Continuously variable transmission

• US 5,888,160 A
• Filed: 11/07/1997
• Issued: 03/30/1999
• Est. Priority Date: 11/13/1996
• Status: Expired due to Term

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Itoh, Hiroyuki, Miyata, Shinji, Machida, Hisashi
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US08/966,356
• Time in Patent Office: 508 Days
• Field of Search: 475/215, 475/216
• US Class Current: 475/216
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 37/022 the toothed gearing having orbital motion
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member

Abstract

A load applied to the constituent member of a toroidal type continuously variable transmission is mitigated to thereby improve the durability thereof. During low speed running, a clutch for low speed is connected and a clutch for high speed and a clutch for backward movement are disconnected. During high speed running, the clutch for high speed is connected and the clutch for low speed and the clutch for backward movement are disconnected. During the high speed running, a torque is applied to the output side disc of the toroidal type continuously variable transmission. This torque becomes smaller as the transmission ratio as a whole is displaced to the high speed side. Correspondingly thereto, the load applied to the constituent member of the toroidal type continuously variable transmission can be mitigated.

Claims

1. A continuously variable transmission provided with an input shaft connected to a drive source and rotatively driven by said drive source, an output shaft for taking out power based on the rotation of said input shaft, a toroidal type continuously variable transmission and a single-stage double pinion type planetary gear mechanism, said toroidal type continuously variable transmission being for changing the angle of inclination of a power roller sandwiched between an input side disc and an output side disc disposed concentrically with each other to thereby change the transmission ratio between said input side disc and said output side disc rotated on the basis of the rotation of said input shaft, said planetary gear mechanism comprising a planetary gear provided between a sun gear for rotating said output shaft and a ring gear disposed around said sun gear and rotatably supported on a carrier rotatably supported concentrically with said sun gear, said planetary gear being brought into meshing engagement with said sun gear and said ring gear, characterized in that said carrier and said output side disc are connected together so as to be capable of transmitting a rotational force by a first power transmitting mechanism, and said input shaft and said ring gear being made capable of being connected together so as to be capable of transmitting the rotational force by a second power transmitting mechanism, and said continuously variable transmission further comprises a clutch mechanism for connecting the constituent member of said second power transmission to said ring gear and another clutch mechanism for connecting two of the constituent members of said planetary gear mechanism, one of said clutches being used for a forward drive.

2. The continuously variable transmission of claim 1, wherein said toroidal type continuously variable transmission is a single cavity toroidal type continuously variable transmission, and said planetary gear mechanism and said single cavity toroidal type continuously variable transmission are disposed so that their axes may be parallel to each other.