JP5861349B2 - Ball type constant velocity joint cage stress analyzer - Google Patents

Description

  The present invention relates to a stress analysis device for a cage of a ball type constant velocity joint.

  Of the components of ball type constant velocity joints, the cage is often the least durable component. Therefore, durability evaluation of the cage is very important. It is desired to perform more accurate numerical analysis when evaluating the durability of the cage. In addition, although it is not a ball-type constant velocity joint, it is described in Unexamined-Japanese-Patent No. 2008-1116040 (patent document 1) about the stress analysis of the cage of a rolling bearing.

JP 2008-1106040 A

  In recent years, software has been developed as a method to perform numerical analysis with high accuracy, which can perform coupled analysis between structural analysis by finite element method using direct integration and mechanism analysis by kinematics and dynamics calculation. ing. And when such a coupled analysis is applied to a cage of a ball type constant velocity joint, a technique capable of obtaining a highly accurate analysis result has been studied.

  The present invention has been made in view of such circumstances, and it is possible to hold a ball-type constant velocity joint that can obtain a more accurate analysis result by applying a coupled analysis of a structural analysis and a mechanism analysis. An object of the present invention is to provide a stress analysis device for a vessel.

(Claim 1) A stress analysis apparatus for a cage of a ball type constant velocity joint according to the present invention includes an outer ring having an outer ring ball groove formed on an inner peripheral surface, an inner ring having an inner ring ball groove formed on an outer peripheral surface, The outer ring ball groove and the inner ring ball groove are disposed so as to be capable of rolling, and a torque is transmitted between the outer ring and the inner ring, and a window portion is disposed between the outer ring and the inner ring and holds the ball. Is a device for performing stress analysis of the cage in a ball-type constant velocity joint comprising: a finite element method using a direct integration method by dividing the cage into hexahedral elements Applying coupled analysis of structural analysis and mechanism analysis using an analysis model composed of components of the ball-type constant velocity joint and components connected to the component, the cage is adjacent in the circumferential direction. Fit Comprising a pillar portion that partitions the Kimado portion, the circumferential width of the outer peripheral surface side of the pillar portion is larger than the circumferential width of the inner peripheral surface side of the pillar portion, the outer peripheral surface of the pillar portion, the outer ring The number of the hexahedron elements in the circumferential direction on the outer peripheral surface side of the column part is larger than the number of the hexahedron elements in the circumferential direction on the inner peripheral surface side of the column part. Is set.

(Claim 2) In addition, the cage includes the pillar portion and an axial edge portion defining an axial portion of the cage in the window portion, and the outer peripheral surface side periphery of the axial edge portion. The difference between the axial length and the circumferential length of the axial edge on the inner circumferential surface side is the difference between the circumferential width on the outer circumferential surface side of the column portion and the circumferential width on the inner circumferential surface side of the column portion. The number of the hexahedral elements in the circumferential direction on the outer peripheral surface side of the axial edge portion is the same as the number of the hexahedral elements in the circumferential direction on the inner peripheral surface side of the axial edge portion. You may make it set so.

  (Claim 1) The circumferential width on the outer peripheral surface side of the pillar portion of the cage is larger than the circumferential width on the inner peripheral surface side. Here, the window portion of the cage is generally formed by, for example, punching press processing or cutting processing by an end mill. By forming the window portion in this manner, the difference between the circumferential width on the outer peripheral surface side of the column portion and the circumferential width on the inner peripheral surface side is increased.

  According to the present invention, the finite element method is divided into hexahedral elements in the coupled analysis. Here, in order to perform a highly accurate structural analysis, it is desired that the aspect ratio of the hexahedral element be close to 1. In other words, the ideal hexahedral element is a cube. According to this invention, it is divided | segmented so that the number of elements of the circumferential direction in the outer peripheral surface side of a pillar part may be larger than the number of elements of the circumferential direction in the inner peripheral surface side. Therefore, even if the circumferential width on the outer peripheral surface side of the column portion is larger than the circumferential width on the inner peripheral surface side, the aspect ratio of each element of the column portion can be prevented from becoming so large. That is, a highly accurate coupled analysis of the column portion is possible.

  Moreover, the outer peripheral surface side of the pillar part of the cage receives a pressing load by contacting the inner peripheral edge on the opening side of the outer ring. Therefore, it is very important to analyze the outer peripheral surface side of the column part with high accuracy. By increasing the number of elements in the circumferential direction on the outer peripheral surface side of the column portion as in the present invention, the stress distribution resulting from the contact with the outer ring can be analyzed with high accuracy. That is, highly accurate coupled analysis of the column part can be performed by increasing the aspect ratio of each element of the column part to 1 and increasing the number of elements in the circumferential direction on the outer peripheral surface side of the column part.

  (Claim 2) About the axial direction edge part of a holder | retainer, the circumferential direction length on the outer peripheral surface side is long compared with the circumferential direction length on the inner peripheral surface side. However, the ratio of the difference between the circumferential length on the outer circumferential surface side and the circumferential length on the inner circumferential surface side in the axial edge portion is the difference between the circumferential width on the outer circumferential surface side and the circumferential width on the inner circumferential surface side in the column portion. Small compared to the rate of difference. Thus, with respect to the axial edge, it is possible to perform sufficiently accurate coupled analysis by making the number of elements in the circumferential direction on the outer peripheral surface side the same as the number of elements in the circumferential direction on the inner peripheral surface side. At the same time, setting of elements becomes easy.

It is an axial sectional view showing a drive shaft as a coupled analysis model in the present embodiment. It is the figure which looked at the cage which is a stress analysis object from the diameter direction outside. It is the figure which looked at the holder | retainer from the axial direction. This corresponds to the bottom view of FIG. Further, a punching die used for the punching press is also illustrated. It is the enlarged view which mesh-divided the cage | basket shown in FIG. 2 into the hexahedral primary element, the outline of a cage | basket is shown with a thick line, and the divided | segmented element line is shown with a thin line. 4 is a cross-sectional view taken along the line AA of FIG. 4, and similarly to FIG. 4, the outline of the cage is indicated by a bold line, and the divided element lines are indicated by thin lines.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment embodying a stress analysis device for a cage of a ball type constant velocity joint according to the invention will be described with reference to the drawings.

(Coupled analysis model)
The coupled analysis model of this embodiment will be described with reference to FIG. As shown in FIG. 1, the coupled analysis model is exemplified by a drive shaft of an automobile. The object of the stress analysis is the cage 140 constituting the ball type constant velocity joint 100. In addition, the cage 140 is subjected to a coupled analysis of a structural analysis by a finite element method and a mechanism analysis that is a dynamics (multibody dynamics) calculation by multibody dynamics. In particular, the structural analysis is performed using a direct integration method.

  As shown in FIG. 1, the coupled analysis model includes a shaft 10, a ball type constant velocity joint 100 connected to one end of the shaft 10, and a sliding tripod type constant velocity joint connected to the other end of the shaft 10. 200. The ball type constant velocity joint 100 is a fixed ball type constant velocity joint (also referred to as a “Zepper type constant velocity joint”). The ball-type constant velocity joint 100 includes an outer ring 110, an inner ring 120, a plurality of balls 130, and a cage 140.

  The outer ring 110 is formed in a cup shape (bottomed cylindrical shape) having an opening on one side. A connecting shaft 111 is integrally formed on the outer side of the cup bottom of the outer ring 110 so as to extend in the direction of the outer ring axis. Furthermore, the inner peripheral surface 112 of the outer ring 110 is formed in a spherical concave shape. Further, on the inner peripheral surface 112 of the outer ring 110, a plurality of outer ring ball grooves 113 whose outer ring axis orthogonal cross section is formed in a substantially arc concave shape are formed so as to extend substantially in the outer ring axis direction. The plurality of outer ring ball grooves 113 are formed at equal intervals in the circumferential direction in the radial cross section. Here, the outer ring axial direction means a direction passing through the central axis of the outer ring 110, that is, a rotation axis direction of the outer ring 110.

  The inner ring 120 is formed in an annular shape and is disposed inside the cup of the outer ring 110. The outer peripheral surface 121 of the inner ring 120 is formed in a spherical convex shape. Further, a plurality of inner ring ball grooves 122 whose inner ring axis orthogonal cross section is substantially arc-shaped are formed on the outer peripheral surface 121 of the inner ring 120 so as to extend substantially in the inner ring axis direction. The plurality of inner ring ball grooves 122 are formed at equal intervals in the circumferential direction in the radial cross section and the same number as the outer ring ball grooves 113 formed in the outer ring 110. That is, each inner ring ball groove 122 is positioned to face each outer ring ball groove 113 of the outer ring 110.

  The plurality of balls 130 are disposed so as to be sandwiched between the outer ring ball groove 113 of the outer ring 110 and the inner ring ball groove 122 of the inner ring 120 facing the outer ring ball groove 113. Each ball 130 is rotatable and engaged with each outer ring ball groove 113 and each inner ring ball groove 122 in the circumferential direction. Therefore, the ball 130 transmits torque between the outer ring 110 and the inner ring 120.

  The retainer 140 is formed in an annular shape. The outer peripheral surface 141 of the cage 140 is formed in a partial spherical shape substantially corresponding to the inner peripheral surface 112 of the outer ring 110, that is, a spherical convex shape. On the other hand, the inner peripheral surface 142 of the retainer 140 is formed in a partial spherical shape substantially corresponding to the outer peripheral surface 121 of the inner ring 120, that is, a spherical concave shape. The cage 140 is disposed between the inner peripheral surface 112 of the outer ring 110 and the outer peripheral surface 121 of the inner ring 120. Furthermore, the retainer 140 is formed with a plurality of window portions 143 that are substantially rectangular through holes at equal intervals in the circumferential direction. One ball 130 is accommodated and held in each window portion 143.

  The sliding tripod type constant velocity joint 200 is a known sliding type tripod type constant velocity joint. This sliding tripod type constant velocity joint includes an outer ring 210, a tripod 220, and three rollers 230.

  The shaft 10 is an elastic body. That is, the shaft 10 is allowed to undergo elastic deformation, for example, bending deformation, in the coupled analysis. Here, the shaft 10 is grasped as a divided elastic beam element in order to simplify the arithmetic processing. Furthermore, the shaft 10 shall have the mass. That is, the weight of the shaft 10 is taken into account in the coupled analysis.

  The other end of the shaft 10 is connected to the tripod 220 of the sliding tripod type constant velocity joint 200. Therefore, the other end of the shaft 10 can slide in the axial direction of the outer ring 210 with respect to the outer ring 210 of the sliding tripod type constant velocity joint 200. Here, as the constraint conditions, the rotation center axis of the outer ring 110 of the ball type constant velocity joint 100, the position of the outer ring 110 with respect to the rotation center axis, the rotation center axis of the outer ring 210 of the sliding tripod type constant velocity joint 200, and It is assumed that the position of the outer ring 210 with respect to the rotation center axis is fixed.

(Detailed configuration of cage)
Next, the configuration of the cage 140 that is a stress analysis target will be described in detail with reference to FIGS. 2 and 3. As shown in FIGS. 2 and 3, the retainer 140 forms a plurality of window portions 143 in the circumferential direction. That is, the retainer 140 includes a plurality of column portions 144 that define the window portions 143 that are adjacent to each other in the circumferential direction, and axial edge portions 145 and 146 that define axial portions of the window portion 143. In other words, the window portion 143 is formed by being surrounded by the two column portions 144 and the axial edge portions 145 and 146. The retainer 140 is formed by a plurality of column portions 144, a plurality of axial edge portions 145, and a plurality of axial edge portions 146.

  The window part 143 is formed by punching press processing. Specifically, as shown in FIG. 3, one window portion 143 is formed by moving the punching die 300 from the radially outer side of the cage 140 toward the radially inner side. In this way, the other window portions 143 are formed in the same manner. In addition, the window part 143 can also be formed by cutting with the peripheral surface of the end mill. The window part 143 in this case is formed in the shape substantially the same as the window part 143 by stamping press work.

  Therefore, the peripheral shape of the window portion 143 is formed in a shape parallel to the moving direction of the punching die 300. That is, the side surface of the column portion 144 and the opposite side surface of the column portion 144 adjacent in the circumferential direction are formed in parallel. Moreover, the axial direction opposing surfaces of the axial edge portions 145 and 146 are also formed in parallel. Therefore, the circumferential width on the outer peripheral surface side of the column portion 144 is significantly larger than the circumferential width on the inner peripheral surface side.

  Here, the outer peripheral surface 141 and the inner peripheral surface 142 of the cage 140 are formed in a spherical shape. Therefore, the circumferential length on the outer circumferential surface side of the axial edge portions 145 and 146 of the cage 140 is longer than the circumferential length on the inner circumferential surface side. However, since the window portion 143 is formed as described above, the ratio (ΔL / La) of the difference between the circumferential length on the outer circumferential surface side and the circumferential length on the inner circumferential surface side at the axial edge portions 145 and 146 is The ratio of the difference between the circumferential width on the outer circumferential surface side and the circumferential width on the inner circumferential surface side in the column portion 144 (ΔH / Ha) is small. Here, ΔL is the difference between the circumferential lengths of the outer and inner circumferences of the axial edge portions 145 and 146, and La is the circumferential length of the axial edge portions 145 and 146 on the outer circumferential surface side. ΔH is the difference in the circumferential width of the outer periphery of the column portion 144, and Ha is the circumferential width of the column portion 144 on the outer peripheral surface side.

(Ball type constant velocity joint operation)
Next, the operation of the ball type constant velocity joint 100 will be described with reference to FIG. 1 again. In a state where the joint angle is applied, the ball 130 is engaged with the outer ring ball groove 113 and the inner ring ball groove 122, whereby torque is transmitted between the outer ring 110 and the inner ring 120. At this time, due to the contact of the ball 130 with the outer ring ball groove 113 and the inner ring ball groove 122, a load is applied in a direction in which the ball 130 moves toward the opening side of the outer ring 110. However, the cage 140 holds the ball 130, and the ball 130 is engaged with the outer ring ball groove 113 and the inner ring ball groove 122 by contacting the inner peripheral edge of the outer ring 110 on the opening side. To maintain.

  Thus, the outer peripheral surface 141 of the retainer 140 contacts the inner peripheral edge of the outer ring 110 on the opening side. In particular, the outer peripheral surface side of the pillar portion 144 of the cage 140 is in contact with the inner peripheral edge of the outer ring 110 on the opening portion side. Therefore, the outer peripheral surface side of the column portion 144 of the cage 140 receives a load from the outer ring 110.

(Divided mesh of cage 140)
Next, in order to perform structural analysis by the finite element method for the cage 140, the cage 140 is divided into a number of elements. This divided mesh will be described with reference to FIG. 4 and FIG. As shown in FIGS. 4 and 5, in this coupled analysis, the element of the cage 140 to be divided is a hexahedral primary element. That is, one hexahedral primary element has six boundary surfaces, twelve boundary line segments, and eight nodes (each corner point). However, the element of the cage 140 to be divided may be a hexahedral secondary element. One hexahedral secondary element has 6 boundary surfaces, 12 boundary segments, and 20 nodes.

  Furthermore, as shown in FIG. 5, the number of nodes is set to 4 or more in the direction from the inner peripheral surface to the outer peripheral surface of the cage 140. Here, in the direction from the inner peripheral surface of the cage 140 to the outer peripheral surface, the divided mesh is generated so as to have five-step hexahedral primary elements. That is, the number of nodes is 6.

  Also, the number of hexahedral primary elements in the circumferential direction on the outer peripheral surface side of the column portion 144 is set to seven, and the number of primary hexahedral elements in the circumferential direction on the inner peripheral surface side of the column portion 144 is set to be three. doing. That is, the number of elements in the circumferential direction on the outer peripheral surface side of the column part 144 is set to be larger than the number of elements in the circumferential direction on the inner peripheral surface side. In the column portion 144, the number of elements in the circumferential direction increases from the inner peripheral surface side to the outer peripheral surface side. On the other hand, the number of elements in the circumferential direction on the outer peripheral surface of the axial edge portions 145, 146 is set to be the same as the number of elements in the circumferential direction on the inner peripheral surface side of the axial edge portions 145, 146.

  By the way, in order to perform a highly accurate structural analysis, it is desired that the aspect ratio of the hexahedral primary element be close to 1. In other words, the ideal hexahedral primary element is a cube. The column portion 144 and the axial edge portions 145 and 146 can be made as close as possible to the aspect ratio by dividing the mesh as described above. This will be described in detail.

  The circumferential width on the outer peripheral surface side of the column portion 144 is larger than the circumferential width on the inner peripheral surface side. In particular, the difference with respect to the width is large. Therefore, the pillar portion 144 is mesh-divided so that the number of elements in the circumferential direction on the outer peripheral surface side is larger than the number of elements in the circumferential direction on the inner peripheral surface side. Therefore, even if the circumferential width on the outer circumferential surface side of the column portion 144 is larger than the circumferential width on the inner circumferential surface side, the aspect ratio of each element of the column portion 144 can be prevented from becoming so large. That is, a highly accurate coupled analysis of the column portion 144 is possible.

  Further, as described above, the outer peripheral surface side of the column portion 144 receives a pressing load by contacting the inner peripheral edge of the outer ring 110 on the opening portion side. Therefore, it is very important to analyze the outer peripheral surface side of the column part 144 with high accuracy. And by increasing the number of elements in the circumferential direction on the outer peripheral surface side of the column part 144, the stress distribution resulting from the contact with the outer ring 110 can be analyzed with high accuracy. That is, by making the aspect ratio of each element of the column part 144 close to 1 and increasing the number of elements in the circumferential direction on the outer peripheral surface side of the column part 144, it is possible to perform highly accurate coupled analysis of the column part 144. Become.

  Further, since the outer inner peripheral surface of the cage 140 is spherical, the circumferential length on the outer peripheral surface side of the axial edge portions 145 and 146 is longer than the circumferential length on the inner peripheral surface side. However, the number of elements in the circumferential direction on the outer peripheral surfaces of the axial edge portions 145 and 146 is set to be the same. That is, the element shapes of the axial edge portions 145 and 146 are slightly increased from the inner peripheral surface side to the outer peripheral surface side.

  Here, the ratio (ΔL / La) of the difference in the circumferential length on the outer inner peripheral surface side in the axial edge portions 145 and 146 is the ratio of the difference in the circumferential width on the outer inner peripheral surface side in the column portion 144 ( Smaller than ΔH / Ha). Thus, with respect to the axial edges 145 and 146, even with the same number of elements in the circumferential direction on the outer peripheral surface side, it is possible to perform sufficiently accurate coupled analysis. In particular, setting the number of elements makes it easy to set the elements. As described above, the pillar portion 144 and the axial edge portions 145 and 146 are mesh-divided into corresponding elements, whereby the stress analysis of the cage 140 can be performed with high accuracy.

  Further, the number of nodes on the boundary line segment of the hexahedral primary element is set to four or more in the direction from the inner peripheral surface to the outer peripheral surface of the cage 140. As a result, when a radial force is applied to the cage 140, the contour shape of the window portion 143 of the cage 140 after deformation can be approximated to a curved shape, and the contour shape. Can be prevented from becoming an acute angle. As a result, a highly accurate analysis result can be obtained.

  Here, it is known that a secondary couple acts on the ball-type constant velocity joint 100 and the shaft 10 is bent and deformed. Therefore, as a coupled analysis model in the present embodiment, the shaft 10 is made elastic so that the shaft 10 is allowed to bend and deform when a force for bending the shaft 10 is generated by a secondary couple. Is done. Therefore, the stress generated in the cage 140 in the coupled analysis can be very close to the stress generated in the actual cage 140.

  Furthermore, by taking into account bending deformation due to the weight of the shaft 10 and performing a coupled analysis with the other end of the shaft 10 coupled to a sliding tripod constant velocity joint 200 slidable in the axial direction. The bending deformation of the shaft 10 in the coupled analysis can be brought into a state close to the actual state. As a result, the stress analysis of the cage 140 can be performed with high accuracy.

100: Ball type constant velocity joint, 110: Outer ring, 112: Inner circumferential surface of outer ring, 113: Outer ring ball groove, 120: Inner ring, 121: Outer ring surface of inner ring, 122: Inner ring ball groove, 130: Ball, 140: Holding 143: Window part 144: Column part 145, 146: Axial edge

Claims (2)

An outer ring having an outer ring ball groove formed on the inner circumferential surface, an inner ring having an inner ring ball groove formed on the outer circumferential surface, and the outer ring ball groove and the inner ring ball groove arranged so as to be rollable. Stress analysis of the cage in a ball type constant velocity joint comprising: a ball that transmits torque between the outer ring and the inner ring; and a cage that is disposed between the outer ring and the inner ring and that has a window portion that holds the ball. A device for performing
Based on a structural analysis performed by a finite element method using a direct integration method by dividing the cage into hexahedral elements, and an analysis model composed of components of the ball-type constant velocity joint and components connected to the components Apply coupled analysis with mechanical analysis,
The retainer includes a column part that partitions the window part adjacent in the circumferential direction,
The circumferential width on the outer peripheral surface side of the column portion is larger than the circumferential width on the inner peripheral surface side of the column portion,
The outer peripheral surface of the column portion is in contact with the inner peripheral edge on the opening side of the outer ring,
The number of the hexahedron elements in the circumferential direction on the outer peripheral surface side of the column part is greater than the number of the hexahedral elements in the circumferential direction on the inner peripheral surface side of the column part. Cage stress analyzer. In claim 1,
The cage includes the pillar portion and an axial edge portion defining an axial portion of the cage in the window portion,
The rate of the difference between the circumferential length on the outer circumferential surface side of the axial edge and the circumferential length on the inner circumferential surface side of the axial edge is the circumferential width on the outer circumferential surface side of the column portion and the column portion. Smaller than the rate of difference in the circumferential width on the inner peripheral surface side of
A ball set so that the number of the hexahedral elements in the circumferential direction on the outer peripheral surface side of the axial edge portion is the same as the number of the hexahedral elements in the circumferential direction on the inner peripheral surface side of the axial edge portion Stress analysis device for cage of mold constant velocity joint.

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