TW201727092A - Connection structure for shaft - Google Patents

Abstract

The connection structure for shaft of present disclosure has a coupling that has a cylindrical shape and a slit extending in the axis direction on the inner wall surface, a pair of shafts that has a serration embedded into the slit on the outer peripheral surface and is inserted toward inside from two ends of the coupling. At least one of the serration of the shaft and the slit of the coupling has a shape shown as the following A or B: A: on the pair of shafts, the width of at least one serration of each shaft becomes narrower toward the direction of entering into the coupling. B: the width of at least one slit becomes narrower from end part of the coupling toward the center part of the coupling.

Description

Connection structure of drive shaft

The present invention relates to a connection structure of a transmission shaft that stabilizes a torque.

In various industrial devices, power transmission devices for automobiles, and the like, a connector for power transmission is used for connection between a rotating shaft of a driving source such as a motor and a driven shaft such as a speed reducer (for example, Patent Document 1). The width of the slit formed in the connector corresponds to the tooth width of the serration formed on the rotating shaft or the driven shaft (drive shaft).

Such a connector corresponding to the width of the slit and the width of the serration can be freely moved in the axial direction, and the degree of connection between the connector and the transmission shaft is not stable. Therefore, when such a connector is used to connect the drive shaft, there is a problem that the torque characteristics are not stabilized.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-205923

An object of the present invention is to provide a connection structure of a transmission shaft that stabilizes torque characteristics.

The connecting structure of the drive shaft of the present invention comprises: a connector having a cylindrical shape and having a slit extending in the axial direction on the inner wall surface; and a pair of transmission shafts having serrations with embedded slots on the outer peripheral surface and the connector The two ends are inserted into the inside, and the connecting structure of the drive shaft has a shape shown by the following A or B in at least one of the serration of the drive shaft and the slit of the connector.

A. In the pair of transmission shafts, the width of at least one of the serrations of each of the transmission shafts is a shape that narrows toward the direction in which the connector enters.

B. The width of at least one slit is a shape that narrows from the end of the connector toward the central portion.

According to the present invention, the torque characteristics can be stabilized.

1, 1', 1" ‧‧‧ connectors

2, 2', 2" ‧ ‧ drive shaft

11‧‧‧Shell

12, 121, 122‧‧‧ sliding materials

13, 131, 132‧‧ ‧ slit

21‧‧‧Rotary axis

22‧‧‧ driven shaft

23, 23', 23", 231, 232‧‧ ‧ sawtooth

Fig. 1 is an explanatory view showing an embodiment of a connection structure of a transmission shaft according to the present invention.

Fig. 2 is a plan view of the connector shown in Fig. 1 as seen from the direction of arrow A.

Fig. 3(A) is a plan view of the transmission shaft shown in Fig. 1 as seen from the direction of the arrow B, and Fig. 3(B) is an enlarged view of a portion surrounded by a broken line in Fig. 3(A).

Fig. 4(A) is a side view seen from the direction of arrow C in Fig. 1, and Fig. 4(B) is an explanatory view showing a state in which the drive shaft is inserted into the connector in Fig. 4(A).

Fig. 5(A) is a plan view for explaining another shape of the sawtooth, and Fig. 5(B) is an enlarged view of a portion surrounded by a broken line of Fig. 5(A).

Figure 6 is a side view showing another shape of the serration.

Fig. 7 is an explanatory view showing another embodiment in which the slit of the connector is formed into a tapered shape.

Fig. 8 is an explanatory view showing still another embodiment in which both the serration and the slit are tapered.

Hereinafter, a connection structure of a transmission shaft according to an embodiment will be described with reference to Figs. 1 to 4 . The connection structure of the transmission shaft shown in Fig. 1 includes a connector 1 and a transmission shaft 2. As shown in Fig. 2, the connector 1 has a two-layer structure, the outer layer is formed by the outer casing 11, and the inner layer is formed by the sliding material 12. The connector 1 has a cylindrical shape and has a slit 13 extending in the axial direction on the inner wall surface.

The material of the outer casing 11 is not particularly limited, and examples thereof include metals such as iron, steel, stainless steel, and aluminum. As shown in Fig. 1, the outer casing 11 is provided with irregularities on the surface in accordance with the shape of the slit 13, and may be a smooth surface. The size of the outer casing 11 is not particularly limited, and can be appropriately set in accordance with the use of the connection structure of the transmission shaft of the embodiment. Since the outer casing 11 forms the outermost layer of the connector 1, the size of the outer casing 11 is the size of the connector 1.

The sliding material 12 is, for example, made of an elastic material and a fiber member. The formation can be obtained by impregnating an elastic material with a fiber member such as a canvas. The elastic material is not particularly limited, and examples thereof include nitrile rubber, chloroprene rubber, chlorosulfonated polyethylene, polybutadiene rubber, natural rubber, ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), and hydrogenated nitrile. Rubber (H-NBR), millable urethane, acrylic rubber, silicone rubber, fluororubber, carboxylated nitrile rubber, thermoplastic elastomer, and the like. These rubber types may be used alone or in combination of two or more.

Examples of the fiber forming the fiber member of the sliding member 12 include kapok, ramie, hemp, amide fiber, nylon, urethane, polyester, acetate, rayon, and the like. Further, as the canvas, for example, a woven fabric, a woven fabric, a non-woven fabric, or the like can be mentioned.

The sliding material 12 is attached to the inner circumferential surface of the outer casing 11. The method of attaching the sliding member 12 to the outer casing 11 is not particularly limited, and for example, a method of mounting using an adhesive can be mentioned. The adhesive agent may, for example, be an acrylic resin-based adhesive, an olefin resin-based adhesive, a urethane-based adhesive, or an epoxy-based adhesive.

The sliding member 12 forms the innermost layer of the connector 1 so as to be in contact with the propeller shaft 2, that is, the inner wall surface of the connector 1. A slit 13 extending in the axial direction is formed on the inner wall surface. In the connection structure of the transmission shaft according to the embodiment, eight slits 13 are formed in the inner wall surface of the connector 1. The slit 13 is formed on the inner wall surface of the connector 1 from a one end portion to the other end portion with a fixed width.

The connector 1 has a sliding material 12 formed of rubber and fibers, and it is only necessary to have a saw formed into a bevel shape as will be described later. The pre-deformation (preload) can be imparted by inserting the drive shaft of the tooth into the connector. By this pre-deformation, the free movement of the connector 1 in the axial direction can be suppressed, and the connector 1 can be fixed at a fixed position. Further, by using the sliding member 12 formed of rubber and fibers, noise generation can be suppressed during use.

Next, the drive shaft 2 will be described by way of an example of the rotary shaft 21 and the driven shaft 22. The drive shaft 2 has serrations 23 on the outer peripheral surface. The serrations 23 are formed in the rotation shaft 21 and the driven shaft 22, respectively, so as to correspond to the slits 13 of the connector 1.

The serrations 23 are not formed in a fixed size (width). As shown in FIGS. 3(A) and 3(B), the width of the serrations 23 is formed to be narrower as it goes in the entering direction of the connector 1 (the arrow direction of FIG. 3(A)). Tapered. The side surface of the serration 23 is preferably inclined by about 2 to 7 degrees with respect to the axial direction. The serrations 23 formed on the rotating shaft 21 and the driven shaft 22 are each of the rotating shaft 21 and the driven shaft 22, and at least one of the serrations 23 may have a tapered shape. However, in order to securely fix the connector 1, it is preferable that all of the saw teeth have a tapered shape.

The width of the narrowest portion of the serration 23 corresponds to the width of the slit 13 of the connector 1. Further, as described above, the sliding member 12 of the connector 1 is formed of an elastic material and a fiber member. Therefore, as shown in FIGS. 4(A) and 4(B), when the serrations 23 of the propeller shaft 2 are inserted into the slit 13 of the connector 1, the sliding member 12 can be pre-deformed. Therefore, as shown in Fig. 4(B), since the serrations 23 inserted from both ends of the connector 1 are fixed at a fixed position, the connector 1 is also fixed and the movement can be restricted.

As a result, as long as the drive shaft of the above embodiment is employed The connection structure, that is, the power of the rotating shaft 21 can be transmitted to the driven shaft 22 with stable torque characteristics. The connection structure of the drive shaft of the embodiment can be suitably used, for example, in various industrial machines, power transmission devices for automobiles (for example, work machines such as NC lathes, electric power steering devices, etc.).

The connection structure of the transmission shaft of the present invention is not limited to the above embodiment. For example, the zigzag shape formed on the transmission shaft is not particularly limited as long as it can be fixed at a fixed position and restrains the movement of the connector when inserted from both ends of the connector. Examples of such serrations include serrations of the shapes shown in Figs. 5 and 6.

Fig. 5(A) is a plan view for explaining another shape of the sawtooth, and Fig. 5(B) is an enlarged view of a portion surrounded by a broken line of Fig. 5(A). The serrations 23 have a shape in which both side faces are inclined toward the inner side and become narrower as the direction in which the connector 1 enters (the arrow direction of FIG. 3). On the other hand, the serrations 23' shown in Fig. 5(A) have the direction in which the connector 1 is inserted (the direction of the arrow in Fig. 5(A)), and only one side is inclined to the inside. Narrow shape.

Figure 6 is a side view showing another shape of the serration. The serrations 23" shown in Fig. 6 have a shape that is narrowed as the direction in which the connector 1 enters (the arrow direction of Fig. 6) is not the side surface but the upper surface is inclined downward.

Even the serrations 23' and 23" shown in Figs. 5 and 6 are fixed to a fixed position when inserted from both ends of the connector. Therefore, the connector can be fixed to restrict movement. The sawtooth 23" shown in the figure may also have at least one side as shown in Fig. 3 or Fig. 5 Sawtooth in the shape of a side slant.

In another embodiment shown in Fig. 7, the slit 131 of the connector 1' is formed in a tapered shape. That is, the width of the slit 131 is narrowed from the end portion of the connector 1' toward the center portion. When the slit 131 has such a shape, when the drive shaft is inserted from both ends of the connector, the front end of the serration 231 of the drive shaft comes into contact with the wall surface (sliding material 121) of the slit 131 near the center of the slit 131. Therefore, the connector 1' cannot be moved to either the left or the right side, but can be limited.

In still another embodiment shown in Fig. 8, both the slit 132 of the connector 1" and the serration 232 of the drive shaft are formed in a tapered shape. Both the slit 132 and the serration 232 are tapered. In the case of the case, when the drive shaft is inserted from both ends of the connector, the front end of the saw tooth 232 of the drive shaft is also in contact with the wall surface (sliding material 122) of the slit 132 near the center of the slit 132. Therefore, the connector 1 "It cannot be moved to either side of the left or right, but can be limited.

In the connection structure of the transmission shaft according to the above-described embodiment, the connector 1 in which eight slits 13 are formed is used. The number of slits is not particularly limited as long as at least one strip is formed in the connector 1, preferably from 4 to 10. The number of serrations formed on the drive shaft is appropriately set in accordance with the number of slits formed in the connector.

The embodiments of the present invention have been described above, but the present invention is not limited thereto, and various modifications and improvements can be made without departing from the scope of the invention.

1‧‧‧Connector

2‧‧‧ drive shaft

11‧‧‧Shell

12‧‧‧Sliding materials

13‧‧‧ slit

21‧‧‧Rotary axis

22‧‧‧ driven shaft

23‧‧‧Sawtooth

Claims (4)

A coupling structure of a transmission shaft, comprising: a connector having a cylindrical shape and having a slit extending in an axial direction on an inner wall surface; and a pair of transmission shafts having serrations embedded in the slits on the outer peripheral surface, and from the aforementioned joint The two ends of the transmission shaft are inserted into the inside; the connection structure of the transmission shaft is at least one of the serration of the transmission shaft and the slit of the connector having the shape shown in the following A or B: A, the transmission shaft of the pair The width of at least one of the serrations of each of the transmission shafts is a shape that narrows toward an entrance direction of the connector; B. The width of at least one of the slits is a shape that is narrowed from an end portion of the connector toward a central portion. The coupling structure of the transmission shaft according to claim 1, wherein the connector has at least two layers, the outermost layer is formed of a casing, and the innermost layer is formed of a sliding material that impregnates the fiber member with the elastic member. The coupling structure of the drive shaft according to the first or second aspect of the invention, wherein the connector is formed with 4 to 10 slits. The coupling structure of the transmission shaft according to any one of the first to third aspect, wherein the side surface of the serration is inclined by substantially 2 to 7 degrees with respect to the axial direction of the coupling.