gearbox

Abstract

The gearbox has a high-speed shaft (1) with a pinion (2), a low-speed shaft (6) with a low-speed gear (7), and at least two power split branches including a power split shaft (3). A support disc (9) is located within the gearbox, and this support disc is connected to shafts (1), (6) and / or pinion (2) and / or low-speed gear (7) via flexible members (10) or joints (11) to tilt the axis of the support disc (9). A sliding connection is formed between the support disc (9) and the power split branch shafts (3), and each of the power split branch shafts (3) is provided with a first sliding fit to capture axial forces, and the outer circumference of the support disc (9) is provided with a corresponding second sliding fit. When one branch is loaded with a greater load, the axial force generated by the gears increases. Such a force causes the branch receiving the greater load to shift axially, thereby tilting the support disc (9). As a result, the branch with the lower load is simultaneously drawn in the direction that meshes more closely, and consequently, the load on that branch increases.

Description

Technical Field

[0001] The present invention relates to the field of gear transmissions for transmitting rotational motion, particularly to the field of power split gearbox design.

[0002] Background of the Invention One known type of gearbox is the power split gearbox. In this type of gearbox, power is transmitted simultaneously by a plurality of, usually two or three branches. A branch means that one shaft has two gears of different diameters. One gear meshes with the gear on the input shaft, and the other gear meshes with the gear on the output shaft. From the perspective of gearbox design, it is preferable but not essential that the input shaft and the output shaft are coaxial with each other, and for a gearbox having two branches, both branches are rotated 180° relative to each other, and for a gearbox having three branches, these branches are rotated 120° relative to each other.

[0003] In order to equalize the transmitted power across the branches, a differential between or within the branches is required. This is usually provided using a floating high-speed shaft that floats radially to the optimal position where the power is equally divided. However, the high-speed shaft in the radial direction can be particularly unstable when not loaded.

[0004] Summary of the Invention The present invention provides a power split gearbox design. This gearbox has a high-speed shaft equipped with a pinion and fitted in at least one radial bearing. Further, this gearbox has a low-speed shaft equipped with a low-speed gear. The low-speed shaft may be fitted in at least one radial bearing or may be suspended only on the downstream shaft.

[0005] Furthermore, the gearbox has two or three power splitters. Each power splitter has a power split shaft. The power split shaft is fitted into a radial bearing and has a larger diameter gear that is firmly mounted and a smaller diameter gear that is firmly mounted.

[0006] The larger gear in the power splitter is connected to the pinion on the high-speed shaft, and these are combined to form the high-speed gear stage. The smaller gear in the power splitter is connected to the low-speed gear on the low-speed shaft, and these are combined to form the low-speed gear stage. Helical gears are provided in the high-speed and / or low-speed gear stages. The helix angle of the high-speed gear stage is different from that of the low-speed gear stage. Therefore, when the power splitter shaft moves axially, the high-speed and low-speed gear stages rotate differently in the angular direction. This results in differential power distribution.

[0007] A support disc is coaxially fitted to the shaft of at least one gear having a helical gear. A flexible member or joint is used to connect the support disc to the high-speed or low-speed shaft and / or pinion of the coaxially arranged gear having a helical gear. The flexible member or joint can tilt the axis of the support disc relative to the axis of the coaxially arranged gear having a helical gear. Furthermore, the flexible member or joint prevents mutual rotation between the support disc and the elements connected to the support disc via the flexible member (i.e., the shaft and / or pinion and / or low-speed gear of the coaxially arranged gear having a helical gear). The center of the axial position of the support disc remains unchanged.

[0008] Joints provide an even distribution of power within each branch. However, this design is more complex from various perspectives and requires lubrication. The joint may be a ball joint, and both parts of this ball joint are fixed so as not to rotate relative to each other about the longitudinal axis (i.e., the axis parallel to the axis of the gear with helical gears). Flexible connections do not provide a perfectly equal power distribution because the power division is affected by the stiffness of the connection. Compared to joints, flexible connections are easier to manufacture and do not require lubrication. To achieve the most even power division possible, flexible connections need to be designed to have low bending stiffness but sufficient axial stiffness. Flexible connections exhibit high stiffness in movement in all axial directions and rotation about the longitudinal axis (the axis parallel to the axis of the gear with helical gears), but low stiffness in rotation about an axis perpendicular to the longitudinal axis. The above can be achieved, for example, by various diameters and material parameters, and the flexible connection may be hollow, etc.

[0009] Each power splitter shaft is provided with a first portion of a sliding fit, and the outer circumference of the support disk is provided with a corresponding second portion of the sliding fit. The technical effect of the sliding fit is to form a sliding connection between the support disk and the power splitter shaft, and to capture axial forces.

[0010] In a preferred embodiment, the low-speed gear stage is a gear stage equipped with helical gears. This configuration is advantageous because the low-speed gear stage generates higher axial forces than the high-speed gear stage. The support disk captures the axial force, and this force is not transmitted to the drive and driven machinery.

[0011] Depending on the specific embodiment of the gearbox, the low-speed gear may have internal or external teeth.

[0012] A support disc may be positioned between the high-speed and low-speed axes. This means that the length of the axes does not interfere with the support disc, and the support disc is positioned in the free space between them.

[0013] In another embodiment, the support disc may have a central hole through which a high-speed or low-speed shaft passes. In this case, the support disc appears as a ring retracted onto one of the shafts. This embodiment allows for the selection of different machine configurations.

[0014] The flexible member may have the form of an axial projection of a support disk, fixed to the high-speed or low-speed shaft and / or pinion and / or low-speed gear of the coaxially arranged gear having helical gears.

[0015] In another embodiment, the flexible member may have the form of at least one spring arranged around the central axis of the support disk. The spring must be firmly attached to the support disk on a first side and firmly attached on the other side to the shaft and / or pinion and / or low-speed gear of the coaxially arranged gear having a helical gear.

[0016] The above-described principle of power splitting using a tilting support disc may be used for a gearbox in which power is transmitted simultaneously by multiple branches. Optimal differential occurs only when the branches are in an optimized axial position. This is provided by the support disc, which captures the axial force of each power split branch and provides the relative axial position of the gears, which are equipped with simple helical gears. The tilting support disc provides the optimized branch position of each branch relative to each other and relative to the output shaft. If one branch should be subjected to a greater load, the axial force generated by the gears increases. Such a force causes the branch receiving the greater load to shift axially, thereby tilting the support disc. This simultaneously pulls the less loaded branch in the direction of greater meshing, resulting in an increased load. Uneven loads on specific branches are continuously and repeatedly balanced.

[0017] Exemplary embodiments of the present invention will be described with reference to the drawings. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic longitudinal cross-sectional view showing a gearbox according to the present invention. [Figure 2] This is a schematic longitudinal cross-section showing a support disc with a joint connected to a low-speed gear. [Figure 3] This is a schematic longitudinal cross-sectional view showing a support disc with a flexible member in the form of an axial projection that is firmly connected to a low-speed gear. [Figure 4] This is a schematic longitudinal cross-sectional view showing a support disc comprising a central hole and a flexible member in the form of a spring, positioned around the central hole of the support disc and connected to a low-speed gear.

[0019] Examples of the Invention Example 1 The power split gearbox is pinion 2 It has a high-speed shaft 1 equipped with radial bearings, and this high-speed shaft has radial bearings 8 It is fitted into. Furthermore, the gearbox has low-speed gears. 7including a low-speed shaft 6 provided with a radial bearing 8 fitted therein. The high-speed shaft 1 and the low-speed shaft 6 are coaxial. The low-speed gear 7 has external teeth.

[0020] Furthermore, the gearbox has two power-split branches. Each power-split branch has a power-split shaft 8 fitted in a radial bearing 3 . Each power-split shaft 3 is provided with two gears firmly attached thereto, namely the larger gear 4 having a relatively large diameter and the smaller gear 5 having a relatively small diameter.

[0021] The larger gear 4 of the power-split branch is connected to the pinion 1 of the high-speed shaft 2 , and they are combined to form a high-speed gear stage. The smaller gear 5 of the power-split branch is connected to the low-speed gear 6 of the low-speed shaft 7 , and they are combined to form a low-speed gear stage.

[0022] The high-speed gear stage and the low-speed gear stage are provided with helical gears. In this embodiment, the helix angle of the high-speed gear stage is smaller than that of the low-speed gear stage. A relatively large helix angle in a gear means that the gear is one of the gear mechanisms that cause axial movement of the power-split branch. During axial movement, an undesired axial force is generated on the gear, and such a force must be captured. Otherwise, this force will be undesirably transmitted to the technology downstream of the gearbox. The capture of the undesired axial force can be more easily achieved by the support disk 9 of the low-speed gear stage due to its low speed.

[0023] The gearbox is the high-speed shaft 1and low-speed shaft 6 coaxially supported disk 9 It contains (support disk) 9 The axis of rotation is both axes 1 , 6 (This is the same as the axis of rotation.) High-speed axis 1 and low-speed shaft 6 Support disk between 1 It is located there.

[0024] Support disc 9 is a support disk 9 To tilt the axis of the low-speed gear relative to the axis of the low-speed gear, a flexible member 10 Low gears via low gear stages 7 Connected. Support disk 9 The center of the axial position remains unchanged. Flexible member 10 This is the low-speed gear of the low-speed gear stage. 7 A support disc that is firmly attached to it. 9 This is the axial projection of the flexible member. 10 This is the low-speed gear of the low-speed gear stage. 7 Support disk for 9 This prevents mutual rotation.

[0025] Power split branch shaft 3 Each of these is provided with a first sliding fit portion, in this case the first sliding fit portion is a circumferential groove. Support disc 9 The outer circumference is formed by the corresponding second part of the sliding fit. Support disc 9 The outer circumference is the power split branch shaft 3 By fitting into the circumferential grooves of the support disc, 9 and power split branch shaft 3 A sliding connection is created between them that can capture axial forces.

[0026] This embodiment is shown in Figures 1 and 3.

[0027] Example 2 In this example, the power split gearbox differs from Example 1 in that it has a support disk. 9However, joint 11 Low gears via low gear stages 7 Connected. Joint 11 is a support disk 9 The axis of the support disc can be tilted relative to the axis of the low-speed gear. 9 The center of the axial position of the joint remains unchanged. 11 This is a ball joint, and both parts of this ball joint are aligned along the longitudinal axis (i.e., the low-speed axis). 6 They are fixed so as not to rotate relative to each other around an axis parallel to it. Therefore, the joint 11 This is the low-speed gear of the low-speed gear stage. 7 Support disk for 9 This prevents mutual rotation.

[0028] This embodiment is shown in Figures 1 and 2. [Explanation of Symbols]

[0029] 1 High speed axis 2. High-speed shaft pinion 3 Power split branch shaft 4. The larger gear 5 The smaller gear 6 Low speed axis 7 Low-speed gear 8 Radial bearings 9. Support disc 10 Flexible member 11 joints

Claims

1. A gearbox comprising a high-speed shaft (1) fitted to at least one radial bearing (8), A low-speed shaft (6) equipped with a low-speed gear (7), Two or three power splitters, each having a power split shaft (3) fitted into a radial bearing (8) and provided with two firmly mounted gears (4), (5) of different diameters, and It has, The larger gear (4) of the power split branch is connected to the pinion (2) of the high-speed shaft (1), and together they form a high-speed gear stage, and the smaller gear (5) of the power split branch is connected to the low-speed gear (7) of the low-speed shaft (6), and together they form a low-speed gear stage. The high-speed gear stage and / or the low-speed gear stage are provided with helical gears. In the gearbox, A support disc (9) is fitted into the gearbox coaxially with the shafts (1), (6) of at least one gear having a helical gear, and the support disc (9) is attached to the shafts (1), (6) and / or the pinion (2) and / or the low-speed gear (7) of the coaxially arranged gear having a helical gear via a flexible member (10) or joint (11) to tilt the axis of the support disc (9) with respect to the axis of the coaxially arranged gear having a helical gear. The central axis position of the support disc (9) is fixed, and the flexible member (10) or the joint (11) is adapted so that the support disc (9) does not rotate relative to the shafts (1), (6) and / or the pinion (2) and / or the low-speed gear (7) of the coaxially arranged gear having the helical gear. A sliding connection is formed between the support disk (9) and the power splitting shaft (3), and in order to capture axial forces, each of the power splitting shafts (3) is provided with a first sliding fit portion, and the outer circumference of the support disk (9) is provided with a corresponding second sliding fit portion. The helix angle of the high-speed gear stage is different from the helix angle of the low-speed gear stage. A gearbox characterized by the following features.

2. The gearbox according to claim 1, characterized in that the helical gear is provided in the low-speed gear stage.

3. The gearbox according to claim 1 or 2, characterized in that the low-speed gear (7) has internal teeth or external teeth.

4. The gearbox according to any one of claims 1 to 3, characterized in that the support disc (9) is located between the high-speed shaft (1) and the low-speed shaft (6).

5. The gearbox according to any one of claims 1 to 3, characterized in that the support disc (9) is provided with a central hole, and the high-speed shaft (1) or the low-speed shaft (6) penetrates the central hole.

6. The gearbox according to any one of claims 1 to 4, characterized in that the flexible member (10) is an axial projection of the support disc (9) that is firmly connected to the shafts (1), (6) and / or the pinion (2) and / or the low-speed gear (7) of the coaxially arranged gear having the helical gear.

7. The gearbox according to any one of claims 1 to 5, wherein the flexible member (10) is at least one spring arranged around the central axis of the support disk (9), the spring being firmly connected to the support disk (9) on a first side and firmly connected on the other side to the shafts (1), (6) and / or the pinion (2) and / or the low-speed gear (7) of the coaxially arranged gear having the helical gear.

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