JP4997475B2 - Drive shaft - Google Patents

Description

  The present invention relates to a drive shaft used in a steel rolling mill or the like.

In a steel rolling facility, a drive shaft provided between a motor and a rolling roll has a cylindrical outer shaft and an inner shaft fitted in the outer shaft in order to cope with an axial shift of the rolling roll. The two shafts are connected to each other so as to be integrally rotatable and relatively movable in the axial direction (Patent Document 1).
Japanese Utility Model Publication No. 4-39452

  In this type of drive shaft, a gap is provided between the roll and the roll to facilitate roll replacement work. If the outer shaft and the inner shaft move relative to each other in the axial direction, the inner shaft is the outer shaft. When the amount of entering the inside becomes large and the entire length of the drive shaft becomes short, the drive shaft may come off the rolling roll. Therefore, it is preferable to provide an elastic body that urges both shafts in a direction separating them from each other. However, when an elastic body is added, there is a concern that abnormal noise and wear may increase due to deformation of the elastic body by centrifugal force. The

  An object of the present invention is to provide a drive shaft that provides an elastic body that urges an outer shaft and an inner shaft in directions away from each other, and that can suppress the occurrence of abnormal noise and wear that are a concern in this case. It is in.

  A drive shaft according to the present invention includes a cylindrical outer shaft, and an inner shaft that is fitted into the outer shaft from one end side of the outer shaft and a part of the inner shaft projects axially outward from the outer shaft. In the drive shaft that is connected so as to be able to rotate integrally and relatively move in the axial direction, the outer shaft side holding member provided at one end of the outer shaft and the inner shaft side holding provided at the outer periphery of the protruding portion of the inner shaft An elastic body that urges the two shafts in a direction to separate them from each other is interposed between the members and prevents the holding members from interfering when the two shafts move relative to each other in the axial direction. A gap is provided, and either one of the holding members is configured to hold a portion larger than half the axial length of the elastic body.

  The other end portion of the outer shaft is connected to, for example, a motor drive portion, and the end portion of the protruding portion of the inner shaft is connected to, for example, a rolling roll. The connection between the outer shaft and the motor and the connection between the inner shaft and the rolling roll are both performed through universal joints, whereby the driving force is transmitted from the motor to the rolling roll and the axial shift of the rolling roll is performed. Is absorbed by the relative axial movement of the outer shaft and the inner shaft.

  The connection between the outer shaft and the inner shaft is, for example, by spline fitting, but is not limited to this, and may be by a ball spline in which a plurality of balls are interposed between the spline grooves.

  By providing the holding member on one end portion of the outer shaft and the outer periphery of the protruding portion of the inner shaft, the elastic body is disposed on the outer peripheral side of the portion of the inner shaft where the outer shaft is not fitted. In this way, the axial length of the elastic body can be shortened compared to the case where the elastic body is disposed over substantially the entire length of the fitting portion between the outer periphery of the inner shaft and the inner periphery of the outer shaft. The elastic body can be made difficult to deform in the radial direction.

  The elastic body is, for example, a coil spring, but is not limited thereto.

  When the outer shaft and the inner shaft move relative to each other in the axial direction, the holding members approach and separate from each other, and the elastic body is compressed or expanded in the axial direction, whereby the outer shaft and the inner shaft are separated from each other ( It is relatively moved in the axial direction while being urged in the direction in which the length of the entire drive shaft becomes longer. Between the holding members, a gap having a size of 0 or more is provided when the holding members come closest to each other with the relative movement of both axes in the axial direction, thereby preventing the holding members from interfering with each other. The

  Each holding member includes an end surface receiving portion that receives the end surface of the elastic body, and a guide portion that extends in the axial direction and extends to the elastic body from the inside in the radial direction. The length of the guide portion of the holding member in the axial direction should be as long as possible from the viewpoint of suppressing the radial movement of the elastic body (the gap between the holding members should be approximately equal to the axial relative movement distance of both shafts). Preferably, the length of the guide portion in the axial direction is not the same between the two holding members, but one holding member holds the central portion of the elastic body in the axial direction (length). The That is, the axial length of the guide portion of one holding member is set to a value larger than half of the maximum length of the elastic body when the relative movement between the outer shaft and the inner shaft is taken into account. The length of the guide portion in the axial direction is shortened so that the holding member faces the one holding member with a predetermined gap. If it does in this way, the central part of the axial direction of the elastic body with the largest deflection can be held by one holding member.

  According to the drive shaft of the present invention, since the elastic body that urges the outer shaft and the inner shaft in a direction separating from each other is provided, the drive shaft is prevented from being detached from the rolling roll, and either one of the holding members By holding a portion that is larger than half of the axial length of the elastic body, the central portion in the axial direction of the elastic body that has the largest deflection can be held by one holding member, and the elastic body is attached to the holding member. Collisions are suppressed, and abnormal noise and wear due to the use of the elastic body can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left and right refer to the left and right in the figure.

  FIG. 1 shows a drive shaft (1) according to the present invention.

  This drive shaft (1) is interposed between a driving device and a driven device in a steel rolling mill to transmit torque, and is fitted with a driving side fitting connected to a driving device (not shown) such as a motor. A yoke (2), a centering universal joint (3) whose left end is connected to this driving side fitting yoke (2), and a driving side shaft body connected to the right end of this universal joint (3) A cylindrical outer shaft (4), an inner shaft (5) as a driven side shaft coupled to the outer shaft (4) so as to be integrally rotatable, and a right end of the inner shaft (5) The universal joint for alignment (6) and the driven joint in which a roll neck (not shown) of a rolling roll as a driven device is inserted into the universal joint (6) so as to be integrally rotatable. As an elastic body that urges the side fitting yoke (7) and both shafts (4) and (5) away from each other Yl and a spring (8).

  The inner shaft (5) is fitted into the outer shaft (4) from the right end side of the outer shaft (4), and protrudes rightward (axially outward) from the outer shaft (4). (9)

  The outer shaft (4) and the inner shaft (5) are spline-fitting (10), and a plurality of spline grooves (4a) provided in the outer shaft (4) extending in the axial direction and the inner shaft (5 ), The outer shaft (4) and the inner shaft (5) are connected to each other so as to be relatively movable in the axial direction. The entire length of the drive shaft (1) can be expanded and contracted in accordance with the axial shift of the rolling roll.

  The right end portion of the drive shaft (1) and the rolling roll are fitted by a gap in order to improve roll exchange workability. Therefore, when the outer shaft (4) and the inner shaft (5) move in directions approaching each other due to vibration during the rolling operation, the drive shaft (1) may be detached from the rolling roll. The coil spring (8) is for preventing the outer shaft (4) and the inner shaft (5) from moving relative to each other in the direction in which the drive shaft (1) is removed from the rolling roll. As shown, an outer shaft side holding member (31) provided at the right end of the outer shaft (4) and an inner shaft side holding member (32) provided on the outer periphery of the protruding portion (9) of the inner shaft (5) Is sandwiched between. A gap (33) is provided between the holding members (31) and (32) to prevent interference between the holding members (31) and (32) when the shafts (4) and (5) are relatively moved in the axial direction. ing.

  As shown in FIG. 2, the carrier (16) holds a rolling bearing (20) that supports the inner shaft (5), and a bracket (21 provided on the outer peripheral portion of the outer shaft (4)). ) And the bracket (19) of the stepped portion (9a) of the inner shaft (5) is provided with an elastic cover (22) that can extend and contract in the axial direction and covers the coil spring (8) from the outside in the radial direction. ing.

  Since a gap (33) is required between the holding members (31) and (32), if these holding members (31) and (32) have the same shape, the central portion of the length of the coil spring (8) is held. When the centrifugal force is applied by the rotation of the drive shaft (1), the deflection at the central portion of the length of the coil spring (8) increases, and the coil spring (8 ) May collide with the holding members (31) and (32), which may cause abnormal noise and wear.

  Therefore, in the drive shaft (1) according to the present invention, the central portion of the length of the coil spring (8) having the largest deflection is held by one holding member (31), and the length of the coil spring (8) is increased. In order to reduce the deflection at the center, the holding members having the same shape are not symmetrically arranged, but the axial length of one holding member (31) is relatively increased, and the other is The axial length of the holding member (32) is reduced.

  That is, the outer shaft side holding member (31) is in contact with the carrier (16) provided on the right end surface of the outer shaft (4) from the left and receives the left end surface of the coil spring (8). And extends from the end face receiving portion (34) to the right along the outer peripheral surface of the inner shaft (5) and is applied from the radially inner side over a portion larger than half of the axial length on the left side of the coil spring (8). The inner shaft side holding member (32) consists of a cylindrical guide portion (35), and the inner shaft side holding member (32) is a bracket (9a) provided on the projecting portion (9) of the inner shaft (5) ( 19) along the outer peripheral surface of the projecting portion (9) of the inner shaft (5) from the end surface receiving portion (37). It consists of a cylindrical guide part (38) extending in the axial direction and applied to the right end part of the coil spring (8) from the inside in the radial direction, and by these holding members (31) (32), both shafts (4) A coil spring (8) that biases (5) away from each other is It is held. The axial length of the guide portion (35) of the outer shaft side holding member (31) is the maximum of the coil spring (8), taking into account that both shafts (4) and (5) move away from each other. It is said to be more than half of the length.

  Therefore, as shown in FIG. 2 (a), the central portion of the coil spring (8) indicated by (8a) and (8b) is supported by the guide portion (35) of the outer shaft side holding member (31). As shown in FIG. 2 (b), the shafts (4) and (5) are moved away from each other, and the gap between the shafts (4) and (5) ( Even if (33) becomes larger, the central portions (8a) and (8b) of the coil spring (8) are held by the outer shaft side holding member (31), thereby arranging the holding members of the same shape symmetrically. Compared to the case, the force that the bent part of the coil spring (8) contacts (collises) the tip part of the guide part (35) (38) of the holding member (31) (32) is greatly reduced. Occurrence of abnormal noise and wear associated with is prevented.

FIG. 1 is a partial sectional view showing an embodiment of a drive shaft according to the present invention. FIG. 2 is an enlarged vertical sectional view of a main part.

Explanation of symbols

(1) Drive shaft
(4) Outer shaft
(5) Inner shaft
(8) Coil spring
(9) Protruding part
(31) Outer shaft side holding member
(32) Inner shaft side holding member
(33) Gap

Claims (2)

  A cylindrical outer shaft, and an inner shaft that is fitted into the outer shaft from one end side of the outer shaft and partially protrudes outward in the axial direction from the outer shaft. In the drive shaft that is connected so as to be relatively movable in the direction, both the outer shaft holding member provided at one end of the outer shaft and the inner shaft holding member provided on the outer periphery of the protruding portion of the inner shaft An elastic body that urges the shafts in a direction separating them from each other is interposed, and a gap is provided between the holding members to prevent the holding members from interfering with each other when the shafts move relative to each other in the axial direction. One of the holding members is configured to hold a portion larger than half of the axial length of the elastic body. Each holding member is composed of an end surface receiving portion that receives the end surface of the elastic body, and a guide portion that extends in the axial direction and extends to the elastic body from the inside in the radial direction. The axial length of the guide portion is set to a value larger than half of the maximum length of the elastic body when the relative movement between the outer shaft and the inner shaft is taken into consideration, and the other holding member is connected to one holding member. 2. The drive shaft according to claim 1, wherein the length of the guide portion in the axial direction is shortened so as to face each other with a predetermined gap.

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