Automotive transmission

The present application claims priority to Korean Patent Application No. 10-2018-0074722, filed Jun. 28, 2018, the entire contents of which is incorporated herein for all purposes by this reference.

The present invention relates to an automotive transmission and, more particularly, to an automotive transmission providing driving force using a motor.

Generally, hybrid vehicles or electric vehicles are driven with the power from a motor, and have a simple decelerator or a 2 to 3-speed transmission between the motor and driving wheels to secure the suitable driving force required to a vehicle while reducing the capacity of the motor.

It is preferred that such a transmission has a simple configuration with less transmission loss during traveling of a vehicle, thereby securing high power transmission efficiency.

The information disclosed in the present Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgement or any form of suggestion that the present information forms the prior art already known to a person skilled in the art.

Various aspects of the present invention are directed to providing an automotive transmission having a simple configuration with less transmission loss during traveling of a vehicle, securing high power transmission efficiency and thus increasing fuel efficiency and the mileage of a vehicle.

In various aspects of the present invention, according to one aspect, various aspects of the present invention are directed to providing an automotive transmission including: a first planetary gear set having first to third rotation elements; an input shaft engaged with the first rotation element of the first planetary gear set; an output shaft engaged with the second rotation element of the first planetary gear set; and a sleeve section sliding linearly along an axial direction of the first planetary gear set to selectively switch to a first state in which the third rotation element is secured to a transmission housing, a second state in which the third rotation element is engaged with a further rotation element, or a neutral state in which the third rotation element is not secured to or engaged with the transmission housing or the further rotation element.

A brake device may be provided between the transmission housing and the sleeve section to restrict rotation of the sleeve section with friction force.

The sleeve section may be operated to switch sequentially between the first state, the neutral state, and the second state during the linear sliding thereof.

The sleeve section may be operated to switch sequentially between the first state, the neutral state, the second state, and an third state during the linear sliding thereof, wherein the brake device is engaged with the sleeve section only in the first state, the neutral state, and the second state, and is disengaged from the sleeve section in the third state.

The first rotation element may be a sun gear, the second rotation element may be a first planet carrier, and the third rotation element may be a first ring gear.

In the second state of the sleeve section, the first planet carrier may be engaged with the first ring gear.

The sleeve section may be respectively provided, on internal and external circumferential surfaces, with internal and external splines to be engaged with both the transmission housing and the first planet carrier, and both the brake device and the first ring gear.

A second planetary gear set may be additionally engaged with the second rotation element of the first planetary gear set to decelerate the speed of driving power.

According to an exemplary embodiment of the present invention, the automotive transmission has a simple configuration with less transmission loss during traveling of a vehicle, securing high power transmission efficiency and thus increasing fuel efficiency and the mileage of a vehicle.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

FIG. 1 is a schematic view illustrating the configuration of an automotive transmission according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic view illustrating a sleeve section of the transmission shown in FIG. 1 in a neutral state;

FIG. 3 is a schematic view illustrating the sleeve section in a first state, forming a first speed stage;

FIG. 4 is a schematic view illustrating a flow of power in the first speed stage shown in FIG. 3 ;

FIG. 5 is a schematic view illustrating the sleeve section switched to the neutral state before changing to a second speed stage from the first speed stage shown in FIG. 3 ;

FIG. 6 is a schematic view illustrating the sleeve section in a second state, forming a second speed stage;

FIG. 7 is a schematic view illustrating a flow of power in the second speed stage shown in FIG. 6 ;

FIG. 8 is a schematic view illustrating the sleeve section in a third state, forming a 2D speed stage; and

FIG. 9 is a schematic view illustrating the configuration of an automotive transmission according to various exemplary embodiments of the present invention.

It may be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particularly intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments of the present invention, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the other hand, the invention(s) is/are intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Hereinbelow, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to an exemplary embodiment of the present invention, referring to FIG. 1 , FIG. 2 , and FIG. 3 , an automotive transmission includes: a first planetary gear set PG 1 having first to third rotation elements; an input shaft IN engaged with the first rotation element of the first planetary gear set PG 1 ; an output shaft OUT engaged with the second rotation element of the first planetary gear set PG 1 to which the first rotation element of the first planetary gear set PG 1 is engaged; and a sleeve section SB sliding linearly along an axial direction of the first planetary gear set PG 1 to selectively switch to a first state in which the third rotation element engaged with the second rotation element is secured to a transmission housing CS, a second state in which the third rotation element is engaged with a further rotary element, or a neutral state in which the third rotation element is not secured to or engaged with the transmission housing CS or the further rotary element.

Furthermore, a brake device B 1 is provided between the transmission housing CS and the sleeve section SB to restrict rotation of the sleeve section SB with friction force.

That is, the transmission is operated to receive power from a motor at the first rotation element of the first planetary gear set PG 1 , to output the power to the second rotation element, and to properly control the operation of the third rotation element using the sleeve section SB and the brake device B 1 , changing gear speed from the power.

The sleeve section SB is operated to sequentially switch to the first state, the neutral state, and the second state while it is sliding linearly.

The first state is a state of forming a first speed stage, and the second state is a state of forming a second speed stage.

As illustrated in FIG. 2 , FIG. 3 , FIG. 4 , FIG. 5 , FIG. 6 , FIG. 7 , and FIG. 8 , the sleeve section SB may be operated to switch sequentially between the first state, the neutral state, the second state, and an third state during the linear sliding thereof. The brake device B 1 is engaged with the sleeve section SB only in the first state, the neutral state, and the second state, and is disengaged from the sleeve section SB in the third state.

The third state is a state in which although it is similar to the second state in that it forms the second speed stage, it reduces unnecessary drag through disengagement from the bake device B 1 to resultantly render power transmission efficiency to be greater. The third state will be referred to hereinafter as a ‘2D speed stage’.

In an exemplary embodiment of the present invention, in the planetary gear set PG 1 , the first rotation element is a first sun gear 51 , the second rotation element is a first planet carrier C 1 , and the third rotation element is a first ring gear R 1 .

In the second state of the sleeve section SB, the first planet carrier C 1 of the second rotation element is engaged with the first ring gear R 1 of the third rotation element.

The sleeve section SB is respectively provided, on internal and external circumferential surfaces, with internal and external splines IP and OP to be engaged with both the transmission housing CS and the first planet carrier C 1 , and both the brake device B 1 and the first ring gear R 1 .

Furthermore, a shift fork SF is mounted on the sleeve section SB to externally apply an axial manipulating force.

Subsequently, the operation of the automotive transmission will be described.

FIG. 3 is a schematic view illustrating the sleeve section SB in a first state, forming a first speed stage, wherein the sleeve section SB shifts to the left side from the neutral state of FIG. 2 , forming the first speed stage.

In the instant state, the left side of the internal spline IP of the sleeve section SB is engaged with the transmission housing CS, and the external spline OP is engaged with the first ring gear R 1 of the first planetary gear set PG 1 , so that the first ring gear R 1 is secured to the transmission housing CS.

Thus, as illustrated in FIG. 4 , the power output to the first ring gear R 1 from the motor is transmitted to the output shaft OUT in a decelerated state through the first planet carrier C 1 , forming the first speed stage.

To change speed from the first speed stage of FIG. 3 to the second speed stage, the brake device B 1 is first engaged to restrict the rotation of the sleeve section SB, and then the sleeve section SB is operated to shift to the neutral state shown in FIG. 5 . In the instant state, even when the sleeve section SB is disengaged from the transmission housing CS, the brake device B 1 maintains the state of restricting the rotation of the first ring gear R 1 .

As such, when the brake device B 1 slips to increase rotation speed of the first ring gear R 1 , and the driving speed of the motor is decreased in synchronization with the second speed stage, the first ring gear G 1 and the first planet carrier C 1 are synchronized in speed. Here, as illustrated in FIG. 6 , the sleeve section SB is shifted to the second state so that the first ring gear R 1 and the first planet carrier C 1 are mechanically integrated with each other by the sleeve section SB, and the brake device B 1 is completely disengaged.

Thus, all of the rotation elements in the planetary gear set PG 1 rotate together, and the power from the motor is output through the output shaft OUT as illustrated in FIG. 7 , forming the second speed stage.

Although the state of FIG. 7 itself can stably maintain the second speed stage continuously, when the sleeve section SB is shifted to the third state as illustrated in FIG. 8 , the brake device B 1 is disengaged from the sleeve section SB while the sleeve section SB is being engaged with the first ring gear R 1 and the first planet carrier C 1 . This prevents consumption of a portion of the power, which is caused due to the drag action from the brake device B 1 , while maintaining the second speed stage, resultantly increasing the power transmission efficiency furthermore.

FIG. 9 is a schematic view illustrating the configuration of an automotive transmission according to various exemplary embodiments of the present invention. The basic configuration of the present exemplary embodiment of the present invention is the same as or substantially the same as that of FIG. 1 , except that a second planetary gear set PG 2 is additionally engaged with the first planet carrier C 1 of the second rotation element of the first planetary gear set PG 1 to additionally decelerate the speed of driving power.

In the exemplary embodiment of the present invention, in the second planetary gear set PG 2 , a second sun gear S 2 is engaged with the first planet carrier C 1 of the first planetary gear set PG 1 , a second ring gear R 2 is secured to or integrally formed with the transmission housing CS, and the output shaft OUT is formed on a second planet carrier C 2 engaged to the second ring gear R 2 and the second sun gear S 2 , rendering the power input to the second sun gear S 2 to be additionally decelerated, and outputting the decelerated power via the second planet carrier C 2 .

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”, “upper”, “lower”, “upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”, “inwardly”, “outwardly”, “internal”, “external”, “inner”, “outer”, “forwards”, and “backwards” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the invention and their practical application, to enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.