A bearing structure for a driving cam of a presser foot or needle bar

Abstract

The utility model provides a bearing structure for driving cam of presser foot or needle bar, including being located on the eccentric wheel for driving presser foot or needle bar of driving shaft, eccentric wheel include eccentric inner wheel and eccentric outer wheel, eccentric outer wheel is equipped with drive rod outside, eccentric inner wheel and eccentric outer wheel are equipped with two rows of ball bearings between, two rows of balls are symmetrically arranged, ball and inner and outer ring point contact, are not easy to wear and tear, wear and tear is not easy to be uneven, noise is small, rotation accuracy is high.

Description

Technical Field

[0001] This utility model relates to the technical field of presser foot and needle bar drive devices, and in particular to a bearing structure for a drive cam for a presser foot or needle bar. Background Technology

[0002] Existing embroidery machines typically have an eccentric wheel on their drive shaft to drive the presser foot or needle bar. A drive rod is located outside the eccentric wheel, and a bearing facilitates rotation between the drive rod and the eccentric wheel. Current bearings generally use needle roller bearings, which are roller bearings with cylindrical rollers that are relatively thin and long compared to their diameter. These rollers are called needle rollers because their cylindrical shape results in a large contact area between the rollers and the inner and outer rings, leading to line contact. Although needle roller bearings can withstand high forces, wear at any point on the needle rollers, inner ring, or outer ring can cause uneven radial force. This uneven contact between the needle rollers and the inner and outer rings can easily lead to imbalances, causing wobbling in the seam and generating noise. This uneven fit further exacerbates wear. Utility Model Content

[0003] To address the problems of the prior art, this invention provides a bearing structure for a drive cam of a presser foot or needle bar, using ball bearings instead of roller bearings, resulting in higher rotational accuracy and lower noise.

[0004] The technical solution adopted is as follows: A bearing structure for a drive cam for a presser foot or needle bar includes an eccentric wheel mounted on a drive shaft for driving the presser foot or needle bar. The eccentric wheel includes an inner eccentric wheel and an outer eccentric wheel. A drive rod is provided outside the outer eccentric wheel. Two rows of ball bearings are provided between the inner eccentric wheel and the outer eccentric wheel.

[0005] Furthermore, two rows of balls are provided between the eccentric inner wheel and the eccentric outer wheel. The eccentric inner wheel serves as the inner ring of the ball bearing, and the eccentric outer wheel serves as the outer ring of the ball bearing. The eccentric inner wheel, the eccentric outer wheel, and the two rows of balls constitute a ball bearing.

[0006] Furthermore, the ball bearing is provided with separate inner and outer rings, with balls between the inner and outer rings, and the ball bearing with inner and outer rings is integrally positioned between the eccentric inner wheel and the eccentric outer wheel.

[0007] Furthermore, the eccentric inner wheel and the eccentric outer wheel are provided with two single-row ball bearings or at least one double-row ball bearing.

[0008] Furthermore, two single-row ball bearings are arranged and fitted together in the axial direction of the eccentric wheel.

[0009] Furthermore, the width of each row of ball bearings is consistent.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention provides a bearing structure for a drive cam of a presser foot or needle bar. Two rows of ball bearings are arranged between an eccentric inner wheel and an eccentric outer wheel, using balls instead of rollers. The balls make point contact with the inner and outer rings, and the two points form a line to support the eccentric inner and outer wheels. Even with slight wear, the two points can provide balanced support. The two rows of balls are symmetrically arranged, and the contact points are symmetrically aligned, which reduces uneven wear, lowers noise, and reduces frictional resistance from point contact, resulting in smoother movement and higher rotational accuracy, thereby reducing further wear from shaking. Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a side view of the present invention; Figure 3 for Figure 2 A cross-sectional view facing the CC direction; Figure 4 This is a partial disassembly diagram of the bearing structure; Figure 5 This is a schematic diagram showing the structure of the bearing where the eccentric inner wheel and eccentric outer wheel directly form the inner and outer rings.

[0012] Among them, there are eccentric wheel 1, eccentric inner wheel 11, eccentric outer wheel 12, drive rod 2, ball bearing 3, inner ring 31, outer ring 32, ball 33, and cage 34. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments.

[0014] refer to Figure 1-5 A bearing structure for a drive cam for a presser foot or needle bar includes an eccentric wheel 1 mounted on a drive shaft for driving the presser foot or needle bar. The eccentric wheel 1 includes an inner eccentric wheel 11 and an outer eccentric wheel 12. A drive rod 2 is provided outside the outer eccentric wheel 12. Two rows of ball bearings 3 are provided between the inner eccentric wheel 11 and the outer eccentric wheel 12.

[0015] See Figure 5 In one embodiment, two rows of balls 33 are provided between the eccentric inner wheel 11 and the eccentric outer wheel 12. The eccentric inner wheel 11 serves as the inner ring of the ball bearing 3, and the eccentric outer wheel 12 serves as the outer ring of the ball bearing 3. The eccentric inner wheel, the eccentric outer wheel, and the two rows of balls constitute the ball bearing 3. Grooves are directly provided on the side walls of the eccentric inner wheel 11 and the eccentric outer wheel, and ball retainers are installed in the grooves. The balls can be fitted with retainers.

[0016] See Figure 4 In another embodiment, the ball bearing 3 is provided with an inner ring 31 and an outer ring 32 separately. Balls 33 are provided between the inner ring and the outer ring, and a cage 34 can be further provided. The ball bearing 3 with the inner ring and the outer ring is integrally provided between the eccentric inner wheel and the eccentric outer wheel.

[0017] The drive shaft drives the eccentric wheel 1 to rotate, which in turn drives the drive rod 2 outside the eccentric outer wheel to rotate. The drive rod is connected to the transmission assembly, which lifts the pressure foot or needle bar. The eccentric inner wheel is eccentrically mounted on the drive shaft, and its center of gravity is not on the drive shaft. When rotating, it is prone to uneven force, which can easily cause wear on the bearings between the eccentric inner wheel and the eccentric outer wheel. Moreover, at high speeds, the force is greater, making it more susceptible to damage.

[0018] If existing roller bearings are used, the large contact area easily leads to wear of the rollers, and uneven wear results in increased noise, shortened service life, and affects the fitting accuracy, causing inaccurate drive positioning. Therefore, ball bearings 3 are used instead of roller bearings, positioned between the eccentric inner and outer wheels. The balls 33 have point contact with both the inner ring 31 and the outer ring 32, resulting in low frictional resistance, smoother movement, and higher rotational accuracy.

[0019] Furthermore, two single-row ball bearings 3 or at least one double-row ball bearing 3 are provided between the eccentric inner wheel 11 and the eccentric outer wheel 12.

[0020] Two single-row ball bearings 3 or at least one double-row ball bearing 3 are installed to provide support at two points in a line, forming the support for the inner and outer wheels. Even after slight wear, it can still provide relatively balanced and stable support and withstand radial force.

[0021] Two single-row ball bearings 3 are arranged axially towards the eccentric wheel 1 and fitted together, ensuring a seamless fit between the eccentric wheel and the drive rod, resulting in smoother rotation. Preferably, the connecting part 21 is arranged side-by-side with the eccentric wheel 1, and each single-row ball bearing 3 has the same width. Furthermore, the two rows of balls in the ball bearings 3 are symmetrically arranged, with the contact points of the two rows forming a symmetrical line, reducing the likelihood of uneven wear. The force is evenly distributed across the two bearings, resulting in higher rotational accuracy, less noise, and a longer service life.

[0022] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A bearing structure for a drive cam of a presser foot or needle bar, comprising an eccentric wheel (1) mounted on a drive shaft for driving the presser foot or needle bar, wherein the eccentric wheel (1) comprises an inner eccentric wheel (11) and an outer eccentric wheel (12), and a drive rod (2) is provided outside the outer eccentric wheel (12), characterized in that: Two rows of ball bearings (3) are provided between the eccentric inner wheel (11) and the eccentric outer wheel (12).

2. The bearing structure for the drive cam of the presser foot or needle bar as described in claim 1, characterized in that: Two rows of balls (33) are provided between the eccentric inner wheel (11) and the eccentric outer wheel (12). The eccentric inner wheel (11) serves as the inner ring of the ball bearing (3); the eccentric outer wheel (12) serves as the outer ring of the ball bearing (3). The eccentric inner wheel, the eccentric outer wheel and the two rows of balls constitute the ball bearing (3).

3. The bearing structure for the drive cam of the presser foot or needle bar as described in claim 1, characterized in that: The ball bearing (3) is provided with an inner ring (31) and an outer ring (32) separately, and a ball (33) is provided between the inner ring and the outer ring. The ball bearing (3) with the inner ring and the outer ring is integrally located between the eccentric inner wheel and the eccentric outer wheel.

4. The bearing structure for the drive cam of the presser foot or needle bar as described in claim 3, characterized in that: The eccentric inner wheel (11) and the eccentric outer wheel (12) are provided with two single-row ball bearings (3) or at least one double-row ball bearing (3).

5. The bearing structure for the drive cam of the presser foot or needle bar as described in claim 4, characterized in that: Two single-row ball bearings (3) are arranged and fitted together in the axial direction of the eccentric wheel (1).

6. The bearing structure for the drive cam of the presser foot or needle bar as described in claim 4, characterized in that: The width of each row of ball bearings (3) is the same.

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