Planetary gear train of automatic transmission for vehicle

A planetary gear train of an automatic transmission for a vehicle, comprising:

• an input shaft receiving torque of an engine;
• an output shaft outputting changed torque of the engine;
• a first planetary gear set including first, second, and third rotation elements;
• a second planetary gear set including fourth, fifth, and sixth rotation elements;
• a third planetary gear set including seventh, eighth, and ninth rotation elements;
• a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements;
• a first rotation shaft including the first rotation element and selectively connected to a transmission housing;
• a second rotation shaft including the second and sixth rotation elements;
• a third rotation shaft including the third and seventh rotation elements;
• a fourth rotation shaft including the fourth rotation element and directly connected to the input shaft;
• a fifth rotation shaft including the fifth rotation element, selectively connected to the transmission housing, and selectively connected to the third rotation shaft or the fourth rotation shaft;
• a sixth rotation shaft including the eighth and twelfth rotation elements and selectively connected to the first rotation shaft or the fourth rotation shaft;
• a seventh rotation shaft including the ninth and eleventh rotation elements and directly connected to the output shaft;
• and
• an eighth rotation shaft including the tenth rotation element and selectively connected to the transmission housing.

A planetary gear train of an automatic transmission for a vehicle, comprising:

• an input shaft receiving torque of an engine;
• an output shaft outputting changed torque;
• a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear;
• a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear;
• a third planetary gear set including a third sun gear, a third planet carrier, and a third ring gear;
• and
• a fourth planetary gear set including a fourth sun gear, a fourth planet carrier, and a fourth ring gear,
• wherein the input shaft is directly connected to the second sun gear,
• the output shaft is directly connected to the third ring gear and the fourth planet carrier,
• the first planet carrier is directly connected to the second ring gear,
• the first ring gear is directly connected to the third sun gear,
• the third planet carrier is directly connected to the fourth ring gear,
• the second sun gear is selectively connected to the third planet carrier,
• the second planet carrier is selectively connected to the second sun gear,
• the second planet carrier is selectively connected to the first ring gear and the third sun gear,
• the first sun gear is selectively connected to the third planet carrier and the fourth ring gear,
• the second planet carrier is selectively connected to a transmission housing,
• the first sun gear is selectively connected to the transmission housing, and
• the fourth sun gear is selectively connected to the transmission housing.