JP2011528777A - Drive device for continuously variable transmission for automobile - Google Patents

Abstract

  The present invention relates to a continuously variable transmission, and more particularly to a drive for a crank CVT for an automobile. The drive device has a drive shaft (1), the end region of the drive shaft is supported in the transmission casing, the drive shaft has a notch (3), and the adjustment shaft (2) in the notch Is arranged to be rotatable. The eccentric component of the eccentric device arranged on the drive shaft is adjusted steplessly by the rotation of the adjustment shaft. The drive shaft has a plurality of cylindrical and disc-shaped reinforcing regions (4) spaced apart from each other in the axial direction in the middle region. The adjusting shaft has a plurality of circumferential grooves (5) spaced apart from each other in the axial direction, the circumferential grooves being aligned with the reinforcing region with the adjusting shaft being incorporated in the notch of the drive shaft. In the circumferential groove, the rolling elements (9) are supported on the one hand on the bottom surface of the circumferential groove used as the inner race surface and on the other hand on the inner surface used as the outer race surface of the reinforcement region. It is arranged in a state that can be.

Description

  The present invention relates to a driving device for a continuously variable transmission, and more particularly to a driving device for a crank CVT for an automobile.

  German Offenlegungsschrift 10 243 535 A1 describes a continuously variable transmission for a motor vehicle, which substantially comprises a drive shaft and a driven shaft, And the driven shaft are arranged parallel to each other and are rotatably supported in the transmission casing. Both shafts are connected to each other via an eccentric device provided on the drive shaft and a freewheel device arranged on the driven shaft. The eccentric device (eccentric body device) is composed of a plurality of eccentric units, and the eccentric units (eccentric body units) are arranged on the drive shaft side by side in the axial direction. The freewheel device includes a plurality of freewheel units, and the freewheel units are arranged on the driven shaft side by side in the axial direction.

  In order to form each eccentric unit, the drive shaft has a guide region that is eccentrically (eccentric) with respect to the rotation axis, and the eccentric component rotates on the outer peripheral surface of the guide region. It is supported as possible. A connecting rod is rotatably supported on the eccentric component (eccentric component) when a continuously variable transmission is formed as a crank CVT (Continuous-Variable-Transmission).

  Each eccentric component has a notch for receiving the guide region of the drive shaft, and an inner peripheral tooth row is formed in the notch over the entire circumference. The inner peripheral tooth row is configured in accordance with the outer peripheral surface of the guide region so that the eccentric component portion is centered on the guide region by the inner peripheral tooth row.

  The drive shaft or the guide region thereof has a notch extending in the direction of the rotation axis of the drive shaft, and the adjustment shaft is rotatably or rotatably disposed in the notch. The adjusting shaft has an outer peripheral tooth row, and the outer peripheral tooth row meshes with the inner peripheral tooth row of the eccentric component. The adjustment shaft is supported in the notch portion of the drive shaft, with the section defining the tip circle of the teeth of the outer circumferential dentition. The guide region is formed in a crescent shape so that the notch is opened over a predetermined angle range. In the angle range where the notch is opened, the outer peripheral tooth row of the adjusting shaft is outside the guide region. It is possible to project in the radial direction from the peripheral surface of the shaft, and it is possible to engage with the inner peripheral tooth row of the eccentric component.

  The central axis of the guide region, which is based on the cylindrical peripheral surface of the guide region formed in a disk shape, is eccentrically arranged over a predetermined distance with respect to the rotational axis of the drive shaft. The center axis of the eccentric component with respect to the cylindrical peripheral surface of the eccentric component is the amount of eccentricity between the center axis of the eccentric component and the rotation axis of the drive shaft, and the center axis of the guide region It is arranged eccentrically with respect to the central axis of the guide region over a distance that is twice the amount of eccentricity with the rotational axis of the drive shaft.

  Due to the rotation of the adjusting shaft within the notch of the drive shaft, the eccentric component of the eccentric unit is rotated about the central axis of the corresponding guide region, so that the central axis of the eccentric component is guided. Moving around the central axis of the region, as a result, the value of the amount of eccentricity between the central axis of the eccentric component and the rotational axis of the drive shaft is changed.

  In the known stepless crank CVT (crank CVT), the adjusting shaft is generally inserted into the drive shaft with little play without a bearing. The problem is that the flexible drive shaft is supported by the adjustment shaft under load, and a high operating moment is generated due to metal friction due to the tightening of the adjustment shaft in the notch in the axial direction of the drive shaft. . Such a high operating moment increases the amount of current demand in the electric drive for driving the adjusting shaft during adjustment.

  According to the form of the invention described in the applicant's patent application filed on the same date, the flexible drive shaft deflection is achieved by driving the drive shaft supported in the outer region in the transmission casing. Minimized by bearing against the transmission casing additionally in the middle region of the shaft. Further, a cylindrical reinforcing region spaced apart from each other in the axial direction is provided between the support portions outside the drive shaft. Based on the arrangement of the additional bearings, an axial configuration space is required.

  Accordingly, an object of the present invention is to improve a drive device for a continuously variable transmission for an automobile and to significantly reduce the deflection of the drive shaft without requiring additional space in the axial direction. To reduce or avoid.

  In order to solve the above-mentioned problems, the end region of the drive shaft provided for a continuously variable transmission, particularly for a crank CVT for automobiles, can be rotated in the transmission casing. It is supported by. The drive shaft has a notch, and the adjustment shaft is rotatably disposed in the notch, and the eccentric component of the eccentric device disposed on the drive shaft is rotated by the rotation of the adjustment shaft. In this way, the guide area is adjusted steplessly. The drive shaft has at least one cylinder-shaped and disk-shaped or disk-shaped reinforcing area in the middle area. The adjustment shaft has at least one circumferential groove or a plurality of circumferential grooves spaced apart from each other in the axial direction, and the circumferential groove is formed in a state where the adjustment shaft is incorporated in the notch portion of the drive shaft and the reinforcing region. Aligned. In the circumferential groove, the rolling elements are supported on the one hand on the bottom surface of the circumferential groove used as the inner race surface and on the other hand on the inner cylindrical surface used as the outer race surface in the reinforcement region. It is arranged in a state that can be.

  The main advantage of the drive device according to the present invention is that the adjusting shaft can be supported in the notch portion of the drive shaft with almost no friction, and a cylindrical surface (inner circumference) in the middle reinforcing region of the drive shaft Cylindrical surface) is used as a race surface for rolling bearings. Particularly advantageously, in order to achieve a friction-free bearing of the adjusting shaft, a plurality of reinforcing regions are arranged in the middle region in the axial direction of the adjusting shaft, spaced apart from each other, the adjusting shaft being located in the reinforcing region. Correspondingly, it has a plurality of circumferential grooves.

  According to a particularly advantageous form of the invention, the rolling elements of the respective rolling bearings are held in respective annular cages, which are preferably separated by an opening at one location. With such a configuration, it is possible to particularly easily and quickly assemble the rolling elements into the circumferential groove.

  The adjustment shaft has an outer peripheral dentition made of teeth extending in the direction of the axis of the adjustment shaft for adjusting the eccentric component, and the outer dentition is divided at the region of the peripheral groove. According to an advantageous embodiment of the invention, the drive shaft is a component of the crank CVT, and the rotation of the drive shaft is parallel to the drive shaft via an eccentric device and a connecting rod arranged on the drive shaft. The eccentric device includes a plurality of eccentric components separated from each other in the axial direction on the drive shaft. The eccentric component has a respective notch for receiving a guide area which is arranged eccentrically with respect to the axis of rotation of the drive shaft, particularly preferably two adjacent said reinforcing areas In between, each eccentric component is arranged.

  Next, the present invention will be described in detail based on the illustrated embodiment.

It is a longitudinal cross-sectional view of a drive shaft of a known crank CVT, the drive shaft has a plurality of reinforcement regions for preventing deflection that are separated from each other in the axial direction, and an adjustment shaft is provided in a notch portion of the drive shaft. The rolling bearing is disposed in the circumferential groove of the adjustment shaft in a state supported by the inner circumferential surface of the reinforcing region and the bottom surface of the circumferential groove. FIG. 2 is a perspective view of the apparatus of FIG. It is a perspective view of the adjustment shaft of the drive device concerning the present invention, and a rolling bearing is not drawn in order to make a bottom surface used as a race track of a peripheral groove visible. It is a figure which shows the adjustment axis | shaft provided with the rolling bearing arrange | positioned in the circumferential groove of FIG. It is a perspective view of a rolling bearing having a flexible cage. The adjustment shaft is shown in a perspective view, with the rolling bearing in contact with the inner peripheral surface of the reinforcing region partially visible. It is the end elevation seen in the direction shown by the VII-VII line of the adjustment axis of FIG. It is the end elevation seen in the direction shown by the VIII-VIII line of the drive device of FIG.

  The following description is helpful for understanding the present invention. Supporting the drive shaft on the adjustment shaft with a small configuration space and small friction makes use of a cylindrical reinforcing region arranged in the central region of the drive shaft, and allows the inner support portion of the drive shaft to be adjusted relative to the adjustment shaft. This is achieved by trying to form the inner peripheral surface of the reinforcing region.

  In FIG. 1, the drive shaft of the continuously variable transmission is indicated by reference numeral 1. An adjustment shaft 2 is arranged or supported in the axial cutout 3 of the drive shaft 1 as will be described in detail later. The outer end region of the drive shaft 1 is rotatably supported in the transmission casing by using a bearing (not shown) in a known manner. The corresponding part of the drive shaft 1 is indicated by the symbol L in FIG.

  The drive shaft 1 has a reinforcing region 4 which has already been described, and the reinforcing region 4 is disposed in an intermediate region of the drive shaft 1 while being separated from each other in the axial direction of the drive shaft 1. This contributes to increasing the strength of the drive shaft 1. The reinforcing regions 4 each have the shape of a cylindrical disk disposed coaxially with the rotational axis of the drive shaft 1. The reinforcing regions 4 may be provided in various numbers. It is also conceivable that only one reinforcing region is provided in the middle region of the adjusting shaft. Between the reinforcing regions 4 there is provided an eccentric component 14 of the eccentric device as already mentioned and as is apparent from the drawing.

  The adjustment shaft 2 has a plurality of circumferential grooves 5 that are spaced apart from each other in the axial direction corresponding to the number and interval of the reinforcing regions 4, and a rolling bearing 6 is disposed in the circumferential grooves. The rolling bearing is advantageously constructed in the embodiment shown in FIG. The circumferential groove 5 is aligned with the reinforcing region 4 as can be seen particularly in FIG. 1 when the adjusting shaft 2 is inserted into the notch 3 of the drive shaft 1 as shown in FIG. As can be seen in particular in FIG. 1, the rolling elements 9 of the rolling bearing 6 contact on the one hand the bottom surface 8 used as the inner race surface of the circumferential groove 5 and on the other hand as the outer race surface of the reinforcing region 4. It is in contact with the inner cylindrical surface 13 used.

  FIG. 3 shows the adjusting shaft 2, and the outer peripheral tooth row 7 of the adjusting shaft 2 in which teeth extend in the axial direction meshes with the inner peripheral tooth row of the eccentric component. The outer circumferential tooth row 7 formed of teeth extending in the axial direction is divided by the region of the circumferential groove 5.

  As shown in FIG. 4, the rolling bearing 6 is mounted in the circumferential groove 5 before the adjustment shaft 2 is assembled into the notch 3 of the drive shaft 1.

  FIG. 5 shows a rolling bearing 6 according to an advantageous embodiment, the rolling bearing 9 being held in a flexible retainer 10 so that the rolling groove 9 can be integrated into a circumferential groove without being disassembled. 5 is attached. The cage 10 is divided by a cut or opening 11 and is therefore open and widened for easy and quick assembly of the rolling bearing 6 into the circumferential groove 5.

  In another embodiment, instead of the rolling bearing 6 shown in FIG. 5, an arrangement of rolling element circumferentially arranged bearings composed of rolling elements arranged closely to each other without a cage can be considered.

  DESCRIPTION OF SYMBOLS 1 Drive shaft, 2 Adjustment axis | shaft, 3 Hole, 4 Reinforcement area | region, 5 Circumferential groove, 6 Rolling bearing, 7 Outer periphery tooth row | line | column, 8 Bottom surface, 9 Rolling body, 10 Cage, 11 Opening part, 12 Rotation axis, 13 surface, 14 Eccentric components

Claims (7)

  A drive device for a continuously variable transmission type transmission device, in particular a drive device for a crank CVT for an automobile, having a drive shaft (1), the end region of the drive shaft being It is rotatably supported in the casing, the drive shaft has a notch (3), and the adjusting shaft (2) is rotatably arranged in the notch. In the type in which the eccentric component (14) of the eccentric device arranged on the drive shaft (1) is adjusted steplessly by the rotation of the adjustment shaft, the drive shaft (1 ) Has at least one cylindrical and disc-shaped reinforcing region (4) in the middle region, and the adjusting shaft (2) has at least one circumferential groove (5) The circumferential groove is assembled with the adjustment shaft (2) in the notch (3) of the drive shaft (1). In a state of being aligned with the reinforcing region (4), and in the circumferential groove (5), a rolling element (9) is used as an inner race surface of the circumferential groove (5). Supported by the bottom surface (8), and on the other hand, supported by the inner cylindrical surface (13) used as the outer race surface of the reinforcing region (4). A drive unit for a continuously variable transmission.   The drive shaft (1) has a plurality of the reinforcing regions (4) spaced apart from each other in the axial direction in an intermediate region thereof, and the adjusting shaft (2) is connected to the reinforcing region (4). The drive device according to claim 1, comprising a number of the circumferential grooves corresponding to a number.   The drive device according to claim 1 or 2, wherein the rolling element (9) is held in an annular retainer (10).   The drive device according to claim 3, wherein the annular cage (10) is divided at one part by an opening (11).   The adjusting shaft (2) has an outer peripheral tooth row (7) composed of teeth extending in the axial direction of the adjusting shaft (2) for adjusting the eccentric component, and the outer peripheral tooth row (7). The drive device according to claim 1, wherein the drive device is divided at a region of the circumferential groove (5).   The drive shaft (1) is a constituent part of the crank CVT, and the rotation of the drive shaft (1) is performed via the eccentric device and the connecting rod arranged on the drive shaft (1). ) Is transmitted to the freewheel unit of the driven shaft supported in the transmission device casing in parallel to the drive shaft, and the eccentric devices are separated from each other on the drive shaft (1) in the axial direction. A plurality of eccentric components (14), the eccentric components having a notch for receiving a guide region arranged eccentrically with respect to the rotational axis of the drive shaft The drive device according to claim 5, wherein an inner peripheral tooth row of the eccentric component part meshes with the outer peripheral tooth row (7) of the adjustment shaft (2).   The drive unit according to claim 6, wherein each eccentric component (14) is arranged between two adjacent reinforcing regions (4).

Images