JP7536264B2 - clutch - Google Patents

Description

The present invention relates to a clutch that transmits input rotational torque, and in particular to a clutch that stops rotation when a rotational torque of a predetermined value or more is input from the output shaft.

Conventionally, in a transmission device for transmitting rotational torque, a one-way clutch is known in which the input torque is not transmitted when the input shaft rotates in the reverse direction. The clutch disclosed in Patent Document 1 has a structure in which a roller 13 is disposed between the input shaft 1 and the output outer ring 3, as shown in FIG. 2 of Patent Document 1. When the input shaft 1 rotates in one direction, the roller 13 is pressed into a wedge-shaped space provided between the input shaft 1 and the output outer ring 3. The pressed roller 13 enters and is fixed between the input shaft 1 and the output outer ring 3, becoming a connecting member that integrates the two, and the input shaft 1 and the output outer ring 3 are connected. As a result, the input shaft 1 and the output outer ring 3 rotate integrally.

On the other hand, if the input shaft rotates in the opposite direction to the above, or if the output shaft receives a torque input of a predetermined value or more in the same direction as the input, the roller 13 is released from the wedge-shaped space, and the input shaft 1 and the output outer ring 3 are in a disconnected state in which the input torque is not transmitted.

JP 2017-15173 A

However, because the roller 13 is constantly sliding against the surrounding components while moving, it is difficult to use it at high speeds from the standpoint of stable operation. For this reason, for example, when inputting motor output, the motor output rotation is slowed down to below the clutch's allowable rotation speed before being input. In other words, there was a restriction that it could only be used at input rotation speeds below the clutch's allowable rotation speed.

The present invention was made to solve the above problems, and aims to provide a clutch that transmits rotational torque even at high speeds, and does not transmit input rotational torque when the rotational torque input from the output shaft is equal to or exceeds a predetermined value relative to the rotational torque input to the input shaft.

The clutch in this embodiment comprises an input member having a recess to which rotational torque is input, an output member which outputs the rotational torque transmitted from the input member, and a case member which rotatably holds the input member and the output member, the output member being inserted into the recess and having a torque relay portion through which the rotational torque is transmitted, the input member being disposed in the recess and having a torque transmission member having a hollow portion into which the torque relay portion is inserted, and a spring which biases the torque transmission member, and when a rotational torque of a predetermined value or greater is input from the output member, it comes into contact with the case member and a braking force acts on the input member.

Therefore, the clutch according to this embodiment is constructed without the conventional structure in which a member enters a wedge space to connect. This allows for the transmission of rotational torque at high rotational speeds, and the rotation of the clutch can be stopped when a reverse input is applied from the output shaft.

FIG. 2 is a perspective view showing the clutch according to the present embodiment. 2 is a cross-sectional view of the clutch of FIG. 1 taken along a cross section parallel to a rotation axis. FIG. 2 is a schematic diagram showing components of the clutch of FIG. 1; FIG. 2 is a front view showing a first member of the clutch of FIG. 1 . FIG. 2 is a left side view showing a first member of the clutch of FIG. 1 . FIG. 2 is a right side view showing a first member of the clutch of FIG. 1 . FIG. 2 is a front view showing a second member of the clutch of FIG. 1 . FIG. 2 is a right side view showing a second member of the clutch of FIG. 1 . FIG. 2 is a front view showing a torque transmission member of the clutch of FIG. 1 . FIG. 2 is a left side view showing a torque transmission member of the clutch of FIG. 1 . FIG. 2 is a front view showing a roller of the clutch of FIG. 1; FIG. 2 is a left side view showing a roller of the clutch of FIG. 1 . FIG. 2 is a front view showing an output member of the clutch of FIG. 1 . FIG. 2 is a left side view showing an output member of the clutch of FIG. 1 . FIG. 2 is a right side view showing an output member of the clutch of FIG. 1 . 2 is a cross-sectional view of the clutch of FIG. 1 taken along a cross section perpendicular to a rotation axis thereof; FIG. 17 is a partial enlarged view of part A in FIG. 16 . FIG. 18 is a partial enlarged view of part D in FIG. 17.

<Embodiment>
A clutch 100 according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view showing the clutch 100. Figure 2 is a cross-sectional view of the clutch 100 in Figure 1, taken along a plane parallel to the rotation axis X. Figure 3 is a schematic view showing components of the clutch 100.

As shown in FIG. 1, the clutch 100 includes an input member 10 having an input shaft 23 to which rotational torque is input, an output member 80 having an output shaft 83 to which rotational torque is transmitted from the input member 10, and a case member 90 that rotatably holds the input member 10 and the output member 80. Both the input member 10 and the output member 80 have a circular outer diameter shape, and the cylindrical case member 90 surrounds the entire outer periphery of these members.

Next, the components of the clutch 100 will be described with reference to Figures 4 to 18 in addition to Figures 1 to 3.

The input member 10 has a first member 20 to which rotational torque is input, a second member 30 fixed to the first member 20, a fastening member 70 that fastens the first member 20 and the second member 30, and a torque transmission member 40 and a spring 50 housed in the first member 20.

Figures 4 to 6 show the first member 20, and are a front view, a left side view, and a right side view, respectively. The first member 20 is a member to which rotational torque is input. The first member 20 has a cylindrical portion 21 formed in a cylindrical shape, an end face 22 which is one end face of the cylindrical portion 21, and an input shaft 23 provided on the end face 22. The first member 20 is arranged so that the rotation axis X1 of the first member 20 is coaxial with the rotation axis X of the clutch 100.

As shown in the right side view of FIG. 6, on the surface opposite to the surface on which the input shaft 23 is provided, two recesses 24 are provided at 180° intervals in the circumferential direction with the longitudinal direction as the radial direction. Each recess 24 has an outer peripheral recess 24a arranged on the outer peripheral side of the recess 24 and an inner peripheral recess 24b arranged on the inner peripheral side of the outer peripheral recess 24a. The outer peripheral recess 24a and the inner peripheral recess 24b are arranged in series in the radial direction, and the connecting portions are provided with protrusions 25 facing each other toward the opposing walls. The surface on which the recesses 24 of the cylindrical portion 21 are provided has four fitting holes into which the fastening member 70 is inserted. Each recess 24 accommodates a torque transmission member 40 and a spring 50.

Figures 9 and 10 show the torque transmission member 40, and are a front view and a left side view, respectively. The torque transmission member 40 is formed in a frame shape with a roughly rectangular outer shape, and has a frame portion 41 with a hollow portion 43 on the inside, and a spring retaining portion 42 connected to the frame portion 41. The frame portion 41 has an outer diameter portion 45, an inner diameter portion 44 facing the outer diameter portion 45, and a radial portion 46 connecting the outer diameter portion 45 and the inner diameter portion 44.

A cylindrical spring retaining portion 42 is connected to the inner diameter portion 44. A tip enlarged diameter portion 47 is provided at the tip of the spring retaining portion 42, which has a larger outer diameter than the other portions of the spring retaining portion 42. Rollers 60 rotatably held by the torque relay portion 82 of the output member 80 are inserted into the hollow portion 43.

Figure 18 shows a peripheral portion of a portion of the frame portion 41. The inner surface 45a of the outer diameter portion 45 is formed to protrude toward the inner diameter portion 44 as it approaches both ends of the outer diameter portion 45, i.e., the radial portion 46. As described below, the roller 60 is located in the center of the inner surface 45a of the outer diameter portion 45 in the left-right direction when the clutch 100 is stopped and when a rotational torque is input to the input shaft 23 and no rotational torque is input from the output shaft 83.

The torque transmission member 40 and the spring 50 are housed in the recesses 24 with the spring retaining portion 42 inserted into the spring 50 and assembled together. The frame portion 41 is housed in the outer peripheral recess 24a, and the spring retaining portion 42 and the spring 50 are housed in the inner peripheral recess 24b. In this state, one end of the spring 50 is in contact with the protrusion 25, and the other end is in contact with the tip enlarged diameter portion 47 of the spring retaining portion 42. Therefore, the torque transmission member 40 is biased by the spring 50 in the direction of the rotation axis X1, which is the center of the torque transmission member 40.

Since the torque transmission member 40 is biased toward the rotation axis X1 by the spring 50, the inner surface 45a of the outer diameter portion 45 of the torque transmission member 40 is pressed against the outer peripheral surface of the roller 60. In addition, the inner surface 45a of the outer diameter portion 45 of the torque transmission member 40 is formed to protrude toward the inner diameter portion 44 side toward both ends of the outer diameter portion 45. The roller 60 moves on the inner surface 45a of the outer diameter portion 45 when a rotational torque of a predetermined value or more is input to the output shaft 83 in response to the rotational torque input to the input shaft 23. In other words, in order for the roller 60 to move on the inner surface 45a of the outer diameter portion 45, a circumferential rotational torque that overcomes the biasing force of the spring 50 biasing toward the rotation axis X1 on the inner surface 45a of the outer diameter portion 45, which is formed as a steep slope toward both ends of the outer diameter portion 45, must act on the roller 60 via the torque relay portion 82. The specified value of the rotational torque input to the output shaft 83 at which a braking force is applied to the input member 10 is determined by the slope shape of the inner surface 45a of the outer diameter portion 45, i.e., the slope degree, and the biasing force of the spring 50. Therefore, by changing these, it is possible to change the value of the rotational torque input to the output shaft 83 when a braking force is applied to the input member 10.

Figures 7 and 8 show the second member 30. Figure 7 is a front view of the second member 30, and Figure 8 is a right side view of the second member 30. The second member 30 is fixed to the first member 20 with a plurality of fastening members 70 so as to close the recess 24 with the torque transmission member 40 and the spring 50 housed in the recess 24. The second member 30 is a disk formed with the same diameter as the outer diameter of the cylindrical portion 21 of the first member 20. The second member 30 is arranged so that the rotation axis X2 of the second member 30 is coaxial with the rotation axis X of the clutch 100. The second member 30 has two first through holes 31 spaced 180° apart in the circumferential direction, which penetrate from one end surface 30a that contacts the first member 20 to the other end surface 30b that is the opposite surface.

In addition, the second member 30 has second through holes 32 into which the fastening members 70 are inserted at positions that avoid the first through holes 31 and correspond to the four fitting holes 26 provided in the first member 20. The second through holes 32 have an enlarged diameter portion 33, which is a circular groove larger in diameter than the second through hole 32, formed coaxially with the second through hole 32 on the other end surface 30b side. The fastening member 70 is a member having a head 71, such as a bolt. The enlarged diameter portion 33 is a groove that accommodates the head 71 of the fastening member 70 that is passed through the second through hole 32. The head 71 of the fastening member 70 that fastens the second member 30 to the first member 20 is accommodated in the enlarged diameter portion 33, so that the head 71 does not protrude from the other end surface 30b of the second member 30, and the other end surface 30b becomes flat. As a result, the output member 80 arranged on the other end face 30b side can be arranged close to the other end face 30b with a small gap between them, making it possible to reduce the axial dimension of the clutch 100.

Figures 13 to 15 show the output member 80. Figures 13 to 15 are front, left and right side views of the output member 80, respectively. The output member 80 is arranged so that the rotation axis X3 of the output member 80 is coaxial with the rotation axis X of the clutch 100. The output member 80 has a disk portion 81, cylindrical torque relay portions 82 provided at 180° intervals in the circumferential direction corresponding to the first through holes 31 on one end face 81a of the disk portion 81, which is the first member 20 side, and an output shaft 83 provided in the center of the other end face 81b, which is the opposite face to the one end face 81a of the disk portion 81. The output member 80 is assembled to the second member 30 by inserting the torque relay portions 82 into the first through holes 31 of the second member 30.

The torque relay parts 82 are inserted into the hollow part 61 of the roller 60, which has a hollow cylindrical shape, and each of them holds the roller 60 rotatably. That is, each torque relay part 82 is inserted into the hollow part 61 of the roller 60 while passing through the first through hole 31 of the second member 30. The inner diameter of the first through hole 31 is formed to be larger than the outer diameter of the torque relay part 82. Therefore, when the output member 80 is assembled to the second member 30, it can rotate around the rotation axis X3 of the output shaft 83 until the roller 60 hits one of the radial parts 46 of the frame part 41.

As shown in FIG. 2, the case member 90 rotatably holds the first member 20, the second member 30, and the output member 80 in a connected state. As shown in FIG. 3, the case member 90 has a case body 91, a plurality of rollers 92 arranged around the entire circumference of the inner circumferential surface of the case body 91, and a roller retainer 93 that rotatably holds the plurality of rollers 92 at regular intervals in the circumferential direction.

The case body 91 is a hollow cylindrical member that surrounds the entire outer circumference of the circular input member 10 and the output member 80. Both end faces of the case body 91 are provided with side portions 94 of a predetermined length from the cylindrical end toward the center. The side portions 94 are formed to a length that reaches both axial ends of a roller holder 93 that holds multiple cylindrical rollers 92, and have a small gap between them and both axial ends of the roller holder 93 to prevent the roller holder 93 from coming loose. The roller holder 93 has multiple holes slightly larger than the rollers 92, evenly spaced in the circumferential direction, in order to hold the multiple rollers 92 at equal intervals.

As described above, the clutch 100 is configured such that the input member 10 and the output member 80 are connected and rotatably held inside the case member 90.

<Operation of the clutch 100>
The operation of the clutch 100 will be described with reference to Figures 16 to 18. Figure 16 is a cross-section of the clutch 100 taken along a plane perpendicular to the rotation axis X, that is, a cross-section of the clutch 100 taken along a cross section. Figure 17 is a partially enlarged view of part A in Figure 16, and Figure 18 is a partially enlarged view of part D in Figure 17. The operation of the clutch 100 when a rotational torque is input to the input shaft 23 differs between a case where there is no input from the output shaft 83 and a case where there is an input of a predetermined value or more from the output shaft 83. When there is no input from the output shaft 83, the rotational torque input to the input shaft 23 is transmitted to the output shaft 83. When there is an input from the output shaft 83 in any rotational direction, a braking force is generated in the input member 10, and the rotation is stopped. Each case will be described below.

When there is no rotational torque input to the clutch 100, the input member 10 and the output member 80 do not rotate relative to the case member 90 and are in a state where rotation is stopped. In this state, the outer peripheral surface of the roller 60 is in contact with the inner surface 45a of the outer diameter portion 45 that constitutes the frame portion 41 of the torque transmission member 40. In addition, the outer peripheral surface of the roller 60 is not in contact with any of the radial portions 46 of the frame portion 41 and is separated from the radial portions 46 with a gap.

(1) Operation of the clutch 100 when there is no rotational torque input from the output shaft 83 (1-1)
In FIG. 16, when a rotational torque in the counterclockwise direction is input, the first member 20 and the torque transmission member 40 included in the first member 20 start to rotate about the rotation axis X.
(1-2)
The rollers 60 housed within the frame 41 of the torque transmission member 40 are biased toward the rotation axis X by the springs 50. As shown in Fig. 18, the inner surface 45a of the outer diameter portion 45 is formed with an inclined surface E along which the rollers 60 roll up toward both ends, and the inclination is steeper toward both ends. When no rotational torque is input from the output shaft 83, the rollers 60 do not roll up the inner surface 45a due to the biasing force in the direction B by the springs 50 and the inclined surface E, and a force is applied to the torque relay portion 82 via the rollers 60 to rotate about the rotation axis X while the rollers 60 remain in contact with approximately the center of the outer diameter portion 45.
(1-3)
While the roller 60 remains positioned approximately in the center of the inner surface 45a of the outer diameter portion 45, the roller 60 and the torque relay portion 82 inserted into the roller 60 begin to move in the same rotational direction as the torque transmission member 40, and the output member 80 begins to move in the same rotational direction as the input member 10, thereby outputting the input torque.

(2) Operation of the clutch 100 when a rotational torque of a predetermined value or more is input from the output shaft 83 (2-1)
In FIG. 16, when a rotational torque in the counterclockwise direction is input to the input shaft 23 of the input member 10, the torque transmission member 40 starts to rotate about the rotation axis X, similarly to the above (1-1).
(2-2)
When a rotational torque equal to or greater than a predetermined value in the clockwise direction acts on output shaft 83, a force in the opposite rotational direction to the rotational direction of torque transmission member 40, that is, a force in the clockwise direction about rotation axis X in Fig. 16, acts on roller 60 via torque relay part 82. Then, roller 60 overcomes the pressing force against inner surface 45a by the biasing force of spring 50, and moves to the right relative to torque transmission member 40 while rolling on inner surface 45a.
(2-3)
The inner surface 45a is formed as a steeply inclined surface that protrudes toward the inner diameter portion 44 as it approaches both ends of the outer diameter portion 45, i.e., the radial portion 46. Therefore, when the roller 60 moves to the right while rotating in contact with the outer diameter portion 45, the inner surface 45a of the outer diameter portion 45 is pressed against the outer peripheral surface of the roller 60, and a force is applied to the torque transmission member 40 to move it toward the outer periphery of the clutch 100.
(2-4)
The torque transmission member 40 overcomes the biasing force of the spring 50 in the direction B and moves in the direction C toward the outer periphery.
(2-5)
When the torque transmission member 40 moves outward, the outer surface 45b of the outer diameter portion 45 presses the case member 90, specifically, the rollers 92. The rollers 92 are sandwiched between the case body 91 and the outer surface 45b of the outer diameter portion 45, making it difficult for them to rotate, and rotational resistance is generated. The generated rotational resistance acts as a braking force on the input member 10, and the rotation of the clutch 100 stops.

The clutch 100 can transmit the input rotational torque in either direction. In addition, although the case where the rotational direction of the rotational torque input from the output shaft 83 is the opposite rotational direction to the rotational torque input to the input shaft 23 has been described, even if the rotational torque input from the output shaft 83 is greater than the rotational torque input to the input shaft 23 by a predetermined value or more and both have the same rotational direction, a braking force acts on the input member 10 and rotation stops in the same manner as described above.

In addition, when there is a rotational torque input from the output shaft 83, the ease with which the roller 60 moves left and right relative to the frame 41, i.e., in the circumferential direction of the clutch 100, varies depending on the biasing force of the spring 50 and the degree of inclination of the inner surface 45a of the outer diameter portion 45. For example, the stronger the biasing force of the spring 50 is, or the steeper the inclination of the inner surface 45a of the outer diameter portion 45 is that protruding toward the inner diameter portion 44 at both ends, the more difficult it becomes for the roller 60 to move left and right on the frame 41, i.e., in the circumferential direction of the clutch 100, and the less likely a braking force is applied to the clutch 100 in response to the rotational torque input from the output shaft 83. In addition, if the above is reversed, braking force becomes more easily applied to the clutch 100.

The clutch 100 according to this embodiment has a recess 24 and is equipped with an input member 10 to which rotational torque is input, an output member 80 that outputs the rotational torque transmitted from the input member 10, and a case member 90 that rotatably holds the input member 10 and the output member 80. The output member 80 is inserted into the recess 24 and has a torque relay part 82 to which the rotational torque is transmitted. When a rotational torque of a predetermined value or more is input from the output member 80, the input member 10 comes into contact with the case member 90, and a braking force acts on the input member 10.

Therefore, the clutch 100 is constructed without rollers or balls and a wedge space as in the conventional clutch. This allows it to transmit rotational torque at high rotational speeds, and when a reverse input is applied from the output shaft, it is possible to stop the rotation of the clutch.

The input member 10 of the clutch 100 according to this embodiment is disposed in the recess 24 and has a torque transmission member 40 having a hollow portion 43 into which the torque relay portion 82 is inserted, and a spring 50 that biases the torque transmission member 40.

Therefore, by optimizing the biasing force of the spring 50, torque can be transmitted reliably and the clutch 100 can be braked at the desired reverse input torque value.

The clutch 100 according to this embodiment has multiple torque relay parts 82 and corresponding torque transmission members 40, which are arranged at equal intervals in the circumferential direction.

Therefore, by increasing the number of pairs of torque relay parts 82 and the corresponding torque transmission members 40, the transmission torque can be increased. This makes it possible to transmit high rotational speeds and high rotational torques.

The torque relay part 82 of the clutch 100 in this embodiment is rotatably held and has a roller 60 that contacts the torque transmission member 40 to transmit the rotational torque.

Because the cross-sectional shape of the roller 60 is circular, the roller 60 can move smoothly. Therefore, when there is an input from the output shaft 83, it can operate efficiently.

10 Input member, 24 Recessed portion, 40 Torque transmission member, 43 Hollow portion,
50 spring, 60 roller, 80 output member, 82 torque relay portion,
90 Case member.

Claims (3)

an input member (10) having a recess (24) and receiving a rotational torque;
an output member (80) that outputs a rotational torque transmitted from the input member (10);
a case member (90) that rotatably holds the input member (10) and the output member (80),
The output member (80) has a torque relay portion (82) that is inserted into the recess (24) and transmits rotational torque,
The input member (10) is disposed in the recess (24), and includes a torque transmission member (40) having a hollow portion (43) into which the torque relay portion (82) is inserted, and a spring (50) that biases the torque transmission member (40), and when a rotational torque equal to or greater than a predetermined value is input from the output member (80), the input member (10) comes into contact with the case member (90), and a braking force acts on the input member (10). 2. The clutch according to claim 1 , wherein a plurality of the torque relay portions and a plurality of the torque transmission members corresponding thereto are provided and are disposed at equal intervals in the circumferential direction. 3. The clutch according to claim 1 , wherein the torque relay portion (82) has a roller (60) that is rotatably held and contacts the torque transmission member ( 40 ) to transmit rotational torque.