EP-4737768-A1 - GEARBOX CENTRAL SHAFT FOR WIND TURBINE GENERATOR

EP4737768A1EP 4737768 A1EP4737768 A1EP 4737768A1EP-4737768-A1

Abstract

A gearbox central shaft for a wind turbine generator, which is configured to simplify the complicated structure of the gearbox central shaft. The gearbox central shaft includes a sun shaft (2), an output shaft (3) and a connecting shaft (4); where the sun shaft is configured to be connected to a sun gear (5) and driven to rotate by the sun gear; the output shaft is configured to be connected to and drive an output gear (6) to rotate; and the connecting shaft includes a sun shaft connecting portion (7), a middle section (8) and an output shaft connecting portion (9), the sun shaft connecting portion being connected to the sun shaft at an axial end of the connecting shaft and being elastically connected to the middle section, and the output shaft connecting portion being connected to the output shaft at the other axial end of the connecting shaft and being elastically connected to the middle section.

Inventors

ZHOU, DAN

Assignees

ZF Wind Power (Tianjin) Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240801

Claims (10)

A gearbox central shaft for a wind turbine generator, characterized by comprising: a sun shaft configured to be connected to a sun gear and driven to rotate by the sun gear; an output shaft configured to be connected to and drive an output gear to rotate; and a connecting shaft comprising a sun shaft connecting portion, a middle section and an output shaft connecting portion, the sun shaft connecting portion being connected to the sun shaft at one axial end of the connecting shaft and being elastically connected to the middle section, and the output shaft connecting portion being connected to the output shaft at the other axial end of the connecting shaft and being elastically connected to the middle section.
The gearbox central shaft according to claim 1, characterized in that the connecting shaft further comprises elastic necks, and the sun shaft connecting portion and the output shaft connecting portion are connected to the middle section by means of the elastic necks, respectively; and each of the elastic necks comprises a bent portion that extends from a first end and is bent to a second end, the first end is fixed to the middle section, the second end is connected to the sun shaft connecting portion or the output shaft connecting portion, and the bent portion has a thickness less than that of the middle section.
The gearbox central shaft according to claim 2, characterized in that the bent portion extends from the first end and is bent at 90 degrees to the second end.
The gearbox central shaft according to claim 2, characterized in that the elastic neck further comprises a thickness-reduced portion, the thickness-reduced portion extends from the middle section to the first end of the bent portion, and a thickness of the thickness-reduced portion is reduced gradually from the middle section to the first end of the bent portion.
The gearbox central shaft according to claim 4, characterized in that a thickness of the bent portion is a thickness of the thickness-reduced portion at a connection with the first end of the bent portion.
The gearbox central shaft according to claim 1, characterized in that the sun shaft connecting portion comprises a flange, and the flange is bolted to a shaft end surface of the sun shaft.
The gearbox central shaft according to claim 1, characterized in that the sun shaft connecting portion comprises a side wall, and the side wall is located at an outer periphery of the sun shaft and fits against an outer peripheral surface of the sun shaft.
The gearbox central shaft according to claim 1, characterized in that the output shaft connecting portion comprises a flange, and the flange is bolted to a shaft end surface of the output shaft.
The gearbox central shaft according to claim 1, characterized in that the output shaft connecting portion comprises a bearing mounting groove, and the bearing mounting groove protrudes toward an outer periphery of the output shaft to assemble an inner ring of a bearing supporting the output shaft.
The gearbox central shaft according to claim 9, characterized in that the bearing mounting groove comprises an outer peripheral wall and a shaft end wall that are connected to each other, the outer peripheral wall is configured to support an inner peripheral surface of a bearing inner ring, and the shaft end wall is configured to fit against a shaft end surface of the bearing inner ring.

Description

Technical Field The present invention relates to a shaft, and in particular to a gearbox central shaft for a wind turbine generator. Background Art A main shaft of a wind turbine generator drives a generator by means of a planetary speed-increasing gearbox, the main shaft of the wind turbine generator provides a low-speed and high-torque rotational input to the gearbox, the gearbox realizes speed increasing and torque reducing, and thus provides a high-speed and low-torque rotational output to the generator. A gearbox central shaft includes a sun shaft driven to rotate by a sun gear, and further includes an output shaft which drives an output gear to rotate, and thus a gearbox output shaft connected to the main shaft of the generator is driven to rotate. The sun shaft is engaged with the output shaft by means of a spline to drive the output shaft to rotate, and the gearbox central shaft needs to be provided with a lubrication structure for lubricating the spline, resulting in a complex structure. Summary An objective of the present invention is to provide a gearbox central shaft for a wind turbine generator, which is configured to simplify the complicated structure of the gearbox central shaft. According to embodiments of the present invention, the gearbox central shaft includes a sun shaft, an output shaft and a connecting shaft; where the sun shaft is configured to be connected to a sun gear and driven to rotate by the sun gear; the output shaft is configured to be connected to and drive an output gear to rotate; and the connecting shaft includes a sun shaft connecting portion, a middle section and an output shaft connecting portion, the sun shaft connecting portion being connected to the sun shaft at one axial end of the connecting shaft and being elastically connected to the middle section, and the output shaft connecting portion being connected to the output shaft at the other axial end of the connecting shaft and being elastically connected to the middle section. In one or more embodiments, the connecting shaft further includes elastic necks, and the sun shaft connecting portion and the output shaft connecting portion are connected to the middle section by means of the elastic necks, respectively; and each of the elastic necks includes a bent portion that extends from a first end and is bent to a second end, the first end is fixed to the middle section, the second end is connected to the sun shaft connecting portion or the output shaft connecting portion, and the bent portion has a thickness less than that of the middle section. In one or more embodiments, the bent portion extends from the first end and is bent at 90 degrees to the second end. In one or more embodiments, the elastic neck further includes a thickness-reduced portion, the thickness-reduced portion extends from the middle section to the first end of the bent portion, and a thickness of the thickness-reduced portion is reduced gradually from the middle section to the first end of the bent portion. In one or more embodiments, a thickness of the bent portion is a thickness of the thickness-reduced portion at a connection with the first end of the bent portion. In one or more embodiments, the sun shaft connecting portion includes a flange, and the flange is bolted to a shaft end surface of the sun shaft. In one or more embodiments, the sun shaft connecting portion includes a side wall, and the side wall is located at an outer periphery of the sun shaft and fits against an outer peripheral surface of the sun shaft. In one or more embodiments, the output shaft connecting portion includes a flange, and the flange is bolted to a shaft end surface of the output shaft. In one or more embodiments, the output shaft connecting portion includes a bearing mounting groove, and the bearing mounting groove protrudes toward an outer periphery of the output shaft to assemble an inner ring of a bearing supporting the output shaft. In one or more embodiments, the bearing mounting groove includes an outer peripheral wall and a shaft end wall that are connected to each other, the outer peripheral wall is configured to support an inner peripheral surface of the bearing inner ring, and the shaft end wall is configured to fit against a shaft end surface of the bearing inner ring. The embodiments of the present invention have at least the following beneficial effects. The sun shaft drives the output shaft to rotate by means of the connecting shaft, a torque is transmitted between the sun shaft and the output shaft without providing a spline structure, and the gearbox central shaft does not need spline lubrication structures such as a lubrication oil passage, a spline oil pocket and an oil retainer, and thus has a simpler structure, lighter weight and lower cost. Brief Description of the Drawings The above and other features, properties, and advantages of the present invention will become more apparent from the following description with reference to the drawings an