Multi-speed transmission device with single planetary carrier

Abstract

A multi-speed transmission device, comprising a single planetary carrier and a sun gear, at least two stages of duplex planetary gears and corresponding inner gears being arranged on the single planetary carrier in a helical form, and the sun gear being meshed with the first-stage duplex planetary gears. By arranging the duplex planetary gears in a helical form, a plurality of speed ratios can be achieved on just the single planetary carrier according to transmission requirements, thus having the advantages of simple structure, easy manufacturing and convenient installation.

Description

FIELD OF TECHNOLOGY

[0001] The present application belongs to the technical field of planetary gear transmission devices, and particularly relates to a multi-speed transmission device with a single planetary carrier. BACKGROUND

[0002] Planetary gear transmission is widely applied, mainly for vehicle speed change, especially extensively used in the automotive field, yet rarely adopted for transmission and speed change of other machinery. Nevertheless, existing planetary gear transmission devices usually require a plurality of planetary carriers to realize multi-speed shifting, resulting in multiple axes and multiple centers, and accordingly suffering from complicated structure as well as difficult manufacturing and installation. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a multi-speed transmission device with a single planetary carrier, which is scientifically and reasonably structured and simple and easy to manufacture.

[0004] To solve the above-mentioned technical problem, the present application adopts the following technical solutions:

[0005] A multi-speed transmission device with a single planetary carrier comprises a single planetary carrier, a sun gear and inner gears. At least two stages of duplex planetary gears and corresponding inner gears are helically arranged on the single planetary carrier, and the sun gear meshes with the duplex planetary gear of the first stage.

[0006] Four stages of duplex planetary gears are helically arranged on the single planetary carrier.

[0007] In view of the defects existing in the conventional planetary gear transmission devices, the inventor has designed and developed a multi-speed transmission device with a single planetary carrier, which includes a single planetary carrier, a sun gear and inner gears. At least two stages of duplex planetary gears and corresponding inner gears are helically disposed on the single planetary carrier, and the sun gear meshes with the duplex planetary gear of the first stage. By virtue of the helically-arranged duplex planetary gears, multiple speed gears can be provided merely on the single planetary carrier according to speed-change requirements. The device features simple structure, easy manufacture and convenient installation. Theoretically, the present invention can realize unlimited speed gears arranged on one single axis, satisfy requirements of various machines requiring speed change, and provide an entirely-new gear speed-change solution for reducer design. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic structural diagram of a first embodiment of the multi-speed transmission device with a single planetary carrier according to the present application.

[0009] FIG. 2 is a schematic structural-principle diagram of a first embodiment of the multispeed transmission device with a single planetary carrier according to the present application.

[0010] FIG. 3 is a schematic structural diagram of a second embodiment of the multi-speed transmission device with a single planetary carrier according to the present application.

[0011] FIG. 4 is a schematic structural diagram of a duplex planetary gear with an internal gear in the multi-speed transmission with a single planetary carrier shown in FIG. 3.

[0012] Reference numerals in the drawings: 1 internal gear, 2 single planetary carrier, 3 duplex planetary gear, 4 sun gear, 5 duplex planetary gear with internal gear, 6 internal tooth, 7 external tooth. DESCRIPTION OF THE EMBODIMENTS

[0013] I. Basic Structure

[0014] As shown in FIG. 1 and FIG. 2, a multi-speed transmission device with a single planetary carrier according to the first embodiment of the present application comprises a single planetary carrier, a sun gear and inner gears. At least two stages of duplex planetary gears 3 and corresponding inner gears 1 are helically arranged on the single planetary carrier 2, and the sun gear 4 meshes with the duplex planetary gear of the first stage. A plurality of speed gears are disposed in the single planetary carrier according to speed-gear requirements. FIG.1 and FIG.2 illustrate a four-speed transmission device, therefore four stages of duplex planetary gears and corresponding inner gears are helically arranged on the single planetary carrier.

[0015] As shown in FIG.3, the second embodiment of the present application is improved on the basis of the first embodiment. The difference lies in that, starting from the second-stage duplex planetary gear, each-stage duplex planetary gear is configured as a duplex planetary gear 5 with an internal gear which is provided with internal teeth 6 and external teeth 7 (as shown in FIG.4).

[0016] II. Working Principle

[0017] The multi-speed transmission device of the present application is provided with only one single planetary carrier and one sole sun gear. Power is input from the sun gear, all inner gears and duplex planetary gears are configured to rotate together while each internal gear rotates at a different rotational speed. When one of the inner gears is locked, the planetary carrier rotates to output speed-reduced or speed-changed power. Conversely, when power is input from the single planetary carrier, the sun gear outputs speed-increased or speed-changed power. To achieve the aforesaid effects, each-stage duplex planetary gears and corresponding inner gears shall be helically arranged on the single planetary carrier so as to cooperate for operation. The details are set forth as follows:

[0018] In the first embodiment, the transmission rule is that adjacent stages rotate in opposite directions. That is, when the first-stage internal gear is fixed, the single planetary carrier outputs forward rotation; when the second-stage internal gear is fixed, the single planetary carrier outputs reverse rotation; when the third-stage internal gear is fixed, the single planetary carrier outputs forward rotation; and when the fourth-stage internal gear is fixed, the single planetary carrier outputs reverse rotation. Accordingly, multi-speed transmission devices with different stages and opposite rotation directions of respective stages can be designed as required.

[0019] In the second embodiment, since the duplex planetary gears 5 with inner gears are adopted starting from the second stage, the transmission rule is that all stages rotate in the same direction. Specifically, the first-stage duplex planetary gear meshes with the second-stage duplex planetary gear with an internal gear; the second-stage duplex planetary gear with an internal gear meshes with the third-stage duplex planetary gear with an internal gear; and the third-stage duplex planetary gear with an internal gear meshes with the fourth-stage duplex planetary gear with an internal gear. Accordingly, multi-speed transmission devices with different stages and identical rotation directions of respective stages can be designed as required.

[0020] Similarly, with reference to the second embodiment, identical rotation directions of all stages can also be realized by adding idle gears between respective-stage duplex planetary gears in the first embodiment.

[0021] In summary, the above-mentioned three embodiments can be used independently or in combination, with the sole precondition that each-stage duplex planetary gears shall be helically arranged on the single planetary carrier. In addition, for processing convenience, the single planetary carrier may be manufactured as an integral-type structure, or designed as a split-type structure which is assembled integrally prior to use.

[0022] III. Application Scope

[0023] Conventional bench drills require adjustment of belt positions for gear shifting, which is quite troublesome. Adoption of the multi-speed transmission device of the present application can eliminate belt displacement and realize easy gear shifting. Similarly, the present application can also be applied to electric power tools such as electric drills and impact drills.

[0024] For electric bicycles, electric tricycles and the like with low power and light load, by adopting the multi-speed transmission device of the present application, vehicles with low power can also haul heavy loads.

[0025] The speed-ratio range of conventional automotive continuously-variable transmission mechanisms is narrow, which hardly adapts to complex and variable road conditions. When the present application is used in combination with a continuously-variable transmission mechanism, the speed-ratio range is enlarged, which helps satisfy requirements of various road conditions.

[0026] The multi-speed transmission device with a single planetary carrier of the present application is particularly suitable for heavy-duty trucks or other vehicles. Cooperated with braking, it can avoid brake failure as well as consequent vehicle damage and personal injury. When a vehicle travels on an expressway and encounters a steep downhill requiring braking, the accelerator can be cut off, and the multi-speed transmission device of the present application can be used for down-shifting. Speed reduction is realized through engine resistance, fuel supply can be resumed for continuous driving after the speed drops to a safe value, so as to achieve both safety and fuel economy.

[0027] Furthermore, the present application enables existing vehicles to realize control of various gears without canceling the clutch mechanism, so as to reduce costs and failure rates. Only foot-operated control over hydraulic oil circuits is required to replace existing clutch engagement-disengagement operations without changing operating habits.

[0028] In conclusion, the present application is applicable to any machine that requires speed change.

Claims

1. A multi-speed transmission device with a single planetary carrier, comprising a single planetary carrier, a sun gear and inner gears, characterized in that, at least two stages of duplex planetary gears and corresponding inner gears are helically arranged on said single planetary carrier, and the sun gear meshes with the first-stage duplex planetary gear.

2. The multi-speed transmission device according to claim 1, characterized in that four stages of duplex planetary gears are helically arranged on said single planetary carrier.

Images