view of these problems, the present invention aims to provide a drive transmission device that can reduce the thrust load generated in the drive gear and driven gear when the parking lock is activated, thereby enabling the bearings and the drive transmission device to be made smaller and less expensive. [Means for solving the problem]

[0009] In order to solve the above problems, a typical configuration of a drive transmission device according to the present invention includes a gear with an inclined tooth trace (such as a helical gear, a screw gear (spiral gear), or a spiral bevel gear), a parking lock gear that rotates integrally with the gear, and a lock lever that meshes with the parking lock gear to suppress its rotation, and is characterized in that the tooth trace of the parking lock gear is inclined in a direction that alleviates the thrust load generated in the gear.

[0010] In order to solve the above problems, another representative configuration of a drive transmission device according to the present invention includes a driven gear to which driving force is input from a motor gear, a drive gear that outputs driving force to a differential gear, an intermediate shaft that is the rotation axis of the driven gear and the drive gear, a pair of bearings that support both ends of the intermediate shaft, a parking lock gear attached to the intermediate shaft, and a lock lever that meshes with the parking lock gear to suppress rotation, wherein the driven gear and the drive gear are helical gears, and the tooth trace of the parking lock gear is inclined in a direction that alleviates the thrust load generated in the driven gear and the drive gear.

[0011] It is preferable that the lock lever is inclined in the same direction as the tooth trace of the parking lock gear. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a drive transmission device that can reduce the thrust load generated in the drive gear and driven gear when the parking lock is activated, thereby enabling the bearings and therefore the drive transmission device to be made smaller and less expensive. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating a drive transmission device according to a first embodiment. [Figure 2] 2 is an enlarged schematic view of the vicinity of an intermediate shaft of the drive transmission device of the first embodiment shown in FIG. 1. FIG. [Figure 3] FIG. 10 is an enlarged schematic view of the vicinity of an intermediate shaft of a conventional drive transmission device. [Figure 4] FIG. 6 is a diagram illustrating a drive transmission device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0015] Fig. 1 is a diagram illustrating a drive transmission device 100 according to a first embodiment. Fig. 2 is a schematic enlarged view of the vicinity of an intermediate shaft 140 of the drive transmission device 100 of the first embodiment shown in Fig. 1.

[0016] 1 is mounted on a vehicle (not shown), and outputs the driving force input from an input shaft 102a of a motor 102 to a motor gear 104 to a differential gear 106. The driving force output to the differential gear 106 is transmitted to wheels (not shown) via an output shaft 108.

[0017] The drive transmission device 100 of the first embodiment includes a driven gear 110, a drive gear 120, a parking lock gear 130, and an intermediate shaft 140. The driven gear 110 is a helical gear that rotates around the intermediate shaft 140 as its rotation axis, and is meshed with the motor gear 104. The drive gear 120 is a helical gear that rotates around the intermediate shaft 140 as its rotation axis, and is meshed with the differential gear 106.

[0018] When the motor gear 104 rotates, the driven gear 110 rotates in conjunction with it, and the driving force from the motor 102 is input to the driven gear 110. When the driven gear 110 rotates, the drive gear 120, which has the same rotation axis as the driven gear 110, rotates. The drive gear 120 has fewer teeth than the driven gear 110, so that the speed is reduced and the torque increases. When the drive gear 120 rotates, the differential gear 106 rotates in conjunction with it, and the driving force is output to the differential gear 106.

[0019] 2, the intermediate shaft 140 is supported by a pair of bearings 150 arranged at both ends thereof. The bearings 150 are deep groove ball bearings, and are configured to include an outer ring 152, an inner ring 154, and rolling elements 156 that roll between them. In the first embodiment, the intermediate shaft 140 is inserted through the inner ring 154.

[0020] The drive transmission device 100 of the first embodiment also includes a parking lock mechanism made up of a parking lock gear 130 and a lock lever 160. The parking lock gear 130 is a "gear with oblique tooth traces" attached to the intermediate shaft 140. The lock lever 160 is formed with a protrusion 162 that meshes with the tooth groove 132 of the parking lock gear 130. The lock lever 160 is also installed at an angle in the same direction as the tooth trace of the parking lock gear 130.

[0021] When a vehicle occupant shifts the shift lever to the parking position or operates a parking button (not shown), an actuator (solenoid) (not shown) activates the parking lock mechanism, and the protrusion 162 of the lock lever 160 meshes with the tooth groove 132 of the parking lock gear 130. This suppresses the rotation of the intermediate shaft 140, and ultimately the rotation of the output shaft 108 and the wheels.

[0022] Fig. 3 is an enlarged schematic diagram of the vicinity of the intermediate shaft 140 of the conventional drive transmission device 10. In the conventional drive transmission device 10 illustrated in Fig. 3, components that are common to the drive transmission device 100 of the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0023] As shown in Figure 3, the conventional drive transmission device 10 also has a parking lock mechanism consisting of a parking lock gear 30 and a lock lever 60. The parking lock gear 30 is a "gear with non-slanted teeth" attached to an intermediate shaft 140, which is the rotation axis of the driven gear 110 and the drive gear 120. The lock lever 60 also has a protrusion 62 that meshes with the tooth groove 32 of the parking lock gear 30.

[0024] When the parking lock mechanism of the conventional drive transmission device 10 is activated, the protrusion 62 of the lock lever 60 meshes with the tooth groove 32 of the parking lock gear 30, preventing the rotation of the intermediate shaft 140. At this time, because the teeth of the driven gear 110 and the drive gear 120, which are helical gears, are inclined, when a thrust load L1 acting to the right in the figure is applied to the driven gear 110, a thrust load L2 acting to the left in the figure (the opposite direction to the thrust load L1) is applied to the drive gear 120. Note that because the parking lock gear 130 is a spur gear, no thrust load is generated when the parking lock mechanism is activated.

[0025] 3, because the drive transmission device 10 is a reducer, the torque applied to the drive gear 120 is greater than the torque applied to the driven gear 110. Then, although it depends on the respective torsion angles, the thrust load L2 generated by the drive gear 120 is greater than the thrust load L1 generated by the driven gear 110. For this reason, a thrust load (L2-L1) in the left direction in the drawing, which is equal to "thrust load L2-thrust load L1", is applied to the intermediate shaft 140. Then, the force that tries to move the intermediate shaft 140 in the L2 direction shifts the inner ring 154 of the bearing 150, and the rolling elements 156 ride up on the shoulder of the inner ring 154.

[0026] Therefore, in the drive transmission device 100 of the first embodiment, the tooth trace 134 of the parking lock gear 130 is inclined in a direction that alleviates the thrust load (L2-L1) generated in the driven gear 110 and the drive gear 120.

[0027] According to the above configuration, when the parking lock mechanism operates and the convex portion 162 of the lock lever 160 meshes with the tooth groove 132 of the parking lock gear 130, a thrust load L3 is applied to the parking lock gear 130 in the right direction in the figure, i.e., in the direction opposite to the thrust load L2. This makes it possible to alleviate the thrust loads generated in the driven gear 110 and the drive gear 120, and suppresses axial movement of the intermediate shaft 140 caused by the thrust load.

[0028] As described above, according to the drive transmission device 100 of the first embodiment, axial movement of the intermediate shaft 140 caused by thrust load is suppressed, and therefore, it is possible to prevent the rolling elements 156 of the bearing 150 that supports the intermediate shaft 140 from riding on the shoulder. As a result, it is possible to reduce the load resistance required of the bearing 150. Therefore, it is possible to reduce the size and cost of the bearing 150 and, ultimately, the drive transmission device 100.

[0029] 4 is a diagram illustrating a drive transmission device 100A according to a second embodiment. The drive transmission device 100A does not include an intermediate shaft.

[0030] The drive transmission device 100A includes a drive gear 120 that is directly attached to the shaft of the motor 102, and a parking lock gear 130 that rotates integrally with the drive gear 120. The parking lock gear 130 is provided with a lock lever 160 that meshes with the parking lock gear 130 to restrict rotation.

[0031] 4, the tooth traces 134 of the drive gear 120 and the parking lock gear 130 are inclined in opposite directions. Because rotational torques in the same direction are applied to the drive gear 120 and the parking lock gear 130, thrust loads (relaxation) are generated in opposite directions. In other words, the tooth trace 134 of the parking lock gear 130 is inclined in a direction that relieves the thrust load generated in the drive gear 120.

[0032] As described above, the drive transmission device 100A of the second embodiment also suppresses axial movement caused by thrust load by the parking lock gear 130, making it possible to prevent rolling elements from riding up onto the shoulders of the bearing (not shown in FIG. 4) that supports the parking lock gear 130. As a result, the load resistance required of the bearing can be reduced, making it possible to reduce the size and cost of the bearing and therefore the drive transmission device.

[0033] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0034] The present invention can be used as a drive transmission device equipped with a parking lock device. [Explanation of symbols]

[0035] L1...thrust load, L2...thrust load, L3...thrust load, 10...drive transmission device, 30...parking lock gear, 60...lock lever, 62...convex portion, 100, 100A...drive transmission device, 102...motor, 102a...input shaft, 104...motor gear, 106...differential gear, 108...output shaft, 110...driven gear, 120...drive gear, 122...tooth lead, 130...parking lock gear, 132...tooth space, 134...tooth lead, 140...intermediate shaft, 150...bearing, 152...outer ring, 154...inner ring, 156...rolling element, 160...lock lever, 162...convex portion

Claims

1. A gear with slanted teeth, a parking lock gear that rotates integrally with the gear; a lock lever that meshes with the parking lock gear to suppress rotation; Equipped with A drive transmission device characterized in that the tooth trace of the parking lock gear is inclined in a direction that alleviates the thrust load generated in the gear.

2. a driven gear to which driving force is input from the motor gear; a drive gear that outputs driving force to the differential gear; an intermediate shaft that is a rotation shaft of the driven gear and the drive gear; a pair of bearings supporting both ends of the intermediate shaft; a parking lock gear attached to the intermediate shaft; a lock lever that meshes with the parking lock gear to suppress rotation; Equipped with the driven gear and the drive gear are helical gears, a tooth trace of the parking lock gear inclined in a direction that alleviates a thrust load generated in the driven gear and the drive gear;

3. 3. The drive transmission device according to claim 1, wherein the lock lever is inclined in the same direction as the tooth trace of the parking lock gear.

Images