Reciprocating Saw Motion Converter With Eccentric Pendulum Guide
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Solution Overview
Problem
Existing reciprocating saws are often heavy, complex, and costly due to their design, making them unsuitable for easy handling in confined spaces and inefficient in energy conversion.
Innovation Solution
A reciprocating saw with a motion converter that includes an eccentric element and a pendulum element with a guide element, allowing for efficient conversion of rotary motion into reciprocating motion, reducing weight, complexity, and cost while enhancing cutting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional motion converters (swashplate, eccentric drives) are used, then rotary motion can be converted to reciprocating motion, but the device becomes heavy and complex
Solution Approach 1:
The motion converter is divided into separate functional elements: an eccentric element for generating asymmetric motion and a pendulum element for amplifying and directing the reciprocating motion. This segmentation allows each component to be optimized independently, reducing overall complexity while maintaining functionality.
Solution Approach 2:
Instead of using a complex mechanism to directly convert rotary motion to reciprocating motion, the invention inverts the approach by using a simple eccentric offset that naturally creates asymmetric motion when rotated, which then drives the pendulum element to produce the desired reciprocating action. This inversion simplifies the overall mechanism.
2Ease of manufacture
If traditional motion converters are used, then motion conversion is achieved, but the device becomes costly
Solution Approach 1:
The motion converter uses simple, easily manufactured components such as an eccentric element and pendulum arm that can be produced cost-effectively. These components are designed to be straightforward to manufacture without requiring precision machining or expensive materials, making the overall device more cost-effective.
Solution Approach 2:
The invention changes the motion parameters by using an eccentric offset to create asymmetric motion characteristics. By adjusting the eccentricity distance and pendulum length, the motion conversion can be optimized for different applications without requiring complex mechanisms, thereby reducing manufacturing costs.
3Use of energy by moving object
If conventional motion conversion mechanisms are used, then reciprocating motion is produced, but energy efficiency is reduced
Solution Approach 1:
The motion converter uses dynamic elements including a rotating eccentric element that continuously varies the motion characteristics, and a pendulum element that naturally oscillates to amplify the reciprocating motion. This dynamic approach reduces energy losses compared to static or rigid conversion mechanisms.
Solution Approach 2:
The eccentric element rotates periodically, creating cyclic variations in the motion that drive the pendulum element. This periodic action is efficiently transferred through the mechanism, minimizing energy losses and maximizing the conversion efficiency from rotary to reciprocating motion.
4Ease of operation
If traditional reciprocating saw designs are used, then cutting function is achieved, but weight is considerable
Solution Approach 1:
The invention extracts only the essential motion conversion function from complex traditional mechanisms, using a minimal set of components (eccentric element, pendulum arm, coupling point). This extraction of essential functionality eliminates unnecessary weight while maintaining the reciprocating motion capability needed for cutting.
Solution Approach 2:
Instead of adding complex mechanisms to achieve motion conversion, the invention inverts the approach by using a simple rotating eccentric offset that naturally produces the required reciprocating motion through minimal components, thereby significantly reducing the overall weight of the saw.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a lightweight, robust, and cost-effective reciprocating saw with improved cutting performance and energy efficiency, enabling efficient sawing in confined spaces.
Implementation Method 1
a motion converter for converting a rotary motion of the output shaft into a reciprocating motion of the spindle. The motion converter comprises an eccentric element driven by the output shaft for rotation about a rotational axis, with a driver part arranged eccentrically to the rotational axis
Implementation Method 2
a pendulum element pivotally mounted about a bearing point and connected to the spindle via a coupling point
Data Source
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AI summary
The invention relates to a hand-held machine tool (100), in particular a reciprocating saw (100), comprising a housing (110, 112), a drive motor (200) having an output shaft (210), a spindle (112, 400) for receiving a tool (114), in particular a saw blade, and a motion converter (500) for converting a rotation of the output shaft (210) into a reciprocating motion of the spindle (112, 400). The motion converter (500) comprises an eccentric element (300) driven in rotation about an axis of rotation (220) by the output shaft (210) and having a driver part (310) arranged eccentrically to the axis of rotation (220), and comprises a pendulum element (400) which is mounted pivotally about a bearing point and is connected to the spindle (112, 400) via a coupling point. According to the invention, the pendulum element (400) is provided with a guide element (430) for guiding the driver part (310). The guide element (430) is arranged between the bearing point and the coupling point. The invention further relates to a motion converter (500) for converting a rotation of the output shaft (210) of a drive motor.