Search

EP-4353984-B1 - CAM CLUTCH

EP4353984B1EP 4353984 B1EP4353984 B1EP 4353984B1EP-4353984-B1

Inventors

  • NAKAGAWA, EIICHI
  • SHIMANAKA, Yoshihito

Dates

Publication Date
20260506
Application Date
20220330

Claims (7)

  1. A cam clutch (100) comprising: at least one set of an inner race (110) and an outer race (120) that are coaxial and relatively rotatable; a plurality of cams (131) circumferentially arranged between the inner race (110) and the outer race (120); a biasing means radially biasing the plurality of cams (131); and an operating mode switch mechanism (140) for switching between two or more of a free state that allows relative rotation between the outer race (120) and the inner race (110) in both directions, a one-way clutch mode that allows relative rotation between the outer race (120) and the inner race (110) in one of forward and reverse directions, and a locked state that prohibits relative rotation between the outer race (120) and the inner race (110) in both directions, the operating mode switch mechanism (140) including a cam orientation changing part (141) axially movable independently of rotation of the inner race (110) and the outer race (120), some or all of the plurality of cams (131) including an engaging portion (136) protruding from a side face toward the cam orientation changing part (141) characterized in that the cam orientation changing part (141) is formed in a circular groove-like shape such as to restrict a radial position of the engaging portion (136) in both directions while making sliding contact with the engaging portion (136), when having come into contact with the engaging portion (136).
  2. The cam clutch (100) according to claim 1, wherein the plurality of cams (131) include first cams (131a) that tilt to make frictional engagement with the outer race (120) and the inner race (110) when the outer race (120) or the inner race (110) rotates in one direction, and second cams (131b) that tilt to make frictional engagement with the outer race (120) and the inner race (110) when the outer race (120) or the inner race (110) rotates in an other direction.
  3. The cam clutch (100) according to any one of claims 1 to 2, wherein at least two sets of the outer race (120) and the inner race (110) are provided, each of the outer race (120) and the inner race (110) being disposed axially on both sides of the operating mode switch mechanism (140).
  4. The cam clutch (100) according to claim 3, wherein the first cams (131a) are provided between the outer race (120) and the inner race (110) arranged on one side of the operating mode switch mechanism (140), and the second cams (131b) are provided between the outer race (120) and the inner race (110) arranged on an other side of the operating mode switch mechanism (140).
  5. The cam clutch (100) according to claim 3, wherein the first cams (131a) and the second cams (131b) are arranged on a same circumference.
  6. The cam clutch (100) according to claim 5, wherein the first cams (131a) and the second cams (131b) are arranged alternately.
  7. The cam clutch (100) according to any one of claims 2 to 6, wherein at least two sets of the outer race (120) and the inner race (110) are coaxially provided with different diameters.

Description

[Technical Field] The present invention relates to a cam clutch with an operating mode switch mechanism for switching between two or more of a free state that allows relative rotation between an outer race and an inner race in both directions, a one-way clutch mode that allows relative rotation between the outer race and the inner race in either the forward or the reverse direction, and a locked state that prohibits relative rotation between the outer race and the inner race in both directions. [Background Art] As one type of clutch that controls transmission and interruption of a rotary force, two-way switchable clutches that can drive and freewheel in both forward and reverse directions are known. Some types of two-way clutches are configured to switch between a locked state that prohibits relative rotation between the inner race and the outer race (transmits the rotary force) and a free state that allows relative rotation between the inner race and the outer race (interrupts the rotary force) by tilting cams or sprags (see, for example, Patent Literature 1 and Patent Literature 2). Patent Literature 3 describes a two-way clutch with a switch mechanism that can switch between three operating modes, i.e., two-way free mode, one-way lock mode, and two-way lock mode, by controlling a retainer that retains rollers or power transmission members either at a neutral position or at one engaged position on a cam surface formed on the inner circumference of the outer race. Patent Literature 5 describes: A switchable locking element freewheel with two concentric cage rings and locking elements lodged in pockets thereof, the cage rings being movable relative to each other for switching the freewheel. In order to make such a freewheel basically operable in two opposing directions and to provide simple switchover facilities herefor and also for cases in which switchability is required only in one direction, the relative movement of the two cage rings serving to switch the freewheel is an axial displacement which, with a view to any further embodiments of the freewheel, can be converted into a rotary movement. Further background art for the present invention is described in Patent Literature 6-7. [Citation List] [Patent Literature] [Patent Literature 1] Japanese Patent Application Publication No. 2011-220509[Patent Literature 2] Japanese Patent Application Publication No. H11-182589[Patent Literature 3] Japanese Patent Application Publication No. 2014-219015[Patent Literature 4] Japanese Patent Application Publication No. 2020-190255[Patent Literature 5] US 5 343 992 A[Patent Literature 6] US 2009/266667 A1[Patent Literature 7] WO 2015/033409 A1 [Summary of Invention] [Technical Problem] The two-way clutch described in Patent Literature 1 switches the states of engagement and separation between an input-side rotary member and an output-side rotary member by means of sprags that are tilted in the same direction as the rotation direction of the input-side rotary member when the input-side rotary member is rotated relative to the output-side rotary member. This poses the problem of poor responsiveness due to the time lost when the rotation direction is switched. The two-way clutch described in Patent Literature 2 entails the same problem. The two-way clutch described in Patent Literature 3 uses plate spring members to allow power transmission in both directions. The problem with this two-way clutch, however, is that the torque the two-way clutch can transmit is small for its size because it relies on friction for the power transmission. With a view to provide a cam clutch that solves these problems and is capable of switching from one operating mode to another with a simple structure and high responsiveness and of securing a desired torque capacity, the applicants invented a cam clutch with an operating mode switch mechanism presented in Patent Literature 4. The cam clutch according to the first, second, and fourth embodiments described in Patent Literature 4 entailed an issue that a complex mechanism would be required to allow operation of the operating mode switch mechanism from the fixed side in an application where the outer race is used as a rotating member. The cam clutch according to the third embodiment had issues that it required cams of a special shape, and that the cam clutch tended to be large in the axial direction. The present invention solves these problems, and aims at providing a cam clutch capable of switching from one operating mode to another with a simple structure and high responsiveness and of securing a desired torque capacity, a cam clutch that allows use of the outer race as a rotating member without requiring a complex structure, and that allows a size reduction in the axial direction. [Solution to Problem] The present invention solves the above problems by providing a cam clutch including: at least one set of an inner race and an outer race that are coaxial and relatively rotatable; a plurality