KR-20260062621-A - IMPROVED OPERATIONAL QUALITY GEAR BOX

KR20260062621AKR 20260062621 AKR20260062621 AKR 20260062621AKR-20260062621-A

Abstract

The present invention relates to a gearbox with improved operating quality provided in a slide device for sliding a vehicle seat in the forward and backward directions, and in particular, to a gearbox with improved operating quality that can enhance the operating sensation when the gearbox is slid along the lead screw by providing a non-contact area in the screw coupling section between the male threaded part of the lead screw and the female threaded part of the worm wheel nut.

Inventors

심재원
석성철

Assignees

대원정밀공업(주)

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (7)

In a gearbox provided in a sliding device of a vehicle seat, The above gearbox is, A worm shaft that rotates by a driving means; A worm wheel nut that meshes with the worm shaft and rotates according to the rotation of the worm shaft; A lead screw having a male threaded portion that screw-couples with the female threaded portion of the worm wheel nut of the above-mentioned worm wheel nut; A housing in which the above worm wheel nut and the above worm shaft are accommodated; and A seat bracket connecting the above housing and the vehicle seat; is included, The above gearbox is a gearbox having a contact area where the female threaded portion of the worm wheel nut and the male threaded portion of the lead screw come into contact with each other, and a non-contact area where the female threaded portion of the worm wheel nut and the male threaded portion of the lead screw do not come into contact with each other.
In paragraph 1, The above-mentioned female threaded portion of the worm wheel nut includes a first worm wheel nut thread groove and a second worm wheel nut thread groove, and The first worm wheel nut screw groove is in contact with the lead screw thread of the male lead screw portion, and the area where the first worm wheel nut screw groove is located is the contact area. A gearbox in which the second worm wheel nut screw groove does not come into contact with the lead screw threads of the lead screw male screw portion, so that the area where the second worm wheel nut screw groove is located is the non-contact area.
In paragraph 2, A gearbox in which the second worm wheel nut flanks disposed on both sides of the second worm wheel nut screw groove are positioned further outward than the first worm wheel nut flanks disposed on both sides of the first worm wheel nut screw groove, so that the flank angle of the second worm wheel nut flank is formed to be greater than the flank angle of the first worm wheel nut flank.
In paragraph 2, A gearbox in which the female thread of the worm wheel nut is formed by two or more rows of screws in which one of the first worm wheel nut screw grooves and one or more of the second worm wheel nut screw grooves are sequentially repeated.
In paragraph 1, The above lead screw male thread portion includes a first lead screw thread and a second lead screw thread, and The first lead screw thread is in contact with the worm wheel nut thread groove of the female thread portion of the worm wheel nut, and the area where the first lead screw thread is located is the contact area. A gearbox in which the second lead screw thread does not come into contact with the worm wheel nut thread groove of the female thread portion of the worm wheel nut, so that the area where the second lead screw thread is located is the non-contact area.
In paragraph 5, A gearbox in which the second lead screw flanks disposed on both sides of the second lead screw thread are positioned inwardly compared to the first lead screw flanks disposed on both sides of the first lead screw thread, so that the flank angle of the second lead screw flank is formed to be smaller than the flank angle of the first lead screw flank.
In paragraph 5, A gearbox in which the male lead screw portion is formed by two or more rows of screws in which one of the first lead screw threads and one or more of the second lead screw threads are sequentially repeated.

Description

Improved Operational Quality Gear Box The present invention relates to a gearbox with improved operating quality provided in a slide device that slides a vehicle seat in the forward and backward directions. The vehicle seat is composed of a seat back and a seat cushion, and the sliding device slides the seat cushion along a seat track arranged in the front-to-rear direction of the vehicle. The seat track is configured to include a lower rail fixedly installed on a floor panel and an upper rail coupled to the upper part of the lower rail and on which a seat cushion is installed, and the slide device is configured to include a driving means for sliding the upper rail and a gearbox that rotates along a lead screw installed on the lower rail to slide the upper rail in the forward and backward directions. The gearbox is installed orthogonally so that the worm shaft and the worm wheel nut maintain a meshing state with each other, and when the worm shaft rotates by a driving means, the worm wheel nut to which the lead screw is coupled rotates, thereby causing the gearbox to slide in the forward and backward directions along the lead screw. In this case, a male thread of the lead screw is formed on the surface of the lead screw, and a female thread of the worm wheel nut is formed on the worm wheel nut. Therefore, when the lead screw and the worm wheel nut are combined, the male thread of the lead screw and the female thread of the worm wheel nut mesh with each other. Thus, when the worm wheel nut rotates due to the lead screw threads as described above, the gearbox and the vehicle seat can slide in the forward and backward directions along the lead screw. In the case of conventional gearboxes, the male thread of the lead screw and the female thread of the worm wheel nut are screwed together with all the threads and grooves in contact. Therefore, when the worm wheel nut rotates and the gearbox slides in the forward and backward directions along the lead screw threads, there is a problem where the operational feel of the gearbox is reduced due to dimensional variation between the threads. FIG. 1 is a perspective view of a slide device for a vehicle seat equipped with a gear box according to a first embodiment of the present invention. FIG. 2 is a perspective view of a gearbox according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view of the gearbox of FIG. 2. FIG. 4 is a perspective view of the worm wheel nut of FIG. 3. FIG. 5 is a cross-sectional view of the worm wheel nut of FIG. 4. FIG. 6 is an enlarged view showing the contact area and non-contact area of the female threaded portion of the worm wheel nut and the male threaded portion of the lead screw of a gearbox according to the first embodiment of the present invention. FIG. 7 is an enlarged view showing the contact area and non-contact area of the female threaded portion of the worm wheel nut and the male threaded portion of the lead screw of a gearbox according to a second embodiment of the present invention. FIG. 8 is an enlarged view showing the contact area and non-contact area of the worm wheel nut female thread portion and the lead screw male thread portion of a gearbox according to the third embodiment of the present invention. FIG. 9 is an enlarged view showing the contact area and non-contact area of the worm wheel nut female thread portion and the lead screw male thread portion of a gearbox according to the fourth embodiment of the present invention. Gear box (10) according to the first embodiment of the present invention Hereinafter, a gearbox (10) according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view of a slide device for a vehicle seat equipped with a gearbox according to a first embodiment of the present invention, FIG. 2 is a perspective view of a gearbox according to a first embodiment of the present invention, FIG. 3 is an exploded perspective view of the gearbox of FIG. 2, FIG. 4 is a perspective view of a worm wheel nut of FIG. 3, FIG. 5 is a cross-sectional view of a worm wheel nut of FIG. 4, and FIG. 6 is an enlarged view showing the contact area and non-contact area between the female threaded part of the worm wheel nut and the male threaded part of the lead screw of the gearbox according to a first embodiment of the present invention. The gear box (10) according to the first embodiment of the present invention is a gear box (10) with improved operating quality and is provided in a slide device (20) to slide a vehicle seat. A sliding device (20) for sliding a vehicle seat may be configured to include a gear box (10), a fixed bracket (21), a driving means, a lower rail, and an upper rail. The gear box (10) may be configured to include a worm shaft (100), a worm wheel nut (200) that meshes with the worm shaft (100) and rotates according to the rotation of the worm shaft, a lead screw (300) having a lead screw male threa