Planetary gear train transmission mechanism of electric forklift speed reducer

Abstract

The utility model provides a planetary gear train transmission mechanism of an electric forklift speed reducer, which comprises a gear ring, a speed reducer shell, a planetary gear, a planetary carrier, a sun wheel shaft and a brake bracket, and the gear ring is pressed in the speed reducer shell; the planetary gear is mounted on the planetary carrier and is fixed by the snap spring I; the planetary gear is meshed with the gear ring; the sun wheel shaft is provided with an external spline and a clamp spring groove, the brake support is provided with an external spline and an internal spline, the sun wheel shaft and the brake support are matched through the splines and are axially fixed through a second clamp spring, and an axial gap is reserved; the sun gear shaft is meshed with the planetary gear; the brake support and a first-stage driven gear of the speed reducer are fixed together through a bolt. The sun wheel shaft and the brake support are axially fixed through the clamping spring, an axial gap is reserved, the effect of automatically adjusting the meshing position of the sun wheel shaft and the planetary gear is achieved, it is guaranteed that the gear is always located at the ideal meshing position during transmission, and therefore the service life of the speed reducer is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of reducers, in particular to a planetary gear train transmission mechanism of an electric forklift reducer. Background Art

[0002] The current dual-motor driven electric counterbalanced forklift usually has a reducer installed at the left and right front wheel positions respectively. After the reducer input receives the power of the drive motor, it finally transmits the power to the wheels through the planetary gear train inside the shell, realizing the driving of the vehicle.

[0003] Currently, the planetary gear systems of common reducers mostly use cylindrical spur gear transmission, and because the brake friction plate is usually integrated inside the reducer, the sun gear shaft and the brake bracket on which the friction plate is installed are often designed as a whole. The gear tooth processing of the sun gear shaft is therefore restricted, and high-precision processing techniques such as gear grinding cannot be used to achieve higher gear accuracy. With the further promotion of the electrification of forklifts, there will inevitably be higher requirements for the driving noise and transmission life of electric forklifts in the future, and the transmission structure design of forklift reducers will face new challenges. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a planetary gear transmission mechanism of an electric forklift reducer, wherein the gears of the planetary gear train are all designed with cylindrical helical gears to achieve a higher overlap, so as to reduce the transmission noise of the gears. At the same time, the sun gear shaft and the brake bracket are designed as two separate parts, so that the structure of the sun gear shaft is simplified, and processes such as gear grinding can be used to achieve higher gear accuracy, and the sun gear shaft and the brake bracket are axially fixed by a retaining spring, and a certain axial clearance is reserved in the design, which plays a role in automatically adjusting the meshing position of the sun gear shaft and the planetary gear, ensuring that the gears are always in an ideal meshing position during transmission, thereby increasing the working life of the electric forklift reducer and reducing the working noise.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A planetary gear transmission mechanism of an electric forklift reducer comprises a ring gear, a reducer housing, planetary gears, a planetary carrier, a sun gear shaft and a brake bracket, wherein the ring gear is press-fitted into the reducer housing; the planetary gears and cylindrical roller bearings are press-fitted and installed on the planetary carrier and fixed by a first retaining spring; the planetary gears and the ring gear are meshed together; the sun gear shaft is provided with an external spline and a retaining spring groove, the brake bracket is provided with an external spline and an internal spline, the sun gear shaft and the brake bracket are matched by splines and axially fixed by a second retaining spring, and an axial clearance is left; the sun gear shaft and the planetary gears are meshed with each other; the brake bracket and the first-stage passive gear of the reducer are fixed together by bolts.

[0007] As a further improvement of this solution, a ball bearing is press-fitted on the brake bracket, and a thrust bearing seat is press-fitted in the reducer housing; the thrust bearing seat serves as the bearing seat for the ball bearing.

[0008] As a further improvement of this solution, the ring gear, the planetary gears, and the gears on the sun gear shaft are all cylindrical helical gears.

[0009] As a further improvement of this solution, friction plates are installed on the external spline of the brake bracket.

[0010] As a further improvement of this solution, steel sheets are installed in the reducer housing.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows: In the planetary gear train transmission mechanism of the electric forklift reducer of the present utility model, all the gears of the planetary gear train are designed as cylindrical helical gears to achieve a higher contact ratio, so as to reduce the transmission noise of the gears. By designing the sun gear shaft and the brake bracket as two parts, the structure of the sun gear shaft is simplified. At the same time, the sun gear shaft and the brake bracket are fixed by a circlip, and a certain axial clearance is reserved between the sun gear shaft and the brake bracket, between the brake brackets, and between the circlip, which plays a role in automatically adjusting the meshing position between the sun gear shaft and the planetary gears, making the entire planetary gear train have the technical characteristics of high transmission accuracy, low gear noise, and long gear life. Description of the Drawings

[0012] The following further illustrates the present utility model with reference to the drawings.

[0013] Att Figure 1 is a schematic internal structure diagram designed for the planetary gear train transmission mechanism of the electric forklift reducer of the present utility model.

[0014] Att Figure 2 is an axonometric sectional view designed for the planetary gear train transmission mechanism of the electric forklift reducer of the present utility model.

[0015] In the figure, the markings are as follows: 1 - ring gear; 2 - reducer housing; 3 - planetary gear; 4 - cylindrical roller bearing; 5 - planet carrier; 6 - circlip one; 7 - sun gear shaft; 8 - brake bracket; 9 - circlip two; 10 - ball bearing; 11 - thrust bearing seat; 12 - friction plate; 13 - steel sheet; 14 - bolt. Detailed Embodiment

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0017] As Figure 1 shown, this embodiment provides a planetary gear train transmission mechanism for an electric forklift reducer, including a ring gear 1, a reducer housing 2, a planetary gear 3, a planet carrier 5, a sun gear shaft 7, and a brake bracket 8. The ring gear 1 is press-fitted into the reducer housing 2; the planetary gear 3 and the cylindrical roller bearing 4 are press-fitted and then installed on the planet carrier 5, and are fixed with a first snap ring 6; the planetary gear 3 meshes with the ring gear 1; the sun gear shaft 7 is provided with an external spline and a snap ring groove, and the brake bracket 8 is provided with an external spline and an internal spline. The sun gear shaft 7 and the brake bracket 8 are in spline fit and axially fixed by a second snap ring 9, and an axial clearance is left; the sun gear shaft 7 meshes with the planetary gear 3; the brake bracket 8 and the driven gear of the first stage of the reducer are fixed together by bolts 14.

[0018] A ball bearing 10 is press-fitted on the brake bracket 8, and a thrust bearing seat 11 is press-fitted into the reducer housing 2; the thrust bearing seat 11 serves as the bearing seat of the ball bearing 10.

[0019] The gears of the ring gear 1, the planetary gear 3, and the sun gear shaft 7 are all cylindrical helical gears. The gears of the planetary gear train are all designed with cylindrical helical gears to achieve a higher contact ratio and reduce the transmission noise of the gears.

[0020] Friction plates 12 are installed on the external spline of the brake bracket 8. The friction plates 12 are circular thin sheets, with internal splines on the inner holes and friction materials on both end faces. Steel sheets 13 are installed in the reducer housing 2. The steel sheets 13 are circular thin sheets. During operation, the friction plates 12 and the steel sheets 13 are paired to generate a braking torque to achieve vehicle braking.

[0021] By designing the sun gear shaft and the brake bracket as two parts, the structure of the sun gear shaft is simplified. At the same time, the sun gear shaft and the brake bracket are fixed by a snap ring, and a certain axial clearance is reserved between the sun gear shaft and the brake bracket, between the brake brackets, and between the snap rings, which plays a role in automatically adjusting the meshing position between the sun gear shaft and the planetary gear, enabling the entire planetary gear train to have the technical characteristics of high transmission accuracy, low gear noise, and long gear life.

[0022] During operation, after the reducer receives power from the drive motor, the power is transmitted to the brake bracket 8 through a set of helical gears in the first stage. The brake bracket 8 transmits the power to the sun gear shaft 7 through spline connection. After the sun gear shaft 7 meshes with the planetary gear 3 and the planetary gear 3 meshes with the ring gear 1, the power is transmitted to the planet carrier 5, and the power of the planet carrier 5 is finally transmitted to the wheels to achieve vehicle drive.

[0023] The above content is only an illustrative example of the structure of the present utility model. Those skilled in the art to which the present technology pertains can make various modifications or supplements to the described specific embodiments, or use similar methods for substitution, as long as they do not deviate from the structure of the present utility model or exceed the scope defined by this claim book, they shall fall within the protection scope of the present utility model.

Claims

1. A planetary gear transmission mechanism of an electric forklift reducer, comprising a ring gear (1), a reducer housing (2), planetary gears (3), a planet carrier (5), a sun gear shaft (7) and a brake bracket (8), characterized in that: The gear ring (1) is press-fitted into the reducer housing (2); the planetary gears (3) and the cylindrical roller bearings (4) are press-fitted and mounted on the planetary carrier (5), and fixed by a first retaining ring (6); the planetary gears (3) and the gear ring (1) are meshed together; the sun gear shaft (7) is provided with an external spline and a retaining ring groove, the brake bracket (8) is provided with an external spline and an internal spline, the sun gear shaft (7) and the brake bracket (8) are matched by splines, and are axially fixed by a second retaining ring (9), and an axial clearance is left; the sun gear shaft (7) and the planetary gears (3) are meshed with each other; the brake bracket (8) and the first-stage passive gear of the reducer are fixed together by bolts (14).

2. The planetary gear transmission mechanism of the electric forklift reducer according to claim 1, characterized in that: A ball bearing (10) is pressed onto the brake bracket (8), and a thrust bearing seat (11) is pressed into the reducer housing (2); the thrust bearing seat (11) serves as a bearing seat for the ball bearing (10).

3. The planetary gear transmission mechanism of the electric forklift reducer according to claim 1, characterized in that: The gears of the ring gear (1), the planetary gears (3) and the sun gear shaft (7) are all cylindrical helical gears.

4. The planetary gear transmission mechanism of the electric forklift reducer according to claim 1, characterized in that: The friction plate (12) is mounted on the outer spline of the brake bracket (8).

5. The planetary gear transmission mechanism of the electric forklift reducer according to claim 1, characterized in that: A steel sheet (13) is installed in the reducer housing (2).

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