CN214788838U

CN214788838U - K-shaped sheath of 3D RWW-shaped ball worm gear

Info

Publication number: CN214788838U
Application number: CN202120661052.9U
Authority: CN
Inventors: 安俊堂
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2021-11-19
Anticipated expiration: 2031-04-01

Abstract

The utility model discloses a K-shaped sheath of a 3D RWW-shaped ball worm gear, wherein the middle section of the middle part of the inner hole of the sheath body of the K-shaped sheath, the length of which is 2L, is matched with a ball to form a ball working section, the extension arc sections at the two ends of the middle section of the inner hole of the sheath body of the K-shaped sheath are matched with the ball to form a ball natural returning section, and the two sides of the extension arc sections inside and outside the sheath body of the K-shaped sheath are straight line sections for installing a Q-shaped returning ball retainer ring; two ports of the sleeve body of the K-shaped sheath are provided with worms through bearings; the K-shaped bottom surface of the sleeve body of the K-shaped sheath is matched with the excircle inclined surface of the worm wheel. The utility model relates to a rationally, fine practical application is worth having.

Description

K-shaped sheath of 3D RWW-shaped ball worm gear

Technical Field

The utility model relates to a worm gear technical field specifically is a K type sheath of 3D RWW type ball worm gear.

Background

Worm and worm gear structures are commonly used to transfer motion and power between two interleaved shafts. The advantages are that: the structure is simple, and the transmission ratio is large; the disadvantages are as follows: low efficiency, low precision and short service life.

Disclosure of Invention

The utility model aims at providing a novel K type sheath structural design of ball worm gear, satisfy the high accuracy transmission requirement.

The utility model discloses an adopt following technical scheme to realize:

a K-shaped jacket of a 3D RWW type ball worm gear is characterized in that a ball, a worm and a Q-shaped retainer ring are assembled in the K-shaped jacket, and the ball and the worm gear form a transmission pair for transmitting speed and torque.

The 3D RWW type ball worm gear comprises a worm gear, a worm, a K-shaped sheath, a Q-shaped retainer ring, a bearing and other parts except for balls.

3D: double-ended, Double head; a dual node, Double node; double lead, Double lead.

RWW: scrolling, Roll; worm gear, word gear; worm, word.

Drawings

FIG. 1 is a schematic view of a ball worm gear; in the figure, the lead of the worm is L, D is the pitch diameter of the worm wheel, De is the outer diameter of the worm wheel, and Di is the root diameter of the worm wheel.

FIG. 1: 1-a worm gear; 2-worm, 201-double-head ball groove, 202-ball returning hole channel, 203-worm shaft hole channel; 3-K type sheath; 4-Q type ball return retainer ring; 5-a bearing; 6-rolling balls.

FIG. 1-1 shows a cross-sectional view A-A of FIG. 1; in the figure, B is the pitch of the double pitch circle of the worm wheel, d is the pitch diameter of the worm, and 2 delta is the wrap angle of the center of the worm.

FIG. 2 shows a schematic view of the construction of a 3D RWW worm (only one end of the back ball returning groove is shown).

FIG. 2-1 shows a cross-sectional view (only one side is shown) along the line A of FIG. 2.

FIG. 3 is a schematic view showing the meshing state of the balls and the worm wheel in the tooth surface working section of the worm wheel; in the figure, β_kIs a helix angle (lead angle).

Fig. 3-1 shows a cross-sectional view of fig. 3.

Fig. 3-2 shows the meshing curve after trimming at a helix angle.

Fig. 4 shows an analysis diagram of a meshing curve (double C-shaped raceway) of a single raceway (single tooth groove) of the worm wheel and a ball.

Fig. 5 shows a schematic view of a K-type jacket.

Fig. 5-1 shows a side view of a K-type jacket.

Fig. 5-2 shows a schematic B-B cross-sectional view of a K-type jacket.

Fig. 6 shows a side view of a Q-shaped ball-returning retainer.

Fig. 6-1 shows a front view of a Q-shaped beadback retainer.

Fig. 6-2 shows a schematic view of a Q-shaped ball-returning retainer.

Fig. 7 shows an outline of the worm wheel.

Detailed Description

The following describes in detail specific embodiments of the present invention with reference to the accompanying drawings.

First, the working principle

1. Basic structure

A3D RWW type ball worm gear is characterized in that a transmission pair is formed by a ball and a worm gear, and speed and torque are transmitted.

Except the ball, the transmission mechanism mainly comprises parts such as a worm wheel, a worm, a K-shaped sheath, a Q-shaped retainer ring, a bearing and the like.

2. The transmission is characterized in that: double-head, double-node and double-guide-distance

Double-end: the worm wheel and the worm are both double-ended, and the functions of the worm wheel and the worm are that no back clearance exists, and the output force is uniform and stable. If only power transmission is performed, the transmission precision is not required, and a single head can be adopted. The worm with large structural size can adopt multiple threads when the strength allows.

The following explanation of this patent is for the double head.

Double-node: when the ball works in the working section, the outer surface of the ball is in line contact with the raceway surface of the worm, and the outer surface of the ball is in point contact with the tooth groove of the worm wheel. However, there are two nodes on each tooth slot of the worm gear through which the ball makes line contact with the worm gear, and these two nodes are defined as the nominal node of the worm gear and also the calculation node of the worm gear. The line contact nodes on the worm wheel form two parallel circles, namely a double pitch circle of the worm wheel.

Double lead: the ball and worm work interval is two leads, namely 720 degrees around the axis of the worm. The rest are non-working sections, and the ball rounds the axis angle of the worm by 360 degrees. One revolution of the ball is 1080 around the worm axis angle.

3. Ball circulation process

The ball circulation is designed to be in the worm, so the ball circulation process is explained from the perspective of the worm.

The ball is divided into a working section and a non-working section according to the position of the worm. See fig. 2, the working section is the section where the balls are meshed with the worm gear and the worm and the gear and the worm and the torque are transmitted, and points a-o in fig. 2₁Point-b. Of course, the working section is divided into a working area and a non-working area, which are also described in the section of worm wheel.

The non-working section is a ball returning part and is divided into five sections.

First stage, natural bead returning: points b to c

Namely, the balls sink down from the pitch circle surface of the worm to the lower part of the outer circle of the worm gradually and integrally under the action of the worm wheel raceway and the worm raceway (in a non-working state).

Second stage, forced return: c point to d point

After the ball continues to sink under the action of the Q-shaped ball return retainer ring (in the radial direction of the worm), the steering is completed (in the axial direction of the worm).

Third section, perforation: d point to e point

The balls pass through the worm along the bore of the worm axis.

Fourth stage, forced bead discharging: e point to f point

Corresponding to the second segment, the position is symmetrical.

Fifth stage, naturally bead generation: f point to a point

Corresponding to the first segment, the position is symmetrical.

If the worm is reversed, the cycle from the first segment to the fifth segment is reversed, i.e., from the fifth segment to the first segment.

4. Curve of engagement

The ball is in line contact with the worm, and the track is a reducing spiral line.

The ball and the worm wheel are in point contact in the working interval (transmitting torque) except for the point of the pitch circle of the worm wheel, which is in line contact. After the point contact tracks of the ball and the worm wheel are arranged according to the helical angle, a special curve is presented, the shape of the curve is similar to the framework of a Chinese lantern, and therefore, the curve is named as a Chinese lantern line, and is shown in figure 3.

Secondly, the technical characteristics (innovation point)

1. The meshing curve is Chinese lantern line

The worm wheel and the worm are both double-headed, and the meshing parts are bilaterally symmetrical with a central node O (shown in figure 1). The non-backlash transmission pair adopting the double-head ball worm gear structure effectively increases the contact point of the worm and the worm wheel, namely the force output point, so that the structure has larger output torque, transmission precision and rigidity.

The working interval of the ball subdivided according to the position of the worm wheel is as follows: the width between the two pitch circles of the worm wheel is B (as shown in figure 1-1) and the length between the two pitch circles of the worm is 2L. The contact area of the ball and the K-shaped sheath is a non-working area, and the ball returning area is also a non-working area.

The ball rotates twice (720 degrees) in the worm working range, and the corresponding worm wheel meshing part is 2 raceways (tooth grooves), i.e. the worm wheel generally has 4 adjacent tooth grooves (2 heads of the worm) working at the same time. Of course, when the 5 th tooth slot of the worm wheel starts to operate, the part of the 1 st tooth slot is still operated, and the 1 st tooth slot is completely withdrawn when the 5 th tooth slot is all operated.

The meshing state of the worm wheel and the ball at this time will be described by taking the time in the standard operating state (4 th tooth groove is operated, 5 th tooth groove is not yet operated) as an example. Fig. 3-2 shows the state of engagement between the balls and the worm wheel in the operating region at this time. Starting from the left:

a first tooth groove: the meshing curve is arc-shaped on the left side of the tooth socket, the arc is leftward, and the radian is large.

A second gear groove: the meshing curve is arc-shaped on the left side of the tooth socket, the arc is leftward, and the radian is smaller.

A third tooth groove: the meshing curve is arc-shaped on the right side of the tooth socket, the arc is right, and the radian is small.

A fourth tooth groove: the meshing curve is arc-shaped on the right side of the tooth socket, the arc is rightward, and the radian is large.

2. Double-node worm wheel and double C roller path thereof

The Chinese lantern line in the upper section refers to the whole meshing surface of the worm gear and the worm, and the section is a raceway (tooth groove) of the worm gear.

Double node of worm wheel:

the double node is the starting point of the transmission pair design; the double node is the focus of the transmission pair engagement; the double node is the origin of the gear pair calculation.

Double C raceway of worm wheel

When the ball is meshed with the tooth space of the worm wheel, the contact point of each ball and the inner cambered surface of the tooth space of the worm wheel is similar to the matching of the ball and the outer ring of the bearing in the radial thrust ball bearing (except for two nodes of the tooth space of the worm wheel), and the ball bears loads in two directions, namely the axial direction and the radial direction of the worm. Unlike bearings, however, the direction and magnitude of the force applied to the ball varies under constant load.

The meshing curve analysis of the worm wheel single raceway (single tooth groove) and the ball is shown in figure 4.

Setting: the N point and the S point are double nodes of a worm wheel

The single head of the worm has n balls in 2L (double lead)

l₁₁The first ball rotates the track of the roller path for the first time

……

l_n1The n-th ball rotates the track of the roller path for the first time

l₁₂The first ball rotates for the second time through the track of the roller path

……

l_n2The n-th ball rotates the track of the roller path for the second time

From fig. 4, it can be taken:

the N and S double nodes are like two magnetic poles in a magnetic field, and the track of each ball is like a magnetic line of force. The raceway (tooth groove) is divided into two parts along the spiral line direction, and two conjugate arc curved surfaces, namely 'double C raceways', are presented.

3. A double-head and double-lead internal circulation worm, which is shown in figure 1, figure 2 and figure 2-1.

The worm is designed into a double-head structure so as to ensure the transmission precision, namely no backlash.

The working section is designed to be 2 times of lead, if the working section is lengthened, the worm and the worm wheel raceway are interfered, if the working section is shortened, the transmission rigidity and the torque of the meshing pair are reduced, and therefore the lead is exactly 2 times.

The non-working section is a bead returning section which is divided into natural bead returning, forced bead returning and perforation. The ball returning section rotates exactly one circle (360 degrees) when viewed from the direction of the head of the worm shaft.

4. K-shaped sheath

As shown in FIG. 5, the K-shaped jacket is a support of the worm, and is matched with the ball returning surface of the worm and the ball returning section of the worm, so that the K-shaped jacket is the most important structural component of the transmission pair of the design.

(1) And two ends of the worm are arranged in the K-shaped sheath through bearings, so that the K-shaped sheath determines the axial and radial positions of the worm and also determines the position of the worm in the whole transmission pair, as shown in figure 1.

(2) The middle section (length 2L) of the inner hole of the K-shaped sheath is matched with the ball, and is a ball non-working area except the range of Bx 2L in the 2L working section of the worm, as shown in figure 1.

(3) And the extension arc sections (from the 2L line to the worm and the shaft shoulder of the Q-shaped ball return retainer ring) at the two ends of the middle section of the inner hole of the K-shaped sheath are ball natural ball return sections, as shown in figure 1.

(4) Straight line sections on two sides of the natural bead returning section of the inner hole of the K-shaped sheath are installation positions of the Q-shaped bead returning retaining ring, as shown in figure 1.

(5) A rectangular (approximate) notch is arranged on the outer circular surface of the K-shaped sheath and is vertical to the axis, the upper side and the lower side of the notch are arc-shaped oblique planes which are matched with the outer circular oblique plane of the worm wheel and are the interface of a ball working area and a non-working area in a 2L working area, as shown in figure 1.

5. Q-shaped ball-returning retainer ring

The ball is forced to return after finishing natural returning: after the ball continues to sink under the action of the Q-shaped ball return retainer ring (in the radial direction of the worm), the steering is completed (in the axial direction of the worm). The reverse bead-out process is reversed as opposed to bead-back.

As shown in fig. 6 and 6-1, the inner hole of the Q-shaped ball-returning retainer ring has two symmetrical circular arcs, and the two circular arcs gradually become shallow along the oblique angle (the angle is set during design) until the two circular arcs disappear.

The Q-shaped ball return retainer ring is fixed on the worm, and the worm is connected into a whole when working. Thereby realizing the circulation of the balls in the worm.

Claims

1. The utility model provides a K type sheath of 3D RWW type ball worm gear which characterized in that: the middle section with the length of 2L in the middle of the inner hole of the sleeve body of the K-shaped sheath is matched with the ball to form a ball working section, the extension arc sections at two ends of the middle section of the inner hole of the sleeve body of the K-shaped sheath are matched with the ball to form a ball natural ball returning section, and two sides of the extension arc sections inside and outside the sleeve body of the K-shaped sheath are straight line sections for mounting a Q-shaped ball returning retaining ring; two ports of the sleeve body of the K-shaped sheath are provided with worms through bearings; the K-shaped bottom surface of the sleeve body of the K-shaped sheath is matched with the excircle inclined surface of the worm wheel.